PLAN: the Ham Share player and the Transcode device setting; e2e-player.mjs

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

PLAN.md

@@ -810,6 +810,51 @@ something long in one, switch away and back, refresh — it's all still there.
   - Tested (`TestSeekRestartsTheEncode`): a 64 s 1080p clip, a request for segment 12 right
     after the start runs from 48 s, the gap is filled, all 16 segments joined behind the one
     init decode with no hole.
+- **The player is Ham Share's; a Transcode device setting** — **2026-10-23** (v0.1.0-226,
+  `internal/media/{encode,play}.go`, `internal/api/play.go`, `Player.tsx`, `vr.ts`,
+  `Settings.tsx`). Asked for as "redo the HamLab one with the one you sent … a 'Transcode
+  Device' setting … the A380 on Grid selected … other options being the other transcode
+  devices like the iGPUs on the various CPUs that have HamLab installed". **Replaces** the
+  previous two entries' design: no codec/size picker, no single-quality re-encode, no
+  repackaging; the old streamer (`hls.go`) is gone.
+  - **YouTube's way:** Auto (hls.js reads the connection), any quality by hand, or Original
+    (the file as it is, `/api/files/read`, falling back to Auto when the browser can't). A
+    ladder by size (`Ladder`): flat 2160p/1440p/1080p/720p/480p by the short side, plus the
+    file's own size on top when it sits between steps (a 2292×960 capture gets 960p); 360
+    files by width, named as YouTube does (2160s 3840 … 720s). 720 and down at ≤30 fps.
+    H.264 High + AAC only.
+  - **Pieces made when asked for**, 3 s MPEG-TS, every quality's playlist written whole up
+    front. One ffmpeg per play: it starts at the piece asked, runs ahead, and is paused
+    (SIGSTOP; a root run through `run-ffmpeg`, which now reads `stop`/`cont` on stdin) 10
+    pieces ahead; a piece more than 3 past what's made, or at another quality, starts a new
+    run there. Keyframes only on the 3 s marks and every run's times offset alike
+    (`-output_ts_offset start+10`), so pieces from any run and quality join (`TestPieces`
+    checks it; `SRC=… DEVICE=… go test ./internal/media -run Pieces` on a machine with a GPU).
+    At most 3 runs a machine, the one asked of least lately ended for a fourth; 2 GiB of
+    pieces a play; forgotten after 30 min.
+  - **hls.js is patched** (`PatientAbr`): the wait for a piece being made isn't counted
+    against the connection, and a piece isn't abandoned before its first byte. Without it
+    Auto dropped to the bottom after every seek.
+  - **Transcode device** (Settings, hub-side, `store.Transcode`): every machine's devices
+    asked live (`GET /api/files/play-devices` on each), unusable ones greyed with the reason
+    (hamtv's UHD 600: the render permission; mac and gate: no ffmpeg). Set to **grid's Arc
+    A380**. "The machine the file is on" is the other choice. `POST /api/play` on the hub
+    opens the play where the setting says; **a machine transcoding another's file reads it
+    through the hub** at `/api/play-src/<token>` — a random token good for that one file, 12
+    h from its last use, ranges passed through to the file's machine (ffmpeg reconnects).
+    If that machine fails, the file's own makes it and the player says so.
+  - Recipes per device: same-card decode first, then CPU decode + upload, then libx264 as
+    the fallback whatever was asked. A card without `vainfo` (core) is tried anyway: core's
+    UHD encodes. **Rotation:** the card path turns a phone's picture itself
+    (`transpose_vaapi`, `-noautorotate`; ffmpeg's autorotate never applied to VAAPI frames,
+    so iPhone clips came out sideways). **HLG** is shown as it is (tonemap_vaapi refuses it);
+    HDR10 is tone-mapped on the card, else zscale/hable before the upload.
+  - 360 files: the look-around view, zoom 8°–300° (ordinary lens into stereographic, the
+    "little planet"), drag/pinch/wheel, phone motion. Full screen is the element's, or the
+    whole window on an iPhone.
+  - Measured (`web/scripts/e2e-player.mjs`, Chromium): an iPhone HLG clip on `core` made on
+    grid's A380 — 3.2 s to play, a seek 1.0 s, a quality change 1.5 s; the 8K 360 Disney day on
+    grid — 3.1 s, 2160s on Auto, a seek 4.9 s (10 s source keyframes).
 - **Files edge sweep** — **2026-10-11** (v0.1.0-214), asked for as "a full bug sweep of
   the Files section, every example and edge case". Every handler and both UI files read
   through with odd inputs in mind, then a battery of ~60 requests against the live hub

internal/api/play.go

@@ -1,141 +1,162 @@
 package api
 
-// Playing a video the browser cannot play as it is: POST /api/files/play starts an HLS
-// re-encode on this machine (internal/media), GET …/play/{id}/index.m3u8 and the segments
-// feed the player, GET …/play/{id} is its progress, DELETE ends it. /api/files/play-caps
-// says which codecs this machine can make and on what. Root mode (?sudo=1) reads the file
-// and runs ffmpeg as root, through the same sudo the file reads use.
+// Playing a video in the Files viewer, YouTube's way: Auto (the player reads the connection),
+// any quality by hand, or the file itself. The qualities are made on the fly as HLS by
+// internal/media, on the device the Transcode device setting names — which may be on another
+// machine than the file.
+//
+// On every machine:
+//   POST /api/files/play[?sudo=1] {path | url, name, device}   open a play
+//   GET  /api/files/play/{id}/master.m3u8, /{rung}.m3u8, /{rung}/{n}.ts
+//   GET  /api/files/play/{id}                                    what it is doing
+//   DELETE /api/files/play/{id} (or POST …/close, for a beacon)  end it
+//   GET  /api/files/play-devices                                 what it can encode on
+// On the hub:
+//   POST /api/play {node, path, sudo}   open a play of a file on node, wherever the setting
+//                                       says, answering which machine the play is on
+//   GET|PUT /api/transcode              the setting, and every machine's devices
+//   GET  /api/play-src/{token}          a file, for a machine transcoding it, by a token
+//                                       that names that one file; ranges pass through
 
 import (
 	"context"
+	"crypto/rand"
+	"encoding/hex"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"io"
 	"log"
+	"net"
 	"net/http"
+	"net/url"
 	"path/filepath"
+	"strconv"
 	"strings"
+	"sync"
 	"time"
 
 	"hamlab/internal/files"
 	"hamlab/internal/media"
+	"hamlab/internal/store"
 )
 
-const playLimit = 3 // re-encodes at once on one machine; a GPU does two or three, a CPU one
+// playRuns is how many plays may be encoding at once on one machine; a fourth ends the one
+// asked of least lately. The A380 makes about two 8K-sourced streams in real time.
+const playRuns = 3
 
-type playCaps struct {
-	Codecs    []playCodec     `json:"codecs"`
-	Qualities []media.Quality `json:"qualities"`
-	Error     string          `json:"error,omitempty"`
+type playReq struct {
+	Path   string `json:"path,omitempty"`
+	URL    string `json:"url,omitempty"` // a file on another machine, as the hub serves it
+	Name   string `json:"name,omitempty"`
+	Device string `json:"device,omitempty"`
 }
 
-type playCodec struct {
-	media.Codec
-	Engine string `json:"engine,omitempty"` // "" when nothing here encodes it
+type playOut struct {
+	Node   string           `json:"node"` // the machine the play is on: "" for the hub; filled in by the hub
+	Play   *media.Play      `json:"play"`
+	Master string           `json:"master"` // the playlist, under that machine's /api
+	Engine string           `json:"engine"`
+	Host   string           `json:"host"` // that machine's name, for the menu
+	Note   string           `json:"note,omitempty"`
+	Status media.PlayStatus `json:"status"`
 }
 
-// playCapsHandler: GET /api/files/play-caps[?sudo=1]
-func (s *Server) playCapsHandler(w http.ResponseWriter, r *http.Request) {
+// playDevices: GET /api/files/play-devices — what this machine could make the player's H.264
+// on, probed as the daemon's own user (a play from another machine never runs as root).
+func (s *Server) playDevices(w http.ResponseWriter, r *http.Request) {
+	caps, err := s.thumbs.capsFor(r.Context(), false, false)
+	if err != nil {
+		caps.Error = err.Error()
+	}
+	jsonOK(w, 200, map[string]any{"host": s.hostName(), "devices": media.Devices(caps)})
+}
+
+// playStart: POST /api/files/play[?sudo=1] — open a play of a file here, or of a URL the hub
+// serves a file on another machine at.
+func (s *Server) playStart(w http.ResponseWriter, r *http.Request) {
+	var body playReq
+	if err := json.NewDecoder(io.LimitReader(r.Body, 64<<10)).Decode(&body); err != nil {
+		jsonErr(w, 400, "bad request")
+		return
+	}
 	root := r.URL.Query().Get("sudo") == "1"
 	if root && s.fsSudo == nil {
 		jsonErr(w, 403, "root access needs passwordless sudo on the host")
 		return
 	}
-	caps, err := s.thumbs.capsFor(r.Context(), root, false)
-	pc := playCaps{Codecs: []playCodec{}, Qualities: media.Qualities}
+	out, code, err := s.openPlay(r.Context(), body, root)
 	if err != nil {
-		pc.Error = err.Error()
-	} else if caps.Error != "" {
-		pc.Error = caps.Error
+		jsonErr(w, code, err.Error())
+		return
 	}
-	for _, c := range media.Codecs {
-		x := playCodec{Codec: c}
-		if pc.Error == "" {
-			x.Engine = media.EngineFor(caps, c.ID)
-		}
-		pc.Codecs = append(pc.Codecs, x)
-	}
-	jsonOK(w, 200, pc)
+	jsonOK(w, 200, out)
 }
 
-// playStart: POST /api/files/play[?sudo=1] {path, codec, quality}
-func (s *Server) playStart(w http.ResponseWriter, r *http.Request) {
-	fsys, ok := s.fsFor(w, r)
-	if !ok {
-		return
+func (s *Server) openPlay(ctx context.Context, body playReq, root bool) (playOut, int, error) {
+	if root && s.fsSudo == nil && body.URL == "" {
+		return playOut{}, 403, errors.New("root access needs passwordless sudo on the host")
 	}
-	root := r.URL.Query().Get("sudo") == "1"
-	var body struct{ Path, Codec, Quality string }
-	if err := json.NewDecoder(io.LimitReader(r.Body, 64<<10)).Decode(&body); err != nil {
-		jsonErr(w, 400, "bad request")
-		return
+	in, name := body.Path, body.Name
+	if body.URL != "" {
+		u, err := url.Parse(body.URL)
+		if err != nil || (u.Scheme != "http" && u.Scheme != "https") || body.Path != "" {
+			return playOut{}, 400, errors.New("a play is of a path or of an http URL")
 		}
+		in, root = body.URL, false
+	} else {
 		p, err := files.Clean(body.Path)
 		if err != nil {
-		jsonErr(w, 400, err.Error())
-		return
+			return playOut{}, 400, err
 		}
 		if media.Kind(p) != "video" {
-		jsonErr(w, 415, "not a video")
-		return
+			return playOut{}, 415, errors.New("not a video")
 		}
-	if err := media.ValidChoice(body.Codec, body.Quality); err != nil {
-		jsonErr(w, 400, err.Error())
-		return
+		fsys := s.fsLocal
+		if root {
+			fsys = s.fsSudo
 		}
-	if _, err := fsys.Stat(r.Context(), p); err != nil {
-		fsErr(w, err)
-		return
+		if _, err := fsys.Stat(ctx, p); err != nil {
+			return playOut{}, 404, err
+		}
+		in = p
+		if name == "" {
+			name = filepath.Base(p)
+		}
+	}
+	caps, err := s.thumbs.capsFor(ctx, root, false)
+	if err == nil && caps.Error != "" {
+		err = errors.New(caps.Error)
 	}
-	caps, err := s.thumbs.capsFor(r.Context(), root, false)
 	if err != nil {
-		jsonErr(w, 503, err.Error())
-		return
+		return playOut{}, 503, err
 	}
-	if caps.Error != "" {
-		jsonErr(w, 503, caps.Error)
-		return
-	}
-	ictx, cancel := context.WithTimeout(r.Context(), 30*time.Second)
-	src, err := media.Inspect(ictx, caps, p, root)
+	ictx, cancel := context.WithTimeout(ctx, 30*time.Second)
+	src, err := media.Inspect(ictx, caps, in, root)
 	cancel()
 	if err != nil {
-		playErr(w, err)
-		return
-	}
-	st, err := s.plays.Open(r.Context(), caps, root, p, body.Codec, body.Quality, src)
-	if err != nil {
-		playErr(w, err)
-		return
-	}
-	log.Printf("files: play %s as %s %s on %s (from %s)", p, st.Codec, st.Quality, st.Engine, clientIP(r))
-	jsonOK(w, 200, map[string]any{"stream": st, "url": "/api/files/play/" + st.ID + "/index.m3u8"})
-}
-
-func playErr(w http.ResponseWriter, err error) {
 		var de *media.DecodeError
-	switch {
-	case errors.As(err, &de):
-		jsonErr(w, 422, de.Msg)
-	case strings.Contains(err.Error(), "already being re-encoded"):
-		jsonErr(w, 429, err.Error())
-	case strings.HasPrefix(err.Error(), "unknown ") || strings.HasPrefix(err.Error(), "nothing on this machine encodes"):
-		jsonErr(w, 400, err.Error())
-	case errors.Is(err, context.DeadlineExceeded):
-		jsonErr(w, 504, "the file took too long to read")
-	default:
-		jsonErr(w, 500, err.Error())
+		if errors.As(err, &de) {
+			return playOut{}, 422, errors.New(de.Msg)
 		}
+		return playOut{}, 504, err
+	}
+	p, err := s.plays.Open(caps, root, in, name, src, body.Device)
+	if err != nil {
+		return playOut{}, 422, err
+	}
+	log.Printf("files: play %s on %s (%d qualities, %s)", name, p.Engine(), len(p.Rungs), map[bool]string{true: "from another machine", false: "here"}[p.Remote])
+	return playOut{Play: p, Master: "/api/files/play/" + p.ID + "/master.m3u8", Engine: p.Engine(), Host: s.hostName(), Status: p.Status()}, 200, nil
 }
 
 // playStatus: GET /api/files/play/{id}
 func (s *Server) playStatus(w http.ResponseWriter, r *http.Request) {
-	st, ok := s.plays.Find(r.PathValue("id"))
+	p, ok := s.plays.Find(r.PathValue("id"))
 	if !ok {
-		jsonErr(w, 404, "no such stream")
+		jsonErr(w, 404, "no such play")
 		return
 	}
-	jsonOK(w, 200, st.Status())
+	jsonOK(w, 200, p.Status())
 }
 
 // playStop: DELETE /api/files/play/{id}, or POST …/close — the form a page can send on its
@@ -145,33 +166,47 @@ func (s *Server) playStop(w http.ResponseWriter, r *http.Request) {
 	w.WriteHeader(204)
 }
 
-// playFile: GET /api/files/play/{id}/{file} — the playlist, the init segment, a segment.
-// A seekable stream's playlist is written whole, up front; a segment of it that isn't on disk
-// yet is waited for, or re-encoded from there if the encode isn't heading that way (a seek).
-func (s *Server) playFile(w http.ResponseWriter, r *http.Request) {
-	st, ok := s.plays.Find(r.PathValue("id"))
+// playPlaylist: GET /api/files/play/{id}/{file} — master.m3u8, or one quality's <name>.m3u8.
+func (s *Server) playPlaylist(w http.ResponseWriter, r *http.Request) {
+	p, ok := s.plays.Find(r.PathValue("id"))
 	if !ok {
-		jsonErr(w, 404, "no such stream")
+		jsonErr(w, 404, "no such play")
 		return
 	}
-	name := r.PathValue("file")
-	p, ok := st.File(name)
-	if !ok {
-		jsonErr(w, 404, "not a stream file")
+	f := r.PathValue("file")
+	var b []byte
+	if f == "master.m3u8" {
+		b = p.Master()
+	} else if name, isList := strings.CutSuffix(f, ".m3u8"); isList {
+		if b, ok = p.Media(name); !ok {
+			jsonErr(w, 404, "no such quality")
+			return
+		}
+	} else {
+		jsonErr(w, 404, "not a play file")
 		return
 	}
-	w.Header().Set("Cache-Control", "no-store")
-	w.Header().Set("X-Content-Type-Options", "nosniff")
-	if st.Seekable {
-		if name == "index.m3u8" {
 	w.Header().Set("Content-Type", "application/vnd.apple.mpegurl")
-			_, _ = w.Write(st.Playlist())
+	w.Header().Set("Cache-Control", "no-store")
+	_, _ = w.Write(b)
+}
+
+// playPiece: GET /api/files/play/{id}/{rung}/{seg} — a piece, made first if need be.
+func (s *Server) playPiece(w http.ResponseWriter, r *http.Request) {
+	p, ok := s.plays.Find(r.PathValue("id"))
+	if !ok {
+		jsonErr(w, 404, "no such play")
 		return
 	}
-		if i, isSeg := media.SegmentIndex(name); isSeg {
-			sp, err := st.Segment(r.Context(), i)
+	ns, isTS := strings.CutSuffix(r.PathValue("seg"), ".ts")
+	n, err := strconv.Atoi(ns)
+	if !isTS || err != nil || strconv.Itoa(n) != ns {
+		jsonErr(w, 404, "not a piece")
+		return
+	}
+	file, err := p.Segment(r.Context().Done(), r.PathValue("rung"), n)
 	switch {
-			case errors.Is(err, media.ErrNotInFilm):
+	case errors.Is(err, media.ErrNotFound):
 		jsonErr(w, 404, err.Error())
 		return
 	case r.Context().Err() != nil:
@@ -180,14 +215,316 @@ func (s *Server) playFile(w http.ResponseWriter, r *http.Request) {
 		jsonErr(w, 503, err.Error())
 		return
 	}
-			p = sp
+	w.Header().Set("Content-Type", "video/mp2t")
+	w.Header().Set("Cache-Control", "private, max-age=3600")
+	http.ServeFile(w, r, file)
 }
+
+// ---- on the hub: where plays are made ----
+
+// transcodeChoice is the setting; nil is the machine the file is on.
+func (s *Server) transcodeChoice() *store.Transcode {
+	var t *store.Transcode
+	s.store.View(func(st *store.State) {
+		if st.Transcode != nil {
+			c := *st.Transcode
+			t = &c
 		}
-	switch filepath.Ext(p) {
-	case ".m3u8":
-		w.Header().Set("Content-Type", "application/vnd.apple.mpegurl")
+	})
+	return t
+}
+
+type transcodeMachine struct {
+	Node    string         `json:"node"` // "" is the hub
+	Host    string         `json:"host"`
+	Devices []media.Device `json:"devices"`
+	Error   string         `json:"error,omitempty"` // the machine didn't answer
+}
+
+// getTranscode: GET /api/transcode — the setting, and what every machine can encode on,
+// asked of each now.
+func (s *Server) getTranscode(w http.ResponseWriter, r *http.Request) {
+	names := []string{""}
+	if s.nodes != nil {
+		names = append(names, s.nodes.Names()...)
+	}
+	out := make([]transcodeMachine, len(names))
+	var wg sync.WaitGroup
+	for i, n := range names {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			m := transcodeMachine{Node: n, Host: n}
+			ctx, cancel := context.WithTimeout(r.Context(), 8*time.Second)
+			defer cancel()
+			if n == "" {
+				caps, err := s.thumbs.capsFor(ctx, false, false)
+				if err != nil {
+					caps.Error = err.Error()
+				}
+				m.Host, m.Devices = s.hostName(), media.Devices(caps)
+			} else {
+				code, b, err := s.nodes.Do(ctx, n, "GET", "/api/files/play-devices", nil, nil)
+				var d struct {
+					Host    string         `json:"host"`
+					Devices []media.Device `json:"devices"`
+				}
+				switch {
+				case err != nil:
+					m.Error = err.Error()
+				case code == 404:
+					m.Error = "runs an older Ham Lab"
+				case code != 200 || json.Unmarshal(b, &d) != nil:
+					m.Error = fmt.Sprintf("answered %d", code)
 				default:
-		w.Header().Set("Content-Type", "video/mp4")
+					m.Devices = d.Devices
 				}
-	http.ServeFile(w, r, p)
+			}
+			out[i] = m
+		}()
+	}
+	wg.Wait()
+	jsonOK(w, 200, map[string]any{"selected": s.transcodeChoice(), "machines": out})
+}
+
+// putTranscode: PUT /api/transcode {node, device}, or {} for the machine the file is on.
+func (s *Server) putTranscode(w http.ResponseWriter, r *http.Request) {
+	var body *store.Transcode
+	if err := json.NewDecoder(io.LimitReader(r.Body, 4096)).Decode(&body); err != nil {
+		jsonErr(w, 400, "expected {\"node\": …, \"device\": …}")
+		return
+	}
+	if body != nil && body.Device == "" {
+		body = nil
+	}
+	if body != nil {
+		known := body.Node == ""
+		if s.nodes != nil {
+			for _, n := range s.nodes.Names() {
+				known = known || n == body.Node
+			}
+		}
+		if !known {
+			jsonErr(w, 400, "no such machine")
+			return
+		}
+		if body.Device != media.CPU && !strings.HasPrefix(body.Device, "/dev/dri/") {
+			jsonErr(w, 400, "a device is a render node or \"cpu\"")
+			return
+		}
+	}
+	if err := s.store.Update(func(st *store.State) { st.Transcode = body }); err != nil {
+		jsonErr(w, 500, err.Error())
+		return
+	}
+	s.getTranscode(w, r)
+}
+
+// hubPlay: POST /api/play {node, path, sudo} — open a play of a file on node ("" the hub) on
+// the device the setting names. When that is on another machine, that machine reads the file
+// through this hub, by a token good for that one file. If it can't be reached, the file's own
+// machine makes it instead, and the answer says so.
+func (s *Server) hubPlay(w http.ResponseWriter, r *http.Request) {
+	var body struct {
+		Node string `json:"node"`
+		Path string `json:"path"`
+		Sudo bool   `json:"sudo"`
+	}
+	if err := json.NewDecoder(io.LimitReader(r.Body, 64<<10)).Decode(&body); err != nil {
+		jsonErr(w, 400, "bad request")
+		return
+	}
+	p, err := files.Clean(body.Path)
+	if err != nil {
+		jsonErr(w, 400, err.Error())
+		return
+	}
+	if body.Node != "" && (s.nodes == nil || !has(s.nodes.Names(), body.Node)) {
+		jsonErr(w, 404, "no such machine")
+		return
+	}
+	choice := s.transcodeChoice()
+	var note string
+	if choice != nil && choice.Node != body.Node {
+		if s.nodes != nil && choice.Node != "" && !has(s.nodes.Names(), choice.Node) {
+			note = "The transcode machine " + choice.Node + " is no longer managed here; made where the file is."
+		} else {
+			src, err := s.srcURL(choice.Node, body.Node, p, body.Sudo)
+			if err == nil {
+				req := playReq{URL: src, Name: filepath.Base(p), Device: choice.Device}
+				out, code, err := s.playOn(r.Context(), choice.Node, req, false)
+				if err == nil {
+					jsonOK(w, 200, out)
+					return
+				}
+				if code == 422 || code == 415 {
+					jsonErr(w, code, err.Error())
+					return
+				}
+			}
+			log.Printf("files: play on %s failed (%v); making it where the file is", nodeLabel(choice.Node), err)
+			note = "Couldn't make it on " + nodeLabel(choice.Node) + " (" + err.Error() + "), so it is made where the file is."
+		}
+	}
+	device := ""
+	if choice != nil && choice.Node == body.Node {
+		device = choice.Device
+	}
+	out, code, err := s.playOn(r.Context(), body.Node, playReq{Path: p, Device: device}, body.Sudo)
+	if err != nil {
+		jsonErr(w, code, err.Error())
+		return
+	}
+	out.Note = note
+	jsonOK(w, 200, out)
+}
+
+func nodeLabel(n string) string {
+	if n == "" {
+		return "the hub"
+	}
+	return n
+}
+
+func has(list []string, x string) bool {
+	for _, v := range list {
+		if v == x {
+			return true
+		}
+	}
+	return false
+}
+
+// playOn opens a play on a machine: here, or through that node's API.
+func (s *Server) playOn(ctx context.Context, node string, req playReq, sudo bool) (playOut, int, error) {
+	if node == "" {
+		out, code, err := s.openPlay(ctx, req, sudo)
+		return out, code, err
+	}
+	b, _ := json.Marshal(req)
+	path := "/api/files/play"
+	if sudo {
+		path += "?sudo=1"
+	}
+	code, resp, err := s.nodes.Do(ctx, node, "POST", path, b, http.Header{"Content-Type": []string{"application/json"}})
+	if err != nil {
+		return playOut{}, 502, err
+	}
+	if code != 200 {
+		var e struct{ Error string }
+		_ = json.Unmarshal(resp, &e)
+		if e.Error == "" {
+			e.Error = fmt.Sprintf("%s answered %d", node, code)
+		}
+		return playOut{}, code, errors.New(e.Error)
+	}
+	var out playOut
+	if err := json.Unmarshal(resp, &out); err != nil {
+		return playOut{}, 502, err
+	}
+	out.Node = node
+	return out, 200, nil
+}
+
+// ---- the file, for the machine transcoding it ----
+
+type srcGrant struct {
+	node, path string
+	sudo       bool
+	until      time.Time
+}
+
+type srcGrants struct {
+	mu sync.Mutex
+	m  map[string]*srcGrant
+}
+
+const srcLife = 12 * time.Hour // from its last use: a film paused overnight still plays
+
+var grants = &srcGrants{m: map[string]*srcGrant{}}
+
+func (g *srcGrants) mint(node, path string, sudo bool) string {
+	b := make([]byte, 24)
+	_, _ = rand.Read(b)
+	tok := hex.EncodeToString(b)
+	now := time.Now()
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	for k, v := range g.m {
+		if now.After(v.until) {
+			delete(g.m, k)
+		}
+	}
+	g.m[tok] = &srcGrant{node: node, path: path, sudo: sudo, until: now.Add(srcLife)}
+	return tok
+}
+
+func (g *srcGrants) use(tok string) (srcGrant, bool) {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	v, ok := g.m[tok]
+	if !ok || time.Now().After(v.until) {
+		return srcGrant{}, false
+	}
+	v.until = time.Now().Add(srcLife)
+	return *v, true
+}
+
+// srcURL is where the machine `to` can read a file on machine `from` through this hub: this
+// hub's own address as `to` reaches it, and a token for that one file.
+func (s *Server) srcURL(to, from, path string, sudo bool) (string, error) {
+	host, port, err := net.SplitHostPort(s.cfg.Listen)
+	if err != nil {
+		return "", err
+	}
+	ip := net.ParseIP(host)
+	if host == "" || ip == nil || ip.IsUnspecified() || ip.IsLoopback() {
+		// Listening everywhere: the address this machine reaches `to` from is one it answers on.
+		target := "127.0.0.1:1"
+		if to != "" {
+			if u, err := url.Parse(s.nodes.URL(to)); err == nil && u.Host != "" {
+				target = u.Host
+			}
+		}
+		c, err := net.Dial("udp", target)
+		if err != nil {
+			return "", err
+		}
+		host = c.LocalAddr().(*net.UDPAddr).IP.String()
+		c.Close()
+	}
+	scheme := "http"
+	if s.fingerprint != "" {
+		scheme = "https"
+	}
+	return scheme + "://" + net.JoinHostPort(host, port) + "/api/play-src/" + grants.mint(from, path, sudo), nil
+}
+
+// playSrc: GET /api/play-src/{token} — the one file a token names, ranges and all, read from
+// its machine. The token is the only key: it is minted for a machine transcoding that file.
+func (s *Server) playSrc(w http.ResponseWriter, r *http.Request) {
+	g, ok := grants.use(r.PathValue("token"))
+	if !ok {
+		jsonErr(w, 404, "no such file")
+		return
+	}
+	q := url.Values{"path": {g.path}}
+	if g.sudo {
+		q.Set("sudo", "1")
+	}
+	r2 := r.Clone(r.Context())
+	r2.URL.RawQuery = q.Encode()
+	r2.Header.Del("Cookie")
+	if g.node == "" {
+		r2.URL.Path = "/api/files/read"
+		s.filesRead(w, r2)
+		return
+	}
+	p, ok := s.nodes.Proxy(g.node)
+	if !ok {
+		jsonErr(w, 404, "no such machine")
+		return
+	}
+	r2.URL.Path = "/api/nodes/" + g.node + "/files/read"
+	p.ServeHTTP(w, r2)
 }

internal/api/play_test.go

@@ -0,0 +1,51 @@
+package api
+
+import (
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"hamlab/internal/config"
+	"hamlab/internal/files"
+)
+
+// The file a machine transcodes from another is read through the hub by a token naming that
+// one file: ranges pass through, the query can't point it anywhere else, and an unknown token
+// is nothing.
+func TestPlaySrc(t *testing.T) {
+	dir := t.TempDir()
+	p := filepath.Join(dir, "film.mp4")
+	if err := os.WriteFile(p, []byte("0123456789"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(dir, "other.mp4"), []byte("secret"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	s := &Server{fsLocal: files.Local{}, cfg: &config.Config{Listen: "10.0.0.234:8100"}}
+	u, err := s.srcURL("", "", p, false)
+	if err != nil || !strings.HasPrefix(u, "http://10.0.0.234:8100/api/play-src/") {
+		t.Fatalf("url %q %v", u, err)
+	}
+	tok := strings.TrimPrefix(u, "http://10.0.0.234:8100/api/play-src/")
+	get := func(tok, query, rng string) *httptest.ResponseRecorder {
+		r := httptest.NewRequest("GET", "/api/play-src/"+tok+query, nil)
+		r.SetPathValue("token", tok)
+		if rng != "" {
+			r.Header.Set("Range", rng)
+		}
+		w := httptest.NewRecorder()
+		s.playSrc(w, r)
+		return w
+	}
+	if w := get(tok, "", "bytes=2-4"); w.Code != 206 || w.Body.String() != "234" {
+		t.Fatalf("range: %d %q", w.Code, w.Body)
+	}
+	if w := get(tok, "?path="+filepath.Join(dir, "other.mp4"), ""); w.Body.String() != "0123456789" {
+		t.Fatalf("the query moved it: %q", w.Body)
+	}
+	if w := get("nope", "", ""); w.Code != 404 {
+		t.Fatalf("unknown token: %d", w.Code)
+	}
+}

internal/api/server.go

@@ -79,7 +79,7 @@ type Server struct {
 	fsLocal     files.FS
 	fsSudo      files.FS // nil without passwordless sudo
 	thumbs      *thumbSvc
-	plays       *media.Streamer
+	plays       *media.Plays
 	self        string // this binary, for helpers run as tasks
 	nodes       *nodes.Manager
 	fingerprint string
@@ -103,7 +103,7 @@ func New(cfg *config.Config, sessions *auth.Sessions, mgr *term.Manager, col *me
 	s.self = self
 	s.space = space.New(self, filepath.Join(cfg.DataDir(), "space"))
 	s.thumbs = newThumbSvc(cfg.DataDir(), self)
-	s.plays = media.NewStreamer(cfg.DataDir(), self, playLimit)
+	s.plays = media.NewPlays(cfg.DataDir(), self, playRuns)
 	s.hostName() // read it once now so the first request doesn't have to
 	if u, err := user.Current(); err == nil && u.Username != "" {
 		s.user = u.Username
@@ -279,12 +279,17 @@ func (s *Server) routes() *http.ServeMux {
 	m.HandleFunc("GET /api/files/thumbs", s.auth(s.thumbsStatus))
 	m.HandleFunc("POST /api/files/thumbs/install", s.auth(s.thumbsInstall))
 	m.HandleFunc("POST /api/files/thumbs/gpu-access", s.auth(s.thumbsGPUAccess))
-	m.HandleFunc("GET /api/files/play-caps", s.auth(s.playCapsHandler))
+	m.HandleFunc("GET /api/files/play-devices", s.auth(s.playDevices))
 	m.HandleFunc("POST /api/files/play", s.auth(s.playStart))
 	m.HandleFunc("GET /api/files/play/{id}", s.auth(s.playStatus))
 	m.HandleFunc("DELETE /api/files/play/{id}", s.auth(s.playStop))
 	m.HandleFunc("POST /api/files/play/{id}/close", s.auth(s.playStop))
-	m.HandleFunc("GET /api/files/play/{id}/{file}", s.auth(s.playFile))
+	m.HandleFunc("GET /api/files/play/{id}/{file}", s.auth(s.playPlaylist))
+	m.HandleFunc("GET /api/files/play/{id}/{rung}/{seg}", s.auth(s.playPiece))
+	m.HandleFunc("POST /api/play", s.auth(s.hubPlay))
+	m.HandleFunc("GET /api/transcode", s.auth(s.getTranscode))
+	m.HandleFunc("PUT /api/transcode", s.auth(s.putTranscode))
+	m.HandleFunc("GET /api/play-src/{token}", s.playSrc) // the token is the key
 	m.HandleFunc("GET /api/hardware", s.auth(s.hardwareReport))
 	m.HandleFunc("GET /api/network", s.auth(s.networkOverview))
 	m.HandleFunc("GET /api/vpn", s.auth(s.vpnReport))

internal/media/encode.go

@@ -1,280 +1,337 @@
 package media
 
-// What to run when a file is to be re-encoded for a browser that cannot play it as it is:
-// the codecs and sizes on offer, the output size and bit rate a choice comes to for a
-// given source, the ways this machine could do it in the order worth trying, and the
-// ffmpeg argument list for one of them. All decisions, no processes, so it can be tested.
+// What to run when a video is played in the browser: the qualities it is offered in (the
+// ladder), the ways a machine could make one of them on the device asked for, in the order
+// worth trying, and the ffmpeg argument list for one piece-making run. All decisions, no
+// processes, so it can be tested. Everything is H.264 High and AAC: what every browser plays.
 
 import (
 	"fmt"
 	"math"
 	"sort"
 	"strconv"
+	"strings"
 )
 
-// Codec is one target a stream may be re-encoded to. "copy" keeps the codec and only
-// repackages: for a browser that lacks the container, not the decoder.
-type Codec struct {
-	ID    string `json:"id"`
-	Label string `json:"label"`
+// Rung is one quality the player can pick: a size, a frame rate and a bit rate.
+type Rung struct {
+	Name    string  `json:"name"`  // in URLs: the width, "1920"
+	Label   string  `json:"label"` // what the menu says: "1080s", "720p"
+	Width   int     `json:"width"`
+	Height  int     `json:"height"`
+	FPS     float64 `json:"fps"`
+	Bitrate int     `json:"bitrate"` // video, bits a second, on average
+	Peak    int     `json:"peak"`    // what the playlist promises, sound included
+	level   string  // H.264 level, "5.2"
+	codecs  string  // for the master playlist
 }
 
-var Codecs = []Codec{{"h264", "H.264"}, {"hevc", "HEVC"}, {"av1", "AV1"}, {"copy", "Original codec, repackaged"}}
-
-// Quality is a picture height; the bit rate follows from the size the output ends up at.
-type Quality struct {
-	ID     string `json:"id"`
-	Label  string `json:"label"`
-	Height int    `json:"height"` // 0: the source's own
+// One step of the ladder: the long side for a 360 video (its width), the short side for a flat
+// one, and the bit rate (Mb/s ×10) at more than 30 frames a second and at 30 or fewer.
+type step struct {
+	size   int
+	label  string
+	hi, lo int
+	cap30  bool
 }
 
-var Qualities = []Quality{{"original", "Original size", 0}, {"1080p", "1080p", 1080}, {"720p", "720p", 720}, {"480p", "480p", 480}}
-
-func qualityByID(id string) (Quality, bool) {
-	for _, q := range Qualities {
-		if q.ID == id {
-			return q, true
-		}
-	}
-	return Quality{}, false
+// A 360 picture is seen a quarter of its width at a time, so it needs more pixels than a flat
+// one for the same sharpness; YouTube names its sizes by the flat picture they look like
+// ("1080s"), and so does this.
+var vrSteps = []step{
+	{3840, "2160s", 220, 160, false},
+	{2880, "1440s", 120, 90, false},
+	{1920, "1080s", 60, 45, false},
+	{1280, "720s", 25, 25, true},
 }
 
-// ValidChoice says whether a codec and quality are ones on offer — checked before any work.
-func ValidChoice(codec, quality string) error {
-	if !codecKnown(codec) {
-		return fmt.Errorf("unknown codec %q", codec)
-	}
-	if _, ok := qualityByID(quality); !ok {
-		return fmt.Errorf("unknown quality %q", quality)
+var flatSteps = []step{
+	{2160, "2160p", 160, 120, false},
+	{1440, "1440p", 90, 65, false},
+	{1080, "1080p", 50, 35, false},
+	{720, "720p", 25, 25, true},
+	{480, "480p", 12, 12, true},
 }
+
+const audioRate = 160_000
+
+func even(x float64) int { return int(math.Round(x/2)) * 2 }
+
+// Ladder is the qualities a video is offered in, best first: every step no bigger than the
+// picture itself, or the picture's own size if it is smaller than all of them.
+func Ladder(i Info) []Rung {
+	v := i.Video
+	if v == nil || v.Width <= 0 || v.Height <= 0 {
 		return nil
 	}
-
-func codecKnown(id string) bool {
-	for _, c := range Codecs {
-		if c.ID == id {
-			return true
+	vr := v.Spherical
+	steps := flatSteps
+	w, h := v.Shown()
+	src := min(w, h) // a flat picture is named by its short side
+	if vr {
+		steps, src = vrSteps, w
 	}
+	// A picture between two steps (a 2292×960 capture) gets its own size on top, at the bit
+	// rate of the step above, so the best on offer is never less than the file.
+	var out []Rung
+	for k, s := range steps {
+		if s.size > src {
+			continue
 		}
-	return false
+		if len(out) == 0 && s.size < src && k > 0 { // never above the top step: H.264 stops there
+			own := steps[k-1]
+			own.size, own.label, own.cap30 = src, strconv.Itoa(src)+map[bool]string{true: "s", false: "p"}[vr], false
+			out = append(out, rung(i, own))
+		}
+		out = append(out, rung(i, s))
+	}
+	if len(out) == 0 {
+		last := steps[len(steps)-1]
+		last.size, last.label = src, strconv.Itoa(src)+map[bool]string{true: "s", false: "p"}[vr]
+		out = append(out, rung(i, last))
+	}
+	return out
 }
 
-// fit is the output: never larger than the source, even dimensions, and a bit rate by the
-// size it comes to — a quarter more at 50 fps and up, less for the codecs that need less.
-func fit(q Quality, src Info, codec string) (w, h, kbps int) {
-	w, h = src.Video.Width, src.Video.Height
-	if q.Height > 0 && h > q.Height {
-		w = int(math.Round(float64(w) * float64(q.Height) / float64(h)))
-		h = q.Height
-	}
-	w, h = w&^1, h&^1
+func rung(i Info, s step) Rung {
+	v := i.Video
+	sw, sh := v.Shown()
+	var w, h int
 	switch {
-	case h >= 2160:
-		kbps = 20000
-	case h >= 1440:
-		kbps = 12000
-	case h >= 1080:
-		kbps = 8000
-	case h >= 720:
-		kbps = 4000
-	default:
-		kbps = 2000
+	case v.Spherical:
+		w, h = s.size, even(float64(s.size)*float64(sh)/float64(sw))
+	case sw >= sh:
+		h, w = s.size, even(float64(s.size)*float64(sw)/float64(sh))
+	default: // standing up
+		w, h = s.size, even(float64(s.size)*float64(sh)/float64(sw))
 	}
-	if src.Video.FPS >= 50 {
-		kbps = kbps * 5 / 4
+	fps := v.FPS
+	if fps <= 0 {
+		fps = 30
 	}
-	if codec == "hevc" || codec == "av1" {
-		kbps = kbps * 6 / 10
+	for fps > 60.5 || (s.cap30 && fps > 30.5) {
+		fps /= 2
 	}
-	return w, h, kbps
+	fps = math.Round(fps*1000) / 1000
+	br := s.lo
+	if fps > 30.5 {
+		br = s.hi
+	}
+	r := Rung{Name: strconv.Itoa(w), Label: s.label, Width: w, Height: h, FPS: fps, Bitrate: br * 100_000}
+	r.Peak = r.Bitrate*3/2 + audioRate
+	r.level = level(w, h, fps)
+	lv, _ := strconv.ParseFloat(r.level, 64)
+	r.codecs = fmt.Sprintf("avc1.6400%02x", int(math.Round(lv*10)))
+	if i.Audio != nil {
+		r.codecs += ",mp4a.40.2"
+	}
+	return r
 }
 
-// Recipe is one way to make the stream: the engine's name for the record, and the ffmpeg
-// arguments that go before the input, the video filter, and the video codec.
+// level is the lowest H.264 level that takes this many macroblocks a frame and a second.
+func level(w, h int, fps float64) string {
+	mbs := ((w + 15) / 16) * ((h + 15) / 16)
+	rate := float64(mbs) * fps
+	for _, l := range []struct {
+		name  string
+		mbps  float64
+		frame int
+	}{
+		{"3.1", 108000, 3600}, {"3.2", 216000, 5120}, {"4.0", 245760, 8192}, {"4.2", 522240, 8704},
+		{"5.0", 589824, 22080}, {"5.1", 983040, 36864}, {"5.2", 2073600, 36864},
+	} {
+		if rate <= l.mbps && mbs <= l.frame {
+			return l.name
+		}
+	}
+	return "6.2"
+}
+
+// fpsArg is a frame rate as ffmpeg's fps filter takes it, exactly for the NTSC rates.
+func fpsArg(f float64) string {
+	for _, n := range []float64{24, 30, 60, 120} {
+		if math.Abs(f-n*1000/1001) < 0.01 {
+			return fmt.Sprintf("%d/1001", int(n*1000))
+		}
+	}
+	return strings.TrimRight(strings.TrimRight(strconv.FormatFloat(f, 'f', 3, 64), "0"), ".")
+}
+
+// Recipe is one way to make a quality: the engine's name for the record, the device it runs
+// on ("cpu" for the software encoder), and the ffmpeg arguments that go before the input, the
+// video filter, and the video codec.
 type Recipe struct {
 	Engine string
+	Device string
 	Pre    []string
 	VF     string
 	Video  []string
 }
 
-// recipes are the ways to try, best first: a card on the bus before the integrated GPU;
-// on a GPU, decoding on the same card (frames never leave it) before decoding in software
-// and uploading; the software encoders last. An empty list means nothing here can.
-func recipes(c Caps, codec string, src Info, w, h, kbps int) []Recipe {
-	if codec == "copy" {
-		v := []string{"-c:v", "copy"}
-		if src.Video.Codec == "hevc" {
-			v = append(v, "-tag:v", "hvc1") // Safari reads hvc1, not hev1
+// CPU is the device name for software encoding.
+const CPU = "cpu"
+
+// Device is one thing a machine can make H.264 on, for the Transcode device setting.
+type Device struct {
+	ID         string `json:"id"`   // a render node, or "cpu"
+	Name       string `json:"name"` // "Intel Arc A380", "CPU (libx264)"
+	Integrated bool   `json:"integrated,omitempty"`
+	OK         bool   `json:"ok"`
+	Reason     string `json:"reason,omitempty"` // when not OK: why
 }
-		return []Recipe{{Engine: "Original codec", Video: v}}
+
+// Devices lists what this machine could make the player's H.264 on: every GPU, usable or not
+// (and why not), then the CPU.
+func Devices(c Caps) []Device {
+	var out []Device
+	if c.Error != "" {
+		return []Device{{ID: CPU, Name: "CPU", Reason: c.Error}}
 	}
-	var out []Recipe
-	gpus := append([]GPU(nil), c.GPUs...)
-	sort.SliceStable(gpus, func(i, j int) bool { return !gpus[i].Integrated && gpus[j].Integrated })
-	rate := []string{"-b:v", strconv.Itoa(kbps) + "k", "-maxrate", strconv.Itoa(kbps*5/4) + "k", "-bufsize", strconv.Itoa(kbps*5/2) + "k"}
-	for i := range gpus {
-		g := &gpus[i]
-		if g.API != "vaapi" || !has(g.Encodes, codec) {
-			continue
+	for _, g := range c.GPUs {
+		d := Device{ID: g.Device, Name: g.Name, Integrated: g.Integrated}
+		if d.Name == "" {
+			d.Name = g.Device
 		}
-		video := append([]string{"-c:v", codec + "_vaapi"}, rate...)
-		switch codec {
-		case "h264":
-			video = append(video, "-profile:v", "high")
-		case "hevc":
-			video = append(video, "-tag:v", "hvc1")
+		switch {
+		case g.API != "vaapi":
+			d.Reason = "only VAAPI devices encode here"
+		case g.Encodes != nil && !has(g.Encodes, "h264"):
+			d.Reason = "doesn't encode H.264"
+		default:
+			d.OK = true
 		}
+		out = append(out, d)
+	}
+	for _, g := range c.Unusable {
 		name := g.Name
 		if name == "" {
 			name = g.Device
 		}
-		scale := fmt.Sprintf("scale_vaapi=w=%d:h=%d:format=nv12", w, h)
-		if has(g.Codecs, src.Video.Codec) {
-			vf := scale
-			if src.HDR() {
-				vf = "tonemap_vaapi=format=nv12:t=bt709:p=bt709:m=bt709," + vf
+		out = append(out, Device{ID: g.Device, Name: name, Integrated: g.Integrated, Reason: g.Reason})
 	}
-			out = append(out, Recipe{Engine: name + " (vaapi)", Pre: []string{"-hwaccel", "vaapi", "-hwaccel_device", g.Device, "-hwaccel_output_format", "vaapi"}, VF: vf, Video: video})
+	d := Device{ID: CPU, Name: "CPU (libx264)", OK: has(c.Encoders, "libx264")}
+	if !d.OK {
+		d.Reason = "this ffmpeg has no libx264"
 	}
-		out = append(out, Recipe{Engine: name + " (vaapi, decoded on the CPU)", Pre: []string{"-init_hw_device", "vaapi=va:" + g.Device, "-filter_hw_device", "va"},
-			VF: fmt.Sprintf("format=nv12,scale=%d:%d,hwupload", w, h), Video: video})
+	return append(out, d)
 }
-	swVF := fmt.Sprintf("scale=%d:%d,format=yuv420p", w, h)
-	if src.HDR() {
-		swVF = fmt.Sprintf("zscale=t=linear:npl=100,format=gbrpf32le,zscale=p=bt709,tonemap=hable,zscale=t=bt709:m=bt709,scale=%d:%d,format=yuv420p", w, h)
+
+// recipes are the ways to make quality r of src on device, best first: on a GPU, decoding on
+// the same card (frames never leave it) before decoding in software and uploading; the CPU
+// last, as the fallback whatever was asked. device "" is any: a card on the bus before the
+// integrated GPU. An empty list means nothing here can.
+func recipes(c Caps, device string, src Info, r Rung) []Recipe {
+	var out []Recipe
+	gpus := append([]GPU(nil), c.GPUs...)
+	sort.SliceStable(gpus, func(i, j int) bool { return !gpus[i].Integrated && gpus[j].Integrated })
+	kbps := r.Bitrate / 1000
+	rate := []string{"-b:v", strconv.Itoa(kbps) + "k", "-maxrate", strconv.Itoa(kbps*3/2) + "k", "-bufsize", strconv.Itoa(kbps*2) + "k",
+		"-profile:v", "high", "-level", r.level}
+	fps := ""
+	if src.Video == nil || src.Video.FPS <= 0 || math.Abs(src.Video.FPS-r.FPS) > 0.01 {
+		fps = "fps=" + fpsArg(r.FPS) + ","
 	}
-	cap := []string{"-maxrate", strconv.Itoa(kbps*5/4) + "k", "-bufsize", strconv.Itoa(kbps*5/2) + "k"}
-	switch {
-	case codec == "h264" && has(c.Encoders, "libx264"):
-		out = append(out, Recipe{Engine: "CPU (libx264)", VF: swVF, Video: append([]string{"-c:v", "libx264", "-preset", "veryfast", "-crf", "23", "-profile:v", "high"}, cap...)})
-	case codec == "hevc" && has(c.Encoders, "libx265"):
-		out = append(out, Recipe{Engine: "CPU (libx265)", VF: swVF, Video: append([]string{"-c:v", "libx265", "-preset", "fast", "-crf", "26", "-tag:v", "hvc1"}, cap...)})
-	case codec == "av1" && has(c.Encoders, "libsvtav1"):
-		out = append(out, Recipe{Engine: "CPU (SVT-AV1)", VF: swVF, Video: append([]string{"-c:v", "libsvtav1", "-preset", "8", "-crf", "35"}, cap...)})
+	if device != CPU {
+		for i := range gpus {
+			g := &gpus[i]
+			// Encodes is vainfo's answer; without vainfo there is none, and the card is tried
+			// anyway, with the next recipe behind it.
+			if g.API != "vaapi" || (g.Encodes != nil && !has(g.Encodes, "h264")) || (device != "" && g.Device != device) {
+				continue
+			}
+			video := append(append([]string{"-c:v", "h264_vaapi"}, rate...), "-bf", "0")
+			name := g.Name
+			if name == "" {
+				name = g.Device
+			}
+			// The card doesn't turn a phone's picture by itself (ffmpeg's own turning is for
+			// pictures in memory), so it is told to, and ffmpeg is told not to.
+			scale := turn(src) + fmt.Sprintf("scale_vaapi=w=%d:h=%d:format=nv12", r.Width, r.Height)
+			// HDR10 (PQ) is tone-mapped on the card, which needs the file's mastering data;
+			// HLG is made to look right on an ordinary screen as it is, so it is only scaled
+			// (tonemap_vaapi refuses it). Either way the next recipe tone-maps in software.
+			if src.Video != nil && has(g.Codecs, src.Video.Codec) {
+				vf := fps + scale
+				if src.PQ() {
+					vf = fps + "tonemap_vaapi=format=nv12:t=bt709:p=bt709:m=bt709," + scale
+				}
+				out = append(out, Recipe{Engine: name, Device: g.Device, Pre: []string{"-noautorotate", "-hwaccel", "vaapi", "-hwaccel_device", g.Device, "-hwaccel_output_format", "vaapi"}, VF: vf, Video: video})
+			}
+			cpuVF := fmt.Sprintf("%sformat=nv12,scale=%d:%d,hwupload", fps, r.Width, r.Height)
+			if src.PQ() {
+				cpuVF = fps + toneMap + fmt.Sprintf(",scale=%d:%d,format=nv12,hwupload", r.Width, r.Height)
+			}
+			out = append(out, Recipe{Engine: name + ", decoded on the CPU", Device: g.Device, Pre: []string{"-init_hw_device", "vaapi=va:" + g.Device, "-filter_hw_device", "va"},
+				VF: cpuVF, Video: video})
+		}
+	}
+	if has(c.Encoders, "libx264") {
+		vf := fmt.Sprintf("%sscale=%d:%d,format=yuv420p", fps, r.Width, r.Height)
+		if src.PQ() {
+			vf = fps + toneMap + fmt.Sprintf(",scale=%d:%d,format=yuv420p", r.Width, r.Height)
+		}
+		out = append(out, Recipe{Engine: "CPU (libx264)", Device: CPU, VF: vf, Video: append([]string{"-c:v", "libx264", "-preset", "veryfast", "-sc_threshold", "0"}, rate...)})
 	}
 	return out
 }
 
-// EngineFor is the engine the picker will say a codec runs on, "" when none can.
-func EngineFor(c Caps, codec string) string {
-	if c.Error != "" {
+// turn is the card's filter that turns a picture the way it is meant to be shown.
+func turn(src Info) string {
+	if src.Video == nil {
 		return ""
 	}
-	if codec == "copy" {
-		return "Original codec"
+	switch src.Video.Rotation {
+	case 90:
+		return "transpose_vaapi=dir=clock,"
+	case 180:
+		return "transpose_vaapi=dir=reversal,"
+	case 270:
+		return "transpose_vaapi=dir=cclock,"
 	}
-	r := recipes(c, codec, Info{Video: &Track{Codec: "h264", Width: 1920, Height: 1080}}, 1920, 1080, 8000)
-	if len(r) == 0 {
 	return ""
 }
-	return r[0].Engine
-}
 
-// hlsArgs is the whole ffmpeg argument list for one recipe: the input, the first video and
-// audio streams, the picture through the recipe, sound as AAC unless it already is, a
-// keyframe every segment, and an event playlist of fragmented-MP4 segments in dir.
-func hlsArgs(dir, in string, src Info, r Recipe, copyCodec bool) []string {
-	a := []string{"-nostdin", "-hide_banner", "-loglevel", "error", "-y"}
-	a = append(a, r.Pre...)
-	a = append(a, "-i", in, "-map", "0:v:0", "-map", "0:a:0?", "-sn", "-dn")
-	if r.VF != "" {
-		a = append(a, "-vf", r.VF)
-	}
-	a = append(a, r.Video...)
-	switch {
-	case src.Audio == nil:
-		a = append(a, "-an")
-	case src.Audio.Codec == "aac":
-		a = append(a, "-c:a", "copy")
-	default:
-		a = append(a, "-c:a", "aac", "-b:a", "160k", "-ac", "2")
-	}
-	if !copyCodec {
-		fps := src.Video.FPS
-		if fps <= 0 {
-			fps = 30
-		}
-		gop := int(math.Round(fps * hlsSeconds))
-		if gop < 24 {
-			gop = 24
-		}
-		if gop > 300 {
-			gop = 300
-		}
-		a = append(a, "-g", strconv.Itoa(gop), "-force_key_frames", fmt.Sprintf("expr:gte(t,n_forced*%d)", hlsSeconds))
-	}
-	a = append(a, "-f", "hls", "-hls_time", strconv.Itoa(hlsSeconds), "-hls_playlist_type", "event", "-hls_segment_type", "fmp4",
-		"-hls_fmp4_init_filename", "init.mp4", "-hls_segment_filename", dir+"/seg%05d.m4s", "-hls_flags", "independent_segments+temp_file",
-		"-progress", dir+"/progress", "-stats_period", "1", dir+"/index.m3u8")
-	return a
-}
+// toneMap turns an HDR10 picture into an ordinary one, in software.
+const toneMap = "zscale=t=linear:npl=100,format=gbrpf32le,zscale=p=bt709,tonemap=hable,zscale=t=bt709:m=bt709:r=tv"
 
-const hlsSeconds = 4
+// Seg is the length of a piece, in seconds.
+const Seg = 3.0
 
-// tsBase is added to every run's timestamps. A run from the top would otherwise start just
-// below zero (the B-frame delay) and the muxer would shift it to make room, while a run from a
-// seek point would not: with the base, no run is ever shifted, and a segment means the same
-// stretch of the film whichever run made it.
+// tsBase is added to every run's times, so pieces from different runs follow on: without it
+// a run from the top would start just below zero (the B-frame and AAC delay) and the muxer
+// would shift that run alone.
 const tsBase = 10
 
-// segArgs is one run of a seekable re-encode: segments from..to-1 of the fixed 4 s grid.
-// Every run is made the same way, the first included, so their segments are interchangeable:
-// an accurate seek to from×4 s, timestamps put back where that is in the film (+ tsBase),
-// kept as they are in each fragment (frag_discont), numbered from `from`, and an end just
-// short of segment `to`, which is already on disk, so the run never writes over it. Segments
-// land in dir as seg%05d.m4s; init is the init segment's name (only the first run's is used).
-func segArgs(dir, in string, src Info, r Recipe, from, to, n int, init string) []string {
-	fps := 30.0
-	if src.Video != nil && src.Video.FPS > 0 {
-		fps = src.Video.FPS
-	}
-	start := from * hlsSeconds
+// pieceArgs is one run making quality r from piece n on, into dir as <n>.ts: an accurate seek
+// to n×Seg, a keyframe on every Seg mark and nowhere else (so every piece starts on one, and
+// pieces from any run and quality line up), times put back where that is in the film. in is a
+// path or, for a file on another machine, an http URL.
+func pieceArgs(dir, in string, src Info, rc Recipe, r Rung, n int) []string {
+	at := strconv.FormatFloat(float64(n)*Seg, 'f', 3, 64)
 	a := []string{"-nostdin", "-hide_banner", "-loglevel", "error", "-y"}
-	a = append(a, r.Pre...)
-	a = append(a, "-ss", strconv.Itoa(start), "-i", in, "-map", "0:v:0", "-map", "0:a:0?", "-sn", "-dn")
-	if r.VF != "" {
-		a = append(a, "-vf", r.VF)
+	a = append(a, rc.Pre...)
+	if strings.HasPrefix(in, "http://") || strings.HasPrefix(in, "https://") {
+		a = append(a, "-reconnect", "1", "-reconnect_on_network_error", "1", "-reconnect_delay_max", "4")
 	}
-	a = append(a, r.Video...)
-	switch {
-	case src.Audio == nil:
+	a = append(a, "-ss", at, "-i", in, "-map", "0:v:0", "-map", "0:a:0?", "-sn", "-dn")
+	if rc.VF != "" {
+		a = append(a, "-vf", rc.VF)
+	}
+	a = append(a, rc.Video...)
+	if src.Audio == nil {
 		a = append(a, "-an")
-	case src.Audio.Codec == "aac":
-		a = append(a, "-c:a", "copy")
-	default:
+	} else {
 		a = append(a, "-c:a", "aac", "-b:a", "160k", "-ac", "2")
 	}
-	gop := int(math.Round(fps * hlsSeconds))
-	if gop < 24 {
-		gop = 24
-	}
-	if gop > 300 {
-		gop = 300
-	}
-	a = append(a, "-g", strconv.Itoa(gop), "-force_key_frames", fmt.Sprintf("expr:gte(t,n_forced*%d)", hlsSeconds))
-	if to < n {
-		a = append(a, "-t", strconv.FormatFloat(float64((to-from)*hlsSeconds)-0.5/fps, 'f', 3, 64))
-	}
-	a = append(a, "-output_ts_offset", strconv.Itoa(start+tsBase),
-		"-f", "hls", "-hls_time", strconv.Itoa(hlsSeconds), "-hls_playlist_type", "event", "-hls_segment_type", "fmp4",
-		"-hls_segment_options", "movflags=+frag_discont", "-start_number", strconv.Itoa(from),
-		"-hls_fmp4_init_filename", init, "-hls_segment_filename", dir+"/seg%05d.m4s", "-hls_flags", "independent_segments+temp_file",
-		"-progress", dir+"/progress", "-stats_period", "1", dir+"/run.m3u8")
+	gop := int(math.Ceil(r.FPS*Seg)) * 4
+	a = append(a, "-g", strconv.Itoa(gop), "-force_key_frames", fmt.Sprintf("expr:gte(t,n_forced*%g)", Seg),
+		"-output_ts_offset", strconv.FormatFloat(float64(n)*Seg+tsBase, 'f', 3, 64),
+		"-f", "hls", "-hls_time", strconv.FormatFloat(Seg-0.5, 'f', 2, 64), "-hls_list_size", "0",
+		"-hls_flags", "temp_file", "-hls_segment_type", "mpegts", "-start_number", strconv.Itoa(n),
+		"-hls_segment_filename", dir+"/%d.ts", dir+"/ffmpeg.m3u8")
 	return a
 }
 
-// segCount is how many 4 s segments a seekable re-encode of a file this long lists. The last
-// 0.3 s are left out of the count, so a container whose sound runs on past the picture never
-// lists a segment no frame starts.
-func segCount(duration float64) int {
-	d := duration - 0.3
-	if d < 0 {
-		d = 0
-	}
-	return int(d/hlsSeconds) + 1
-}
-
 func has(list []string, x string) bool {
 	for _, v := range list {
 		if v == x {

internal/media/encode_test.go

@@ -9,25 +9,40 @@ func src(codec string, w, h int, fps float64) Info {
 	return Info{Duration: 100, Video: &Track{Codec: codec, Width: w, Height: h, FPS: fps}, Audio: &Track{Codec: "opus", Channels: 2}}
 }
 
-func TestFit(t *testing.T) {
-	q := func(id string) Quality { x, _ := qualityByID(id); return x }
-	for _, c := range []struct {
-		q         string
-		in        Info
-		codec     string
-		w, h, kbs int
-	}{
-		{"1080p", src("hevc", 3840, 2160, 60), "h264", 1920, 1080, 10000},
-		{"original", src("hevc", 3840, 2160, 30), "h264", 3840, 2160, 20000},
-		{"720p", src("h264", 2292, 960, 60), "h264", 1718, 720, 5000},  // odd width made even
-		{"1080p", src("h264", 1280, 720, 30), "h264", 1280, 720, 4000}, // never upscaled
-		{"480p", src("h264", 1920, 1080, 30), "hevc", 852, 480, 1200},  // 853.3 rounds down, then even
-		{"original", src("av1", 640, 360, 24), "av1", 640, 360, 1200},
-	} {
-		w, h, k := fit(q(c.q), c.in, c.codec)
-		if w != c.w || h != c.h || k != c.kbs {
-			t.Errorf("%s %s %dx%d@%.0f → %dx%d %dk, want %dx%d %dk", c.q, c.codec, c.in.Video.Width, c.in.Video.Height, c.in.Video.FPS, w, h, k, c.w, c.h, c.kbs)
+func TestLadder(t *testing.T) {
+	vr := src("hevc", 7680, 3840, 50)
+	vr.Video.Spherical = true
+	r := Ladder(vr)
+	if len(r) != 4 || r[0].Name != "3840" || r[0].Height != 1920 || r[0].level != "5.2" || r[3].FPS != 25 || r[0].Label != "2160s" {
+		t.Fatalf("8K 360: %+v", r)
 	}
+	if r[0].codecs != "avc1.640034,mp4a.40.2" {
+		t.Fatalf("codecs %q", r[0].codecs)
+	}
+	r = Ladder(src("h264", 2292, 960, 60)) // a capture: its own size on top, then the steps under it
+	if len(r) != 3 || r[0].Label != "960p" || r[0].Width != 2292 || r[0].FPS != 60 || r[0].Bitrate != 5_000_000 || r[1].Label != "720p" || r[1].Width != 1720 || r[1].FPS != 30 {
+		t.Fatalf("2292×960: %+v", r)
+	}
+	r = Ladder(src("h264", 1920, 1080, 59.94))
+	if len(r) != 3 || r[0].Label != "1080p" || r[0].FPS != 59.94 || r[1].FPS != 29.97 || r[2].Width != 854 {
+		t.Fatalf("1080p: %+v", r)
+	}
+	if r = Ladder(src("h264", 1080, 1920, 30)); r[0].Width != 1080 || r[0].Height != 1920 { // standing up
+		t.Fatalf("portrait: %+v", r)
+	}
+	if r = Ladder(src("h264", 320, 240, 30)); len(r) != 1 || r[0].Width != 320 || r[0].Label != "240p" {
+		t.Fatalf("tiny: %+v", r)
+	}
+	silent := src("h264", 1280, 720, 30)
+	silent.Audio = nil
+	if r = Ladder(silent); strings.Contains(r[0].codecs, "mp4a") {
+		t.Fatalf("no sound, no AAC: %q", r[0].codecs)
+	}
+	if Ladder(Info{Duration: 10}) != nil {
+		t.Fatal("no picture, no ladder")
+	}
+	if fpsArg(29.97) != "30000/1001" || fpsArg(25) != "25" {
+		t.Fatal(fpsArg(29.97), fpsArg(25))
 	}
 }
 
@@ -47,111 +62,96 @@ func engineNames(r []Recipe) []string {
 	return out
 }
 
-func TestRecipesOrder(t *testing.T) {
+func TestRecipes(t *testing.T) {
 	c := gridCaps()
-	// h264 from hevc: the card first, decoding on it; then the iGPU the same way; then the CPU
-	got := engineNames(recipes(c, "h264", src("hevc", 3840, 2160, 60), 1920, 1080, 10000))
-	want := []string{"Intel Arc A380 (vaapi)", "Intel Arc A380 (vaapi, decoded on the CPU)", "Intel UHD Graphics 750 (vaapi)", "Intel UHD Graphics 750 (vaapi, decoded on the CPU)", "CPU (libx264)"}
-	if strings.Join(got, "|") != strings.Join(want, "|") {
-		t.Fatalf("got %v", got)
+	in := src("hevc", 3840, 2160, 60)
+	r1080 := Ladder(in)[2]
+	// any device: the card first, decoding on it; then the iGPU the same way; then the CPU
+	got := strings.Join(engineNames(recipes(c, "", in, r1080)), "|")
+	if got != "Intel Arc A380|Intel Arc A380, decoded on the CPU|Intel UHD Graphics 750|Intel UHD Graphics 750, decoded on the CPU|CPU (libx264)" {
+		t.Fatalf("any: %s", got)
 	}
-	// av1 source: neither card decodes it, so no same-card recipe, and only the Arc encodes av1
-	got = engineNames(recipes(c, "av1", src("av1", 1920, 1080, 30), 1920, 1080, 4800))
-	want = []string{"Intel Arc A380 (vaapi, decoded on the CPU)", "CPU (SVT-AV1)"}
-	if strings.Join(got, "|") != strings.Join(want, "|") {
-		t.Fatalf("av1: got %v", got)
+	// the iGPU asked for: only it, then the CPU as the fallback
+	if got = strings.Join(engineNames(recipes(c, "/dev/dri/renderD128", in, r1080)), "|"); got != "Intel UHD Graphics 750|Intel UHD Graphics 750, decoded on the CPU|CPU (libx264)" {
+		t.Fatalf("iGPU: %s", got)
 	}
-	// copy is one recipe, no filter, hvc1 for hevc
-	r := recipes(c, "copy", src("hevc", 1920, 1080, 30), 1920, 1080, 0)
-	if len(r) != 1 || r[0].VF != "" || !has(r[0].Video, "hvc1") || !has(r[0].Video, "copy") {
-		t.Fatalf("copy: %+v", r)
+	if got = strings.Join(engineNames(recipes(c, CPU, in, r1080)), "|"); got != "CPU (libx264)" {
+		t.Fatalf("cpu: %s", got)
 	}
-	// a machine with no GPU and no x264: nothing for h264, something for av1
-	bare := Caps{FFmpeg: "ffmpeg", FFprobe: "ffprobe", Encoders: []string{"aac", "libsvtav1"}}
-	if len(recipes(bare, "h264", src("h264", 1280, 720, 30), 1280, 720, 4000)) != 0 {
-		t.Fatal("no x264 means no h264")
+	// an AV1 source: neither card decodes it, so no same-card recipe
+	if got = strings.Join(engineNames(recipes(c, "/dev/dri/renderD129", src("av1", 1920, 1080, 30), r1080)), "|"); got != "Intel Arc A380, decoded on the CPU|CPU (libx264)" {
+		t.Fatalf("av1: %s", got)
 	}
-	if EngineFor(bare, "av1") != "CPU (SVT-AV1)" || EngineFor(bare, "h264") != "" || EngineFor(bare, "copy") != "Original codec" {
-		t.Fatal("engineFor")
+	// a machine with no GPU and no x264: nothing
+	bare := Caps{FFmpeg: "ffmpeg", FFprobe: "ffprobe", Encoders: []string{"aac"}}
+	if len(recipes(bare, "", in, r1080)) != 0 {
+		t.Fatal("no x264 means nothing")
 	}
-	if EngineFor(c, "hevc") != "Intel Arc A380 (vaapi)" {
-		t.Fatalf("engineFor on grid: %q", EngineFor(c, "hevc"))
-	}
-	// HDR gets tone-mapped on both paths
+	// 30 fps from 60 for the lower rungs; HDR tone-mapped on both paths
+	r720 := Ladder(in)[3]
 	hdr := src("hevc", 3840, 2160, 60)
 	hdr.Video.ColorTransfer = "smpte2084"
-	r = recipes(c, "h264", hdr, 1920, 1080, 10000)
-	if !strings.HasPrefix(r[0].VF, "tonemap_vaapi") || !strings.Contains(r[len(r)-1].VF, "tonemap=hable") {
-		t.Fatalf("hdr: %q … %q", r[0].VF, r[len(r)-1].VF)
+	rs := recipes(c, "", hdr, r720)
+	if !strings.HasPrefix(rs[0].VF, "fps=30,tonemap_vaapi") || !strings.Contains(rs[1].VF, "tonemap=hable") || !strings.HasSuffix(rs[1].VF, "hwupload") || !strings.Contains(rs[len(rs)-1].VF, "tonemap=hable") {
+		t.Fatalf("hdr: %q … %q … %q", rs[0].VF, rs[1].VF, rs[len(rs)-1].VF)
+	}
+	hdr.Video.ColorTransfer = "arib-std-b67" // HLG: shown as it is, on every path
+	if rs = recipes(c, "", hdr, r720); strings.Contains(rs[0].VF, "tonemap") || strings.Contains(rs[1].VF, "tonemap") {
+		t.Fatalf("hlg: %q … %q", rs[0].VF, rs[1].VF)
+	}
+	// a phone's picture, upright: the ladder by the shown size, turned on the card
+	phone := src("hevc", 1920, 1080, 30)
+	phone.Video.Rotation = 90
+	lr := Ladder(phone)
+	if lr[0].Width != 1080 || lr[0].Height != 1920 {
+		t.Fatalf("upright: %+v", lr[0])
+	}
+	if rs = recipes(c, "", phone, lr[0]); !strings.HasPrefix(rs[0].VF, "transpose_vaapi=dir=clock,scale_vaapi=w=1080:h=1920") || rs[0].Pre[0] != "-noautorotate" || strings.Contains(rs[1].VF, "transpose") {
+		t.Fatalf("turned: %q %v / %q", rs[0].VF, rs[0].Pre, rs[1].VF)
+	}
+	// no vainfo: the card is tried all the same
+	nov := gridCaps()
+	nov.GPUs[1].Encodes = nil
+	if rs = recipes(nov, "/dev/dri/renderD129", in, r1080); rs[0].Engine != "Intel Arc A380" || !Devices(nov)[1].OK {
+		t.Fatalf("no vainfo: %v", engineNames(rs))
+	}
+	if rs := recipes(c, "", in, r1080); strings.Contains(rs[0].VF, "fps=") {
+		t.Fatalf("same rate needs no fps filter: %q", rs[0].VF)
 	}
 }
 
-func TestHLSArgs(t *testing.T) {
+func TestDevices(t *testing.T) {
+	c := gridCaps()
+	c.Unusable = []GPU{{Device: "/dev/dri/renderD130", Name: "Something", Reason: "permission denied"}}
+	d := Devices(c)
+	if len(d) != 4 || !d[0].OK || !d[1].OK || d[2].OK || d[2].Reason == "" || d[3].ID != CPU || !d[3].OK {
+		t.Fatalf("%+v", d)
+	}
+	if d := Devices(Caps{Error: "ffmpeg is not installed"}); len(d) != 1 || d[0].OK {
+		t.Fatalf("no ffmpeg: %+v", d)
+	}
+}
+
+func TestPieceArgs(t *testing.T) {
 	in := src("h264", 1920, 1080, 60)
-	r := recipes(gridCaps(), "h264", in, 1920, 1080, 10000)[0]
-	a := strings.Join(hlsArgs("/d", "/v.mkv", in, r, false), " ")
-	for _, want := range []string{"-hwaccel vaapi -hwaccel_device /dev/dri/renderD129", "-i /v.mkv", "-map 0:v:0 -map 0:a:0?", "-vf scale_vaapi=w=1920:h=1080:format=nv12", "-c:v h264_vaapi -b:v 10000k -maxrate 12500k", "-c:a aac -b:a 160k -ac 2", "-g 240 -force_key_frames expr:gte(t,n_forced*4)", "-hls_segment_type fmp4", "-hls_segment_filename /d/seg%05d.m4s", "/d/index.m3u8"} {
+	r := Ladder(in)[0]
+	rc := recipes(gridCaps(), "/dev/dri/renderD129", in, r)[0]
+	a := strings.Join(pieceArgs("/d", "/v.mkv", in, rc, r, 12), " ")
+	for _, want := range []string{"-hwaccel vaapi -hwaccel_device /dev/dri/renderD129", "-ss 36.000 -i /v.mkv", "-map 0:v:0 -map 0:a:0?",
+		"-vf scale_vaapi=w=1920:h=1080:format=nv12", "-c:v h264_vaapi -b:v 5000k -maxrate 7500k", "-level 4.2", "-c:a aac -b:a 160k -ac 2",
+		"-force_key_frames expr:gte(t,n_forced*3)", "-output_ts_offset 46.000", "-hls_time 2.50", "-start_number 12", "-hls_segment_filename /d/%d.ts"} {
 		if !strings.Contains(a, want) {
 			t.Errorf("missing %q in\n%s", want, a)
 		}
 	}
-	// aac stays as it is; no audio means none; copy sets no keyframes
-	in.Audio.Codec = "aac"
-	if a := strings.Join(hlsArgs("/d", "/v", in, r, false), " "); !strings.Contains(a, "-c:a copy") {
-		t.Error("aac should be copied")
+	if strings.Contains(a, "-reconnect") {
+		t.Error("a path needs no reconnect")
+	}
+	if a := strings.Join(pieceArgs("/d", "http://10.0.0.234:8100/api/play-src/x", in, rc, r, 0), " "); !strings.Contains(a, "-reconnect 1") {
+		t.Error("a URL reconnects")
 	}
 	in.Audio = nil
-	if a := strings.Join(hlsArgs("/d", "/v", in, r, false), " "); !strings.Contains(a, " -an ") {
-		t.Error("no audio stream → -an")
-	}
-	cp := recipes(gridCaps(), "copy", in, 1920, 1080, 0)[0]
-	if a := strings.Join(hlsArgs("/d", "/v", in, cp, true), " "); strings.Contains(a, "force_key_frames") || strings.Contains(a, "-vf") {
-		t.Error("copy must not ask for keyframes or filter")
-	}
-}
-
-func TestSegArgs(t *testing.T) {
-	in := src("h264", 1920, 1080, 25)
-	r := recipes(gridCaps(), "h264", in, 1920, 1080, 10000)[0]
-	first := strings.Join(segArgs("/d", "/v.mkv", in, r, 0, 900, 900, "init.mp4"), " ")
-	for _, want := range []string{"-ss 0 -i /v.mkv", "-output_ts_offset 10", "-start_number 0", "movflags=+frag_discont", "-hls_fmp4_init_filename init.mp4", "-hls_segment_filename /d/seg%05d.m4s", "/d/run.m3u8", "-force_key_frames expr:gte(t,n_forced*4)"} {
-		if !strings.Contains(first, want) {
-			t.Errorf("first run: missing %q in\n%s", want, first)
-		}
-	}
-	if strings.Contains(first, " -t ") {
-		t.Error("a run to the end has no -t")
-	}
-	// a seek: segments 30..44, stopping half a frame short of 45, which is on disk
-	seek := strings.Join(segArgs("/d", "/v.mkv", in, r, 30, 45, 900, "init-run.mp4"), " ")
-	for _, want := range []string{"-ss 120 -i /v.mkv", "-t 59.980", "-output_ts_offset 130", "-start_number 30", "-hls_fmp4_init_filename init-run.mp4"} {
-		if !strings.Contains(seek, want) {
-			t.Errorf("seek run: missing %q in\n%s", want, seek)
-		}
-	}
-	if strings.Index(seek, "-ss 120") > strings.Index(seek, "-i /v.mkv") || strings.Index(seek, "-hwaccel") > strings.Index(seek, "-i /v.mkv") {
-		t.Error("-ss and the decoder's options go before -i")
-	}
-	for d, n := range map[float64]int{9: 3, 8.2: 2, 8.31: 3, 64: 16, 0.1: 1, 3600: 900} {
-		if got := segCount(d); got != n {
-			t.Errorf("segCount(%v) = %d, want %d", d, got, n)
-		}
-	}
-}
-
-func TestParseProgress(t *testing.T) {
-	b := []byte("frame=10\nout_time_us=1000000\nspeed=2.5x\nprogress=continue\nframe=20\nout_time_us=2500000\nspeed=3.1x\nprogress=continue\n")
-	s, sp := parseProgress(b)
-	if s != 2.5 || sp != 3.1 {
-		t.Fatalf("got %v %v", s, sp)
-	}
-}
-
-func TestValidChoice(t *testing.T) {
-	if err := ValidChoice("h264", "720p"); err != nil {
-		t.Fatal(err)
-	}
-	if ValidChoice("vp8", "720p") == nil || ValidChoice("h264", "9p") == nil || ValidChoice("", "") == nil {
-		t.Fatal("bad choices must be refused")
+	if a := strings.Join(pieceArgs("/d", "/v", in, rc, r, 0), " "); !strings.Contains(a, "-an") {
+		t.Error("no sound means -an")
 	}
 }

internal/media/ffrun.go

@@ -6,13 +6,13 @@ package media
 // transcode never outlives the console that asked for it.
 
 import (
+	"bufio"
 	"bytes"
 	"context"
 	"errors"
 	"io"
 	"os"
 	"os/exec"
-	"strings"
 	"sync"
 	"syscall"
 	"time"
@@ -92,6 +92,35 @@ func (p *ffproc) end() {
 	}
 }
 
+// pause stops ffmpeg where it is (SIGSTOP), and resume lets it go on: a stream far enough
+// ahead of its player waits rather than making the rest of the film. A root run is paused by
+// its helper, which is told on its standard input.
+func (p *ffproc) pause() error  { return p.signal(syscall.SIGSTOP, "stop\n") }
+func (p *ffproc) resume() error { return p.signal(syscall.SIGCONT, "cont\n") }
+
+func (p *ffproc) signal(sig syscall.Signal, word string) error {
+	if done, _ := p.exited(); done {
+		return errors.New("ended")
+	}
+	if p.in != nil {
+		_, err := io.WriteString(p.in, word)
+		return err
+	}
+	return syscall.Kill(-p.cmd.Process.Pid, sig)
+}
+
+// kill ends ffmpeg now, without waiting: a paused one too.
+func (p *ffproc) kill() {
+	if done, _ := p.exited(); done {
+		return
+	}
+	if p.in != nil {
+		p.in.Close() // the helper ends it, waking it first if it is paused
+		return
+	}
+	_ = syscall.Kill(-p.cmd.Process.Pid, syscall.SIGKILL)
+}
+
 // lastWords is what ffmpeg said last, for the record.
 func (p *ffproc) lastWords() string { return p.tail.last() }
 
@@ -141,7 +170,17 @@ func RunFFmpegHelper(args []string, stdin io.Reader, stderr io.Writer) int {
 	}
 	ctx, cancel := context.WithCancel(context.Background())
 	go func() {
-		_, _ = io.Copy(io.Discard, stdin) // returns when the daemon lets go
+		// "stop" and "cont" pause and resume it; the end of input (the daemon letting go)
+		// ends it.
+		sc := bufio.NewScanner(stdin)
+		for sc.Scan() {
+			switch sc.Text() {
+			case "stop":
+				_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGSTOP)
+			case "cont":
+				_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGCONT)
+			}
+		}
 		cancel()
 	}()
 	done := make(chan error, 1)
@@ -151,6 +190,7 @@ func RunFFmpegHelper(args []string, stdin io.Reader, stderr io.Writer) int {
 	case werr = <-done:
 	case <-ctx.Done():
 		_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGTERM)
+		_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGCONT) // a paused one can't act on TERM
 		select {
 		case werr = <-done:
 		case <-time.After(5 * time.Second):
@@ -181,8 +221,3 @@ func clearDir(dir string) error {
 	}
 	return nil
 }
-
-func hasSegments(playlist string) bool {
-	b, err := os.ReadFile(playlist)
-	return err == nil && strings.Contains(string(b), "#EXTINF")
-}

internal/media/hls.go

@@ -1,669 +0,0 @@
-package media
-
-// Playing what the browser cannot play as it is: an HLS stream, re-encoded on demand by
-// ffmpeg on the machine's own GPU where it has one it can use, on its CPU otherwise. A
-// stream is one file at one codec and size, in a folder of its own under
-// <data dir>/transcode/.
-//
-// A re-encode is seekable anywhere from the start. Its playlist is written up front, for
-// the whole film: a fixed grid of 4 s segments, so the player's timeline is the film's.
-// ffmpeg runs ahead from the top as fast as it can; a request for a segment it hasn't
-// reached and won't reach soon — a seek ahead, or back into a stretch never made — ends that
-// run and starts another at the segment asked for, which stops on its own where segments
-// already exist. When a run finishes, the next gap is filled, until the whole file is on
-// disk. Every run is made the same way (segArgs), so segments from different runs join.
-//
-// "Repackaged" (copy) can't cut on a fixed grid — its keyframes are the source's — so it is
-// an event playlist that grows as ffmpeg writes it, seekable within what's done. Repackaging
-// runs at disk speed, so that is all of it within seconds.
-//
-// Nothing is kept: a stream nobody has touched for a while is ended and its folder removed,
-// and the folder is emptied when the daemon starts.
-
-import (
-	"bufio"
-	"bytes"
-	"context"
-	"crypto/rand"
-	"encoding/hex"
-	"errors"
-	"fmt"
-	"log"
-	"os"
-	"path/filepath"
-	"regexp"
-	"strconv"
-	"strings"
-	"sync"
-	"time"
-)
-
-// Stream is one re-encode, in progress or finished.
-type Stream struct {
-	ID       string    `json:"id"`
-	Path     string    `json:"path"`
-	Codec    string    `json:"codec"`
-	Quality  string    `json:"quality"`
-	Engine   string    `json:"engine"`
-	Width    int       `json:"width"`
-	Height   int       `json:"height"`
-	Kbps     int       `json:"kbps"`
-	Source   Info      `json:"source"`
-	Started  time.Time `json:"started"`
-	Root     bool      `json:"root"`
-	Seekable bool      `json:"seekable"` // seeking anywhere restarts the re-encode there
-
-	key      string
-	dir      string
-	mu       sync.Mutex
-	used     time.Time
-	proc     *ffproc // the run going now (or the only one, for copy)
-	finished bool
-	failure  string
-	gone     bool // forgotten by the Streamer
-
-	// seekable streams only
-	caps    Caps
-	self    string
-	recipe  Recipe
-	n       int // segments in the playlist
-	end     int // segments past this are not in the file after all (n until a run finds out)
-	run     *segRun
-	runMu   sync.Mutex // one run change at a time; held across ending one run and starting the next
-	asked   time.Time  // when the request that last moved the run arrived: an older one never moves it back
-	initOK  bool       // a later run's init segment was checked against the first's
-	initBad bool
-}
-
-// segRun is one ffmpeg over segments from..to-1.
-type segRun struct {
-	from, to int
-	proc     *ffproc
-	stopped  bool // ended by us: what it wrote after that is not to be trusted
-}
-
-// StreamStatus is what the player asks for while the file is still going through.
-type StreamStatus struct {
-	Running  bool    `json:"running"`
-	Done     bool    `json:"done"`
-	Error    string  `json:"error,omitempty"`
-	Progress float64 `json:"progress"` // seconds of output written (copy), or on disk (seekable)
-	Speed    float64 `json:"speed"`    // × realtime
-	Segments int     `json:"segments"`
-	From     float64 `json:"from"` // seekable: where the run going now started, seconds
-}
-
-// Streamer keeps one machine's streams.
-type Streamer struct {
-	dir     string
-	self    string
-	limit   int
-	mu      sync.Mutex
-	streams map[string]*Stream
-}
-
-const streamIdle = 10 * time.Minute
-const firstSegmentWait = 40 * time.Second
-
-// segmentWait is how long a request for a segment waits for a run to write it.
-const segmentWait = 45 * time.Second // under the hub proxy's 60 s wait for a node to answer
-
-// lookahead: a segment this many past what the run has written is waited for, not
-// restarted at. A few seconds of film, which any engine here writes faster than that.
-const lookahead = 3
-
-var streamFile = regexp.MustCompile(`^(index\.m3u8|init\.mp4|seg\d{5}\.m4s)$`)
-var segName = regexp.MustCompile(`^seg(\d{5})\.m4s$`)
-
-// NewStreamer empties the folder — a daemon restart orphans every stream — and starts the
-// sweeper.
-func NewStreamer(dataDir, self string, limit int) *Streamer {
-	m := &Streamer{dir: filepath.Join(dataDir, "transcode"), self: self, limit: limit, streams: map[string]*Stream{}}
-	_ = os.MkdirAll(m.dir, 0o755)
-	_ = clearDir(m.dir)
-	go func() {
-		for range time.Tick(30 * time.Second) {
-			m.Sweep(streamIdle)
-		}
-	}()
-	return m
-}
-
-// Open starts a stream, or hands back the one already serving the same request. It
-// returns once the first segment is on disk, so the player's first fetch is answered.
-func (m *Streamer) Open(ctx context.Context, c Caps, root bool, path, codec, quality string, src Info) (*Stream, error) {
-	if c.Error != "" {
-		return nil, errors.New(c.Error)
-	}
-	if err := ValidChoice(codec, quality); err != nil {
-		return nil, err
-	}
-	q, _ := qualityByID(quality)
-	if src.Video == nil {
-		return nil, &DecodeError{Msg: "no video stream"}
-	}
-	if src.Video.Width <= 0 || src.Video.Height <= 0 {
-		return nil, &DecodeError{Msg: "the picture's size is unknown"}
-	}
-	key := fmt.Sprintf("%s|%d|%.0f|%s|%s|%v", path, src.Size, src.Duration, codec, quality, root)
-	m.mu.Lock()
-	for _, s := range m.streams {
-		if s.key == key {
-			if s.failed() { // not the stream to hand back: let it go and make a fresh one
-				delete(m.streams, s.ID)
-				_ = os.RemoveAll(s.dir)
-				break
-			}
-			m.mu.Unlock()
-			s.touch()
-			return s, nil
-		}
-	}
-	running := 0
-	for _, s := range m.streams {
-		if s.running() {
-			running++
-		}
-	}
-	if running >= m.limit {
-		m.mu.Unlock()
-		return nil, fmt.Errorf("%d videos are already being re-encoded on this machine; one must finish or be closed first", running)
-	}
-	s := &Stream{ID: newID(), Path: path, Codec: codec, Quality: quality, Source: src, Started: time.Now(), Root: root, key: key, used: time.Now(),
-		caps: c, self: m.self}
-	s.dir = filepath.Join(m.dir, s.ID)
-	// A fixed grid needs the film's length; without one it can only grow as it goes.
-	s.Seekable = codec != "copy" && src.Duration > 0
-	if s.Seekable {
-		s.n = segCount(src.Duration)
-		s.end = s.n
-	}
-	m.streams[s.ID] = s
-	m.mu.Unlock()
-
-	s.Width, s.Height, s.Kbps = fit(q, src, codec)
-	if codec == "copy" {
-		s.Width, s.Height, s.Kbps = src.Video.Width, src.Video.Height, int(src.BitRate/1000)
-	}
-	rs := recipes(c, codec, src, s.Width, s.Height, s.Kbps)
-	if len(rs) == 0 {
-		m.forget(s)
-		return nil, errors.New("nothing on this machine encodes " + codec)
-	}
-	var last string
-	for _, r := range rs {
-		if err := os.MkdirAll(s.dir, 0o755); err != nil { // the root helper's ffmpeg writes here too
-			m.forget(s)
-			return nil, err
-		}
-		_ = clearDir(s.dir)
-		var args []string
-		if s.Seekable {
-			args = segArgs(s.dir, path, src, r, 0, s.n, s.n, "init.mp4")
-		} else {
-			args = hlsArgs(s.dir, path, src, r, codec == "copy")
-		}
-		p, err := startFF(c, m.self, root, args)
-		if err != nil {
-			last = r.Engine + ": " + err.Error()
-			continue
-		}
-		s.mu.Lock()
-		s.proc, s.Engine, s.recipe = p, r.Engine, r
-		if s.Seekable {
-			s.run = &segRun{from: 0, to: s.n, proc: p}
-		}
-		s.mu.Unlock()
-		msg, ok := s.waitFirstSegment(ctx)
-		if ok {
-			if s.Seekable {
-				go s.watchRun(s.run)
-			} else {
-				go s.watch()
-			}
-			log.Printf("media: stream %s: %s → %s %s %dx%d %dk on %s", s.ID, filepath.Base(path), codec, quality, s.Width, s.Height, s.Kbps, r.Engine)
-			return s, nil
-		}
-		p.end()
-		if ctx.Err() != nil || s.closed() { // the caller left, or somebody closed it meanwhile: not the recipe's fault
-			m.forget(s)
-			return nil, errors.New("cancelled")
-		}
-		last = r.Engine + ": " + msg
-		log.Printf("media: stream %s on %s: %s", filepath.Base(path), r.Engine, msg)
-	}
-	m.forget(s)
-	return nil, &DecodeError{Msg: last}
-}
-
-// waitFirstSegment watches for the first segment, or ffmpeg giving up.
-func (s *Stream) waitFirstSegment(ctx context.Context) (string, bool) {
-	deadline := time.Now().Add(firstSegmentWait)
-	playlist := filepath.Join(s.dir, "index.m3u8")
-	for {
-		if s.Seekable && exists(s.segPath(0)) || !s.Seekable && hasSegments(playlist) {
-			return "", true
-		}
-		if done, err := s.proc.exited(); done {
-			msg := s.proc.lastWords()
-			if msg == "" && err != nil {
-				msg = err.Error()
-			}
-			if msg == "" {
-				msg = "ffmpeg ended before writing a segment"
-			}
-			return msg, false
-		}
-		if time.Now().After(deadline) {
-			return "no segment after " + firstSegmentWait.String(), false
-		}
-		select {
-		case <-ctx.Done():
-			return ctx.Err().Error(), false
-		case <-time.After(250 * time.Millisecond):
-		}
-	}
-}
-
-// watch records how the encode ended (copy streams: one run, start to end).
-func (s *Stream) watch() {
-	<-s.proc.done
-	s.mu.Lock()
-	s.finished = true
-	if s.proc.err != nil {
-		s.failure = s.proc.lastWords()
-		if s.failure == "" {
-			s.failure = s.proc.err.Error()
-		}
-	}
-	s.mu.Unlock()
-	if s.failure != "" {
-		log.Printf("media: stream %s ended early: %s", s.ID, s.failure)
-	}
-}
-
-// ---- seekable streams ----
-
-func (s *Stream) segPath(i int) string { return filepath.Join(s.dir, fmt.Sprintf("seg%05d.m4s", i)) }
-
-// written is the last segment of a run on disk, counting on from where it started.
-func (s *Stream) written(r *segRun) int {
-	i := r.from
-	for i < r.to && exists(s.segPath(i)) {
-		i++
-	}
-	return i - 1
-}
-
-// watchRun follows one run to its end. A run that ends by itself — the end of the film, or
-// the segments it was to stop short of — is followed by the next gap. One that failed fails
-// the stream; one we ended is the business of whoever ended it.
-func (s *Stream) watchRun(r *segRun) {
-	<-r.proc.done
-	s.mu.Lock()
-	if s.gone || r.stopped || s.run != r {
-		s.mu.Unlock()
-		return
-	}
-	if r.proc.err != nil {
-		s.failure = r.proc.lastWords()
-		if s.failure == "" {
-			s.failure = r.proc.err.Error()
-		}
-		s.finished = true
-		s.mu.Unlock()
-		log.Printf("media: stream %s: run from segment %d failed: %s", s.ID, r.from, s.failure)
-		return
-	}
-	if w := s.written(r); w+1 < r.to && r.to == s.n {
-		// ran to the end of the file before the end of the grid: the picture is shorter than
-		// the container says, and those last segments will never exist
-		s.end = w + 1
-		log.Printf("media: stream %s: the film ends at segment %d of %d", s.ID, s.end, s.n)
-	}
-	s.checkInit(r)
-	s.mu.Unlock()
-	s.fillNext(r.to)
-}
-
-// checkInit compares a later run's init segment with the first run's, once. They come out
-// identical (same encoder, same settings); if one day they don't, the log says so.
-func (s *Stream) checkInit(r *segRun) {
-	if r.from == 0 || s.initOK {
-		return
-	}
-	a, err1 := os.ReadFile(filepath.Join(s.dir, "init.mp4"))
-	b, err2 := os.ReadFile(filepath.Join(s.dir, "init-run.mp4"))
-	if err1 != nil || err2 != nil {
-		return
-	}
-	s.initOK = true
-	if !bytes.Equal(a, b) && !s.initBad {
-		s.initBad = true
-		log.Printf("media: stream %s: a restarted run's init segment differs from the first (%s); its segments may not join", s.ID, s.Engine)
-	}
-}
-
-// missingFrom is the first segment not on disk at or after i (wrapping round to the start),
-// or -1 when the whole film is there.
-func (s *Stream) missingFrom(i int) int {
-	end := s.end
-	for k := 0; k < end; k++ {
-		j := (i + k) % end
-		if !exists(s.segPath(j)) {
-			return j
-		}
-	}
-	return -1
-}
-
-// fillNext starts a run at the next gap after `after`; when there is none, the stream is done.
-func (s *Stream) fillNext(after int) {
-	s.runMu.Lock()
-	defer s.runMu.Unlock()
-	s.mu.Lock()
-	if s.gone || s.failure != "" || (s.run != nil && !s.run.done()) {
-		s.mu.Unlock()
-		return
-	}
-	end := s.end
-	s.mu.Unlock()
-	if after >= end {
-		after = 0
-	}
-	next := s.missingFrom(after)
-	if next < 0 {
-		s.mu.Lock()
-		s.finished, s.proc = true, nil
-		s.mu.Unlock()
-		log.Printf("media: stream %s: all %d segments on disk", s.ID, end)
-		return
-	}
-	s.startRun(next)
-}
-
-func (r *segRun) done() bool { d, _ := r.proc.exited(); return d }
-
-// startRun ends the run going now and starts one at segment from, stopping short of the next
-// segment already on disk. The run it ends is asked to stop and waited for, and whatever it
-// finished writing after being asked is removed: ffmpeg closes the segment it was in the
-// middle of on its way out, short. Called with runMu held, mu not.
-func (s *Stream) startRun(from int) {
-	s.mu.Lock()
-	old := s.run
-	end := s.end
-	s.mu.Unlock()
-	if old != nil && !old.done() {
-		had := map[int]bool{}
-		for i := old.from; i < old.to; i++ {
-			had[i] = exists(s.segPath(i))
-		}
-		s.mu.Lock()
-		old.stopped = true
-		s.mu.Unlock()
-		old.proc.end()
-		for i := old.from; i < old.to; i++ {
-			if !had[i] && exists(s.segPath(i)) {
-				_ = os.Remove(s.segPath(i))
-			}
-		}
-	}
-	to := from + 1
-	for to < end && !exists(s.segPath(to)) {
-		to++
-	}
-	s.mu.Lock()
-	if s.gone {
-		s.mu.Unlock()
-		return
-	}
-	s.mu.Unlock()
-	init := "init-run.mp4"
-	if !exists(filepath.Join(s.dir, "init.mp4")) {
-		init = "init.mp4"
-	}
-	p, err := startFF(s.caps, s.self, s.Root, segArgs(s.dir, s.Path, s.Source, s.recipe, from, to, s.n, init))
-	s.mu.Lock()
-	defer s.mu.Unlock()
-	if err != nil {
-		s.failure, s.finished = "restarting at "+strconv.Itoa(from*hlsSeconds)+" s: "+err.Error(), true
-		return
-	}
-	r := &segRun{from: from, to: to, proc: p}
-	s.run, s.proc, s.finished = r, p, false
-	go s.watchRun(r)
-	log.Printf("media: stream %s: run from %d s to %d s", s.ID, from*hlsSeconds, to*hlsSeconds)
-}
-
-// Playlist is the whole film's, written before most of it exists.
-func (s *Stream) Playlist() []byte {
-	var b strings.Builder
-	b.WriteString("#EXTM3U\n#EXT-X-VERSION:7\n")
-	fmt.Fprintf(&b, "#EXT-X-TARGETDURATION:%d\n", hlsSeconds)
-	b.WriteString("#EXT-X-MEDIA-SEQUENCE:0\n#EXT-X-PLAYLIST-TYPE:VOD\n#EXT-X-INDEPENDENT-SEGMENTS\n#EXT-X-MAP:URI=\"init.mp4\"\n")
-	for i := 0; i < s.n; i++ {
-		d := float64(hlsSeconds)
-		if i == s.n-1 {
-			d = s.Source.Duration - float64(i*hlsSeconds)
-		}
-		fmt.Fprintf(&b, "#EXTINF:%.6f,\nseg%05d.m4s\n", d, i)
-	}
-	b.WriteString("#EXT-X-ENDLIST\n")
-	return []byte(b.String())
-}
-
-// ErrNotInFilm is a segment the playlist lists but the film turned out not to reach.
-var ErrNotInFilm = errors.New("past the end of the film")
-
-// Segment is the path of segment i once it is on disk. When the run going now will write it
-// soon, it waits; otherwise this is a seek, and the run moves there — unless a newer request
-// has moved it since this one arrived.
-func (s *Stream) Segment(ctx context.Context, i int) (string, error) {
-	asked := time.Now()
-	deadline := asked.Add(segmentWait)
-	p := s.segPath(i)
-	for {
-		s.touch()
-		if exists(p) {
-			return p, nil
-		}
-		s.mu.Lock()
-		switch {
-		case s.gone:
-			s.mu.Unlock()
-			return "", errors.New("the stream was closed")
-		case i >= s.end:
-			s.mu.Unlock()
-			return "", ErrNotInFilm
-		case s.failure != "":
-			f := s.failure
-			s.mu.Unlock()
-			return "", errors.New(f)
-		}
-		r := s.run
-		coming := r != nil && !r.done() && r.from <= i && i < r.to && i <= s.written(r)+lookahead
-		move := !coming && !asked.Before(s.asked)
-		if move {
-			s.asked = asked
-		}
-		s.mu.Unlock()
-		if move {
-			s.runMu.Lock()
-			// still the newest, and still not on its way? (a run may have moved for a
-			// newer request while this one waited for the lock)
-			s.mu.Lock()
-			r = s.run
-			coming = r != nil && !r.done() && r.from <= i && i < r.to && i <= s.written(r)+lookahead
-			newest := !asked.Before(s.asked)
-			s.mu.Unlock()
-			if !coming && newest && !exists(p) {
-				log.Printf("media: stream %s: seek to %d s", s.ID, i*hlsSeconds)
-				s.startRun(i)
-			}
-			s.runMu.Unlock()
-			continue
-		}
-		if time.Now().After(deadline) {
-			return "", fmt.Errorf("segment %d didn't arrive in %s", i, segmentWait)
-		}
-		select {
-		case <-ctx.Done():
-			return "", ctx.Err()
-		case <-time.After(150 * time.Millisecond):
-		}
-	}
-}
-
-// SegmentIndex reads the number out of a segment's name.
-func SegmentIndex(name string) (int, bool) {
-	m := segName.FindStringSubmatch(name)
-	if m == nil {
-		return 0, false
-	}
-	i, err := strconv.Atoi(m[1])
-	return i, err == nil
-}
-
-// ---- both kinds ----
-
-func (m *Streamer) Find(id string) (*Stream, bool) {
-	m.mu.Lock()
-	defer m.mu.Unlock()
-	s, ok := m.streams[id]
-	return s, ok
-}
-
-// Close ends a stream and removes its folder.
-func (m *Streamer) Close(id string) {
-	m.mu.Lock()
-	s, ok := m.streams[id]
-	m.mu.Unlock()
-	if !ok {
-		return
-	}
-	s.mu.Lock()
-	s.gone = true // a run ending now is ours, not a gap to fill
-	p := s.proc
-	if s.run != nil {
-		s.run.stopped = true
-	}
-	s.mu.Unlock()
-	if p != nil {
-		p.end()
-	}
-	m.forget(s)
-}
-
-func (m *Streamer) forget(s *Stream) {
-	m.mu.Lock()
-	delete(m.streams, s.ID)
-	m.mu.Unlock()
-	s.mu.Lock()
-	s.gone = true
-	s.mu.Unlock()
-	_ = os.RemoveAll(s.dir)
-}
-
-func (s *Stream) closed() bool { s.mu.Lock(); defer s.mu.Unlock(); return s.gone }
-
-func (s *Stream) failed() bool {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-	return s.finished && s.failure != ""
-}
-
-// Sweep closes what nobody has touched for a while.
-func (m *Streamer) Sweep(idle time.Duration) {
-	m.mu.Lock()
-	var old []string
-	for id, s := range m.streams {
-		s.mu.Lock()
-		if time.Since(s.used) > idle {
-			old = append(old, id)
-		}
-		s.mu.Unlock()
-	}
-	m.mu.Unlock()
-	for _, id := range old {
-		log.Printf("media: stream %s idle, closed", id)
-		m.Close(id)
-	}
-}
-
-// File is the on-disk path of one of the stream's files — the playlist (copy streams; a
-// seekable one's is Playlist), the init segment or a media segment — and nothing else.
-func (s *Stream) File(name string) (string, bool) {
-	if !streamFile.MatchString(name) {
-		return "", false
-	}
-	s.touch()
-	return filepath.Join(s.dir, name), true
-}
-
-func (s *Stream) touch() { s.mu.Lock(); s.used = time.Now(); s.mu.Unlock() }
-
-func (s *Stream) running() bool {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-	return s.proc != nil && !s.finished
-}
-
-// Status is read from ffmpeg's own progress file and what is on disk.
-func (s *Stream) Status() StreamStatus {
-	s.mu.Lock()
-	st := StreamStatus{Running: s.proc != nil && !s.finished, Done: s.finished && s.failure == "", Error: s.failure}
-	seekable, end, run := s.Seekable, s.end, s.run
-	s.mu.Unlock()
-	b, err := os.ReadFile(filepath.Join(s.dir, "progress"))
-	if err == nil {
-		st.Progress, st.Speed = parseProgress(b)
-	}
-	if !seekable {
-		if b, err := os.ReadFile(filepath.Join(s.dir, "index.m3u8")); err == nil {
-			st.Segments = strings.Count(string(b), "#EXTINF")
-		}
-		return st
-	}
-	for i := 0; i < end; i++ {
-		if exists(s.segPath(i)) {
-			st.Segments++
-		}
-	}
-	st.Progress = float64(st.Segments * hlsSeconds)
-	if st.Progress > s.Source.Duration {
-		st.Progress = s.Source.Duration
-	}
-	if run != nil && st.Running {
-		st.From = float64(run.from * hlsSeconds)
-	}
-	return st
-}
-
-// parseProgress takes the last out_time_us and speed from ffmpeg's -progress output.
-func parseProgress(b []byte) (seconds, speed float64) {
-	sc := bufio.NewScanner(strings.NewReader(string(b)))
-	for sc.Scan() {
-		k, v, ok := strings.Cut(sc.Text(), "=")
-		if !ok {
-			continue
-		}
-		v = strings.TrimSpace(v)
-		switch k {
-		case "out_time_us":
-			if us, err := strconv.ParseInt(v, 10, 64); err == nil && us >= 0 {
-				seconds = float64(us) / 1e6
-			}
-		case "speed":
-			if x, err := strconv.ParseFloat(strings.TrimSuffix(v, "x"), 64); err == nil {
-				speed = x
-			}
-		}
-	}
-	return seconds, speed
-}
-
-func newID() string {
-	b := make([]byte, 8)
-	_, _ = rand.Read(b)
-	return hex.EncodeToString(b)
-}

internal/media/hls_test.go

@@ -1,220 +0,0 @@
-package media
-
-import (
-	"context"
-	"errors"
-	"math"
-	"os"
-	"os/exec"
-	"path/filepath"
-	"sort"
-	"strconv"
-	"strings"
-	"testing"
-	"time"
-)
-
-// The real thing, when ffmpeg is here: a generated clip goes through as H.264 and comes out
-// as a playlist of segments, the status follows it to the end, and closing removes it all.
-func TestStreamWithFFmpeg(t *testing.T) {
-	if _, err := exec.LookPath("ffmpeg"); err != nil {
-		t.Skip("no ffmpeg")
-	}
-	c := Probe(context.Background())
-	if c.Error != "" {
-		t.Skip(c.Error)
-	}
-	if EngineFor(c, "h264") == "" {
-		t.Skip("nothing here encodes h264")
-	}
-	dir := t.TempDir()
-	clip := filepath.Join(dir, "clip.mp4")
-	out, err := exec.Command("ffmpeg", "-nostdin", "-v", "error", "-f", "lavfi", "-i", "testsrc=size=640x360:rate=25:duration=9", "-f", "lavfi", "-i", "sine=frequency=440:duration=9",
-		"-c:v", "mpeg4", "-q:v", "5", "-c:a", "aac", "-shortest", clip).CombinedOutput()
-	if err != nil {
-		t.Skipf("could not make a clip: %s", out)
-	}
-	src, err := Inspect(context.Background(), c, clip, false)
-	if err != nil || src.Video == nil || src.Audio == nil || src.Video.Codec != "mpeg4" || src.Duration < 8 {
-		t.Fatalf("inspect: %+v %v", src, err)
-	}
-	m := NewStreamer(dir, "hamlab", 2)
-	s, err := m.Open(context.Background(), c, false, clip, "h264", "480p", src)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if s.Width != 640 || s.Height != 360 || s.Engine == "" || !s.Seekable {
-		t.Fatalf("stream: %+v", s)
-	}
-	if _, ok := s.File("index.m3u8"); !ok {
-		t.Fatal("no playlist")
-	}
-	if pl := string(s.Playlist()); !strings.Contains(pl, "#EXT-X-PLAYLIST-TYPE:VOD") || !strings.HasSuffix(pl, "#EXT-X-ENDLIST\n") || strings.Count(pl, "#EXTINF") != 3 {
-		t.Fatalf("playlist for 9 s:\n%s", pl)
-	}
-	if !exists(s.segPath(0)) {
-		t.Fatal("Open returned before the first segment")
-	}
-	for _, bad := range []string{"../x", "progress", "seg1.m4s", "index.m3u8/", "init.mp4.tmp"} {
-		if _, ok := s.File(bad); ok {
-			t.Fatalf("%q must not be served", bad)
-		}
-	}
-	// the same request is the same stream
-	if again, err := m.Open(context.Background(), c, false, clip, "h264", "480p", src); err != nil || again.ID != s.ID {
-		t.Fatal("not reused")
-	}
-	var st StreamStatus
-	for i := 0; i < 120; i++ {
-		st = s.Status()
-		if st.Done || st.Error != "" {
-			break
-		}
-		time.Sleep(250 * time.Millisecond)
-	}
-	if !st.Done || st.Error != "" || st.Segments != 3 || st.Progress < 8 {
-		t.Fatalf("status at the end: %+v", st)
-	}
-	if init, _ := s.File("init.mp4"); !exists(init) {
-		t.Fatal("no init segment")
-	}
-	m.Close(s.ID)
-	if _, ok := m.Find(s.ID); ok || exists(s.dir) {
-		t.Fatal("close must forget and remove")
-	}
-	// an unplayable source is a DecodeError, and leaves nothing behind
-	bad := filepath.Join(dir, "bad.mkv")
-	_ = os.WriteFile(bad, []byte("not a video"), 0o644)
-	if _, err := Inspect(context.Background(), c, bad, false); err == nil {
-		t.Fatal("inspect of garbage")
-	}
-	if left, _ := os.ReadDir(m.dir); len(left) != 0 {
-		t.Fatalf("left behind: %v", left)
-	}
-}
-
-// A seek ahead of the encode: the run moves there, the segment comes from a run that started
-// at it, the gaps are filled afterwards, and the segments of the different runs, joined, are
-// one film with no hole and nothing twice beyond a frame at a join.
-func TestSeekRestartsTheEncode(t *testing.T) {
-	if _, err := exec.LookPath("ffmpeg"); err != nil {
-		t.Skip("no ffmpeg")
-	}
-	c := Probe(context.Background())
-	if c.Error != "" || EngineFor(c, "h264") == "" {
-		t.Skip("nothing here encodes h264")
-	}
-	dir := t.TempDir()
-	clip := filepath.Join(dir, "clip.mkv")
-	// big and busy enough that the first run is still near the start when the seek comes
-	out, err := exec.Command("ffmpeg", "-nostdin", "-v", "error", "-f", "lavfi", "-i", "testsrc2=size=1920x1080:rate=30000/1001:duration=64", "-f", "lavfi", "-i", "sine=frequency=440:duration=64",
-		"-c:v", "libx264", "-preset", "ultrafast", "-g", "250", "-c:a", "libopus", "-shortest", clip).CombinedOutput()
-	if err != nil {
-		t.Skipf("could not make a clip: %s", out)
-	}
-	src, err := Inspect(context.Background(), c, clip, false)
-	if err != nil {
-		t.Fatal(err)
-	}
-	m := NewStreamer(dir, "hamlab", 2)
-	s, err := m.Open(context.Background(), c, false, clip, "h264", "1080p", src)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer m.Close(s.ID)
-	if s.n != 16 {
-		t.Fatalf("%d segments for 64 s", s.n)
-	}
-	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
-	defer cancel()
-	p, err := s.Segment(ctx, 12)
-	if err != nil {
-		t.Fatal(err)
-	}
-	s.mu.Lock()
-	from := s.run.from
-	s.mu.Unlock()
-	if from != 12 {
-		t.Fatalf("the run after the seek starts at segment %d, not 12 (the first run was already there?)", from)
-	}
-	if got := firstVideoPTS(t, filepath.Join(s.dir, "init.mp4"), p); math.Abs(got-(48+tsBase)) > 0.05 {
-		t.Fatalf("segment 12 starts at %.3f, want %d", got, 48+tsBase)
-	}
-	if _, err := s.Segment(ctx, 16); !errors.Is(err, ErrNotInFilm) {
-		t.Fatalf("past the end: %v", err)
-	}
-	var st StreamStatus
-	for i := 0; i < 480; i++ {
-		if st = s.Status(); st.Done || st.Error != "" {
-			break
-		}
-		time.Sleep(250 * time.Millisecond)
-	}
-	if !st.Done || st.Segments != 16 {
-		t.Fatalf("not filled in: %+v", st)
-	}
-	// the joined film: every segment in order behind the one init segment
-	joined := filepath.Join(dir, "joined.mp4")
-	f, _ := os.Create(joined)
-	for _, n := range append([]string{"init.mp4"}, segNames(16)...) {
-		b, err := os.ReadFile(filepath.Join(s.dir, n))
-		if err != nil {
-			t.Fatal(err)
-		}
-		_, _ = f.Write(b)
-	}
-	f.Close()
-	if out, err := exec.Command("ffmpeg", "-v", "error", "-i", joined, "-f", "null", "-").CombinedOutput(); err != nil || strings.Contains(string(out), "error") {
-		t.Fatalf("the joined film doesn't decode cleanly: %v %s", err, out)
-	}
-	pts := videoPTS(t, joined)
-	if len(pts) < 1900 || pts[0] > tsBase+0.1 || pts[len(pts)-1] < tsBase+63.5 {
-		t.Fatalf("%d frames, %.3f .. %.3f", len(pts), pts[0], pts[len(pts)-1])
-	}
-	for i := 1; i < len(pts); i++ {
-		if d := pts[i] - pts[i-1]; d > 0.07 { // a frame is 0.033; a join may lose up to one
-			t.Fatalf("a hole of %.3f s at %.3f", d, pts[i-1])
-		}
-	}
-}
-
-func segNames(n int) []string {
-	var out []string
-	for i := 0; i < n; i++ {
-		out = append(out, "seg"+strconv.FormatInt(int64(100000+i), 10)[1:]+".m4s")
-	}
-	return out
-}
-
-func videoPTS(t *testing.T, file string) []float64 {
-	out, err := exec.Command("ffprobe", "-v", "error", "-select_streams", "v", "-show_entries", "packet=pts_time", "-of", "csv=p=0", file).Output()
-	if err != nil {
-		t.Fatal(err)
-	}
-	var pts []float64
-	seen := map[string]bool{}
-	for _, l := range strings.Fields(string(out)) {
-		if seen[l] { // the same frame from both runs at a join
-			continue
-		}
-		seen[l] = true
-		if v, err := strconv.ParseFloat(l, 64); err == nil {
-			pts = append(pts, v)
-		}
-	}
-	sort.Float64s(pts)
-	return pts
-}
-
-func firstVideoPTS(t *testing.T, init, seg string) float64 {
-	dir := t.TempDir()
-	j := filepath.Join(dir, "one.mp4")
-	a, _ := os.ReadFile(init)
-	b, _ := os.ReadFile(seg)
-	_ = os.WriteFile(j, append(a, b...), 0o644)
-	pts := videoPTS(t, j)
-	if len(pts) == 0 {
-		t.Fatal("no frames in the segment")
-	}
-	return pts[0]
-}

internal/media/inspect.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"math"
 	"os/exec"
 	"strconv"
 	"strings"
@@ -25,6 +26,16 @@ type Track struct {
 	ColorTransfer string  `json:"color_transfer,omitempty"` // smpte2084 / arib-std-b67 mean HDR
 	Channels      int     `json:"channels,omitempty"`
 	AttachedPic   bool    `json:"attached_pic,omitempty"`
+	Spherical     bool    `json:"spherical,omitempty"` // an equirectangular 360 picture
+	Rotation      int     `json:"rotation,omitempty"`  // degrees clockwise to turn it to be shown: 0, 90, 180, 270 (a phone held upright)
+}
+
+// Shown is the picture's size as it is shown, turned by its rotation.
+func (t *Track) Shown() (w, h int) {
+	if t.Rotation == 90 || t.Rotation == 270 {
+		return t.Height, t.Width
+	}
+	return t.Width, t.Height
 }
 
 // Info is what a file holds: the picture to take, the sound to go with it, and the whole.
@@ -37,7 +48,12 @@ type Info struct {
 	Audio     *Track  `json:"audio,omitempty"` // the first sound stream
 }
 
-// HDR reports a picture that needs tone mapping to look right on an SDR screen.
+// PQ reports HDR10 (and Dolby Vision's base layer): a picture that can't be shown on an SDR
+// screen without tone mapping. HLG, the other kind, can, if a little flat.
+func (i Info) PQ() bool { return i.Video != nil && i.Video.ColorTransfer == "smpte2084" }
+
+// HDR reports a picture that needs tone mapping to look right on an SDR screen. (The player
+// tone-maps only PQ: HLG is made to be shown on an SDR screen as it is.)
 func (i Info) HDR() bool {
 	return i.Video != nil && (i.Video.ColorTransfer == "smpte2084" || i.Video.ColorTransfer == "arib-std-b67")
 }
@@ -58,6 +74,11 @@ type probeJSON struct {
 		Disposition   struct {
 			AttachedPic int `json:"attached_pic"`
 		} `json:"disposition"`
+		SideData []struct {
+			Type       string  `json:"side_data_type"`
+			Projection string  `json:"projection"`
+			Rotation   float64 `json:"rotation"`
+		} `json:"side_data_list"`
 	} `json:"streams"`
 	Format struct {
 		FormatName string `json:"format_name"`
@@ -74,7 +95,7 @@ func Inspect(ctx context.Context, c Caps, path string, root bool) (Info, error)
 		return Info{}, errors.New("ffprobe is not installed")
 	}
 	argv := []string{c.FFprobe, "-v", "error", "-show_entries",
-		"stream=index,codec_type,codec_name,profile,pix_fmt,width,height,r_frame_rate,avg_frame_rate,color_transfer,channels,disposition:format=format_name,duration,bit_rate,size",
+		"stream=index,codec_type,codec_name,profile,pix_fmt,width,height,r_frame_rate,avg_frame_rate,color_transfer,channels,disposition:stream_side_data=side_data_type,projection,rotation:format=format_name,duration,bit_rate,size",
 		"-of", "json", path}
 	if root {
 		argv = priv.Wrap(argv...)
@@ -105,6 +126,19 @@ func Inspect(ctx context.Context, c Caps, path string, root bool) (Info, error)
 	for _, s := range pj.Streams {
 		st := &Track{Index: s.Index, Type: s.CodecType, Codec: s.CodecName, Profile: s.Profile, PixFmt: s.PixFmt, Width: s.Width, Height: s.Height,
 			ColorTransfer: s.ColorTransfer, Channels: s.Channels, AttachedPic: s.Disposition.AttachedPic != 0}
+		// A 360 video says so in its spherical tag (ffmpeg reads the old XML one and the sv3d
+		// box); an untagged one is still taken for 360 when it is 2:1 and too big for anything
+		// else.
+		for _, sd := range s.SideData {
+			if sd.Type == "Spherical Mapping" && strings.HasPrefix(sd.Projection, "equirectangular") {
+				st.Spherical = true
+			}
+			if sd.Type == "Display Matrix" {
+				// ffprobe's rotation is counter-clockwise; ffmpeg turns it back the other way
+				st.Rotation = ((-int(math.Round(sd.Rotation/90))*90)%360 + 360) % 360
+			}
+		}
+		st.Spherical = st.Spherical || (s.CodecType == "video" && s.Width == 2*s.Height && s.Width >= 3840)
 		st.FPS = fps(s.AvgFrameRate)
 		if st.FPS == 0 {
 			st.FPS = fps(s.RFrameRate)

internal/media/play.go

@@ -0,0 +1,462 @@
+package media
+
+// Playing a video in the browser at the quality the connection can take: HLS, made on the fly
+// by ffmpeg on the device asked for (the Transcode device setting), YouTube's way. The player
+// is told every quality is all there from the start, in Seg-second pieces, and each piece is
+// made when it is first asked for.
+//
+// One ffmpeg runs per play at a time. It starts at the piece asked for and runs on ahead of the
+// player, paused once it is far enough ahead; a piece asked for well past where it has got to
+// (a seek), or at another quality, ends it and starts a new one there. Every run is made the
+// same way (pieceArgs), so pieces from different runs and qualities follow on from one another.
+//
+// The file is a path on this machine or, when the device asked for is on another one, a URL
+// the hub serves it at. Nothing is kept: a play nobody asks anything of is forgotten, and the
+// folder is emptied when the daemon starts.
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io/fs"
+	"log"
+	"math"
+	"os"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+const (
+	runAhead = 10               // pieces a run may make past the last one asked for before it is paused
+	jump     = 3                // a piece more than this far past what's made is a seek: start again there
+	idleRun  = 45 * time.Second // a run nobody has asked anything of for this long is ended
+	idlePlay = 30 * time.Minute // a play nobody has asked anything of for this long is forgotten
+	budget   = 2 << 30          // bytes of pieces one play keeps; those asked for least lately go first
+	// PieceWait is the longest a request waits for its piece: under the hub proxy's 60 s wait
+	// for a node to answer.
+	PieceWait = 45 * time.Second
+)
+
+var ErrNotFound = errors.New("no such piece")
+
+// Plays is every play on this machine.
+type Plays struct {
+	dir     string
+	self    string // this binary, for root runs through run-ffmpeg
+	maxRuns int
+
+	mu    sync.Mutex
+	plays map[string]*Play
+	stop  chan struct{}
+}
+
+// NewPlays keeps pieces under <dataDir>/transcode, which it empties first.
+func NewPlays(dataDir, self string, maxRuns int) *Plays {
+	dir := filepath.Join(dataDir, "transcode")
+	_ = os.MkdirAll(dir, 0o700)
+	_ = clearDir(dir)
+	m := &Plays{dir: dir, self: self, maxRuns: max(maxRuns, 1), plays: map[string]*Play{}, stop: make(chan struct{})}
+	go m.tend()
+	return m
+}
+
+// Play is one video opened for watching.
+type Play struct {
+	ID     string `json:"id"`
+	Name   string `json:"name"` // the file's name, for the record
+	Info   Info   `json:"info"`
+	Rungs  []Rung `json:"rungs"`  // best first
+	Device string `json:"device"` // asked for: a render node, "cpu", or "" for the best here
+	Remote bool   `json:"remote"` // the file is on another machine, read over the network
+
+	caps Caps
+	in   string
+	root bool
+	segs int
+	dir  string
+	m    *Plays
+
+	mu    sync.Mutex
+	seen  time.Time
+	run   *playRun
+	tried map[int]int // per rung: recipes that failed to make anything, skipped from now on
+}
+
+type playRun struct {
+	rung   int
+	recipe Recipe
+	start  int // the first piece this run makes
+	head   int // the last piece finished (start-1 before the first)
+	want   int // the last piece asked for
+	asked  time.Time
+	proc   *ffproc
+	paused bool
+	dead   bool // ended, or exited
+	killed bool // ended by us, not by itself
+	exited bool
+	err    error
+	tick   chan struct{} // closed when head moves or the run ends
+}
+
+func newPlayID() string {
+	b := make([]byte, 12)
+	_, _ = rand.Read(b)
+	return hex.EncodeToString(b)
+}
+
+// Open starts a play of in (a path, or an http URL for a file on another machine). Nothing
+// runs until a piece is asked for.
+func (m *Plays) Open(c Caps, root bool, in, name string, src Info, device string) (*Play, error) {
+	rungs := Ladder(src)
+	if len(rungs) == 0 || src.Duration <= 0 {
+		return nil, errors.New("this video's length or picture size isn't known, so it can't be played")
+	}
+	if len(recipes(c, device, src, rungs[0])) == 0 {
+		return nil, errors.New("nothing on this machine encodes H.264 (no GPU that does, and no libx264)")
+	}
+	segs := max(int(math.Ceil((src.Duration-0.25)/Seg)), 1) // the last piece takes in what's left
+	p := &Play{ID: newPlayID(), Name: name, Info: src, Rungs: rungs, Device: device, Remote: strings.HasPrefix(in, "http"),
+		caps: c, in: in, root: root, segs: segs, m: m, seen: time.Now(), tried: map[int]int{}}
+	p.dir = filepath.Join(m.dir, p.ID)
+	m.mu.Lock()
+	m.plays[p.ID] = p
+	m.mu.Unlock()
+	return p, nil
+}
+
+func (m *Plays) Find(id string) (*Play, bool) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	p, ok := m.plays[id]
+	return p, ok
+}
+
+// Close ends a play and deletes its pieces.
+func (m *Plays) Close(id string) {
+	m.mu.Lock()
+	p, ok := m.plays[id]
+	delete(m.plays, id)
+	m.mu.Unlock()
+	if ok {
+		p.mu.Lock()
+		p.end()
+		p.mu.Unlock()
+		go os.RemoveAll(p.dir)
+	}
+}
+
+func (p *Play) rung(name string) int {
+	for i, r := range p.Rungs {
+		if r.Name == name {
+			return i
+		}
+	}
+	return -1
+}
+
+// Master is the playlist of qualities, lowest first, so a player that starts on the first one
+// listed starts on the one that surely plays.
+func (p *Play) Master() []byte {
+	var b bytes.Buffer
+	b.WriteString("#EXTM3U\n#EXT-X-VERSION:3\n#EXT-X-INDEPENDENT-SEGMENTS\n")
+	for i := len(p.Rungs) - 1; i >= 0; i-- {
+		r := p.Rungs[i]
+		fmt.Fprintf(&b, "#EXT-X-STREAM-INF:BANDWIDTH=%d,AVERAGE-BANDWIDTH=%d,RESOLUTION=%dx%d,FRAME-RATE=%.3f,CODECS=\"%s\"\n%s.m3u8\n",
+			r.Peak, r.Bitrate+audioRate, r.Width, r.Height, r.FPS, r.codecs, r.Name)
+	}
+	return b.Bytes()
+}
+
+// Media is one quality's playlist: every piece, made or not.
+func (p *Play) Media(name string) ([]byte, bool) {
+	if p.rung(name) < 0 {
+		return nil, false
+	}
+	var b bytes.Buffer
+	last := p.Info.Duration - float64(p.segs-1)*Seg
+	fmt.Fprintf(&b, "#EXTM3U\n#EXT-X-VERSION:3\n#EXT-X-TARGETDURATION:%d\n#EXT-X-MEDIA-SEQUENCE:0\n#EXT-X-PLAYLIST-TYPE:VOD\n#EXT-X-INDEPENDENT-SEGMENTS\n",
+		int(math.Ceil(math.Max(last, Seg))))
+	for n := 0; n < p.segs; n++ {
+		d := Seg
+		if n == p.segs-1 {
+			d = last
+		}
+		fmt.Fprintf(&b, "#EXTINF:%.6f,\n%s/%d.ts\n", d, name, n)
+	}
+	b.WriteString("#EXT-X-ENDLIST\n")
+	return b.Bytes(), true
+}
+
+func (p *Play) piece(rung, n int) string {
+	return filepath.Join(p.dir, p.Rungs[rung].Name, strconv.Itoa(n)+".ts")
+}
+
+// Segment answers the file of piece n at quality name, making it first if need be: it waits
+// for the run already making it, or starts one there.
+func (p *Play) Segment(done <-chan struct{}, name string, n int) (string, error) {
+	ri := p.rung(name)
+	if ri < 0 || n < 0 || n >= p.segs {
+		return "", ErrNotFound
+	}
+	path := p.piece(ri, n)
+	deadline := time.After(PieceWait)
+	for {
+		p.mu.Lock()
+		now := time.Now()
+		p.seen = now
+		r := p.run
+		if r != nil && r.rung == ri && !r.dead {
+			r.want, r.asked = n, now
+		}
+		if exists(path) {
+			p.mu.Unlock()
+			_ = os.Chtimes(path, now, now) // the budget keeps what was asked for last
+			return path, nil
+		}
+		if r != nil && r.exited && !r.killed && r.rung == ri && r.start == n {
+			// This run started at this very piece and ended without it: that way of making
+			// it doesn't work here. The next one is tried, if there is one.
+			p.tried[ri]++
+			log.Printf("files: play %s: %s made nothing at %s piece %d: %v: %s", p.Name, r.recipe.Engine, name, n, r.err, r.proc.lastWords())
+			if p.tried[ri] >= len(recipes(p.caps, p.Device, p.Info, p.Rungs[ri])) {
+				err := fmt.Errorf("couldn't make %s: %s", p.Rungs[ri].Label, r.proc.lastWords())
+				p.mu.Unlock()
+				return "", err
+			}
+			p.run = nil
+			r = nil
+		}
+		if r == nil || r.dead || r.rung != ri || n < r.start || n <= r.head || n > r.head+jump {
+			p.mu.Unlock()
+			p.m.makeRoom(p)
+			p.mu.Lock()
+			if p.run == r { // nobody started one meanwhile
+				if err := p.start(ri, n); err != nil {
+					p.mu.Unlock()
+					return "", err
+				}
+			}
+			p.mu.Unlock()
+			continue
+		}
+		tick := r.tick
+		p.mu.Unlock()
+		select {
+		case <-tick:
+		case <-time.After(200 * time.Millisecond):
+		case <-done:
+			return "", errors.New("gone")
+		case <-deadline:
+			return "", fmt.Errorf("%s piece %d took longer than %s", name, n, PieceWait)
+		}
+	}
+}
+
+// end stops this play's run. p.mu is held.
+func (p *Play) end() {
+	if r := p.run; r != nil && !r.dead {
+		r.dead, r.killed = true, true
+		r.proc.kill()
+	}
+}
+
+// makeRoom ends the run asked of least lately, if every slot is taken by another play. It
+// never holds two plays' locks at once.
+func (m *Plays) makeRoom(except *Play) {
+	m.mu.Lock()
+	plays := make([]*Play, 0, len(m.plays))
+	for _, p := range m.plays {
+		if p != except {
+			plays = append(plays, p)
+		}
+	}
+	m.mu.Unlock()
+	var oldest *Play
+	var when time.Time
+	running := 0
+	for _, p := range plays {
+		p.mu.Lock()
+		if r := p.run; r != nil && !r.dead {
+			running++
+			if oldest == nil || r.asked.Before(when) {
+				oldest, when = p, r.asked
+			}
+		}
+		p.mu.Unlock()
+	}
+	if running >= m.maxRuns && oldest != nil {
+		oldest.mu.Lock()
+		oldest.end()
+		oldest.mu.Unlock()
+		log.Printf("files: %d plays encoding; ended %s's, asked of least lately", running, oldest.Name)
+	}
+}
+
+// start begins a run making quality ri from piece n on, ending the one before. p.mu is held.
+func (p *Play) start(ri, n int) error {
+	p.end()
+	rs := recipes(p.caps, p.Device, p.Info, p.Rungs[ri])
+	if p.tried[ri] >= len(rs) {
+		return errors.New("nothing here can make this quality")
+	}
+	rc := rs[p.tried[ri]]
+	out := filepath.Join(p.dir, p.Rungs[ri].Name)
+	if err := os.MkdirAll(out, 0o700); err != nil {
+		return err
+	}
+	proc, err := startFF(p.caps, p.m.self, p.root, pieceArgs(out, p.in, p.Info, rc, p.Rungs[ri], n))
+	if err != nil {
+		return err
+	}
+	r := &playRun{rung: ri, recipe: rc, start: n, head: n - 1, want: n, asked: time.Now(), proc: proc, tick: make(chan struct{})}
+	p.run = r
+	go func() {
+		<-proc.done
+		p.mu.Lock()
+		defer p.mu.Unlock()
+		r.dead, r.exited, r.err = true, true, proc.err
+		p.scan(r)
+		close(r.tick)
+		r.tick = make(chan struct{})
+	}()
+	return nil
+}
+
+// scan moves a run's head on past the pieces it has finished. p.mu is held.
+func (p *Play) scan(r *playRun) bool {
+	moved := false
+	for r.head+1 < p.segs && exists(p.piece(r.rung, r.head+1)) {
+		r.head++
+		moved = true
+	}
+	return moved
+}
+
+// PlayStatus is what a play is doing, for the player's menu.
+type PlayStatus struct {
+	Engine  string `json:"engine,omitempty"` // what the run going now runs on
+	Quality string `json:"quality,omitempty"`
+	From    int    `json:"from"` // seconds into the film the run started at
+	Ahead   int    `json:"ahead"`
+	Paused  bool   `json:"paused,omitempty"`
+}
+
+func (p *Play) Status() PlayStatus {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	r := p.run
+	if r == nil || r.dead {
+		return PlayStatus{}
+	}
+	return PlayStatus{Engine: r.recipe.Engine, Quality: p.Rungs[r.rung].Label, From: int(float64(r.start) * Seg), Ahead: r.head - r.want, Paused: r.paused}
+}
+
+// Engine is what this play would run on first, for the player to say before anything runs.
+func (p *Play) Engine() string {
+	rs := recipes(p.caps, p.Device, p.Info, p.Rungs[0])
+	if len(rs) == 0 {
+		return ""
+	}
+	return rs[0].Engine
+}
+
+// tend, ten times a second: notices finished pieces, pauses a run that is far enough ahead and
+// wakes it when the player catches up, ends one nobody is asking anything of; and every ten
+// seconds keeps each play inside its budget and forgets plays nobody watches.
+func (m *Plays) tend() {
+	t := time.NewTicker(100 * time.Millisecond)
+	defer t.Stop()
+	for i := 0; ; i++ {
+		select {
+		case <-m.stop:
+			return
+		case <-t.C:
+		}
+		m.mu.Lock()
+		plays := make([]*Play, 0, len(m.plays))
+		for _, p := range m.plays {
+			plays = append(plays, p)
+		}
+		m.mu.Unlock()
+		now := time.Now()
+		for _, p := range plays {
+			p.mu.Lock()
+			if r := p.run; r != nil && !r.dead {
+				if p.scan(r) {
+					close(r.tick)
+					r.tick = make(chan struct{})
+				}
+				ahead := r.head - r.want
+				switch {
+				case now.Sub(r.asked) > idleRun:
+					p.end()
+				case !r.paused && ahead >= runAhead:
+					if r.proc.pause() == nil {
+						r.paused = true
+					}
+				case r.paused && ahead < runAhead-3:
+					if r.proc.resume() == nil {
+						r.paused = false
+					}
+				}
+			}
+			idle := now.Sub(p.seen) > idlePlay
+			p.mu.Unlock()
+			if idle {
+				m.Close(p.ID)
+			} else if i%100 == 0 {
+				p.trim()
+			}
+		}
+	}
+}
+
+// trim deletes the pieces asked for least lately until the play is inside its budget, never
+// the ones its run has made ahead of the player.
+func (p *Play) trim() {
+	type piece struct {
+		path string
+		size int64
+		at   time.Time
+	}
+	var all []piece
+	var total int64
+	_ = filepath.WalkDir(p.dir, func(path string, d fs.DirEntry, err error) error {
+		if err != nil || d.IsDir() || !strings.HasSuffix(path, ".ts") {
+			return nil
+		}
+		if fi, err := d.Info(); err == nil {
+			all = append(all, piece{path, fi.Size(), fi.ModTime()})
+			total += fi.Size()
+		}
+		return nil
+	})
+	if total <= budget {
+		return
+	}
+	p.mu.Lock()
+	keep := map[string]bool{}
+	if r := p.run; r != nil && !r.dead {
+		for n := r.want - 1; n <= r.head+1; n++ {
+			if n >= 0 && n < p.segs {
+				keep[p.piece(r.rung, n)] = true
+			}
+		}
+	}
+	p.mu.Unlock()
+	sort.Slice(all, func(a, b int) bool { return all[a].at.Before(all[b].at) })
+	for _, x := range all {
+		if total <= budget*3/4 {
+			break
+		}
+		if !keep[x.path] && os.Remove(x.path) == nil {
+			total -= x.size
+		}
+	}
+}

internal/media/play_test.go

@@ -0,0 +1,129 @@
+package media
+
+import (
+	"context"
+	"encoding/json"
+	"math"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+)
+
+// inspectPiece answers when a piece's first video packet is shown, whether it is a keyframe,
+// how many keyframes the piece has, and when its last packet is.
+func inspectPiece(t *testing.T, path string) (first float64, key bool, keys int, last float64) {
+	t.Helper()
+	b, err := exec.Command("ffprobe", "-v", "error", "-show_entries", "packet=pts_time,flags,codec_type", "-of", "json", path).Output()
+	if err != nil {
+		t.Fatalf("ffprobe %s: %v", path, err)
+	}
+	var p struct {
+		Packets []struct {
+			PTS   string `json:"pts_time"`
+			Flags string `json:"flags"`
+			Type  string `json:"codec_type"`
+		} `json:"packets"`
+	}
+	_ = json.Unmarshal(b, &p)
+	first = -1
+	for _, k := range p.Packets {
+		if k.Type != "video" {
+			continue
+		}
+		x, _ := strconv.ParseFloat(k.PTS, 64)
+		if first < 0 {
+			first, key = x, strings.HasPrefix(k.Flags, "K")
+		}
+		first = math.Min(first, x)
+		last = math.Max(last, x)
+		if strings.HasPrefix(k.Flags, "K") {
+			keys++
+		}
+	}
+	return
+}
+
+// TestPieces makes pieces of a made-up video (or SRC, on DEVICE, to try the real thing on a
+// machine with a GPU) in order and after a seek, at two qualities, and checks they line up:
+// each starts on a keyframe at its own place in the film, with no other keyframe inside it.
+func TestPieces(t *testing.T) {
+	if _, err := exec.LookPath("ffmpeg"); err != nil {
+		t.Skip("no ffmpeg")
+	}
+	dir := t.TempDir()
+	in := os.Getenv("SRC")
+	if in == "" {
+		in = filepath.Join(dir, "in.mkv")
+		if out, err := exec.Command("ffmpeg", "-v", "error", "-f", "lavfi", "-i", "testsrc2=size=1920x1080:rate=50:duration=40",
+			"-f", "lavfi", "-i", "sine=frequency=440:duration=40", "-c:v", "libx264", "-preset", "ultrafast", "-g", "500",
+			"-c:a", "libopus", "-shortest", in).CombinedOutput(); err != nil {
+			t.Fatalf("making the test video: %v: %s", err, out)
+		}
+	}
+	caps := Probe(context.Background())
+	if caps.Error != "" {
+		t.Skip(caps.Error)
+	}
+	info, err := Inspect(context.Background(), caps, in, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	m := NewPlays(dir, "", 2)
+	device := os.Getenv("DEVICE")
+	if device == "" {
+		device = CPU
+	}
+	p, err := m.Open(caps, false, in, "in.mkv", info, device)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer m.Close(p.ID)
+	if !strings.Contains(string(p.Master()), "RESOLUTION=") {
+		t.Fatal(string(p.Master()))
+	}
+	low := p.Rungs[len(p.Rungs)-1].Name
+	var offset float64
+	far := min(p.segs-2, 60)
+	for i, n := range []int{0, 1, 2, far, far + 1, 3} {
+		t0 := time.Now()
+		path, err := p.Segment(nil, low, n)
+		if err != nil {
+			t.Fatalf("piece %d: %v", n, err)
+		}
+		first, key, keys, last := inspectPiece(t, path)
+		if i == 0 {
+			offset = first
+		}
+		at := first - offset
+		t.Logf("piece %d: %d ms on %s, starts %.3f, %d keyframe(s), %.2f s long", n, time.Since(t0).Milliseconds(), p.Status().Engine, at, keys, last-first)
+		if !key || keys != 1 {
+			t.Errorf("piece %d: first packet keyframe %v, %d keyframes", n, key, keys)
+		}
+		if math.Abs(at-float64(n)*Seg) > 0.05 {
+			t.Errorf("piece %d starts at %.3f, want %.3f", n, at, float64(n)*Seg)
+		}
+		if n < p.segs-1 && math.Abs(last-first-Seg) > 0.1 {
+			t.Errorf("piece %d is %.3f s long", n, last-first)
+		}
+	}
+	// another quality, at a piece already made at the first: its own run, lined up too
+	if len(p.Rungs) > 1 {
+		path, err := p.Segment(nil, p.Rungs[0].Name, 2)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if first, key, _, _ := inspectPiece(t, path); !key || math.Abs(first-offset-2*Seg) > 0.05 {
+			t.Errorf("%s piece 2 starts %.3f (keyframe %v)", p.Rungs[0].Name, first-offset, key)
+		}
+	}
+	if _, err := p.Segment(nil, low, p.segs); err != ErrNotFound {
+		t.Errorf("past the end: %v", err)
+	}
+	if _, err := p.Segment(nil, "999", 0); err != ErrNotFound {
+		t.Errorf("no such quality: %v", err)
+	}
+}

internal/nodes/nodes.go

@@ -404,6 +404,12 @@ func (m *Manager) Do(ctx context.Context, name, method, path string, body []byte
 	return resp.StatusCode, b, err
 }
 
+// URL is a managed machine's address, "" for one not managed here.
+func (m *Manager) URL(name string) string {
+	n, _ := m.node(name)
+	return n.URL
+}
+
 // Names lists the managed machines.
 func (m *Manager) Names() []string {
 	var out []string

internal/store/store.go

@@ -75,6 +75,16 @@ type State struct {
 	KVMCookies map[string]map[string]string `json:"kvm_cookies,omitempty"`
 	SamplerMs  int                          `json:"sampler_ms,omitempty"`  // how often this machine samples; the hub keeps every machine on the console's refresh rate
 	HistorySec int                          `json:"history_sec,omitempty"` // how far back the graphs reach; the hub keeps every machine on the same one
+	// Transcode is where videos played in the Files viewer are made (internal/api/play.go):
+	// a machine and a device on it. nil is the machine the file is on, its best device.
+	Transcode *Transcode `json:"transcode,omitempty"`
+}
+
+// Transcode names a device on a machine: Node "" is the hub itself; Device is a render node
+// or "cpu".
+type Transcode struct {
+	Node   string `json:"node"`
+	Device string `json:"device"`
 }
 
 // UserState returns the prefs of an account, making an empty one if needed.

web/scripts/e2e-player.mjs

@@ -0,0 +1,107 @@
+// The Files player, end to end in Chromium against a running hub. Playwright is borrowed from
+// the wedding site.
+//
+//   BASE=http://10.0.0.234:8100 USER=… PASS=… MACHINE=hub FILE=/path/to/video node scripts/e2e-player.mjs
+//
+// Opens FILE in the Files viewer on MACHINE ("hub" for the hub itself), plays it on Auto,
+// checks the 360 view if it is one, seeks into the middle, picks the lowest quality, tries
+// Original, and reads the menu's "Made on …". Changes nothing. DEVICE="Pixel 7" for a phone;
+// TRACE=1 prints every piece asked for. Screenshots land in $SHOTS (default /tmp/hamlab-shots).
+import { createRequire } from 'node:module'
+import { mkdirSync } from 'node:fs'
+const require = createRequire(import.meta.url)
+const { chromium, devices } = require('/home/core/projects/wedding-website/node_modules/playwright')
+
+const { BASE = 'http://10.0.0.234:8100', USER, PASS, MACHINE = 'hub', FILE, DEVICE, TRACE } = process.env
+const SHOTS = process.env.SHOTS ?? '/tmp/hamlab-shots'
+if (!USER || !PASS || !FILE) { console.error('USER, PASS and FILE are required'); process.exit(2) }
+mkdirSync(SHOTS, { recursive: true })
+
+let failed = 0
+const check = (name, ok, extra = '') => { console.log(`${ok ? 'ok  ' : 'FAIL'} ${name}${extra ? ' — ' + extra : ''}`); if (!ok) failed++ }
+const browser = await chromium.launch({ args: ['--autoplay-policy=no-user-gesture-required', '--use-gl=angle', '--use-angle=swiftshader', '--enable-unsafe-swiftshader'] })
+const ctx = await browser.newContext({ ...(DEVICE ? devices[DEVICE] : { viewport: { width: 1280, height: 860 } }), colorScheme: 'dark' })
+check('signs in', (await ctx.request.post(BASE + '/api/login', { data: { username: USER, password: PASS } })).ok())
+const page = await ctx.newPage()
+const errors = []
+page.on('pageerror', (e) => errors.push(String(e)))
+page.on('console', (m) => { if (m.type() === 'error' && !/401|404|favicon/.test(m.text())) errors.push(m.text()) })
+const T0 = Date.now(), trace = []
+const short = (u) => u.replace(/.*\/files\/play\/[0-9a-f]+\//, '')
+page.on('request', (r) => { if (/\/files\/play\/.*\.ts$/.test(r.url())) trace.push(`${((Date.now() - T0) / 1000).toFixed(1)} ask ${short(r.url())}`) })
+page.on('requestfinished', (r) => { if (/\/files\/play\/.*\.ts$/.test(r.url())) trace.push(`${((Date.now() - T0) / 1000).toFixed(1)} got ${short(r.url())}`) })
+const mark = (m) => trace.push(`${((Date.now() - T0) / 1000).toFixed(1)} -- ${m}`)
+
+const dir = FILE.slice(0, FILE.lastIndexOf('/')) || '/', name = FILE.slice(FILE.lastIndexOf('/') + 1)
+await page.goto(`${BASE}/#/${MACHINE}/files/${encodeURIComponent(dir)}`)
+await page.locator('.file-row', { hasText: name }).first().click()
+await page.locator('.vp').waitFor()
+
+const vstate = () => page.evaluate(() => { const v = document.querySelector('.vp video'); return v ? { t: v.currentTime, paused: v.paused, w: v.videoWidth, h: v.videoHeight, rs: v.readyState, d: v.duration } : null })
+async function playingPast(t, ms = 60000) {
+  const t0 = Date.now()
+  while (Date.now() - t0 < ms) {
+    const s = await vstate()
+    if (s && s.t > t && !s.paused && s.rs >= 3) return Date.now() - t0
+    await page.waitForTimeout(200)
+  }
+  return -1
+}
+async function controls() {
+  if (await page.locator('.vp.bare').count()) {
+    const b = await page.locator('.vp').boundingBox()
+    if (DEVICE) await page.touchscreen.tap(b.x + 40, b.y + 40)
+    else await page.mouse.move(b.x + b.width / 2 + Math.random() * 40, b.y + b.height / 3)
+    await page.waitForTimeout(300)
+  }
+}
+
+let took = await playingPast(1)
+check('plays on Auto', took >= 0, `${((Date.now() - T0) / 1000).toFixed(1)} s from opening`)
+await page.waitForTimeout(6000)
+let s = await vstate()
+check('Auto settles on a quality', s?.w > 0, `${s?.w}×${s?.h}; “${await page.locator('.vp-q span').textContent()}”`)
+if (await page.locator('canvas.vp-sphere').count()) {
+  const px = await page.evaluate(() => { const c = document.querySelector('canvas.vp-sphere'); const g = c.getContext('webgl'); const d = new Uint8Array(64); g.readPixels(c.width >> 1, c.height >> 1, 4, 4, g.RGBA, g.UNSIGNED_BYTE, d); return d.reduce((a, b) => a + b, 0) })
+  check('the 360° view draws', px > 0)
+}
+await page.screenshot({ path: `${SHOTS}/h1-auto.png` })
+
+const mid = Math.floor(s.d / 2)
+mark('seek')
+await page.evaluate((m) => { document.querySelector('.vp video').currentTime = m }, mid)
+took = await playingPast(mid + 0.5)
+check('a seek into the middle plays again', took >= 0, `${(took / 1000).toFixed(1)} s`)
+
+await controls()
+await page.locator('.vp-q').click()
+await page.waitForTimeout(2500) // the menu asks the machine what it is doing
+const items = page.locator('.vp-menu button')
+const n = await items.count()
+check('the menu lists Auto, Original and the qualities', n >= 3, (await items.allTextContents()).join(' | '))
+const foot = await page.locator('.vp-menu-f').textContent()
+check('it says where it is made', /Made on \S+/.test(foot), foot)
+await page.screenshot({ path: `${SHOTS}/h2-menu.png` })
+const lowLabel = await items.nth(n - 1).locator('span').nth(1).textContent()
+mark('pick ' + lowLabel)
+const before = (await vstate()).t
+const t0 = Date.now()
+await items.nth(n - 1).click()
+let ok = false
+for (let i = 0; i < 200 && !ok; i++) { await page.waitForTimeout(200); s = await vstate(); ok = s.t > before + 1 && !s.paused && (await page.locator('.vp-q span').textContent()) === lowLabel }
+check(`picking ${lowLabel} switches to it`, ok, `${s.w}×${s.h} after ${((Date.now() - t0) / 1000).toFixed(1)} s`)
+
+await controls()
+await page.locator('.vp-q').click()
+await page.locator('.vp-menu button', { hasText: 'Original' }).click()
+await page.waitForTimeout(4000)
+const label = await page.locator('.vp-q span').textContent()
+const note = await page.locator('.vp-note').count() ? await page.locator('.vp-note').textContent() : ''
+check('Original plays, or falls back to Auto and says so', label === 'Original' || (/^Auto/.test(label) && /can’t play/.test(note)), `${label}${note ? ' — ' + note : ''}`)
+check('still playing', (await playingPast((await vstate()).t + 0.5)) >= 0)
+await page.screenshot({ path: `${SHOTS}/h3-after-original.png` })
+check('no page errors', errors.length === 0, errors.slice(0, 3).join(' / '))
+if (TRACE) console.log(trace.join('\n'))
+await browser.close()
+console.log(failed ? `${failed} failed` : 'all ok')
+process.exit(failed ? 1 : 0)

web/src/Files.tsx

@@ -267,7 +267,7 @@ function Viewer({ path, sudo, onClose, onChanged }: { path: string; sudo: boolea
         <textarea className="editor file-editor" value={text} spellCheck={false} onChange={(e) => setText(e.target.value)} />
       )}
       {info && text === null && isImage(name) && <div className="preview"><img src={api.fileReadURL(path, sudo)} alt={name} /></div>}
-      {/* Video: the browser's own decoder first, and a re-encode on the machine when that fails. Audio as it is. */}
+      {/* Video: the player (Auto, by hand, or the file as it is), made on the Transcode device. Audio as it is. */}
       {info && text === null && !isImage(name) && info.preview === 'video' && <Player path={path} sudo={sudo} name={name} />}
       {info && text === null && !isImage(name) && info.preview === 'audio' && !cantPlay && (
         <div className="preview audio"><div className="audio-box"><div className="ficon">🎵</div><div className="mono small">{name}</div><audio controls preload="metadata" src={api.fileReadURL(path, sudo)} onError={() => setCantPlay(true)} /></div></div>

web/src/Player.tsx

@@ -1,153 +1,357 @@
-// A video in the Files viewer. First the file as it is, handed to the browser's own
-// decoder; when that fails — Safari and an MKV, HEVC without a hardware decoder — a
-// picker: codec and size, and the machine re-encodes it to HLS on its own GPU (or CPU),
-// which plays natively on Safari and through hls.js everywhere else. The same picker is
-// one tap away even when the file plays, for a 36 Mbps capture over a slow link.
-// A re-encode's timeline is the whole film from the start: seek anywhere, and the machine
-// starts encoding from there (repackaging, which is near-instant, grows as it goes instead).
+// A video in the Files viewer, YouTube's way: Auto, which reads the connection and picks the
+// quality (hls.js), any quality by hand, or Original — the file as it is, for a browser that
+// decodes it. The qualities are made on the fly, from wherever the viewer seeks to, on the device
+// the Transcode device setting names (Settings), which may be on another machine than the file.
+// A 360° video is drawn as the view from inside it (vr.ts): drag, pinch or scroll, and on a
+// phone the motion button. The same player as Ham Share's.
 import { useCallback, useEffect, useRef, useState } from 'react'
-import { api, apiPath, PlayCaps, PlayStatus, PlayStream } from './api'
-import { Btn, Spinner } from './ui'
+import Hls from 'hls.js'
+import { api, nodeAPI, type PlayOpen, type PlayStatus } from './api'
+import { canMotion, Sphere } from './vr'
 
-type Mode = 'native' | 'pick' | 'hls'
-const CODEC_KEY = 'hamlab.play.codec'
-const QUALITY_KEY = 'hamlab.play.quality'
-const remember = (k: string, v: string) => { try { localStorage.setItem(k, v) } catch { /* private mode */ } }
-const recall = (k: string, d: string) => { try { return localStorage.getItem(k) || d } catch { return d } }
+type Choice = 'auto' | 'original' | number // a number is a width: the rung's name
 
-const clock = (sec: number) => { const t = Math.floor(sec), h = Math.floor(t / 3600), m = Math.floor((t % 3600) / 60), x = t % 60; return `${h ? `${h}:${String(m).padStart(2, '0')}` : m}:${String(x).padStart(2, '0')}` }
-const fmtMbps = (bps?: number) => (bps ? `${(bps / 1e6).toFixed(bps >= 10e6 ? 0 : 1)} Mbps` : '')
-const describe = (s: PlayStream) => {
-  const v = s.source.video
-  const src = v ? `${v.codec}${v.profile ? ' ' + v.profile : ''} ${v.width}×${v.height}${v.fps ? ` ${Math.round(v.fps)} fps` : ''}${s.source.bit_rate ? ` ${fmtMbps(s.source.bit_rate)}` : ''} in ${s.source.container.split(',')[0]}` : s.source.container
-  const out = s.codec === 'copy' ? 'repackaged' : `${s.codec === 'h264' ? 'H.264' : s.codec.toUpperCase()} ${s.width}×${s.height} ${(s.kbps / 1000).toFixed(s.kbps >= 10000 ? 0 : 1)} Mbps`
-  return `${src} → ${out} on ${s.engine}`
+// The bandwidth hls.js measured last time, so the next video starts near the right quality
+// rather than at the bottom.
+const BW_KEY = 'hamlab.play.bw'
+const savedBW = () => { try { const n = Number(localStorage.getItem(BW_KEY)); return n > 0 ? n : 0 } catch { return 0 } }
+const saveBW = (n: number) => { try { if (n > 0) localStorage.setItem(BW_KEY, String(Math.round(n))) } catch { /* private mode */ } }
+
+// hls.js reads the connection from how long each piece takes. Here a piece can be slow to
+// start because the machine is still making it (a few seconds after a seek or a change of
+// quality, at 8K), which says nothing about the connection; counted, it drags Auto down to the
+// bottom, and every drop starts the making over again. So: the wait before the first byte is
+// not counted against the connection, and hls.js doesn't give up on a piece before its first
+// byte comes. Once bytes flow, its usual rules apply.
+type AbrLike = { new(hls: Hls): object }
+const Base = Hls.DefaultConfig.abrController as unknown as AbrLike
+type Stats = { loading: { start: number; first: number } }
+type Proto = { initEstimator: () => { sampleTTFB: (ms: number) => void }; onFragBuffered: (ev: unknown, d: unknown) => void }
+const proto = Base.prototype as unknown as Proto
+class PatientAbr extends Base {
+  constructor(hls: Hls) {
+    super(hls)
+    const self = this as unknown as { _abandonRulesCheck: (l?: unknown) => void; fragCurrent: { stats: Stats } | null }
+    const orig = self._abandonRulesCheck
+    self._abandonRulesCheck = (l?: unknown) => {
+      const f = self.fragCurrent
+      if (f && !f.stats.loading.first) return
+      orig(l)
+    }
+  }
+  initEstimator() {
+    const e = proto.initEstimator.call(this)
+    const sample = e.sampleTTFB.bind(e)
+    e.sampleTTFB = (ms: number) => sample(Math.min(ms, 300))
+    return e
+  }
+  onFragBuffered(ev: unknown, d: { frag: { stats: Stats }; part?: { stats: Stats & { loaded: number } } | null }) {
+    const st = d.part?.stats.loaded ? d.part.stats : d.frag.stats
+    const start = st.loading.start
+    if (st.loading.first > start) st.loading.start = st.loading.first
+    try { proto.onFragBuffered.call(this, ev, d) } finally { st.loading.start = start }
+  }
 }
 
-export default function Player({ path, sudo, name }: { path: string; sudo: boolean; name: string }) {
-  const [mode, setMode] = useState<Mode>('native')
-  const [why, setWhy] = useState('') // what brought the picker up
-  const [caps, setCaps] = useState<PlayCaps | null>(null)
-  const [codec, setCodec] = useState(() => recall(CODEC_KEY, 'h264'))
-  const [quality, setQuality] = useState(() => recall(QUALITY_KEY, '1080p'))
-  const [stream, setStream] = useState<{ s: PlayStream; url: string } | null>(null)
-  const [status, setStatus] = useState<PlayStatus | null>(null)
+const mbps = (b: number) => `${b >= 10e6 ? Math.round(b / 1e6) : (b / 1e6).toFixed(1)} Mb/s`
+const clock = (sec: number) => { const t = Math.max(0, Math.floor(sec)), h = Math.floor(t / 3600), m = Math.floor((t % 3600) / 60), x = t % 60; return `${h ? `${h}:${String(m).padStart(2, '0')}` : m}:${String(x).padStart(2, '0')}` }
+const size = (w?: number, h?: number, vr?: boolean) => {
+  if (!w || !h) return ''
+  if (vr) return `${w >= 7680 ? '8K' : w >= 5760 ? '5.7K' : w >= 3840 ? '4K' : w >= 3072 ? '3K' : `${w}×${h}`} 360°`
+  const s = Math.min(w, h)
+  return s >= 2160 ? '4K' : s >= 1440 ? '1440p' : s >= 1080 ? '1080p' : s >= 720 ? '720p' : `${w}×${h}`
+}
+
+const I = ({ d, size: sz = 20, fill }: { d: string; size?: number; fill?: boolean }) => (
+  <svg width={sz} height={sz} viewBox="0 0 24 24" fill={fill ? 'currentColor' : 'none'} stroke={fill ? 'none' : 'currentColor'} strokeWidth="1.8" strokeLinecap="round" strokeLinejoin="round" aria-hidden="true"><path d={d} /></svg>
+)
+const PLAY = 'M7 4.5v15l12.5-7.5z', PAUSE = 'M8 5v14M16 5v14', CHECK = 'M5 12.5l4.5 4.5L19 7.5', TUNE = 'M4 7h10M18 7h2M4 17h4M12 17h8M16 5v4M10 15v4'
+const FULL = 'M4 9V4h5M20 9V4h-5M4 15v5h5M20 15v5h-5', SMALL = 'M9 4v5H4M15 4v5h5M9 20v-5H4M15 20v-5h5', PHONE = 'M8 3h8a1 1 0 0 1 1 1v16a1 1 0 0 1-1 1H8a1 1 0 0 1-1-1V4a1 1 0 0 1 1-1zM3 9a9 9 0 0 0 0 6M21 9a9 9 0 0 1 0 6'
+
+export default function Player({ path, sudo }: { path: string; sudo: boolean; name: string }) {
+  const [open, setOpen] = useState<PlayOpen | null>(null)
   const [err, setErr] = useState('')
+  const [note, setNote] = useState('')
+  const [choice, setChoice] = useState<Choice>('auto')
+  const [showing, setShowing] = useState(0) // the width playing now
+  const [status, setStatus] = useState<PlayStatus | null>(null)
+  const [paused, setPaused] = useState(true)
+  const [waiting, setWaiting] = useState(true)
+  const [time, setTime] = useState(0)
+  const [scrub, setScrub] = useState<number | null>(null)
+  const [buffered, setBuffered] = useState(0)
+  const [menu, setMenu] = useState(false)
+  const [chrome, setChrome] = useState(true)
+  const [motion, setMotion] = useState(false)
+  const [full, setFull] = useState(false) // the browser's full screen, or (an iPhone) the window
+  const box = useRef<HTMLDivElement>(null)
   const video = useRef<HTMLVideoElement>(null)
-  const streamRef = useRef(stream)
-  streamRef.current = stream
+  const canvas = useRef<HTMLCanvasElement>(null)
+  const hls = useRef<Hls | null>(null)
+  const sphere = useRef<Sphere | null>(null)
+  const hideTimer = useRef<number>()
+  const resume = useRef<{ at: number; play: boolean }>({ at: 0, play: true })
+  const openRef = useRef(open)
+  openRef.current = open
+  const menuRef = useRef(menu)
+  menuRef.current = menu
 
-  useEffect(() => { setMode('native'); setWhy(''); setStream(null); setStatus(null); setErr('') }, [path, sudo])
-  useEffect(() => { remember(CODEC_KEY, codec) }, [codec])
-  useEffect(() => { remember(QUALITY_KEY, quality) }, [quality])
-  useEffect(() => { if (mode === 'pick' && !caps) api.playCaps(sudo).then(setCaps).catch((e) => setCaps({ codecs: [], qualities: [], error: e instanceof Error ? e.message : 'failed' })) }, [mode, caps, sudo])
-
-  // a stream is the machine's work: let go of it when this player does — and when the page
-  // itself goes, by a beacon, the one request a browser still sends on its way out
-  const stop = useCallback(() => { const s = streamRef.current; if (s) { api.playStop(s.s.id).catch(() => { /* gone already */ }); setStream(null); setStatus(null) } }, [])
-  useEffect(() => () => stop(), [stop])
+  // Open the play; let it go when this player does, and when the page goes, by a beacon.
   useEffect(() => {
-    const h = () => { const s = streamRef.current; if (s) navigator.sendBeacon(apiPath(`/api/files/play/${s.s.id}/close`)) }
+    let live = true
+    setOpen(null); setErr(''); setNote(''); setChoice('auto'); resume.current = { at: 0, play: true }
+    api.play(path, sudo).then((o) => {
+      if (!live) { api.playStop(o.node, o.play.id).catch(() => {}); return }
+      setOpen(o)
+      if (o.note) setNote(o.note)
+    }).catch((e) => { if (live) setErr(e instanceof Error ? e.message : 'failed') })
+    return () => { live = false; const o = openRef.current; if (o) api.playStop(o.node, o.play.id).catch(() => { /* gone already */ }) }
+  }, [path, sudo])
+  useEffect(() => {
+    const h = () => { const o = openRef.current; if (o) navigator.sendBeacon(nodeAPI(o.node, `/api/files/play/${o.play.id}/close`)) }
     window.addEventListener('pagehide', h)
     return () => window.removeEventListener('pagehide', h)
   }, [])
 
-  const start = async () => {
-    setErr('')
-    try {
-      stop()
-      const r = await api.playStart(path, codec, quality, sudo)
-      setStream({ s: r.stream, url: r.url }); setMode('hls')
-    } catch (e) { setErr(e instanceof Error ? e.message : 'failed') }
-  }
+  const info = open?.play.info
+  const vr = !!info?.video?.spherical
 
-  // feed the stream to the element: Safari plays HLS itself, the rest through hls.js
+  useEffect(() => {
+    if (!vr || !canvas.current || !video.current) return
+    try { sphere.current = new Sphere(canvas.current, video.current) } catch (e) { setErr((e as Error).message) }
+    return () => { sphere.current?.destroy(); sphere.current = null }
+  }, [vr, open])
+
+  // The source: hls.js for Auto and the chosen qualities, the file itself for Original.
   useEffect(() => {
     const v = video.current
-    if (mode !== 'hls' || !stream || !v) return
-    const url = apiPath(stream.url)
-    let hls: { destroy: () => void } | null = null
-    let gone = false
-    ;(async () => {
-      if (v.canPlayType('application/vnd.apple.mpegurl')) {
-        v.src = url
-      } else {
-        const { default: Hls } = await import('hls.js')
-        if (gone) return
-        if (!Hls.isSupported()) { setErr('this browser has neither HLS nor MediaSource — nothing can play here'); return }
-        // a segment the machine hasn't made yet is made when asked for (a seek): its first
-        // byte can take as long as the re-encode takes to start there and write it
-        const slow = { maxTimeToFirstByteMs: 50000, maxLoadTimeMs: 120000, timeoutRetry: { maxNumRetry: 2, retryDelayMs: 0, maxRetryDelayMs: 0 }, errorRetry: { maxNumRetry: 3, retryDelayMs: 1000, maxRetryDelayMs: 8000 } }
-        const h = new Hls({ maxBufferLength: 60, backBufferLength: 30, fragLoadPolicy: { default: slow } })
-        hls = h
-        h.on(Hls.Events.ERROR, (_e, d) => { if (d.fatal) setErr(`playback failed: ${d.details}`) })
-        h.loadSource(url)
-        h.attachMedia(v)
+    if (!open || !v) return
+    const { at, play } = resume.current
+    const start = () => { if (at) v.currentTime = at; if (play) v.play().catch(() => setPaused(true)) }
+    if (choice === 'original') {
+      v.src = api.fileReadURL(path, sudo)
+      v.addEventListener('loadedmetadata', start, { once: true })
+      setShowing(info?.video?.width ?? 0)
+      const bad = () => {
+        resume.current = { at: v.currentTime || at, play: true }
+        setNote('This browser can’t play the file as it is. Back on Auto.')
+        setChoice('auto')
       }
-      v.play().catch(() => { /* needs a tap on some phones */ })
-    })()
-    return () => { gone = true; hls?.destroy() }
-  }, [mode, stream])
+      v.addEventListener('error', bad, { once: true })
+      return () => { v.removeEventListener('error', bad); v.removeEventListener('loadedmetadata', start); v.removeAttribute('src'); v.load() }
+    }
+    const master = nodeAPI(open.node, open.master)
+    if (Hls.isSupported()) {
+      const h = new Hls({
+        abrController: PatientAbr as unknown as typeof Hls.DefaultConfig.abrController,
+        abrEwmaDefaultEstimate: savedBW() || 5_000_000,
+        startPosition: at || -1,
+        maxBufferLength: 30,
+        maxMaxBufferLength: 60,
+        backBufferLength: 60,
+        // A piece being made after a seek can take a while; the machine waits up to 45 s.
+        fragLoadPolicy: { default: { maxTimeToFirstByteMs: 50_000, maxLoadTimeMs: 120_000, timeoutRetry: { maxNumRetry: 2, retryDelayMs: 0, maxRetryDelayMs: 0 }, errorRetry: { maxNumRetry: 4, retryDelayMs: 1000, maxRetryDelayMs: 8000 } } },
+      })
+      hls.current = h
+      h.on(Hls.Events.MANIFEST_PARSED, () => {
+        if (typeof choice === 'number') {
+          const i = h.levels.findIndex((l) => l.width === choice)
+          if (i >= 0) { h.startLevel = i; h.currentLevel = i }
+        }
+        if (play) v.play().catch(() => setPaused(true))
+      })
+      h.on(Hls.Events.LEVEL_SWITCHED, (_, d) => setShowing(h.levels[d.level]?.width ?? 0))
+      h.on(Hls.Events.FRAG_BUFFERED, () => saveBW(h.bandwidthEstimate))
+      let recovered = 0
+      h.on(Hls.Events.ERROR, (_, d) => {
+        if (!d.fatal) return
+        if (d.type === Hls.ErrorTypes.MEDIA_ERROR && recovered++ < 3) { h.recoverMediaError(); return }
+        if (d.type === Hls.ErrorTypes.NETWORK_ERROR && recovered++ < 3) { h.startLoad(v.currentTime); return }
+        setErr(`The video stopped loading (${d.details}).`)
+      })
+      h.loadSource(master)
+      h.attachMedia(v)
+      return () => { saveBW(h.bandwidthEstimate); h.destroy(); hls.current = null }
+    }
+    // Safari without Media Source (an older iPhone): its own HLS, Auto only.
+    v.src = master
+    v.addEventListener('loadedmetadata', start, { once: true })
+    return () => { v.removeEventListener('loadedmetadata', start); v.removeAttribute('src'); v.load() }
+  }, [open, choice === 'original' ? 'o' : 'h']) // eslint-disable-line react-hooks/exhaustive-deps
 
-  // follow the re-encode while it runs
+  // A hand-picked quality, or back to Auto, while hls.js is already playing.
   useEffect(() => {
-    if (mode !== 'hls' || !stream) return
-    let stopPolling = false
-    const tick = async () => { try { const st = await api.playStatus(stream.s.id); if (!stopPolling) { setStatus(st); if (st.running) setTimeout(tick, 2000) } } catch { /* ended */ } }
-    tick()
-    return () => { stopPolling = true }
-  }, [mode, stream])
+    const h = hls.current
+    if (!h || choice === 'original' || !h.levels.length) return
+    if (choice === 'auto') { h.currentLevel = -1; return }
+    const i = h.levels.findIndex((l) => l.width === choice)
+    if (i >= 0) h.currentLevel = i
+  }, [choice])
 
-  const pick = (reason: string) => { setWhy(reason); setMode('pick') }
-  const codecs = caps?.codecs ?? []
+  // What the machine is doing, while the menu is open.
+  useEffect(() => {
+    if (!menu || !open) return
+    let live = true
+    const tick = () => api.playStatus(open.node, open.play.id).then((s) => { if (live) setStatus(s) }).catch(() => {})
+    tick()
+    const t = window.setInterval(tick, 2000)
+    return () => { live = false; window.clearInterval(t) }
+  }, [menu, open])
+
+  // Controls fade while it plays and nobody touches anything.
+  const poke = useCallback(() => {
+    setChrome(true)
+    window.clearTimeout(hideTimer.current)
+    hideTimer.current = window.setTimeout(() => { if (!video.current?.paused && !menuRef.current) setChrome(false) }, 3000)
+  }, [])
+  useEffect(() => () => window.clearTimeout(hideTimer.current), [])
+  useEffect(() => { if (!menu) poke() }, [menu, poke])
+
+  const toggle = useCallback(() => {
+    const v = video.current
+    if (!v) return
+    if (v.paused) void v.play().catch(() => {})
+    else v.pause()
+    poke()
+  }, [poke])
+  const seekBy = useCallback((d: number) => {
+    const v = video.current
+    if (!v) return
+    v.currentTime = Math.max(0, Math.min(info?.duration ?? v.duration, v.currentTime + d))
+    poke()
+  }, [info, poke])
+  // Full screen: the browser's where it has one for an element, else (an iPhone) the window.
+  const fullscreen = useCallback(() => {
+    const el = box.current as (HTMLDivElement & { webkitRequestFullscreen?: () => void }) | null
+    if (!el) return
+    if (document.fullscreenElement) { void document.exitFullscreen(); return }
+    if (el.requestFullscreen) { void el.requestFullscreen().catch(() => setFull((f) => !f)); return }
+    if (el.webkitRequestFullscreen) { el.webkitRequestFullscreen(); return }
+    setFull((f) => !f)
+  }, [])
+  useEffect(() => {
+    const f = () => setFull(!!document.fullscreenElement)
+    document.addEventListener('fullscreenchange', f)
+    return () => document.removeEventListener('fullscreenchange', f)
+  }, [])
+
+  // Keys work while the player has the focus (a click on it gives it).
+  const onKey = (e: React.KeyboardEvent) => {
+    if (e.key === ' ' || e.key === 'k') { e.preventDefault(); toggle() }
+    else if (e.key === 'ArrowLeft' || e.key === 'j') { e.preventDefault(); seekBy(e.key === 'j' ? -10 : -5) }
+    else if (e.key === 'ArrowRight' || e.key === 'l') { e.preventDefault(); seekBy(e.key === 'l' ? 10 : 5) }
+    else if (e.key === 'f') fullscreen()
+    else if (e.key === 'Escape') { if (menu) setMenu(false); else if (full && !document.fullscreenElement) setFull(false) }
+  }
+
+  // Looking around a 360° video: a drag turns the view, a pinch zooms, a tap shows or hides the
+  // controls.
+  const pointers = useRef(new Map<number, { x: number; y: number }>())
+  const moved = useRef(0)
+  const pinch = useRef(0)
+  const onDown = (e: React.PointerEvent) => {
+    (e.target as Element).setPointerCapture(e.pointerId)
+    pointers.current.set(e.pointerId, { x: e.clientX, y: e.clientY })
+    moved.current = 0
+    if (pointers.current.size === 2) { const [a, b] = [...pointers.current.values()]; pinch.current = Math.hypot(a.x - b.x, a.y - b.y) }
+  }
+  const onMove = (e: React.PointerEvent) => {
+    const p = pointers.current.get(e.pointerId)
+    if (!p) return
+    const dx = e.clientX - p.x, dy = e.clientY - p.y
+    pointers.current.set(e.pointerId, { x: e.clientX, y: e.clientY })
+    moved.current += Math.abs(dx) + Math.abs(dy)
+    if (pointers.current.size === 2) {
+      const [a, b] = [...pointers.current.values()]
+      const d = Math.hypot(a.x - b.x, a.y - b.y)
+      if (pinch.current) sphere.current?.zoom(pinch.current / d)
+      pinch.current = d
+    } else sphere.current?.drag(dx, dy)
+  }
+  const onUp = (e: React.PointerEvent) => {
+    pointers.current.delete(e.pointerId)
+    if (pointers.current.size < 2) pinch.current = 0
+    if (pointers.current.size === 0 && moved.current < 6) {
+      if (e.pointerType === 'mouse') toggle()
+      else if (chrome && !menu) setChrome(false)
+      else poke()
+      setMenu(false)
+    }
+  }
+
+  const v = video.current
+  const dur = info?.duration ?? 0
+  const shown = scrub ?? time
+  const rungs = open?.play.rungs ?? []
+  const label = (w: number) => rungs.find((r) => r.width === w)?.label ?? (w && w === info?.video?.width ? 'Original' : '')
+  const choiceLabel = choice === 'auto' ? `Auto${showing ? ` · ${label(showing)}` : ''}` : choice === 'original' ? 'Original' : label(choice)
+  const tooBig = vr && sphere.current && (info?.video?.width ?? 0) > sphere.current.maxTexture
+  const fileRate = info?.bit_rate || (info?.size && dur ? (info.size * 8) / dur : 0)
+  const keep = () => { if (v) resume.current = { at: v.currentTime, play: !v.paused } }
 
   return (
-    <div className="player">
-      {mode === 'native' && (
-        <>
-          <div className="play-bar"><span>as it is</span><span className="spacer" /><button className="btn" onClick={() => pick('')}>Re-encode…</button></div>
-          <div className="preview"><video controls playsInline preload="metadata" src={api.fileReadURL(path, sudo)} onError={() => pick(`This browser can't play ${name} as it is — the container or codec isn't one it decodes.`)} /></div>
-        </>
-      )}
-      {mode === 'pick' && (
-        <div className="play-pick notice">
-          <div>{why || `Re-encode ${name} on this machine and play that instead.`}</div>
-          {caps?.error && <div className="error" style={{ marginTop: 8 }}>{caps.error}</div>}
-          {!caps && !err && <div className="muted small" style={{ marginTop: 8 }}><Spinner /> asking the machine what it can encode…</div>}
-          {caps && !caps.error && (
-            <div className="row">
-              <label>codec
-                <select value={codec} onChange={(e) => setCodec(e.target.value)}>
-                  {codecs.map((c) => <option key={c.id} value={c.id} disabled={!c.engine}>{c.label}{c.engine ? ` — ${c.engine}` : ' — not on this machine'}</option>)}
-                </select>
-              </label>
-              <label>size
-                <select value={quality} onChange={(e) => setQuality(e.target.value)} disabled={codec === 'copy'}>
-                  {caps.qualities.map((q) => <option key={q.id} value={q.id}>{q.label}</option>)}
-                </select>
-              </label>
-              <Btn className="btn on" disabled={!codecs.find((c) => c.id === codec)?.engine} onClick={start}>Play</Btn>
-              <a className="btn" href={api.fileDownloadURL(path, sudo)} download={name}>Download instead</a>
+    <div ref={box} tabIndex={0} onKeyDown={onKey} className={`vp${chrome ? '' : ' bare'}${full ? ' max' : ''}`}
+      onPointerMove={(e) => { if (e.pointerType === 'mouse') poke() }}
+      onWheel={vr ? (e) => { if (!(e.target as Element).closest('.vp-menu')) sphere.current?.zoom(e.deltaY > 0 ? 1.08 : 1 / 1.08) } : undefined}>
+      <video ref={video} className={vr ? 'vp-v vp-hidden' : 'vp-v'} playsInline preload="auto"
+        onPlay={() => { setPaused(false); poke() }} onPause={() => { setPaused(true); setChrome(true) }}
+        onWaiting={() => setWaiting(true)} onPlaying={() => setWaiting(false)} onCanPlay={() => setWaiting(false)} onSeeking={() => setWaiting(true)} onSeeked={() => setWaiting(false)}
+        onTimeUpdate={(e) => {
+          const el = e.currentTarget
+          setTime(el.currentTime)
+          resume.current = { at: el.currentTime, play: !el.paused }
+          for (let i = 0; i < el.buffered.length; i++) if (el.buffered.start(i) <= el.currentTime + 0.5) setBuffered(el.buffered.end(i))
+        }}
+        onClick={vr ? undefined : () => { if (matchMedia('(pointer: coarse)').matches) { if (chrome) setChrome(false); else poke() } else toggle() }}
+        onDoubleClick={vr ? undefined : fullscreen} />
+      {vr && <canvas ref={canvas} className="vp-v vp-sphere" onPointerDown={onDown} onPointerMove={onMove} onPointerUp={onUp} onPointerCancel={onUp} onDoubleClick={fullscreen} />}
+
+      {(waiting || !open) && !err && <div className="vp-spin" aria-label="Loading" />}
+      {err && <div className="vp-err"><p>{err}</p></div>}
+      {open && paused && !waiting && !err && <button className="vp-big" onClick={toggle} aria-label="Play"><I d={PLAY} size={36} fill /></button>}
+      {note && <div className="vp-note" role="status" onClick={() => setNote('')}>{note}</div>}
+      {vr && open && chrome && !menu && time < 8 && !err && <div className="vp-hint">Drag to look around · scroll or pinch to zoom</div>}
+
+      <div className="vp-bottom">
+        <div className="vp-seek" style={{ ['--p' as string]: dur ? `${(shown / dur) * 100}%` : '0%', ['--b' as string]: dur ? `${(buffered / dur) * 100}%` : '0%' }}>
+          <input type="range" min={0} max={dur || 1} step={0.1} value={shown} aria-label="Seek"
+            onChange={(e) => { setScrub(Number(e.target.value)); poke() }}
+            onPointerUp={(e) => { if (v) v.currentTime = Number((e.target as HTMLInputElement).value); setScrub(null) }}
+            onKeyUp={(e) => { if (v) v.currentTime = Number((e.target as HTMLInputElement).value); setScrub(null) }} />
         </div>
-          )}
-          {err && <div className="error" style={{ marginTop: 8 }}>{err}</div>}
-        </div>
-      )}
-      {mode === 'hls' && stream && (
-        <>
-          <div className="play-bar">
-            <span title={describe(stream.s)}>{describe(stream.s)}</span>
-            {status && status.running && (stream.s.seekable
-              ? <span>· {status.speed ? `${status.speed.toFixed(1)}× ` : ''}from {clock(status.from ?? 0)} · {Math.min(100, Math.round(status.progress / stream.s.source.duration * 100))}% ready — seek anywhere</span>
-              : <span>· {status.speed ? `${status.speed.toFixed(1)}×` : ''} {stream.s.source.duration ? `${Math.min(100, Math.round(status.progress / stream.s.source.duration * 100))}% through` : `${Math.round(status.progress)} s done`} — seek within what's done</span>)}
-            {status?.done && <span>· all of it is ready</span>}
-            {status?.error && <span className="error">· stopped early: {status.error}</span>}
+        <div className="vp-row">
+          <button className="vp-icon" onClick={toggle} aria-label={paused ? 'Play' : 'Pause'}>{paused ? <I d={PLAY} fill /> : <I d={PAUSE} />}</button>
+          <span className="vp-time">{clock(shown)} / {clock(dur)}</span>
           <span className="spacer" />
-            <button className="btn" onClick={() => { stop(); setMode('pick'); setWhy('') }}>Change…</button>
+          {vr && canMotion() && (
+            <button className={`vp-icon${motion ? ' on' : ''}`} aria-label="Look around by moving the phone" aria-pressed={motion}
+              onClick={async () => { const s = sphere.current; if (s) setMotion(await s.setGyro(!s.gyroOn)) }}><I d={PHONE} /></button>
+          )}
+          <button className="vp-q" onClick={() => { setMenu((m) => !m); poke() }} aria-label="Quality" aria-expanded={menu}><I d={TUNE} size={16} /><span>{choiceLabel}</span></button>
+          <button className="vp-icon" onClick={fullscreen} aria-label={full ? 'Exit full screen' : 'Full screen'}><I d={full ? SMALL : FULL} /></button>
+        </div>
+      </div>
+
+      {menu && open && (
+        <div className="vp-menu" role="menu">
+          <div className="vp-menu-h">Quality</div>
+          <button role="menuitemradio" aria-checked={choice === 'auto'} onClick={() => { setChoice('auto'); setMenu(false) }}>
+            <span className="ck">{choice === 'auto' && <I d={CHECK} size={16} />}</span><span>Auto</span><small>{choice === 'auto' && showing ? label(showing) : 'fits the connection'}</small>
+          </button>
+          <button role="menuitemradio" aria-checked={choice === 'original'} disabled={!!tooBig} onClick={() => { keep(); setChoice('original'); setMenu(false) }}>
+            <span className="ck">{choice === 'original' && <I d={CHECK} size={16} />}</span><span>Original</span>
+            <small>{tooBig ? 'too big for this device' : [size(info?.video?.width, info?.video?.height, vr), fileRate ? mbps(fileRate) : ''].filter(Boolean).join(' · ')}</small>
+          </button>
+          {rungs.map((r) => (
+            <button key={r.name} role="menuitemradio" aria-checked={choice === r.width} onClick={() => { keep(); setChoice(r.width); setMenu(false) }}>
+              <span className="ck">{choice === r.width && <I d={CHECK} size={16} />}</span><span>{r.label}</span><small>{mbps(r.bitrate)}</small>
+            </button>
+          ))}
+          <div className="vp-menu-f">
+            Made on <b>{open.host}</b> · {status?.engine || open.engine}
+            {status?.engine && <> · {status.paused ? 'far enough ahead, waiting' : `from ${clock(status.from)}`}</>}
+          </div>
         </div>
-          <div className="preview"><video ref={video} controls autoPlay playsInline /></div>
-          {err && <div className="error" style={{ margin: 12 }}>{err}</div>}
-        </>
       )}
     </div>
   )

web/src/Settings.tsx

@@ -1,6 +1,6 @@
 import { useCallback, useEffect, useState } from 'react'
 import { fetchCatalog } from './sensors'
-import { api, Me, TokenInfo, UpdateStatus } from './api'
+import { api, Me, TokenInfo, TranscodeSetting, UpdateStatus } from './api'
 import { savePrefs } from './accents'
 import { applyTheme, currentThemeId, THEMES } from './themes'
 import { Btn, Loading, Spinner, askYes, toast, useEscape } from './ui'
@@ -104,6 +104,7 @@ export default function Settings({ me }: { me: Me }) {
         </div>
       </section>
 
+      <TranscodeDevice />
 
       <div className="dash-bar"><h2 className="section">Access tokens</h2></div>
       <section className="card">
@@ -248,3 +249,59 @@ function TokenDialog({ onClose, onMade }: { onClose: () => void; onMade: (t: { n
     </div>
   )
 }
+
+// Where videos played in Files are made: one device on one machine, for every machine's files.
+// Every machine's devices are asked for live; one that can't be used says why.
+function TranscodeDevice() {
+  const [t, setT] = useState<TranscodeSetting | null>(null)
+  const [err, setErr] = useState('')
+  const [busy, setBusy] = useState('')
+  useEffect(() => { api.transcode().then(setT).catch((e) => setErr(e instanceof Error ? e.message : 'failed')) }, [])
+  const set = async (node: string, device: string) => {
+    setBusy(node + '|' + device); setErr('')
+    try { setT(await api.setTranscode(node, device)) } catch (e) { setErr(e instanceof Error ? e.message : 'failed') }
+    setBusy('')
+  }
+  const sel = t?.selected
+  return (
+    <>
+      <div className="dash-bar"><h2 className="section">Transcode device</h2><span className="spacer" /><span className="muted small">videos in Files, on every machine</span></div>
+      <section className="card">
+        {!t && !err && <div className="muted small"><Spinner /> asking every machine what it can encode on…</div>}
+        {t && (
+          <div className="tc-list">
+            <div className="tc-machine">
+              <div className="tc-host">Anywhere</div>
+              <div className="chips">
+                <button className={'chip' + (!sel ? ' on' : '')} disabled={!!busy} onClick={() => set('', '')}>The machine the file is on, its best device</button>
+              </div>
+            </div>
+            {t.machines.map((m) => (
+              <div key={m.node} className="tc-machine">
+                <div className="tc-host">{m.host}{m.node === '' && <span className="muted small"> · this hub</span>}</div>
+                {m.error && <div className="muted small">{m.error}</div>}
+                <div className="chips">
+                  {(m.devices ?? []).map((d) => {
+                    const on = !!sel && sel.node === m.node && sel.device === d.id
+                    return (
+                      <button key={d.id} className={'chip' + (on ? ' on' : '') + (d.ok ? '' : ' off')} disabled={!d.ok || !!busy} title={d.ok ? d.id : d.reason}
+                        onClick={() => set(m.node, d.id)}>
+                        {busy === m.node + '|' + d.id ? <Spinner size={10} /> : null}{d.name}{d.id !== 'cpu' && d.integrated ? ' (integrated)' : ''}{!d.ok && d.reason ? ` — ${d.reason}` : ''}
+                      </button>
+                    )
+                  })}
+                </div>
+              </div>
+            ))}
+          </div>
+        )}
+        {err && <div className="error" style={{ marginTop: 8 }}>{err}</div>}
+        <div className="muted small" style={{ marginTop: 10 }}>
+          Opening a video in Files plays it YouTube's way — Auto picks the quality the connection takes, any quality can be picked by hand,
+          or the file as it is — and every quality is made on the fly, from wherever you seek to, on this device. When it is on another
+          machine than the file, that machine reads the file through this hub. If it can't be reached, the file's own machine makes it instead.
+        </div>
+      </section>
+    </>
+  )
+}

web/src/api.ts

@@ -4,7 +4,12 @@ export class Unauthenticated extends Error { constructor(msg = 'unauthenticated'
 // is rewritten to /api/nodes/<name>/… and the hub proxies it. Hub-only calls (login,
 // the machine list itself) pass local=true and are never rewritten.
 let base = ''
-export function setMachine(name: string | null) { base = name ? `/api/nodes/${name}` : '' }
+export function setMachine(name: string | null) { base = name ? `/api/nodes/${name}` : ''; machine = name ?? '' }
+let machine = ''
+// The machine the console is looking at: '' is this host.
+export const currentMachine = () => machine
+// A path under another machine's /api, whichever one the console is looking at.
+export const nodeAPI = (node: string, p: string) => (node && p.startsWith('/api/') ? `/api/nodes/${node}${p.slice(4)}` : p)
 export const apiPath = (p: string) => (base && p.startsWith('/api/') ? base + p.slice(4) : p)
 
 // A machine that just failed to answer is left alone for a few seconds instead of
@@ -250,12 +255,18 @@ export interface ARCDetail {
 export interface ARCView { detail: ARCDetail; live: ARCLive | null }
 
 export interface FileEntry { name: string; type: 'dir' | 'file' | 'link' | 'other'; size: number; mode: string; perm: string; mtime: number; user: string; group: string; target?: string; broken?: boolean; preview?: 'image' | 'video' | 'audio' }
-export interface PlayCaps { codecs: { id: string; label: string; engine?: string }[]; qualities: { id: string; label: string; height: number }[]; error?: string }
-export interface PlayTrack { codec: string; profile?: string; pix_fmt?: string; width?: number; height?: number; fps?: number; channels?: number }
-export interface PlayStream { id: string; codec: string; quality: string; engine: string; width: number; height: number; kbps: number; seekable?: boolean; source: { container: string; duration: number; bit_rate?: number; video?: PlayTrack; audio?: PlayTrack } }
-// progress: seconds written (repackaged), or seconds of the film on disk (a seekable re-encode,
-// whose run now going started at `from`)
-export interface PlayStatus { running: boolean; done: boolean; error?: string; progress: number; speed: number; segments: number; from?: number }
+export interface PlayTrack { codec: string; profile?: string; pix_fmt?: string; width?: number; height?: number; fps?: number; channels?: number; spherical?: boolean }
+export interface PlayRung { name: string; label: string; width: number; height: number; fps: number; bitrate: number; peak: number }
+export interface PlayStatus { engine?: string; quality?: string; from: number; ahead: number; paused?: boolean }
+// A play: where it is made (node, '' the hub), its qualities best first, and the playlist under
+// that machine's /api.
+export interface PlayOpen {
+  node: string; master: string; engine: string; host: string; note?: string; status: PlayStatus
+  play: { id: string; name: string; device: string; remote: boolean; rungs: PlayRung[]; info: { container: string; duration: number; bit_rate?: number; size?: number; video?: PlayTrack; audio?: PlayTrack } }
+}
+export interface TranscodeDevice { id: string; name: string; integrated?: boolean; ok: boolean; reason?: string }
+export interface TranscodeMachine { node: string; host: string; devices?: TranscodeDevice[]; error?: string }
+export interface TranscodeSetting { selected: { node: string; device: string } | null; machines: TranscodeMachine[] }
 export interface ThumbGPU { api: string; device: string; name?: string; codecs?: string[]; reason?: string; permission?: boolean }
 // How previews get made on the machine: ok with an engine, or why not and what would fix it.
 export interface ThumbStatus { ok: boolean; engine: 'gpu' | 'cpu' | ''; summary: string; ffmpeg?: string; gpus: ThumbGPU[]; unusable?: ThumbGPU[]; error?: string; install?: { pm: string; package: string }; gpu_fix?: boolean; user: string; cache: { path: string; entries: number; bytes: number } }
@@ -281,6 +292,13 @@ export const api = {
     if (!r.ok) { let m = r.statusText; try { m = (await r.json()).error ?? m } catch { /* */ } throw new Error(m) }
     return r.text()
   },
+  // Playing: opened on the hub, which picks the machine (the Transcode device setting); the
+  // rest goes to that machine.
+  play: (path: string, sudo: boolean) => req<PlayOpen>('POST', '/api/play', { node: currentMachine(), path, sudo }, true),
+  playStatus: (node: string, id: string) => req<PlayStatus>('GET', nodeAPI(node, `/api/files/play/${id}`), undefined, true),
+  playStop: (node: string, id: string) => req<void>('DELETE', nodeAPI(node, `/api/files/play/${id}`), undefined, true),
+  transcode: () => req<TranscodeSetting>('GET', '/api/transcode', undefined, true),
+  setTranscode: (node: string, device: string) => req<TranscodeSetting>('PUT', '/api/transcode', device ? { node, device } : {}, true),
   fileReadURL: (path: string, sudo: boolean) => apiPath(`/api/files/read?${q(path, sudo)}`),
   fileDownloadURL: (path: string, sudo: boolean) => apiPath(`/api/files/download?${q(path, sudo)}`),
   // v carries the file's mtime and size, so a changed file is a new URL and an unchanged one a cached one
@@ -288,11 +306,6 @@ export const api = {
   thumbStatus: (sudo: boolean, refresh = false) => req<ThumbStatus>('GET', `/api/files/thumbs?${sudo ? 'sudo=1&' : ''}${refresh ? 'refresh=1' : ''}`),
   thumbInstall: () => req<TaskInfo>('POST', '/api/files/thumbs/install'),
   thumbGPUAccess: () => req<TaskInfo>('POST', '/api/files/thumbs/gpu-access'),
-  // playback of what the browser can't play as it is: an HLS re-encode on the machine
-  playCaps: (sudo: boolean) => req<PlayCaps>('GET', `/api/files/play-caps${sudo ? '?sudo=1' : ''}`),
-  playStart: (path: string, codec: string, quality: string, sudo: boolean) => req<{ stream: PlayStream; url: string }>('POST', `/api/files/play${sudo ? '?sudo=1' : ''}`, { path, codec, quality }),
-  playStatus: (id: string) => req<PlayStatus>('GET', `/api/files/play/${id}`),
-  playStop: (id: string) => req<void>('DELETE', `/api/files/play/${id}`),
   fileWrite: async (path: string, text: string, sudo: boolean) => {
     const r = await fetch(apiPath(`/api/files/write?${q(path, sudo)}`), { method: 'PUT', credentials: 'same-origin', body: text, headers: { 'Content-Type': 'application/octet-stream' } })
     if (r.status === 401) throw new Unauthenticated()

web/src/styles.css

@@ -145,6 +145,9 @@ button { font: inherit; color: inherit; background: none; border: 0; cursor: poi
 .svc-tools { padding: 10px; display: flex; flex-direction: column; gap: 8px; border-bottom: 1px solid var(--border); }
 .svc-tools input { padding: 8px 10px; background: var(--bg); border: 1px solid var(--border); border-radius: 6px; color: var(--fg); font-size: 14px; }
 .chip.on { color: var(--fg); border-color: var(--accent); } .chip.bad { color: var(--bad); }
+.chip.off { opacity: .55; cursor: default; } .chip.off:hover { color: var(--muted); border-color: var(--border); }
+.tc-list { display: flex; flex-direction: column; gap: 12px; }
+.tc-host { font-weight: 600; margin-bottom: 6px; }
 .svc-rows { flex: 1; overflow-y: auto; }
 .svc-row { display: flex; align-items: center; gap: 10px; padding: 8px 12px; cursor: pointer; border-bottom: 1px solid var(--border); }
 .svc-row:hover { background: var(--bg3); } .svc-row.active { background: var(--bg3); box-shadow: inset 3px 0 0 var(--accent); }
@@ -365,13 +368,48 @@ h2.section { margin: 0; font-size: 13px; font-weight: 600; color: var(--muted);
 .preview { flex: 1; display: flex; align-items: center; justify-content: center; overflow: auto; padding: 12px; }
 .preview img { max-width: 100%; max-height: 100%; object-fit: contain; }
 .preview video { max-width: 100%; max-height: 100%; background: #000; border-radius: 4px; outline: none; }
-.player { flex: 1; min-height: 0; display: flex; flex-direction: column; }
-.player .preview { flex: 1; min-height: 0; }
-.play-bar { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; padding: 6px 12px; font-size: 12px; color: var(--muted); border-bottom: 1px solid var(--border); }
-.play-bar select { padding: 4px 8px; background: var(--bg); border: 1px solid var(--border); border-radius: 5px; color: var(--fg); font-size: 12px; }
-.play-pick { margin: 12px; }
-.play-pick .row { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-top: 10px; }
-.play-pick label { display: flex; align-items: center; gap: 6px; font-size: 12px; color: var(--muted); }
+/* the video player (Player.tsx): Ham Share's, in the viewer; full screen is the browser's, or
+   on an iPhone the whole window */
+.vp { position: relative; flex: 1; min-height: 240px; background: #000; color: #fff; overflow: hidden; user-select: none; -webkit-user-select: none; outline: none; }
+.vp.max { position: fixed; inset: 0; z-index: 1000; }
+.vp-v { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: contain; background: #000; }
+.vp-hidden { opacity: 0; pointer-events: none; }
+.vp-sphere { touch-action: none; cursor: grab; }
+.vp-sphere:active { cursor: grabbing; }
+.vp-bottom { position: absolute; left: 0; right: 0; bottom: 0; padding: 26px 8px calc(env(safe-area-inset-bottom) + 4px); background: linear-gradient(transparent, rgba(0, 0, 0, .75)); transition: opacity .25s; z-index: 2; }
+.vp.bare .vp-bottom, .vp.bare .vp-hint { opacity: 0; pointer-events: none; }
+.vp.bare { cursor: none; }
+.vp-row { display: flex; align-items: center; gap: 4px; }
+.vp-icon { width: 38px; height: 38px; display: grid; place-items: center; border-radius: 19px; color: #fff; }
+.vp-icon:hover { background: rgba(255, 255, 255, .14); }
+.vp-icon.on { color: var(--accent); }
+.vp-time { font-size: 13px; font-variant-numeric: tabular-nums; padding: 0 6px; white-space: nowrap; }
+.vp-q { display: inline-flex; align-items: center; gap: 6px; padding: 7px 10px; border-radius: 17px; font-size: 13px; font-weight: 600; white-space: nowrap; color: #fff; }
+.vp-q:hover { background: rgba(255, 255, 255, .14); }
+.vp-seek { position: relative; height: 24px; margin: 0 8px; display: flex; align-items: center; }
+.vp-seek::before { content: ''; position: absolute; left: 0; right: 0; height: 4px; border-radius: 2px;
+  background: linear-gradient(to right, var(--accent) var(--p), rgba(255, 255, 255, .45) var(--p) var(--b), rgba(255, 255, 255, .2) var(--b)); }
+.vp-seek input { position: relative; width: 100%; margin: 0; background: transparent; border: 0; padding: 0; height: 24px; -webkit-appearance: none; appearance: none; cursor: pointer; }
+.vp-seek input::-webkit-slider-runnable-track { height: 4px; background: transparent; }
+.vp-seek input::-moz-range-track { height: 4px; background: transparent; }
+.vp-seek input::-webkit-slider-thumb { -webkit-appearance: none; width: 14px; height: 14px; margin-top: -5px; border-radius: 50%; background: var(--accent); border: 0; }
+.vp-seek input::-moz-range-thumb { width: 14px; height: 14px; border-radius: 50%; background: var(--accent); border: 0; }
+.vp-big { position: absolute; left: 50%; top: 50%; width: 68px; height: 68px; margin: -34px 0 0 -34px; border-radius: 50%; display: grid; place-items: center; background: rgba(0, 0, 0, .55); color: #fff; z-index: 2; padding-left: 4px; }
+.vp-spin { position: absolute; left: 50%; top: 50%; width: 46px; height: 46px; margin: -23px 0 0 -23px; border-radius: 50%; border: 4px solid rgba(255, 255, 255, .2); border-top-color: var(--accent); animation: vp-spin .8s linear infinite; z-index: 1; pointer-events: none; }
+@keyframes vp-spin { to { transform: rotate(360deg); } }
+.vp-err { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; padding: 24px; text-align: center; z-index: 1; }
+.vp-err p { margin: 0; max-width: 460px; line-height: 1.45; }
+.vp-note { position: absolute; left: 50%; top: 14px; transform: translateX(-50%); max-width: min(92%, 480px); padding: 9px 13px; border-radius: 8px; background: rgba(20, 20, 20, .92); font-size: 13px; line-height: 1.4; z-index: 3; cursor: pointer; }
+.vp-hint { position: absolute; left: 50%; bottom: 86px; transform: translateX(-50%); padding: 5px 11px; border-radius: 14px; background: rgba(0, 0, 0, .55); font-size: 12px; pointer-events: none; transition: opacity .25s; z-index: 1; white-space: nowrap; }
+.vp-menu { position: absolute; right: 8px; bottom: 60px; width: min(290px, calc(100% - 16px)); max-height: calc(100% - 76px); overflow-y: auto; padding: 6px; border-radius: 10px; background: rgba(24, 24, 24, .96); box-shadow: 0 8px 30px rgba(0, 0, 0, .5); z-index: 4; }
+.vp-menu-h { font-size: 11px; font-weight: 700; letter-spacing: .5px; text-transform: uppercase; color: rgba(255, 255, 255, .55); padding: 6px 10px 4px; }
+.vp-menu button { display: flex; align-items: center; gap: 8px; width: 100%; padding: 8px 10px; border-radius: 6px; text-align: left; font-size: 14px; color: #fff; }
+.vp-menu button:hover:not(:disabled) { background: rgba(255, 255, 255, .1); }
+.vp-menu button:disabled { opacity: .45; }
+.vp-menu button small { margin-left: auto; color: rgba(255, 255, 255, .6); font-size: 12px; white-space: nowrap; }
+.vp-menu .ck { width: 16px; flex: none; color: var(--accent); display: grid; place-items: center; }
+.vp-menu-f { border-top: 1px solid rgba(255, 255, 255, .12); margin-top: 6px; padding: 8px 10px 4px; font-size: 12px; color: rgba(255, 255, 255, .6); line-height: 1.4; }
+.vp-menu-f b { color: #fff; font-weight: 600; }
 .preview.audio { align-items: flex-start; }
 .audio-box { display: flex; flex-direction: column; align-items: center; gap: 10px; width: min(560px, 100%); margin-top: 8vh; }
 .audio-box .ficon { font-size: 48px; }

web/src/vr.ts

@@ -0,0 +1,241 @@
+// The 360° view: an equirectangular video drawn onto a canvas as the flat picture a person
+// would see looking out from the middle of it. Drag (or swipe) to look around, pinch or scroll
+// to zoom, and on a phone, optionally, turn the phone. One full-canvas triangle pair; the
+// fragment shader works out, for each pixel, which way it looks and where that is in the video.
+
+const VERT = `
+attribute vec2 a;
+varying vec2 p;
+void main() { p = a; gl_Position = vec4(a, 0.0, 1.0); }`
+
+const FRAG = `
+precision highp float;
+uniform sampler2D tex;
+uniform mat3 view;  // columns: right, up, forward
+uniform vec2 aspect; // the screen's sides over its taller side: (w/h, 1) or (1, h/w)
+uniform float fov;   // radians, across the taller side
+varying vec2 p;
+const float PI = 3.14159265358979;
+void main() {
+  vec2 q = p * aspect;
+  // Narrow: an ordinary lens. Wide: stereographic, which goes on past 180 degrees to the
+  // "little planet". Between 100 and 140 degrees one turns into the other.
+  vec3 rect = normalize(vec3(q * tan(min(fov, 3.0) * 0.5), 1.0));
+  float r = length(q) * 2.0 * tan(fov * 0.25);
+  float th = 2.0 * atan(r * 0.5);
+  vec2 dir = r > 0.0 ? q / length(q) : vec2(0.0);
+  vec3 stereo = vec3(dir * sin(th), cos(th));
+  float t = smoothstep(1.745, 2.443, fov);
+  vec3 d = normalize(view * normalize(mix(rect, stereo, t)));
+  float lon = atan(d.x, -d.z);
+  float lat = asin(clamp(d.y, -1.0, 1.0));
+  gl_FragColor = texture2D(tex, vec2(lon / (2.0 * PI) + 0.5, 0.5 - lat / PI));
+}`
+
+// From a close look at something far off to the whole sphere as a little planet.
+const MIN_FOV = 8, MAX_FOV = 300
+
+type Vec3 = [number, number, number]
+type Quat = [number, number, number, number] // x, y, z, w
+
+function qmul(a: Quat, b: Quat): Quat {
+  const [ax, ay, az, aw] = a, [bx, by, bz, bw] = b
+  return [aw * bx + ax * bw + ay * bz - az * by, aw * by - ax * bz + ay * bw + az * bx, aw * bz + ax * by - ay * bx + az * bw, aw * bw - ax * bx - ay * by - az * bz]
+}
+function qrot(q: Quat, v: Vec3): Vec3 {
+  const [x, y, z, w] = q
+  const ix = w * v[0] + y * v[2] - z * v[1], iy = w * v[1] + z * v[0] - x * v[2], iz = w * v[2] + x * v[1] - y * v[0], iw = -x * v[0] - y * v[1] - z * v[2]
+  return [ix * w + iw * -x + iy * -z - iz * -y, iy * w + iw * -y + iz * -x - ix * -z, iz * w + iw * -z + ix * -y - iy * -x]
+}
+const axis = (v: Vec3, rad: number): Quat => { const s = Math.sin(rad / 2); return [v[0] * s, v[1] * s, v[2] * s, Math.cos(rad / 2)] }
+
+// The phone's orientation as a camera's, the way the W3C spec defines the angles: Z-X'-Y''
+// intrinsic, then turned to look out of the back of the phone, then for the screen's rotation.
+function deviceQuat(alpha: number, beta: number, gamma: number, screen: number): Quat {
+  const d = Math.PI / 180
+  const [a, b, g] = [alpha * d, beta * d, gamma * d]
+  let q = qmul(qmul(axis([0, 1, 0], a), axis([1, 0, 0], b)), axis([0, 0, 1], -g)) // YXZ, in three.js's frame
+  q = qmul(q, [-Math.SQRT1_2, 0, 0, Math.SQRT1_2])
+  return qmul(q, axis([0, 0, 1], -screen * d))
+}
+
+export class Sphere {
+  yaw = 0 // degrees, + is right
+  pitch = 0 // degrees, + is up
+  fov = 80 // degrees, the taller of the two sides
+  private gl: WebGLRenderingContext
+  private tex: WebGLTexture
+  private uView: WebGLUniformLocation
+  private uAspect: WebGLUniformLocation
+  private uFov: WebGLUniformLocation
+  private raf = 0
+  private frameCb = 0
+  private dirty = true
+  private hasFrame = false
+  private gyro: { alpha: number; beta: number; gamma: number } | null = null
+  private gyroYaw = 0 // what dragging adds to the phone's own heading
+  private ro: ResizeObserver
+  maxTexture: number
+
+  constructor(private canvas: HTMLCanvasElement, private video: HTMLVideoElement) {
+    const gl = canvas.getContext('webgl', { antialias: false, alpha: false, preserveDrawingBuffer: false })
+    if (!gl) throw new Error('This browser can’t draw 360° video (no WebGL).')
+    this.gl = gl
+    this.maxTexture = gl.getParameter(gl.MAX_TEXTURE_SIZE) as number
+    const sh = (type: number, src: string) => {
+      const s = gl.createShader(type)!
+      gl.shaderSource(s, src); gl.compileShader(s)
+      if (!gl.getShaderParameter(s, gl.COMPILE_STATUS)) throw new Error(gl.getShaderInfoLog(s) ?? 'shader')
+      return s
+    }
+    const prog = gl.createProgram()!
+    gl.attachShader(prog, sh(gl.VERTEX_SHADER, VERT)); gl.attachShader(prog, sh(gl.FRAGMENT_SHADER, FRAG))
+    gl.linkProgram(prog); gl.useProgram(prog)
+    const buf = gl.createBuffer()
+    gl.bindBuffer(gl.ARRAY_BUFFER, buf)
+    gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([-1, -1, 1, -1, -1, 1, -1, 1, 1, -1, 1, 1]), gl.STATIC_DRAW)
+    const loc = gl.getAttribLocation(prog, 'a')
+    gl.enableVertexAttribArray(loc); gl.vertexAttribPointer(loc, 2, gl.FLOAT, false, 0, 0)
+    this.tex = gl.createTexture()!
+    gl.bindTexture(gl.TEXTURE_2D, this.tex)
+    // No mipmaps (a video changes every frame) and clamped: any size of picture will do.
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
+    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
+    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGB, 1, 1, 0, gl.RGB, gl.UNSIGNED_BYTE, new Uint8Array([0, 0, 0]))
+    this.uView = gl.getUniformLocation(prog, 'view')!
+    this.uAspect = gl.getUniformLocation(prog, 'aspect')!
+    this.uFov = gl.getUniformLocation(prog, 'fov')!
+    this.ro = new ResizeObserver(() => { this.dirty = true })
+    this.ro.observe(canvas)
+    this.watchFrames()
+    const loop = () => { this.draw(); this.raf = requestAnimationFrame(loop) }
+    this.raf = requestAnimationFrame(loop)
+  }
+
+  // A new picture from the video: on the frame callback where there is one, else every draw
+  // while it plays.
+  private watchFrames() {
+    const v = this.video as HTMLVideoElement & { requestVideoFrameCallback?: (cb: () => void) => number }
+    if (v.requestVideoFrameCallback) {
+      const cb = () => { this.upload(); this.frameCb = v.requestVideoFrameCallback!(cb) }
+      this.frameCb = v.requestVideoFrameCallback(cb)
+    }
+    v.addEventListener('loadeddata', this.upload)
+    v.addEventListener('seeked', this.upload)
+  }
+
+  private upload = () => {
+    const v = this.video
+    if (v.readyState < 2 || !v.videoWidth) return
+    const gl = this.gl
+    gl.bindTexture(gl.TEXTURE_2D, this.tex)
+    try {
+      gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGB, gl.RGB, gl.UNSIGNED_BYTE, v)
+      this.hasFrame = true
+      this.dirty = true
+    } catch { /* not ready yet */ }
+  }
+
+  private draw() {
+    const v = this.video as HTMLVideoElement & { requestVideoFrameCallback?: unknown }
+    if (!v.requestVideoFrameCallback && !v.paused) this.upload()
+    if (!this.dirty && !this.gyro) return
+    this.dirty = false
+    const c = this.canvas, dpr = Math.min(window.devicePixelRatio || 1, 2)
+    const w = Math.round(c.clientWidth * dpr), h = Math.round(c.clientHeight * dpr)
+    if (!w || !h) return
+    if (c.width !== w || c.height !== h) { c.width = w; c.height = h }
+    const gl = this.gl
+    gl.viewport(0, 0, w, h)
+    if (!this.hasFrame) { gl.clearColor(0, 0, 0, 1); gl.clear(gl.COLOR_BUFFER_BIT); return }
+    // The field of view applies to the taller side; on a phone held upright that is the height.
+    let right: Vec3, up: Vec3, fwd: Vec3
+    if (this.gyro) {
+      const q = qmul(axis([0, 1, 0], (-this.gyroYaw * Math.PI) / 180), deviceQuat(this.gyro.alpha, this.gyro.beta, this.gyro.gamma, screenAngle()))
+      right = qrot(q, [1, 0, 0]); up = qrot(q, [0, 1, 0]); fwd = qrot(q, [0, 0, -1])
+    } else {
+      const y = (this.yaw * Math.PI) / 180, p = (this.pitch * Math.PI) / 180
+      fwd = [Math.sin(y) * Math.cos(p), Math.sin(p), -Math.cos(y) * Math.cos(p)]
+      right = [Math.cos(y), 0, Math.sin(y)]
+      up = [right[1] * fwd[2] - right[2] * fwd[1], right[2] * fwd[0] - right[0] * fwd[2], right[0] * fwd[1] - right[1] * fwd[0]]
+    }
+    // d = right·x + up·y + fwd·1, column-major
+    gl.uniformMatrix3fv(this.uView, false, new Float32Array([...right, ...up, ...fwd]))
+    gl.uniform2f(this.uAspect, w >= h ? 1 : w / h, w >= h ? h / w : 1)
+    gl.uniform1f(this.uFov, (this.fov * Math.PI) / 180)
+    gl.drawArrays(gl.TRIANGLES, 0, 6)
+  }
+
+  // Dragging by a pixel turns the view by the angle a pixel covers, so what is under the finger
+  // stays under it.
+  drag(dx: number, dy: number) {
+    const per = this.fov / Math.max(this.canvas.clientWidth, this.canvas.clientHeight)
+    if (this.gyro) this.gyroYaw = (this.gyroYaw - dx * per) % 360
+    else {
+      this.yaw = (this.yaw - dx * per) % 360
+      this.pitch = Math.max(-89, Math.min(89, this.pitch + dy * per))
+    }
+    this.dirty = true
+  }
+
+  zoom(factor: number) {
+    this.fov = Math.max(MIN_FOV, Math.min(MAX_FOV, this.fov * factor))
+    this.dirty = true
+  }
+
+  get gyroOn() { return this.gyro !== null }
+
+  private onOrient = (e: DeviceOrientationEvent) => {
+    if (e.alpha === null || e.beta === null || e.gamma === null) return
+    if (!this.gyro) {
+      // Keep looking where the drag left off: the phone's heading now is the drag's yaw.
+      const q = deviceQuat(e.alpha, e.beta, e.gamma, screenAngle())
+      const f = qrot(q, [0, 0, -1])
+      this.gyroYaw = this.yaw - (Math.atan2(f[0], -f[2]) * 180) / Math.PI
+    }
+    this.gyro = { alpha: e.alpha, beta: e.beta, gamma: e.gamma }
+  }
+
+  // Turning on motion asks for permission on an iPhone, which must happen in a tap.
+  async setGyro(on: boolean): Promise<boolean> {
+    if (!on) {
+      window.removeEventListener('deviceorientation', this.onOrient)
+      if (this.gyro) {
+        const q = qmul(axis([0, 1, 0], (-this.gyroYaw * Math.PI) / 180), deviceQuat(this.gyro.alpha, this.gyro.beta, this.gyro.gamma, screenAngle()))
+        const f = qrot(q, [0, 0, -1])
+        this.yaw = (Math.atan2(f[0], -f[2]) * 180) / Math.PI
+        this.pitch = (Math.asin(Math.max(-1, Math.min(1, f[1]))) * 180) / Math.PI
+      }
+      this.gyro = null
+      this.dirty = true
+      return false
+    }
+    const D = DeviceOrientationEvent as unknown as { requestPermission?: () => Promise<string> }
+    if (D.requestPermission) {
+      try { if ((await D.requestPermission()) !== 'granted') return false } catch { return false }
+    }
+    window.addEventListener('deviceorientation', this.onOrient)
+    return true
+  }
+
+  destroy() {
+    cancelAnimationFrame(this.raf)
+    const v = this.video as HTMLVideoElement & { cancelVideoFrameCallback?: (n: number) => void }
+    if (this.frameCb && v.cancelVideoFrameCallback) v.cancelVideoFrameCallback(this.frameCb)
+    v.removeEventListener('loadeddata', this.upload)
+    v.removeEventListener('seeked', this.upload)
+    window.removeEventListener('deviceorientation', this.onOrient)
+    this.ro.disconnect()
+    this.gl.getExtension('WEBGL_lose_context')?.loseContext()
+  }
+}
+
+function screenAngle(): number {
+  const o = screen.orientation?.angle
+  if (typeof o === 'number') return o
+  return (window as unknown as { orientation?: number }).orientation ?? 0
+}
+
+export const canMotion = () => typeof DeviceOrientationEvent !== 'undefined' && matchMedia('(pointer: coarse)').matches