1 files changed, 208 insertions, 0 deletions
diff --git a/ui/client-scripts/src/player/track/mse.ts b/ui/client-scripts/src/player/track/mse.ts
new file mode 100644
index 0000000..efcd0d5
--- /dev/null
+++ b/ui/client-scripts/src/player/track/mse.ts
@@ -0,0 +1,208 @@
+/*
+    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2026 metamuffin <metamuffin.org>
+*/
+import { OVar, show } from "../../jshelper/mod.ts";
+import { test_media_capability, track_to_content_type } from "../mediacaps.ts";
+import { BufferRange, Player } from "../player.ts";
+import { PlayerTrack, AppendRange, TARGET_BUFFER_DURATION, MIN_BUFFER_DURATION } from "./mod.ts";
+import { e } from "../../jshelper/src/element.ts";
+import { FormatInfo, FragmentIndex, StreamContainer, TrackInfo } from "../types_stream.ts";
+import { show_format } from "../mod.ts";
+
+interface UsableFormat { format_index: number, usable_index: number, format: FormatInfo, container: StreamContainer }
+
+export class MSEPlayerTrack extends PlayerTrack {
+  public source_buffer!: SourceBuffer;
+  private current_load?: AppendRange;
+  private loading = new Set<number>();
+  private append_queue: AppendRange[] = [];
+  public index?: FragmentIndex
+  public active_format = new OVar<UsableFormat | undefined>(undefined);
+  public usable_formats: UsableFormat[] = []
+
+  constructor(
+    private player: Player,
+    private base_url: string,
+    track_index: number,
+    public trackinfo: TrackInfo,
+  ) {
+    super(track_index);
+    this.init()
+  }
+
+  async init() {
+    this.buffered.value = [{ start: 0, end: this.player.duration.value, status: "loading" }]
+    try {
+      const res = await fetch(`${this.base_url}?fragmentindex&t=${this.track_index}`, { headers: { "Accept": "application/json" } });
+      if (!res.ok) return this.player.error.value = "Cannot download index.", undefined;
+      let index!: FragmentIndex & { error: string; };
+      try { index = await res.json(); }
+      catch (_) { this.player.set_pers("Error: Failed to fetch node"); }
+      if (index.error) return this.player.set_pers("server error: " + index.error), undefined;
+      this.index = index
+    } catch (e) {
+      if (e instanceof TypeError) {
+        this.player.set_pers("Cannot download index: Network Error");
+      } else throw e;
+    }
+    this.buffered.value = []
+
+    console.log(this.trackinfo);
+
+    for (let i = 0; i < this.trackinfo.formats.length; i++) {
+      const format = this.trackinfo.formats[i];
+      for (const container of format.containers) {
+        if (container != "webm" && container != "mpeg4") continue;
+        if (await test_media_capability(format, container))
+          this.usable_formats.push({ container, format, format_index: i, usable_index: this.usable_formats.length })
+      }
+    }
+
+    // TODO prefer newer codecs
+    const sort_key = (f: FormatInfo) => f.remux ? Infinity : f.bitrate
+    this.usable_formats.sort((a, b) => sort_key(b.format) - sort_key(a.format))
+    if (!this.usable_formats.length)
+      return this.player.logger?.log("No availble format is supported by this device. The track can't be played back.")
+    this.active_format.value = this.usable_formats[0]
+
+    const ct = track_to_content_type(this.active_format.value!.format, this.active_format.value!.container);
+    this.source_buffer = this.player.media_source.addSourceBuffer(ct);
+    this.abort.signal.addEventListener("abort", () => {
+      console.log(`destroy source buffer for track ${this.track_index}`);
+      this.player.media_source.removeSourceBuffer(this.source_buffer);
+    });
+    this.source_buffer.mode = "segments";
+    this.source_buffer.addEventListener("updateend", () => {
+      if (this.abort.signal.aborted) return;
+      if (this.current_load) {
+        this.loading.delete(this.current_load.index);
+        const cb = this.current_load.cb;
+        this.current_load = undefined;
+        cb()
+      } else {
+        console.warn("updateend but nothing is loading")
+      }
+      this.update_buf_ranges();
+      this.tick_append();
+    });
+    this.source_buffer.addEventListener("error", e => {
+      console.error("sourcebuffer error", e);
+    });
+    this.source_buffer.addEventListener("abort", e => {
+      console.error("sourcebuffer abort", e);
+    });
+
+    this.update(this.player.video.currentTime)
+  }
+
+  choose_format() {
+    if (!this.active_format.value) return
+    const ai = this.active_format.value.usable_index
+    const current_br = this.active_format.value.format.bitrate
+    const avail_br = this.player.downloader.bandwidth_avail.value * 8
+    const prev_format = this.active_format.value
+    if (ai < this.usable_formats.length - 1 && current_br > avail_br) {
+      this.active_format.value = this.usable_formats[ai + 1]
+    }
+    if (ai > 0 && avail_br > this.usable_formats[ai - 1].format.bitrate * 1.2) {
+      this.active_format.value = this.usable_formats[ai - 1]
+    }
+    if (prev_format != this.active_format.value) {
+      console.log(`abr ${show.metric(prev_format.format.bitrate)} -> ${show.metric(this.active_format.value.format.bitrate)}`);
+      this.choose_format()
+    }
+  }
+
+  update_buf_ranges() {
+    if (!this.index) return;
+    const ranges: BufferRange[] = [];
+    for (let i = 0; i < this.source_buffer.buffered.length; i++) {
+      ranges.push({
+        start: this.source_buffer.buffered.start(i),
+        end: this.source_buffer.buffered.end(i),
+        status: "buffered"
+      });
+    }
+    for (const r of this.loading) {
+      ranges.push({ ...this.index[r], status: "loading" });
+    }
+    this.buffered.value = ranges;
+  }
+
+  override async update(target: number) {
+    if (!this.index) return;
+    this.update_buf_ranges(); // TODO required?
+
+    const buffer_to = target + (target < 20 ? Math.max(1, target) : TARGET_BUFFER_DURATION)
+
+    const blocking = [];
+    for (let i = 0; i < this.index.length; i++) {
+      const frag = this.index[i];
+      if (frag.end < target) continue;
+      if (frag.start >= buffer_to) break;
+      if (!this.check_buf_collision(frag.start, frag.end)) continue;
+      if (frag.start <= target + MIN_BUFFER_DURATION)
+        blocking.push(this.load(i));
+      else
+        this.load(i);
+    }
+    await Promise.all(blocking);
+  }
+  check_buf_collision(start: number, end: number) {
+    const EPSILON = 0.01;
+    for (const r of this.buffered.value)
+      if (r.end - EPSILON > start && r.start < end - EPSILON)
+        return false;
+    return true;
+  }
+
+  async load(index: number) {
+    this.choose_format()
+    this.loading.add(index);
+    this.update_buf_ranges()
+    // TODO update format selection
+    const url = `${this.base_url}?fragment&t=${this.track_index}&f=${this.active_format.value!.format_index}&i=${index}&c=${this.active_format.value!.container}`;
+    const buf = await this.player.downloader.download(url);
+    await new Promise<void>(cb => {
+      if (!this.index) return;
+      if (this.abort.signal.aborted) return;
+      this.append_queue.push({ buf, ...this.index[index], index, cb });
+      this.tick_append();
+    });
+  }
+  tick_append() {
+    if (this.source_buffer.updating || this.current_load) return;
+    if (this.append_queue.length) {
+      const frag = this.append_queue[0];
+      this.append_queue.splice(0, 1);
+      this.current_load = frag;
+      // TODO why is appending so unreliable?! sometimes it does not add it
+      this.source_buffer.changeType(track_to_content_type(this.active_format.value!.format, this.active_format.value!.container));
+      this.source_buffer.timestampOffset = this.active_format.value?.container == "mpeg4" ? frag.start : 0
+      // this.source_buffer.timestampOffset = this.trackinfo.kind == "video" && !this.active_format.value!.format.remux ? frag.start : 0
+      // this.source_buffer.timestampOffset = this.active_format.value?.format.remux ? 0 : frag.start
+      // this.source_buffer.timestampOffset = 0
+      this.source_buffer.appendBuffer(frag.buf);
+    }
+  }
+
+  public debug(): OVar<HTMLElement> {
+    const rtype = (t: string, b: BufferRange[]) => {
+      const c = b.filter(r => r.status == t);
+      // ${c.length} range${c.length != 1 ? "s" : ""}
+      return `${c.reduce((a, v) => a + v.end - v.start, 0).toFixed(2)}s`
+    }
+    return this.active_format.liftA2(this.buffered, (p, b) =>
+      e("pre",
+        p ?
+          `mse track ${this.track_index}: format ${p.format_index} (${p.format.remux ? "remux" : "transcode"})`
+          + `\n\tformat: ${show_format(p.format)}`
+          + `\n\tbuffer type: ${track_to_content_type(p.format, p.container)}`
+          + `\n\tbuffered: ${rtype("buffered", b)} / queued: ${rtype("queued", b)} / loading: ${rtype("loading", b)}`
+          : ""
+      ) as HTMLElement
+    )
+  }
+}