renames and restructure

- session -> matrixrtc (folder) - move MatrixRtcClient to top level of sdk - RtcTransport -> Transport - backend -> media-backend
2026-10-16 23:45:50 +00:00 · 2026-10-08 13:53:57 +02:00
parent d0a2ff12f1
commit 5b13e1da81
51 changed files with 96 additions and 85 deletions
@@ -0,0 +1,290 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import {
+  observeParticipantEvents,
+  observeParticipantMedia,
+  roomEventSelector,
+} from "@livekit/components-core";
+import {
+  facingModeFromLocalTrack,
+  type LocalParticipant,
+  LocalTrack,
+  LocalVideoTrack,
+  type Participant,
+  ParticipantEvent,
+  RemoteAudioTrack,
+  RemoteTrack,
+  type Room as LivekitRoom,
+  RoomEvent,
+  Track,
+  TrackEvent,
+  type TrackPublication,
+} from "livekit-client";
+import {
+  combineLatest,
+  distinctUntilChanged,
+  fromEvent,
+  interval,
+  map,
+  merge,
+  of,
+  share,
+  startWith,
+  switchMap,
+} from "rxjs";
+
+import { type Behavior } from "../../reactive/Behavior";
+import { type ObservableScope } from "../../reactive/ObservableScope";
+import {
+  type AudioMediaTrack,
+  type LocalAudioMediaTrack,
+  type LocalVideoMediaTrack,
+  type MediaSource,
+  type MediaStreamStats,
+  type MediaTrack,
+  type VideoMediaTrack,
+} from "../../api";
+import { MatrixRTCError } from "../../errors";
+import { LazyBehavior } from "../../utils/LazyBehavior";
+
+export const mediaSources: Record<Track.Source, MediaSource> = {
+  [Track.Source.Microphone]: "microphone",
+  [Track.Source.Camera]: "camera",
+  [Track.Source.ScreenShare]: "screenShare",
+  [Track.Source.ScreenShareAudio]: "screenShareAudio",
+  [Track.Source.Unknown]: "unknown",
+};
+
+export const livekitSources: Record<MediaSource, Track.Source> = {
+  microphone: Track.Source.Microphone,
+  camera: Track.Source.Camera,
+  screenShare: Track.Source.ScreenShare,
+  screenShareAudio: Track.Source.ScreenShareAudio,
+  unknown: Track.Source.Unknown,
+};
+
+// One timer for every track so that a large session does not keep hundreds of
+// them, each firing a statistics request, in the event loop.
+const refreshStats$ = interval(1000).pipe(startWith(0), share());
+
+/**
+ * One publication of a participant as a `MediaTrack`. The publication is
+ * fixed; the track behind it may come and go (a remote track arrives on
+ * subscription), and every attached element follows it.
+ */
+export function createLivekitMediaTrack(
+  scope: ObservableScope,
+  participant: Participant,
+  publication: TrackPublication,
+  room: LivekitRoom,
+): AudioMediaTrack | VideoMediaTrack {
+  const mediaChanged$ = observeParticipantMedia(participant);
+  const track$ = publicationTrack$(scope, participant, publication);
+
+  const attached = new Set<HTMLMediaElement>();
+  let audioContext: AudioContext | undefined;
+  let audioPlugins: AudioNode[] = [];
+  let volume: number | undefined;
+  const applyAudioSettings = (track: Track | undefined): void => {
+    if (!(track instanceof RemoteAudioTrack)) return;
+    track.setAudioContext(audioContext);
+    track.setWebAudioPlugins(audioPlugins);
+    if (volume !== undefined) track.setVolume(volume);
+  };
+
+  let current = track$.value;
+  track$.pipe(scope.bind()).subscribe((track) => {
+    for (const element of attached) current?.detach(element);
+    current = track;
+    applyAudioSettings(track);
+    for (const element of attached) track?.attach(element);
+  });
+  scope.onEnd(() => {
+    for (const element of attached) current?.detach(element);
+    attached.clear();
+  });
+
+  const muted$ = scope.behavior(
+    mediaChanged$.pipe(map(() => publication.isMuted)),
+    publication.isMuted,
+  );
+  const base: MediaTrack = {
+    source: mediaSources[publication.source],
+    kind: publication.kind === Track.Kind.Audio ? "audio" : "video",
+    id: publication.trackSid,
+    muted$,
+    encrypted$: scope.behavior(
+      merge(
+        mediaChanged$,
+        roomEventSelector(room, RoomEvent.ParticipantEncryptionStatusChanged),
+      ).pipe(map(() => publication.isEncrypted)),
+      publication.isEncrypted,
+    ),
+    stats$: new LazyBehavior<MediaStreamStats>(
+      refreshStats$.pipe(
+        switchMap(async () => rtpStreamStats(publication, participant.isLocal)),
+        scope.bind(),
+      ),
+      undefined,
+    ),
+    attach: (element) => {
+      if (attached.has(element)) return;
+      attached.add(element);
+      current?.attach(element);
+    },
+    detach: (element) => {
+      if (!attached.delete(element)) return;
+      current?.detach(element);
+    },
+  };
+
+  if (base.kind === "audio")
+    return {
+      ...base,
+      kind: "audio",
+      // LiveKit detects speakers per participant, so this is the member's
+      // activity, narrowed to the tracks that can be carrying it
+      isActive$: scope.behavior(
+        combineLatest(
+          [
+            observeParticipantEvents(
+              participant,
+              ParticipantEvent.IsSpeakingChanged,
+            ).pipe(map((p) => p.isSpeaking)),
+            muted$,
+          ],
+          (speaking, muted) => speaking && !muted,
+        ),
+        participant.isSpeaking && !publication.isMuted,
+      ),
+      setAudioContext: (ctx, plugins = []) => {
+        audioContext = ctx;
+        audioPlugins = plugins;
+        applyAudioSettings(current);
+      },
+      setVolume: (v) => {
+        // Our own audio is never played back, so there is nothing to scale
+        volume = v;
+        applyAudioSettings(current);
+      },
+    };
+
+  return { ...base, kind: "video" };
+}
+
+/**
+ * One of our own publications, with the controls over it. `setEnabled` goes
+ * through the local member so that what it remembers for a reconnection
+ * stays in step.
+ */
+export function createLocalLivekitMediaTrack(
+  scope: ObservableScope,
+  participant: LocalParticipant,
+  publication: TrackPublication,
+  room: LivekitRoom,
+  setEnabled: (source: MediaSource, enabled: boolean) => Promise<boolean>,
+): LocalAudioMediaTrack | LocalVideoMediaTrack {
+  const base = createLivekitMediaTrack(scope, participant, publication, room);
+  const local = {
+    setEnabled: async (enabled: boolean) => setEnabled(base.source, enabled),
+    setDevice: async (deviceId: string): Promise<void> => {
+      if (base.source !== "microphone" && base.source !== "camera")
+        throw new MatrixRTCError(`A ${base.source} track has no device`);
+      await room.switchActiveDevice(
+        base.kind === "audio" ? "audioinput" : "videoinput",
+        deviceId,
+      );
+    },
+  };
+  if (base.kind === "audio") return { ...base, ...local };
+
+  const videoTrack = (): LocalVideoTrack | undefined =>
+    publication.track instanceof LocalVideoTrack
+      ? publication.track
+      : undefined;
+  return {
+    ...base,
+    ...local,
+    facingMode$: facingMode$(
+      scope,
+      publicationTrack$(scope, participant, publication),
+    ),
+    switchFacingMode: async () => {
+      const track = videoTrack();
+      if (!track) return;
+      const { facingMode } = facingModeFromLocalTrack(track);
+      if (facingMode !== "user" && facingMode !== "environment") return;
+      await track.restartTrack({
+        facingMode: facingMode === "user" ? "environment" : "user",
+      });
+      return track.mediaStreamTrack.getSettings().deviceId;
+    },
+    setProcessor: async (processor) => {
+      const track = videoTrack();
+      // A processor cannot be built on a track that has already ended
+      if (!track || track.mediaStreamTrack.readyState === "ended") return;
+      if (processor) await track.setProcessor(processor);
+      else if (track.getProcessor()) await track.stopProcessor();
+    },
+  };
+}
+
+/** The track behind a publication; a remote one arrives on subscription. */
+function publicationTrack$(
+  scope: ObservableScope,
+  participant: Participant,
+  publication: TrackPublication,
+): Behavior<Track | undefined> {
+  return scope.behavior(
+    merge(
+      observeParticipantMedia(participant),
+      fromEvent(publication, TrackEvent.Subscribed),
+      fromEvent(publication, TrackEvent.Unsubscribed),
+    ).pipe(
+      map(() => publication.track),
+      startWith(publication.track),
+      distinctUntilChanged(),
+    ),
+  );
+}
+
+async function rtpStreamStats(
+  publication: TrackPublication,
+  local: boolean,
+): Promise<MediaStreamStats> {
+  const track = publication.track;
+  if (!(track instanceof RemoteTrack || track instanceof LocalTrack))
+    return undefined;
+  const report = await track.getRTCStatsReport();
+  if (!report) return undefined;
+  const type = local ? "outbound-rtp" : "inbound-rtp";
+  for (const stats of report.values()) if (stats.type === type) return stats;
+  return undefined;
+}
+
+function facingMode$(
+  scope: ObservableScope,
+  track$: Behavior<Track | undefined>,
+): Behavior<"user" | "environment" | undefined> {
+  return scope.behavior(
+    track$.pipe(
+      switchMap((track) => {
+        if (!(track instanceof LocalVideoTrack)) return of(undefined);
+        return fromEvent(track, TrackEvent.Restarted).pipe(
+          startWith(null),
+          map(() => {
+            const { facingMode } = facingModeFromLocalTrack(track);
+            return facingMode === "user" || facingMode === "environment"
+              ? facingMode
+              : undefined;
+          }),
+        );
+      }),
+    ),
+  );
+}