Allow application to reset an audio/video track when fallbacking from all the others' one

src/main_thread/tracks_store/tracks_store.ts

@@ -491,7 +491,10 @@ export default class TracksStore extends EventEmitter<ITracksStoreEvents> {
     periodObj[bufferType].dispatcher = dispatcher;
 
     dispatcher.addEventListener("noPlayableRepresentation", () => {
-      this.onNoPlayableRepresentation(period, bufferType);
+      const events = this.onNoPlayableRepresentation(period, bufferType);
+      for (const event of events) {
+        this.trigger("noPlayableTrack", event);
+      }
     });
     dispatcher.addEventListener("noPlayableLockedRepresentation", () => {
       // TODO check that it doesn't already lead to segment loading or MediaSource
@@ -651,23 +654,27 @@ export default class TracksStore extends EventEmitter<ITracksStoreEvents> {
     }
 
     // Check that we're not both disabling audio and video here
-    if (storedSettings === null) {
-      const periodItem = getPeriodItem(this._storedPeriodInfo, period.id);
-      if (periodItem !== undefined) {
-        const hasNoTrackAtAll = ["audio" as const, "video" as const].every(
-          (ttype) => periodItem[ttype].storedSettings === null,
-        );
-        if (hasNoTrackAtAll) {
-          const err = new MediaError(
-            "NO_AUDIO_VIDEO_TRACKS",
-            "No audio and no video tracks are set.",
+    // Use a setTimeout(..., 0) to let a time window for an audio/video track switch when
+    // receiving a "noPlayableTrack" event
+    setTimeout(() => {
+      if (storedSettings === null) {
+        const periodItem = getPeriodItem(this._storedPeriodInfo, period.id);
+        if (periodItem !== undefined) {
+          const hasNoTrackAtAll = ["audio" as const, "video" as const].every(
+            (ttype) => periodItem[ttype].storedSettings === null,
           );
-          this.trigger("error", err);
-          this.dispose();
-          return [];
+          if (hasNoTrackAtAll) {
+            const err = new MediaError(
+              "NO_AUDIO_VIDEO_TRACKS",
+              "No audio and no video tracks are set.",
+            );
+            this.trigger("error", err);
+            this.dispose();
+            return [];
+          }
         }
       }
-    }
+    }, 0);
 
     typeInfo.dispatcher?.updateTrack(storedSettings);
     return noPlayableTrackToTrigger;

tests/integration/scenarios/drm_base.js

@@ -25,7 +25,11 @@ describe("DRM: Basic use cases", function () {
       ...opts,
     });
     if (isNullOrUndefined(error)) {
-      await waitForPlayerState(player, "LOADED", ["LOADING"]);
+      try {
+        await waitForPlayerState(player, "LOADED", ["LOADING"]);
+      } catch (err) {
+        throw player.getError() ?? err;
+      }
       expect(player.getError()).toBeNull();
     } else {
       await waitForPlayerState(player, "STOPPED", ["LOADING"]);
@@ -688,4 +692,50 @@ describe("DRM: Basic use cases", function () {
     expect(player.getAudioRepresentation().id).toEqual("15-585f233f");
     expect(player.getError()).toBeNull();
   });
+
+  it("should let a time window for an audio track reset if no license for video can be fetched while audio is disabled", async function () {
+    lockLowestBitrates(player);
+    const noPlayableTracksReceived = [];
+    player.addEventListener("newAvailablePeriods", (periods) => {
+      expect(player.getVideoTrack(periods[0].id)).not.toBeNull();
+      player.disableAudioTrack(periods[0].id);
+    });
+    player.addEventListener("noPlayableTrack", (npt) => {
+      noPlayableTracksReceived.push(npt);
+      const period = player.getAvailablePeriods()[0];
+      player.setAudioTrack({
+        periodId: period.id,
+        trackId: player.getAvailableAudioTracks(period.id)[0].id,
+      });
+    });
+    // RxPlayer.LogLevel = "DEBUG";
+    await loadEncryptedContent({
+      onVideoTracksNotPlayable: "continue",
+      keySystems: [
+        {
+          type: "com.microsoft.playready",
+          onKeyOutputRestricted: "fallback",
+          getLicense: generateGetLicenseForFakeLicense({
+            failingKeyIds: {
+              "90953e096cb249a3a2607a5fefead499": {
+                fallbackOnLastTry: true,
+              },
+              "80399bf58a2140148053e27e748e98c0": {
+                fallbackOnLastTry: true,
+              },
+              "80399bf58a2140148053e27e748e98c1": {
+                fallbackOnLastTry: true,
+              },
+            },
+          }),
+        },
+      ],
+    });
+    expect(player.getAvailableVideoTracks()).toEqual([]);
+    expect(noPlayableTracksReceived.length).toEqual(1);
+    expect(noPlayableTracksReceived[0].trackType).toEqual("video");
+    expect(noPlayableTracksReceived[0].period.id).toEqual(
+      player.getAvailablePeriods()[0].id,
+    );
+  });
 });

vitest.config.mjs

@@ -97,10 +97,7 @@ export default defineConfig({
     reporters: "dot",
     include: [
       // integration tests
-      "tests/integration/scenarios/**/*.[jt]s?(x)",
-      "tests/integration/**/*.test.[jt]s?(x)",
-      // memory tests
-      "tests/memory/**/*.[jt]s?(x)",
+      "tests/integration/scenarios/**/drm_base.[jt]s?(x)",
     ],
     globalSetup: "tests/globalSetup.mjs",
     browser: getBrowserConfig(process.env.BROWSER_CONFIG ?? "chrome"),