fix: do not wait for audio appends for muxed segments (#894)

Co-authored-by: Garrett Singer <gesinger@gmail.com>

src/media-segment-request.js

@@ -295,7 +295,7 @@ const transmuxAndNotify = ({
       });
       trackInfoFn = null;
 
-      if (probeResult.hasAudio) {
+      if (probeResult.hasAudio && !isMuxed) {
         audioStartFn(probeResult.audioStart);
       }
       if (probeResult.hasVideo) {
@@ -411,7 +411,6 @@ const handleSegmentBytes = ({
 
     if (tracks.video && tracks.audio) {
       trackInfo.isMuxed = true;
-      trackInfo.hasAudio = false;
     }
 
     // since we don't support appending fmp4 data on progress, we know we have the full
@@ -425,7 +424,7 @@ const handleSegmentBytes = ({
     // decoding).
     const timingInfo = mp4probe.startTime(segment.map.timescales, bytesAsUint8Array);
 
-    if (trackInfo.hasAudio) {
+    if (trackInfo.hasAudio && !trackInfo.isMuxed) {
       timingInfoFn(segment, 'audio', 'start', timingInfo);
     }
 
@@ -438,7 +437,7 @@ const handleSegmentBytes = ({
       // for it to be audio only. See `tracks.video && tracks.audio` if statement
       // above.
       // we make sure to use segment.bytes here as that
-      dataFn(segment, {data: bytes, type: trackInfo.hasAudio ? 'audio' : 'video'});
+      dataFn(segment, {data: bytes, type: trackInfo.hasAudio && !trackInfo.isMuxed ? 'audio' : 'video'});
       if (captions && captions.length) {
         captionsFn(segment, captions);
       }

src/segment-loader.js

@@ -637,9 +637,9 @@ export default class SegmentLoader extends videojs.EventTarget {
     }
 
     if (this.loaderType_ === 'main') {
-      const { hasAudio, hasVideo } = this.startingMedia_;
+      const { hasAudio, hasVideo, isMuxed } = this.startingMedia_;
 
-      if (hasVideo && hasAudio && !this.audioDisabled_) {
+      if (hasVideo && hasAudio && !this.audioDisabled_ && !isMuxed) {
         return this.sourceUpdater_.buffered();
       }
 
@@ -1684,11 +1684,14 @@ export default class SegmentLoader extends videojs.EventTarget {
     }
 
     if (!this.handlePartialData_) {
-      if (this.startingMedia_.hasVideo && !segmentInfo.videoTimingInfo) {
+      const {hasAudio, hasVideo, isMuxed} = this.startingMedia_;
+
+      if (hasVideo && !segmentInfo.videoTimingInfo) {
         return false;
       }
 
-      if (this.startingMedia_.hasAudio && !segmentInfo.audioTimingInfo) {
+      // muxed content only relies on video timing information for now.
+      if (hasAudio && !this.audioDisabled_ && !isMuxed && !segmentInfo.audioTimingInfo) {
         return false;
       }
     }
@@ -2336,8 +2339,10 @@ export default class SegmentLoader extends videojs.EventTarget {
     // Although transmuxing is done, appends may not yet be finished. Throw a marker
     // on each queue this loader is responsible for to ensure that the appends are
     // complete.
-    const waitForVideo = this.loaderType_ === 'main' && this.startingMedia_.hasVideo;
-    const waitForAudio = !this.audioDisabled_ && this.startingMedia_.hasAudio;
+    const {hasAudio, hasVideo, isMuxed} = this.startingMedia_;
+    const waitForVideo = this.loaderType_ === 'main' && hasVideo;
+    // TODO: does this break partial support for muxed content?
+    const waitForAudio = !this.audioDisabled_ && hasAudio && !isMuxed;
 
     segmentInfo.waitingOnAppends = 0;
 

test/master-playlist-controller.test.js

@@ -2930,7 +2930,7 @@ QUnit.test('parses codec from muxed fmp4 init segment', function(assert) {
       'parsed video codec'
     );
     assert.deepEqual(loader.startingMedia_, {
-      hasAudio: false,
+      hasAudio: true,
       hasVideo: true,
       videoCodec: 'avc1.42c00d',
       audioCodec: 'mp4a.40.2',