Properly calculate the amount of sourcebuffers needed for streams wit…

…h multiple non-alternate audio renditions (video-dev#1638)

* set altAudio only if videoCodecFound is true
* check if video is expected in onManifestParsed

src/controller/buffer-controller.js

@@ -83,7 +83,7 @@ class BufferController extends EventHandler {
 
   onManifestParsed (data) {
     let audioExpected = data.audio,
-      videoExpected = data.video || (data.levels.length && data.audio),
+      videoExpected = data.video || (data.levels.length && data.altAudio),
       sourceBufferNb = 0;
     // in case of alt audio 2 BUFFER_CODECS events will be triggered, one per stream controller
     // sourcebuffers will be created all at once when the expected nb of tracks will be reached

src/controller/cap-level-controller.js

@@ -35,7 +35,8 @@ class CapLevelController extends EventHandler {
   onManifestParsed (data) {
     const hls = this.hls;
     this.restrictedLevels = [];
-    if (hls.config.capLevelToPlayerSize) {
+    // Only fire getMaxLevel or detectPlayerSize if video is expected in the manifest
+    if (hls.config.capLevelToPlayerSize && (data.video || (data.levels.length && data.altAudio))) {
       this.autoLevelCapping = Number.POSITIVE_INFINITY;
       this.levels = data.levels;
       hls.firstLevel = this.getMaxLevel(data.firstLevel);

src/controller/level-controller.js

@@ -127,7 +127,7 @@ export default class LevelController extends EventHandler {
         stats: data.stats,
         audio: audioCodecFound,
         video: videoCodecFound,
-        altAudio: audioTracks.length > 0
+        altAudio: audioTracks.length > 0 && videoCodecFound
       });
     } else {
       this.hls.trigger(Event.ERROR, {

tests/test-streams.js

@@ -142,5 +142,11 @@ module.exports = {
     widevineLicenseUrl: 'https://cwip-shaka-proxy.appspot.com/no_auth',
     emeEnabled: true
   }
-  )
+  ),
+  audioOnlyMultipleLevels: {
+    'url': 'https://s3.amazonaws.com/bob.jwplayer.com/~alex/121628/new_master.m3u8',
+    'description': 'Multiple non-alternate audio levels',
+    'live': false,
+    'abr': false
+  }
 };