Do not use "levelCodec" to instantiate SourceBuffer when multiple aud…

…io codec strings are present in the Multivariant Playlist variant CODECS attribute with muxed content (video-dev#6341)

Fixes video-dev#6337

src/controller/buffer-controller.ts

@@ -929,8 +929,11 @@ export default class BufferController implements ComponentAPI {
             `source buffer exists for track ${trackName}, however track does not`,
           );
         }
-        // use levelCodec as first priority
-        let codec = track.levelCodec || track.codec;
+        // use levelCodec as first priority unless it contains multiple comma-separated codec values
+        let codec =
+          track.levelCodec?.indexOf(',') === -1
+            ? track.levelCodec
+            : track.codec;
         if (codec) {
           if (trackName.slice(0, 5) === 'audio') {
             codec = getCodecCompatibleName(codec, this.appendSource);

src/utils/codecs.ts

@@ -193,7 +193,7 @@ export function pickMostCompleteCodecName(
   if (parsedCodec && parsedCodec !== 'mp4a') {
     return parsedCodec;
   }
-  return levelCodec;
+  return levelCodec ? levelCodec.split(',')[0] : levelCodec;
 }
 
 export function convertAVC1ToAVCOTI(codec: string) {