SmoothStream audio track language metadata is not made available

[twcapps]

When we request the Audio tracks on a SmoothStream stream the language attribute on the manifest xml is not made available on the MediaFormat language property return from the getTrackFormat method:

ExoPlayer/library/src/main/java/com/google/android/exoplayer/ExoPlayer.java

Line 327 in 0c060f4

public MediaFormat getTrackFormat(int rendererIndex, int trackIndex);

It seems the language attribute is parsed and passed down to the StreamElement
https://github.com/google/ExoPlayer/blob/master/library/src/main/java/com/google/android/exoplayer/smoothstreaming/SmoothStreamingManifestParser.java#L580

But when the MediaFormat instance is created the language property is linked to the TrackElement (not to the StreamElement):

ExoPlayer/library/src/main/java/com/google/android/exoplayer/smoothstreaming/SmoothStreamingChunkSource.java

Line 417 in c9caaad

format.language);

The TrackElement does not contain the language flag:
https://github.com/google/ExoPlayer/blob/master/library/src/main/java/com/google/android/exoplayer/smoothstreaming/SmoothStreamingManifest.java#L134

As a result the getTrackFormat will always return a MediaFormat with a language set to null, even if the metadata is available on the manifest.

[ojw28]

@AquilesCanta - Fancy looking at this? SmoothStreamingManifestParser needs to be updated so that the Format returned by TrackElement.getFormat includes the language, which it doesn't currently. Note that type is an example of something that's parsed at the stream element level but used in the track element level, which is more or less what needs doing in this case too.

[ojw28]

@bartsidee - Your fix looks good to me (aside from the one comment in just added to one of the ref'd changes). Are you planning to send a pull request to fix this, or do we need to do it ourselves? Thanks!

[bartsidee]

Created a pull request and a new branch which has dev as origin (current was master)

[ojw28]

Fixed in #1155.