Part of https://github.com/shaka-project/shaka-packager/issues/369
This adds read support for some MPEG-TS PMT elementary stream
descriptors:
- ISO639 Language Descriptor providing language code and audio type
- Maximum Bitrate Descriptor providing peak stream bandwidth
Those metadata are propagated to StreamInfo structures:
- StreamInfo.language field
- AudioStreamMetadata.max_bitrate field for audio streams
- audio type is currently not propagated - corresponding field has to be
added to AudioStreamMetadata
Test vector file containing those descriptors is provided.
c09eb831b8