aquilescanta 78d65818c6 Fix HLS format derivation in traditional preparation
ExoPlayer's traditional HLS preparation works by loading a chunk from each track
group, and then tries to use the sample information plus the master playlist
information to generate the preparation's resulting TrackGroups.

There are 3 possible scenarios:
- Supported case: Each variant has a single codec string per track type. We can
  assign each track the codec string which matches the loaded sample's type.
- Supported case: Each variant has more than one codec string, but each track
  group has a single track. This is the case when different languages use
  different codecs. In this case, we can assign whichever codec matches the
  loaded sample's mime type.
- Unsupported case: Each variant has more than one codec string, and track
  groups contain more than one track. We are not able to safely map tracks to
  codec strings because that would require loading a chunk from each track
  (which would considerably delay preparation).

Broken in:
4783c329cc

PiperOrigin-RevId: 343072201
2020-11-23 09:58:48 +00:00
..