tianyifeng 43e6882fb4 Add PreloadMediaSource and PreloadMediaPeriod
The `PreloadMediaSource` has below two new public methods that suppose to be called by the app:

* `preload(long)` allows the apps to preload the source at the passed start position before playback. The preload efforts include preparing the source for a `Timeline`, creating and caching a `MediaPeriod`, preparing the period, selecting tracks on the period and continuing loading the data on the period.
* `releasePreloadMediaSource()` allows the apps to release the preloaded progress.

The `PreloadMediaPeriod` is designed to facilitate the `PreloadMediaSource` for the preloading work. It has a new package-private method `selectTracksForPreloading` which will cache the `SampleStream` that corresponds to the track selection made during the preloading, and when the `PreloadMediaPeriod.selectTracks` is called for playback, it will uses the preloaded streams if the new selection is equal to the selection made during the preloading.

Also add a shortform demo module to demo the usage of `PreloadMediaSource` with the short-form content use case.

PiperOrigin-RevId: 574439529
2023-10-18 04:57:06 -07:00
..

ExoPlayer module

This module provides ExoPlayer, the Player implementation for local media playback on Android.

Getting the module

The easiest way to get the module is to add it as a gradle dependency:

implementation 'androidx.media3:media3-exoplayer:1.X.X'

where 1.X.X is the version, which must match the version of the other media modules being used.

Alternatively, you can clone this GitHub project and depend on the module locally. Instructions for doing this can be found in the top level README.