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
..
2023-10-10 03:02:25 -07:00
2021-10-27 09:12:46 +01:00

Demos

This directory contains apps that demonstrate how to use Android media modules, like ExoPlayer. Browse the individual demos and their READMEs to learn more.

Running a demo

From Android Studio

  • File -> New -> Import Project -> Specify the root media folder.
  • Choose the demo from the run configuration dropdown list.
  • Click Run.

Using gradle from the command line:

  • Open a Terminal window at the root media folder.
  • Run ./gradlew projects to show all projects. Demo projects start with demo.
  • Run ./gradlew :<demo name>:tasks to view the list of available tasks for the demo project. Choose an install option from the Install tasks section.
  • Run ./gradlew :<demo name>:<install task>.

For example, ./gradlew :demo:installNoDecoderExtensionsDebug installs the ExoPlayer demo app in debug mode with no optional modules.