tonihei 87cd644d00 Add remaining proguard config tests.
This ensures we have full test coverage for proguard configs now.
The only configs not covered by tests are:
 - IMA and OkHttp which copy recommended configs from the respective
   library. I couldn't reproduce failures by removing them (and thus
   couldn't write a test that ensures they are correct).
 - Some dontwarn lines that just suppress warnings.

In addition, this change fixes a couple of related issues:
 - Moved AV1 proguard config to correct module.
 - Removed mentioning of deprecated ExtractorMediaSource from README
 - Suppressed warning from IMA code that prevent proguarding under
   strict rules
 - Fixed wrong proguard exclusion in VP9 module.
 - Moved FLAC exclusion (DefaultExtractorsFactory) to correct module.
 - Added AlertDialog suppression for de-jetified code.
 - Removed unusued dependency from UI module that causes large APK
   size increase.

#exofixit
#minor-release

PiperOrigin-RevId: 344427532
2020-11-27 11:08:34 +00:00
..

ExoPlayer IMA extension

The IMA extension is an AdsLoader implementation wrapping the Interactive Media Ads SDK for Android. You can use it to insert ads alongside content.

Getting the extension

The easiest way to use the extension is to add it as a gradle dependency:

implementation 'com.google.android.exoplayer:extension-ima:2.X.X'

where 2.X.X is the version, which must match the version of the ExoPlayer library being used.

Alternatively, you can clone the ExoPlayer repository and depend on the module locally. Instructions for doing this can be found in ExoPlayer's top level README.

Using the extension

To use the extension, follow the instructions on the Ad insertion page of the developer guide. The AdsLoaderProvider passed to the player's DefaultMediaSourceFactory should return an ImaAdsLoader. Note that the IMA extension only supports players which are accessed on the application's main thread.

Resuming the player after entering the background requires some special handling when playing ads. The player and its media source are released on entering the background, and are recreated when returning to the foreground. When playing ads it is necessary to persist ad playback state while in the background by keeping a reference to the ImaAdsLoader. When re-entering the foreground, pass the same instance back when AdsLoaderProvider.getAdsLoader(MediaItem.AdsConfiguration adsConfiguration) is called to restore the state. It is also important to persist the player position when entering the background by storing the value of player.getContentPosition(). On returning to the foreground, seek to that position before preparing the new player instance. Finally, it is important to call ImaAdsLoader.release() when playback has finished and will not be resumed.

You can try the IMA extension in the ExoPlayer demo app, which has test content in the "IMA sample ad tags" section of the sample chooser. The demo app's PlayerActivity also shows how to persist the ImaAdsLoader instance and the player position when backgrounded during ad playback.