Bugfix

[XiaoLongTX]

Hello, I found a playback crash caused by a compilation problem.
My app uses compileSdkVersion of 30, but Exoplayer uses 31. I compile the release version of the apk, when minifyEnabled is set to true, the app plays video on Android 12 mobile phones, and when using 5g, there will be java.lang.AbstractMethodError: abstract method "void android.telephony .TelephonyCallback$DisplayInfoListener.onDisplayInfoChanged(android.telephony.TelephonyDisplayInfo)"
crash.
The reason is that when compileSdkVersion 30 is used to compile the release version apk, the compilation environment cannot find the class android.telephony.TelephonyCallback$DisplayInfoListener, and there is no other code calling related logic, so it is deleted or inline optimized. So the logic of keep must be added here to ensure that the onDisplayInfoChanged method is not deleted. I tried a lot of methods, and finally found that -keepattributes LineNumberTable must be added at the same time to make the following keep logic take effect.
As for the keep of DefaultTrackSelector$SpatializerWrapperV32, it is the same reason.

[icbaker]

The recommended fix for this problem is to increase your compileSdkVersion as described here: #10684 (comment)

I'm going to close this as we don't think playing proguard config whack-a-mole is the right way to fix this.

We're looking into changing the library metadata so that any app depending on it is forced to upgrade their compileSdkVersion (i.e. the error happens at compile time, rather than runtime).