ClippingMediaSource requires isPrepared flag to correctly check clipping assertions

Content description

When creating a ClippingMediaSource with an HTTP MediaSource for an AAC format source it fails to play and gives the following error, but if the startPosition=0 and the endPosition is the total duration of the song it works, meaning when it doesn’t actually clip anything, but setting these parameters two trimming values will result in this error:

E/ExoPlayerImplInternal: Internal runtime error.
    java.lang.IllegalStateException
        at com.google.android.exoplayer2.util.Assertions.checkState(Assertions.java:81)
        at com.google.android.exoplayer2.source.ClippingMediaPeriod.selectTracks(ClippingMediaPeriod.java:115)
        at com.google.android.exoplayer2.source.DeferredMediaPeriod.selectTracks(DeferredMediaPeriod.java:163)
        at com.google.android.exoplayer2.MediaPeriodHolder.applyTrackSelection(MediaPeriodHolder.java:271)
        at com.google.android.exoplayer2.MediaPeriodHolder.applyTrackSelection(MediaPeriodHolder.java:233)
        at com.google.android.exoplayer2.MediaPeriodHolder.handlePrepared(MediaPeriodHolder.java:165)
        at com.google.android.exoplayer2.ExoPlayerImplInternal.handlePeriodPrepared(ExoPlayerImplInternal.java:1632)
        at com.google.android.exoplayer2.ExoPlayerImplInternal.handleMessage(ExoPlayerImplInternal.java:348)
        at android.os.Handler.dispatchMessage(Handler.java:98)
        at android.os.Looper.loop(Looper.java:165)
        at android.os.HandlerThread.run(HandlerThread.java:61)

Link to test content

c4ca4238a0b923820dcc509a6f75849b.zip

Version of ExoPlayer being used

2.10.0

Device(s) and version(s) of Android being used

Tested on Android 8.0 and 9.0 on Emulators then Huawei, Samsung and Nexus physical devices.

[tonihei]

As it turns out, we can’t catch this earlier at the moment because ClippingMediaSource doesn’t know whether the child source is not seekable because it’s actually not seekable or because we don’t have enough information yet. At the moment, we only check the clipping conditions if the duration of the child source is known, under the assumption that a known duration means that all information is available. However, for this particular AAC example, we never know the duration, so the check is not executed.

This problem can be fixed by adding a new flag to Timeline which indicates whether we are still waiting for information. Changing to enhancement to track adding this.

[soygabimoreno]

Thank you so much!! 🚀