ibaker e342b70e93 Fix TextRenderer exception when a subtitle file contains no cues
Discovered while investigating Issue: google/ExoPlayer#10823

Example stack trace with the previous code (I added the index value for
debugging):

```
playerFailed [eventTime=44.07, mediaPos=44.01, window=0, period=0, errorCode=ERROR_CODE_FAILED_RUNTIME_CHECK
  androidx.media3.exoplayer.ExoPlaybackException: Unexpected runtime error
      at androidx.media3.exoplayer.ExoPlayerImplInternal.handleMessage(ExoPlayerImplInternal.java:635)
      at android.os.Handler.dispatchMessage(Handler.java:102)
      at android.os.Looper.loopOnce(Looper.java:202)
      at android.os.Looper.loop(Looper.java:291)
      at android.os.HandlerThread.run(HandlerThread.java:67)
  Caused by: java.lang.IllegalArgumentException: index=-1
      at androidx.media3.common.util.Assertions.checkArgument(Assertions.java:55)
      at androidx.media3.extractor.text.webvtt.WebvttSubtitle.getEventTime(WebvttSubtitle.java:62)
      at androidx.media3.extractor.text.SubtitleOutputBuffer.getEventTime(SubtitleOutputBuffer.java:56)
      at androidx.media3.exoplayer.text.TextRenderer.getCurrentEventTimeUs(TextRenderer.java:435)
      at androidx.media3.exoplayer.text.TextRenderer.render(TextRenderer.java:268)
      at androidx.media3.exoplayer.ExoPlayerImplInternal.doSomeWork(ExoPlayerImplInternal.java:1008)
      at androidx.media3.exoplayer.ExoPlayerImplInternal.handleMessage(ExoPlayerImplInternal.java:509)
      at android.os.Handler.dispatchMessage(Handler.java:102)
      at android.os.Looper.loopOnce(Looper.java:202)
      at android.os.Looper.loop(Looper.java:291)
      at android.os.HandlerThread.run(HandlerThread.java:67)
]
```

#minor-release

PiperOrigin-RevId: 492464180
(cherry picked from commit 5f6fde4d2a90d78a8d58430c88d7dc12849fe163)
2023-01-25 17:39:48 +00:00
..
2021-10-26 14:08:21 +01:00

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 'com.google.android.exoplayer:exoplayer-core:2.X.X'

where 2.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.

Using the module

The developer guide documents how to get started.