buffers.getOutputBuffer(result) must not be null

[vanniktech]

For the following video https://vanniktech.de/transcode.3gp using the demo app with Android API 9, I get the following exception when trying to transcode the video:

Unexpected error while transcoding.
java.lang.NullPointerException: buffers.getOutputBuffer(result) must not be null
  at com.otaliastudios.transcoder.internal.codec.Decoder.drain(Decoder.kt:112)
  at com.otaliastudios.transcoder.internal.pipeline.QueuedStep.step(steps.kt:42)
  at com.otaliastudios.transcoder.internal.pipeline.Pipeline.executeStep(Pipeline.kt:51)
  at com.otaliastudios.transcoder.internal.pipeline.Pipeline.executeStep(Pipeline.kt:54)
  at com.otaliastudios.transcoder.internal.pipeline.Pipeline.execute(Pipeline.kt:28)
  at com.otaliastudios.transcoder.internal.Segment.advance(Segment.kt:18)
  at com.otaliastudios.transcoder.internal.transcode.DefaultTranscodeEngine.transcode(DefaultTranscodeEngine.kt:114)
  at com.otaliastudios.transcoder.internal.transcode.TranscodeEngine$Companion.transcode(TranscodeEngine.kt:48)
  at com.otaliastudios.transcoder.internal.transcode.TranscodeEngine.transcode(Unknown Source:2)
  at com.otaliastudios.transcoder.Transcoder$1.call(Transcoder.java:102)
  at com.otaliastudios.transcoder.Transcoder$1.call(Transcoder.java:99)
  at java.util.concurrent.FutureTask.run(FutureTask.java:266)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
  at java.lang.Thread.run(Thread.java:764)

I used a Pixel 2 emulator with the following system image, that I installed via the sdkmanager: sdkmanager --install "system-images;android-28;google_apis_playstore;arm64-v8a"