code: @Implementation
    protected static void nativeWriteSampleData(
        long nativeObject,
        int trackIndex,
        @NonNull ByteBuffer byteBuf,
        int offset,
        int size,
        long presentationTimeUs,
        @MediaCodec.BufferFlag int flags) {
      int toWrite = size - offset;
      byte[] bytes = new byte[toWrite];
      byteBuf.get(bytes, 0, toWrite);
  
      try {
        getStream(nativeObject).write(bytes);
      } catch (IOException e) {
        throw new RuntimeException("Unable to write to temporary file.", e);
      }
    }
docs: Writes the given data to the FileOutputStream for the associated muxer.