Method openAVCodecContext

src/ffmpeg/ffmpegSource.cpp:258–296

}

void cFFmpegSource::openAVCodecContext(int *streamIndex, AVCodecContext **avCodecContext, AVFormatContext *avFormatContext)
{
  int ret;

  // find audio stream and get decoder for it
  AVCodec *decoder;
  if ((ret = av_find_best_stream(avFormatContext, AVMEDIA_TYPE_AUDIO, -1, -1, &decoder, 0)) < 0) {
    COMP_ERR("Could not find an audio stream in the input file. %s",avGetErrorString(ret));
  } 

  *streamIndex = ret;
  AVStream *stream = avFormatContext->streams[*streamIndex];

  // set discard flag for all other streams so the demuxer may skip them
  // some demuxers ignore this flag so we still need to skip packets manually in readAndSendPacketToDecoder()
  for (int i = 0; i < avFormatContext->nb_streams; i++) {
    if (i != *streamIndex) {
      avFormatContext->streams[i]->discard = AVDISCARD_ALL;
    }
  }

  *avCodecContext = avcodec_alloc_context3(decoder);
  if (!*avCodecContext) {
    COMP_ERR("Could not allocate audio codec context");
  }

  // copy codec parameters from input stream to output codec context
  if ((ret = avcodec_parameters_to_context(*avCodecContext, stream->codecpar)) < 0) {
    COMP_ERR("Could not copy audio codec parameters to decoder context. %s",avGetErrorString(ret));
  }

  // initialize the decoder with reference counting
  AVDictionary *options = NULL;
  av_dict_set(&options, "refcounted_frames", "1", 0);

  if ((ret = avcodec_open2(*avCodecContext, decoder, &options)) < 0) {
    COMP_ERR("Could not open audio codec. %s",avGetErrorString(ret));
  }
}

void cFFmpegSource::readAndSendPacketToDecoder()
{