int main(void) {
  av_log_set_level(AV_LOG_TRACE);

  uint8_t *iframe;
  size_t iframe_sizem = 0;
  read_file("./iframe.raw", &iframe, &iframe_sizem);

  uint8_t *extradata = {0};
  size_t extradata_size = 0;
  read_file("./extradata.raw", &extradata, &extradata_size);

  // Create codec parameters.
  AVCodecParameters *codec_params = avcodec_parameters_alloc();
  codec_params->extradata = extradata;
  codec_params->extradata_size = extradata_size;

  AVCodec *codec = avcodec_find_decoder(AV_CODEC_ID_H264);
  if (!codec) {
    av_log(NULL, AV_LOG_ERROR, "Could not find decoder\n");
    return -1;
  }

  // Create the codec context and initialize it with codec parameters
  AVCodecContext *codec_context = avcodec_alloc_context3(codec);
  if (!codec_context) {
    av_log(NULL, AV_LOG_ERROR, "Could not allocate the codec context\n");
    return AVERROR(ENOMEM);
  }
  avcodec_parameters_to_context(codec_context, codec_params);

  printf("avcodec_open2()\n");
  int ret;
  if ((ret = avcodec_open2(codec_context, codec, NULL)) < 0) {
    av_log(NULL, AV_LOG_ERROR, "Could not open video codec: %s\n",
           av_err2str(ret));
    return ret;
  }

  // Packet must be allocated first.
  AVPacket *pkt = av_packet_alloc();
  av_packet_from_data(pkt, iframe, iframe_sizem);

  AVFrame *frame = av_frame_alloc();
  decode(codec_context, frame, pkt);
}