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• Revision 5b2190b2bf : Reset search_method for non-rd pick mode Reset FAST_HEX search_method, which wa

  3 mars 2014, par Yunqing Wang

  Changed Paths :
   Modify /vp9/encoder/vp9_onyx_if.c

  
  
  Reset search_method for non-rd pick mode

  Reset FAST_HEX search_method, which was lost because of code merging.

  Change-Id : Ic2b2cb9ec2f1751e96f7db0f9226310f605fcc83

• HEVC decoding using FFmpeg with error concealment

  6 mai 2017, par Andy

  I am doing a project where I have to implement slice loss in HEVC encoded bitstream and see the output video after decoding. I am seeing a strange green patch in decoded video(using ffmpeg/UHDcode) in place of lost slices. Is it some sort of concealment ? How can I remove those green patch ?

• ffmpeg H264 Encode Frame at a time for network streaming

  4 février 2017, par Richard Harrow

  I’m working on a remote desktop application, I would like to send an encoded H264 packet over TCP by using ffmpeg for the encoding. However I couldn’t find useful info for the particular case of encoding just one frame (already on YUV444) and get the packet.

  I have several issues, the first was that :

  avcodec_encode_video2

  Was not blocking, I found that most of the time you get the "delayed" frames at the end, however, since this is a real time streaming the solution was :

  av_opt_set(mCodecContext->priv_data, "tune", "zerolatency", 0);

  Now I got the frame, but several issues, it takes a while and even worse I got a gray with trash pixels video as result. My configuration for the Codec Context :

   m_pCodecCtx->bit_rate=8000000;
  
  m_pCodecCtx->codec_id=AV_CODEC_ID_H264;
  
  m_pCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
  
  m_pCodecCtx->width=1920;
  
  m_pCodecCtx->height=1080;
  
  m_pCodecCtx->pix_fmt=AV_PIX_FMT_YUV444P;
  
  m_pCodecCtx->time_base.num = 1;
  
  m_pCodecCtx->time_base.den = 25;
  
  m_pCodecCtx->gop_size = 1;
  
  m_pCodecCtx->keyint_min = 1;
  
  m_pCodecCtx->i_quant_factor = float(0.71);
  
  m_pCodecCtx->b_frame_strategy = 20;
  
  m_pCodecCtx->qcompress = (float)0.6;
  
  m_pCodecCtx->qmax = 51;
  
  m_pCodecCtx->qmin = 20;
  
  m_pCodecCtx->max_qdiff = 4;
  
  m_pCodecCtx->refs = 4;
  
  m_pCodecCtx->max_b_frames = 1;
  
  m_pCodecCtx->thread_count = 1;

  I would like to know how this could be done, how do I set the "I Frames" ? and, that would be the optimal for a "one at a time" encoding ? Also I’m not concerned right now with the quality, just need to be fast enough (under 16 ms).

  For the encoding part :

  nres = avcodec_encode_video2(m_pCodecCtx,&packet,m_pFrame,&framefinished);
  
  
  
  if(nres<0){
  
      qDebug() << "error encoding: " << nres << endl;
  
  }
  
  
  
  if(framefinished){
  
      m_pFrame->pts++;
  
       ofstream vidout("video.h264",ios::app);
  
       if(vidout.good()){
  
           vidout.write((const char*)&packet.data[0],packet.size);
  
       }
  
       vidout.close();
  
  
  
       av_packet_unref(&packet);
  
  
  
  }

  I’m not using a container, just a raw file, ffplay reproduce raw files if the packets are right, and that’s my principal issue. I’m planning to send the packet over tcp and decode on the client. Any help would be greatly appreciated.