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• avutil/log : added av_log_format_line2 which returns buffer length

  27 avril 2016, par Andreas Weis

  avutil/log : added av_log_format_line2 which returns buffer length
  The new function behaves the same as av_log_format_line, but also forwards
  
  the return value from the underlying snprintf call. This will allow
  
  callers to accurately determine the size requirements for the line buffer.
  Signed-off-by : Andreas Weis <github@ghulbus-inc.de>
  
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] doc/APIchanges
  • [DH] libavutil/log.c
  • [DH] libavutil/log.h
  • [DH] libavutil/version.h

• Bad pictures displayed by SDL after decoded using ffmpeg from a rtp stream

  2 juin 2015, par clouyfsail

  My program is a H323 endpoint.I receive a H263 rtp stream from H323 protocol stack,and I need to decode and play it with SDL2.0.

  Here is what I did.Firstly I assembled rtp packets into H263 frames myself before decode them.After I got a H263 frame, I sent it to ffmpeg to decode it.Just like this :

  void DecodeFrame(uint8_t *buff, unsigned size)
  
  {
  
      //There is no rtp header in this buff,just rtp payload,and this is a 
  
      //a complete frame
  
      if(!buff || size <= 0)
  
          return;
  
      AVPacket packet;
  
      av_init_packet(&packet);
  
      int got_picture = 0;
  
  
  
      packet.data = buff;
  
      packet.size = size;
  
  
  
      //I have assigned a H263 codec and initialized corresponding structures.
  
      int len = avcodec_decode_video2(m_codec_context, m_picture, 
  
                                      &got_picture, &packet);
  
  
  
      if(len < 0)
  
          return;
  
  
  
      if (got_picture)
  
      {
  
          packet.pts = AV_NOPTS_VALUE;
  
          sws_scale(m_sws_context, (const uint8_t *  const *)m_picture->data,
  
                    m_picture->linesize, 0, m_codec_context->height, m_yuv_frame->data,
  
                    m_yuv_frame->linesize);
  
  
  
          SDL_UpdateYUVTexture(m_sdl_texture, &m_sdl_rect, 
  
                               m_yuv_frame->data[0], m_yuv_frame->linesize[0],
  
                               m_yuv_frame->data[1], m_yuv_frame->linesize[1],
  
                               m_yuv_frame->data[2], m_yuv_frame->linesize[2]);
  
          SDL_RenderClear(m_sdl_renderer);
  
          SDL_RenderCopy(m_sdl_renderer, m_sdl_texture, nullptr, &m_sdl_rect);
  
          SDL_RenderPresent(m_sdl_renderer);
  
      }
  
  }

  It worked, but not as I wished.At the begining of the play,I got a foggy picture,then it turned to clear in a strange way.The image became clear row by row.After that,it turned to foggy sharply if the scene changed drastically(In remote endpoint,the source of video is a camera),and it became clear slowly row by row again.This confuses me much.I want to know why this happened.

• avcodec/pcm-dvd : fix 20bit 2 channels

  18 novembre 2013, par Michael Niedermayer

  avcodec/pcm-dvd : fix 20bit 2 channels
  Fixes part of ticket3122
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] libavcodec/pcm-dvd.c