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• Revision 3274 : pas nécessite mais utilise

  18 avril 2010, par kent1 — Log

  pas nécessite mais utilise

• Can't convert YUV video with ffmpeg

  3 février 2015, par Luca

  When i try to convert a file with ffmpeg (from command prompt) it always gives me :

  Segmentation fault (core dumped)

  The file name is left_432x240.yuv and I have downloaded it from here.

  the command i do is :

  ffmpeg -f rawvideo -vcodec rawvideo -s 432x240 -r 25 -pix_fmt yuv420p -i left_432x240.yuv -c:v libx264 -preset ultrafast -qp 0 output.mp4

  I have tried various option combination, but the result is always the same.

  doing :
  ffmpeg -i left_432x240.yuv

  produce :

  ffmpeg version 2.1 Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Nov 28 2013 16:44:43 with gcc 4.8 (Ubuntu/Linaro 4.8.1-10ubuntu9)
  
    configuration: --enable-gpl --enable-libfaac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libxvid --enable-nonfree --enable-postproc --enable-version3 --enable-x11grab
  
    libavutil      52. 48.100 / 52. 48.100
  
    libavcodec     55. 39.100 / 55. 39.100
  
    libavformat    55. 19.104 / 55. 19.104
  
    libavdevice    55.  5.100 / 55.  5.100
  
    libavfilter     3. 90.100 /  3. 90.100
  
    libswscale      2.  5.101 /  2.  5.101
  
    libswresample   0. 17.104 /  0. 17.104
  
    libpostproc    52.  3.100 / 52.  3.100
  
  [IMGUTILS @ 0xbff1adc0] Picture size 0x0 is invalid
  
  [IMGUTILS @ 0xbff1a8d0] Picture size 0x0 is invalid
  
  [IMGUTILS @ 0xbff1a950] Picture size 0x0 is invalid
  
  [rawvideo @ 0xa2aaee0] Could not find codec parameters for stream 0 (Video: rawvideo (I420 / 0x30323449), yuv420p, -4 kb/s): unspecified size
  
  Consider increasing the value for the 'analyzeduration' and 'probesize' options
  
  left_432x240.yuv: could not find codec parameters

• Decode compressed frame to memory using LibAV : avcodec_decode_video2 ?

  14 décembre 2016, par Micka

  I am completely new to libAV.

  I have a single video frame coming from somewhere else (it’s in memory, not in a file). It should be H.264 encoded keyframe.

  I’m trying to decode with avcodec_decode_video2 is that the right function for my needs ?

  I’m encountering a problem using this code (basically taken from FFmpeg decode raw buffer with avcodec_decode_video2 ) :

  AVCodecContext  *m_pCodecCtx;
  
  AVCodec         *m_pCodec;
  
  AVFrame         *m_pFrame;
  
  
  
  m_pCodec= avcodec_find_decoder(CODEC_ID_H264);
  
  m_pCodecCtx = avcodec_alloc_context3(m_pCodec);
  
  avcodec_open2(m_pCodecCtx,m_pCodec,0);
  
  
  
  // since avcodec_alloc_frame() isn't existing anymore, I changed to following:
  
  //m_pFrame=m_fc.avcodec_alloc_frame(); // and what is/was m_fc?!?
  
  m_pFrame = av_frame_alloc();
  
  
  
  
  
  AVPacket        packet;
  
  av_init_packet(&packet);
  
  
  
  packet.data = (unsigned char*)mData;
  
  packet.size=(int)mDataSize;
  
  
  
  // this is for decoding a keyframe?
  
  packet.flags |= AV_PKT_FLAG_KEY;
  
  
  
  int framefinished=0;
  
  int nres=avcodec_decode_video2(m_pCodecCtx,m_pFrame,&framefinished,&packet);
  
  
  
  if(framefinished)
  
  {
  
      std::cout << "decoded frame" << std::endl
  
  }

  unfortunately framefinished always returns 0 while nres is 18331 which equals mDataSize

  Where’s my fault ?
  Do I have to specify codec information more clearly ?
  Is my packet broken or incomplete ?
  Am I using the wrong libAV function ?

  In the sample code of the framework I’m using, the image data is succesfully streamed to a file, using av_interleaved_write_frame (and a AvFormatContext). Can this help me configuring my packet or the codec ?