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• parsing different ffmpeg -i output

  11 août 2012, par Jizbo Jonez

  I have a bit of code that gets a video files duration, width, height and framerate which works fine for some videos -

  $output = `ffmpeg -i /var/thismovie.avi`;
  
  preg_match('/Duration: (.*?),.*?Video:.*?0x.*?([0-9]+)x([[0-9]+).*?([0-9]+) fps/i'
  
  ,$output , $result);

  The problem is there are other videos that give a slightly different output information, for example the above code works with this output -

  Input #0, avi, from '/var/www/vhosts/thissite.com/httpdocs/video1.avi':
  
  Duration: 00:00:10.76, start: 0.000000, bitrate: 5180 kb/s
  
  Stream #0:0: Video: h264 (High) (H264 / 0x34363248), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 25 fps, 25 tbr, 25 tbn, 50 tbc
  
  Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, s16, 128 kb/s

  but another video gives this info and will not give any results when used with the above code -

  Input #0, avi, from '/var/www/vhosts/thissite.com/httpdocs/video2.avi':
  
  Duration: 00:00:05.68, start: 0.000000, bitrate: 887 kb/s
  
  Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID / 0x44495658), yuv420p, 640x272 [SAR 1:1 DAR 40:17], 25 tbr, 25 tbn, 25 tbc
  
  Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16, 128 kb/s

  The difference between the two outputs is in the Stream #0:0 part. The fist output shows 7 different pieces of information separated by a comma, the last output only shows 6 bits. The missing piece of info in the last output is the frame rate (fps) but apparently I can use the value for tbr instead.

  So my question is, how can I modify the code I am using to cover both types of outputs ?

• ffmpeg YUV to RGB distored color and position

  15 novembre 2012, par user1542140

  Sorry that I still cannot post images for my question since low reputation.

  I use the ffmpeg function to convert the decoded frame, from YUV to RGB24, but the color and resulted image is distorted seriously. Following is my code snip, the frame width and height is (176, 144)

  len = avcodec_decode_video2(c, picture, &got_picture, &avpkt);
  
      if (got_picture) {
  
              //...
  
  
  
      AVFrame *pFrameRGB = avcodec_alloc_frame();
  
      // Determine required buffer size and allocate buffer
  
      int numBytes=avpicture_get_size(PIX_FMT_RGB24, c->width, c->height);
  
      uint8_t *buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
      avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24, c->width, c->height);
  
  
  
      struct SwsContext *img_convert_ctx = sws_getContext(c->width, c->height, PIX_FMT_YUV420P, c->width, c->height, PIX_FMT_BGR24, SWS_BICUBIC, NULL, NULL, NULL);
  
      sws_scale(img_convert_ctx, picture->data, picture->linesize, 0, picture->height, pFrameRGB->data, pFrameRGB->linesize);
  
      sws_freeContext(img_convert_ctx);
  
      // Save the frame to disk
  
      if(++frame<=5)
  
          SaveFrame(pFrameRGB, c->width, c->height, frame);

• FFMPEG Incompatible sprop-parameter-sets with libstagefright on Android 4.0 for H264

  7 août 2012, par user1582384

  I am having an issue with the RTSP SDP generated by FFMPEG in Android.
  I have the FFMPEG 0.11.1 compiled with NDK and running on Android. I use the FFSERVER to stream an mp4 file locally to the MediaPlayer.

  Here is the generated SDP description :

  08-07 14:04:04.034 : V/rtsp_server(20161) : o=- 0 0 IN IP4 127.0.0.1

  08-07 14:04:04.034 : V/rtsp_server(20161) : s=No Title

  08-07 14:04:04.034 : V/rtsp_server(20161) : c=IN IP4 0.0.0.0

  08-07 14:04:04.034 : V/rtsp_server(20161) : t=0 0

  08-07 14:04:04.034 : V/rtsp_server(20161) : a=tool:libavformat 54.6.100

  08-07 14:04:04.034 : V/rtsp_server(20161) : m=video 0 RTP/AVP 96

  08-07 14:04:04.034 : V/rtsp_server(20161) : b=AS:312

  08-07 14:04:04.034 : V/rtsp_server(20161) : a=x-dimensions:512,384

  08-07 14:04:04.034 : V/rtsp_server(20161) : a=rtpmap:96 H264/90000

  08-07 14:04:04.034 : V/rtsp_server(20161) : a=fmtp:96
  packetization-mode=0 ;profile-level-id=640015 ;sprop-parameter-sets=J2QAH62ECSZuIzSQgSTNxGaSECSZuIzSQgSTNxGaSECSZuIzSQgSTNxGaSEFWuvX1+T+vyfXrrVQgq116+vyf1+T69daq0BAGMg=,KO48sA==

  08-07 14:04:04.034 : V/rtsp_server(20161) : a=control:streamid=0

  08-07 14:04:04.034 : V/rtsp_server(20161) : m=audio 0 RTP/AVP 97

  08-07 14:04:04.034 : V/rtsp_server(20161) : b=AS:29

  08-07 14:04:04.034 : V/rtsp_server(20161) : a=rtpmap:97
  MPEG4-GENERIC/44100/1

  08-07 14:04:04.034 : V/rtsp_server(20161) : a=fmtp:97
  profile-level-id=1 ;mode=AAC-hbr ;sizelength=13 ;indexlength=3 ;indexdeltalength=3 ;
  config=1208

  08-07 14:04:04.034 : V/rtsp_server(20161) : a=control:streamid=1

  Running the same application on Galaxy S2 works since it uses libopencore. But on newer devices it crashes while trying to extract the width and height from the extradata.

  So the problem is with the sprop-parameter-sets.

  My question is why does libstagefright parse the sprop-parameter-sets differently and how could the existing string be converted for compatibility ?