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• How do I configure ffmpeg & openh264 so that the video file can be opened in Windows Media Player 12

  10 mars 2017, par Sacha Guyer

  I have successfully created h264/mp4 movie files with ffmpeg and the x264 library.

  Now I would like to change the h264 library from x264 to openH264. I could replace the x264 library with openH264, recompile ffmpeg and produce movie files, without changing my sources that produce the movie. The resulting movie opens fine in Quicktime on Mac, but on Windows, Windows Media Player 12 cannot play it.

  The documentation about Windows Media Player support for h264 is unclear. File types supported by Windows Media Player states in the table that Windows Media Player 12 supports mp4, but the text below says :

  Windows Media Player does not support the playback of the .mp4 file format.

  From what I have observed, Windows Media Player 12 IS capable of playing h264/mp4 files, but only when created with x264.

  Does anyone know how I need to adjust the configuration of the codec/context so that the movie plays in Windows Media Player ? Does Windows Media Player only support certain h264 profiles ?

  I noticed the warning :

  [libopenh264 @ 0x...] [OpenH264] this = 0x..., Warning:bEnableFrameSkip = 0,bitrate can’t be controlled for RC_QUALITY_MODE,RC_BITRATE_MODE and RC_TIMESTAMP_MODE without enabling skip frame

  With the configuration :

  av_dict_set(&options, "allow_skip_frames", "1", 0);

  I could get rid of this warning, but the movie still does not play. Are there other options that need to be set so that the movie plays in Windows Media Player ?

  Thank you for your help

  ffprobe output of the file that does play fine in Windows Media Player :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test_x264.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      title           : retina
  
      encoder         : Lavf57.56.100
  
      comment         : Creation Date: 2017-03-10 07:47:39.601
  
    Duration: 00:00:04.17, start: 0.000000, bitrate: 17497 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661),
  
        yuv420p, 852x754, 17495 kb/s, 24 fps, 24 tbr, 24k tbn, 48 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler

  ffprobe output of the file that does not play in Windows Media Player :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test_openh264.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      title           : retina
  
      encoder         : Lavf57.56.100
  
      comment         : Creation Date: 2017-03-10 07:49:27.024
  
    Duration: 00:00:04.17, start: 0.000000, bitrate: 17781 kb/s
  
      Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661),
  
        yuv420p, 852x754, 17779 kb/s, 24 fps, 24 tbr, 24k tbn, 48k tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler

• ffmpeg crashes on crossfades between 3 clips if 2 clips coming from same input file [closed]

  14 avril 2020, par Erik

  I observed that ffmpeg 4.2.2 (macOS) crashes in particular cases of crossfades between clips, if one clip comes from file 1.dv, and two clips are cut out of file 2.dv, as shown below :

  



  ffmpeg -f lavfi -i color=black:size=720x576:duration=11:rate=25 -i 1.dv -i 2.dv -filter_complex "\
    [1:v]trim=5:10,setpts=expr=PTS-STARTPTS,yadif,fade=alpha=1:d=2:st=3:type=out,setpts=expr=PTS-STARTPTS,fifo[s5];\
    [2:v]split=2[s7][s8];\
    [s7]trim=5:10,setpts=expr=PTS-STARTPTS,yadif,fade=alpha=1:d=2:type=in,fade=alpha=1:d=2:st=6:type=out,setpts=expr=PTS-STARTPTS+(3/TB),fifo[s15];\
    [s8]trim=12:17,setpts=expr=PTS-STARTPTS,yadif,fade=alpha=1:d=2:type=in,setpts=expr=PTS-STARTPTS+(6/TB),fifo[s22];\
    [0:v][s5]overlay=eof_action=repeat[s6];\
    [s6][s15]overlay=eof_action=repeat[s16];\
    [s16][s22]overlay=eof_action=repeat[s24];\
    [1:a]atrim=5:10,asetpts=expr=PTS-STARTPTS[s26];\
    [2:a]asplit=2[s27][s28];\
    [s27]atrim=5:10,asetpts=expr=PTS-STARTPTS[s30];\
    [s28]atrim=12:17,asetpts=expr=PTS-STARTPTS[s33];\
    [s26][s30]acrossfade=d=2[s31];\
    [s31][s33]acrossfade=d=2[s36]" \
     -map "[s24]" -map "[s36]" -ab 128k -acodec aac -crf 23 -movflags faststart -preset medium -tune film -vcodec libx264 -aspect 1024:576 out.mp4 -y


  



  The order makes a difference : if the two clips from 2.dv are used first and then the clip from 1.dv is appended, everything works fine. Also, if all clips are coming from different files.

  



  ffmpeg 3.4.6 (ubuntu 18.04) shows no issues in any case.

  



  A self-compiled ffmpeg version N-97322-gb1699f4 (commit 2020-04-13) works with short clips as above, but crashes if one of the two clips taken from 2.dv is getting longer. In my tests 1500 frames (64 sec) is OK, 1700 (68 sec) leads to a segmentation fault. That is, if you replace in the command line above :

  



  

  • [s7]trim=5:10... -> [s7]trim=0:68 and accordingly

  


  • [s27]atrim=5:10... -> [s27]atrim=0:68

  


  



  Interestingly, the length of the clip taken from 1.dv does not play a role.

  



  The ffmpeg output shows about 20 times :

  



  frame=    0 fps=0.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x  


  



  before it continues (seg fault case) :

  



  frame=    4 fps=0.3 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   24 fps=1.6 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   25 fps=1.5 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   34 fps=1.9 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   36 fps=2.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   39 fps=2.1 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   40 fps=2.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   40 fps=2.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   40 fps=1.9 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    



  



  success case :

  



  frame=    5 fps=0.4 q=0.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   42 fps=3.2 q=28.0 size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x    
frame=   53 fps=3.9 q=28.0 size=       0kB time=00:00:00.36 bitrate=   2.9kbits/s speed=0.0264x    
frame=   65 fps=4.6 q=28.0 size=       0kB time=00:00:00.84 bitrate=   1.2kbits/s speed=0.0594x 
...   


  



  Slightly older versions included in the newest MacOS builds from zeranoe.com (git-2020-04-13-59e3a9a) and evermeet.cx (N-97308-g14dd0a9057-tessus, from 2020-04-12) are working nicely - also on my production cases (longer clips).

  



  Any feedback would be appreciated !

  


• How to extract frames at 30 fps using FFMPEG APIs on Android ?

  8 septembre 2016, par Amber Beriwal

  We are working on a project that consumes FFMPEG library for video frame extraction on Android platform.

  On Windows, we have observed :

  • Using CLI, ffmpeg is capable of extracting frames at 30 fps using command ffmpeg -i input.flv -vf fps=1 out%d.png.
  • Using Xuggler, we are able to extract frames at 30 fps.
  • Using FFMPEG APIs directly in code, we are getting frames at 30 fps.

  But when we use FFMPEG APIs directly on Android (See Hardware Details), we are getting following results :

  • 720p video (1280 x 720) - 16 fps (approx. 60 ms/frame)
  • 1080p video (1920 x 1080) - 7 fps (approx. 140 ms/frame)

  We haven’t tested Xuggler/CLI on Android yet.

  Ideally, we should be able to get the data in constant time (approx. 30 ms/frame).

  How can we get 30 fps on Android ?

  Code being used on Android :

  if (avformat_open_input(&pFormatCtx, pcVideoFile, NULL, NULL)) {
  
      iError = -1;  //Couldn't open file
  
  }
  
  
  
  if (!iError) {
  
      //Retrieve stream information
  
      if (avformat_find_stream_info(pFormatCtx, NULL) < 0)
  
          iError = -2; //Couldn't find stream information
  
  }
  
  
  
  //Find the first video stream
  
  if (!iError) {
  
  
  
      for (i = 0; i < pFormatCtx->nb_streams; i++) {
  
          if (AVMEDIA_TYPE_VIDEO
  
                  == pFormatCtx->streams[i]->codec->codec_type) {
  
              iFramesInVideo = pFormatCtx->streams[i]->nb_index_entries;
  
              duration = pFormatCtx->streams[i]->duration;
  
              begin = pFormatCtx->streams[i]->start_time;
  
              time_base = (pFormatCtx->streams[i]->time_base.num * 1.0f)
  
                      / pFormatCtx->streams[i]->time_base.den;
  
  
  
              pCodecCtx = avcodec_alloc_context3(NULL);
  
              if (!pCodecCtx) {
  
                  iError = -6;
  
                  break;
  
              }
  
  
  
              AVCodecParameters params = { 0 };
  
              iReturn = avcodec_parameters_from_context(&params,
  
                      pFormatCtx->streams[i]->codec);
  
              if (iReturn < 0) {
  
                  iError = -7;
  
                  break;
  
              }
  
  
  
              iReturn = avcodec_parameters_to_context(pCodecCtx, &params);
  
              if (iReturn < 0) {
  
                  iError = -7;
  
                  break;
  
              }
  
  
  
              //pCodecCtx = pFormatCtx->streams[i]->codec;
  
  
  
              iVideoStreamIndex = i;
  
              break;
  
          }
  
      }
  
  }
  
  
  
  if (!iError) {
  
      if (iVideoStreamIndex == -1) {
  
          iError = -3; // Didn't find a video stream
  
      }
  
  }
  
  
  
  if (!iError) {
  
      // Find the decoder for the video stream
  
      pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
  
      if (pCodec == NULL) {
  
          iError = -4;
  
      }
  
  }
  
  
  
  if (!iError) {
  
      // Open codec
  
      if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0)
  
          iError = -5;
  
  }
  
  
  
  if (!iError) {
  
      iNumBytes = av_image_get_buffer_size(AV_PIX_FMT_RGB24, pCodecCtx->width,
  
              pCodecCtx->height, 1);
  
  
  
      // initialize SWS context for software scaling
  
      sws_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height,
  
              pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height,
  
              AV_PIX_FMT_RGB24,
  
              SWS_BILINEAR,
  
              NULL,
  
              NULL,
  
              NULL);
  
      if (!sws_ctx) {
  
          iError = -7;
  
      }
  
  }
  
  clock_gettime(CLOCK_MONOTONIC_RAW, &end);
  
  delta_us = (end.tv_sec - start.tv_sec) * 1000000
  
          + (end.tv_nsec - start.tv_nsec) / 1000;
  
  start = end;
  
  //LOGI("Starting_Frame_Extraction: %lld", delta_us);
  
  if (!iError) {
  
      while (av_read_frame(pFormatCtx, &packet) == 0) {
  
          // Is this a packet from the video stream?
  
          if (packet.stream_index == iVideoStreamIndex) {
  
              pFrame = av_frame_alloc();
  
              if (NULL == pFrame) {
  
                  iError = -8;
  
                  break;
  
              }
  
  
  
              // Decode video frame
  
              avcodec_decode_video2(pCodecCtx, pFrame, &iFrameFinished,
  
                      &packet);
  
              if (iFrameFinished) {
  
                  //OUR CODE
  
              }
  
              av_frame_free(&pFrame);
  
              pFrame = NULL;
  
          }
  
          av_packet_unref(&packet);
  
      }
  
  }