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• Script - split video file in equivalent segments

  4 octobre 2014, par Code_Ed_Student

  I am currently using ffmpeg to slice video files. I automated the process through a script called ffmpeg_split.sh. To view the full script click HERE.
  When I ran this script on a few .mp4 files I had, it would return nothing :

  __DURATION_HMS=$(ffmpeg -i "$__FILE" 2>&1 | grep Duration | \
   grep '\d\d:\d\d:\d\d.\d\d' -o)

  NOTE : This is line #54.

  So without this value, the calls that come after it to the function parse_duration_info() are returning the error message.

  According to the comments in the original script, there should be 2 arguments to parse_duration_info().

  # arg1: duration in format 01:23:45.67
  
  # arg2: offset for group 1 gives hours, 2 gives minutes, 
  
  #       3 gives seconds, 4 gives milliseconds

  Here is the syntax to slice a video with script : ffmpeg_split.sh -s test_vid.mp4 -o video-part%03d.mp4 -c 00:00:08

  Belowe is where I parse the duration :

  function parse_duration_info() {
  
      if [[ $1 ]] && [[ $2 -gt 0 ]] && [[ $2 -lt 5 ]] ; then
  
          __OFFSET=$2
  
          __DURATION_PATTERN='\([0-9][0-9]\):\([0-9][0-9]\):\([0-9][0-9]\)\.\([0-9][0-9]\)'
  
          echo "$1" | sed "s/$__DURATION_PATTERN/\\$__OFFSET/"
  
      else
  
          echo "Bad input to parse_duration_info()"
  
          echo "Givven duration $1"
  
          echo "Givven offset $2"
  
          echo "Exiting..."
  
          exit 1
  
      fi
  
  }

• What's the best way to get video metadata from a MP4 file in ASP.Net MVC using C# ?

  1er janvier 2017, par Maddhacker24

  I’ve been searching on Google and StackOverflow for a good couple of hours. There seems to be a lot of similar questions on StackOverflow but they are all about 3-5 years old.

  Is using FFMPEG still the best way these days to pull metadata from a video file in a .NET web application ? And if so, what’s the best C# wrapper out there ?

  I’ve tried MediaToolkit, MediaFile.dll without any luck. I saw ffmpeg-csharpe but that looks like it hasn’t been touched in a few years.

  I haven’t found any current data on this subject. Is the ability to pull metadata from a video built into the latest version of .NET now ?

  I’m basically looking for any direction at this point.

  I should add that whatever I use could be invoked thousands of times per hour so it will need to be efficient.

• ffmpeg very big duration and very small fps with mpeg4 rtsp input

  16 septembre 2014, par Xuch

  I’m trying to dump video from network camera to HDD with ffmpeg libraries. It’s fine working with h264 rtsp input, but with mpeg4 rtsp I’ve got corrupted video file : its duration more than 3000 hours and invalid fps but in fact duration is 300 seconds.

  At start I doing (var ’Index’ contain index valid video stream from input rtsp) :

  ofmt = av_guess_format(NULL, FullPath().c_str(), NULL);
  
  Ofcx = avformat_alloc_context();
  
  Ofcx->oformat = ofmt;
  
  avio_open2(&Ofcx->pb, FullPath().c_str(), AVIO_FLAG_WRITE, NULL, NULL);
  
  Ost = avformat_new_stream(Ofcx, Ifcx->streams[Index]->codec->codec);
  
  avcodec_copy_context(Ost->codec, Ifcx->streams[Index]->codec);
  
  Ost->sample_aspect_ratio.num = Iccx->sample_aspect_ratio.num;
  
  Ost->sample_aspect_ratio.den = Iccx->sample_aspect_ratio.den;
  
  Ost->r_frame_rate = Ist->r_frame_rate;
  
  Ost->avg_frame_rate = Ist->avg_frame_rate;
  
  Ost->time_base = Ist->time_base;
  
  Ost->codec->time_base = Ost->time_base;
  
  avformat_write_header(Ofcx, NULL);
  
  Ost->codec->ticks_per_frame = Iccx->ticks_per_frame;
  
  Ost->codec->sample_aspect_ratio.num = Iccx->sample_aspect_ratio.num;

  And next srtart dumping cycle :

  int FfPipeline::DumpCycle()
  
  {
  
    AVPacket pkt;
  
    int index = GetVideoIndex();
  
  
  
    av_init_packet(&pkt);
  
  
  
    av_read_play(Ifcx);
  
  
  
    while((av_read_frame(Ifcx, &pkt) >= 0) && (!IsNeedStop()))
  
      {
  
        if (pkt.stream_index == index)    // Then packet is video
  
          {
  
            if ((IsWaitingKeyframe()) && !(pkt.flags & AV_PKT_FLAG_KEY))
  
              {
  
                av_free_packet(&pkt);
  
                continue;
  
              }
  
  
  
            if (IsWaitingKeyframe())
  
              {
  
                ClearWaitingKeyframeFlag();
  
  
  
                pkt.pts = pkt.dts = AV_NOPTS_VALUE;
  
  
  
                SetStartTimestamp();
  
                SetRecState(REC_WRITING);
  
              }
  
  
  
            pkt.stream_index = Ost->id;   // Need to be remove in next time??
  
  
  
            Ofcx->streams[index]->avg_frame_rate = Ifcx->streams[index]->avg_frame_rate;
  
  
  
            pkt.pts = av_rescale_q(pkt.pts, Ifcx->streams[index]->codec->time_base, Ofcx->streams[index]->time_base);
  
            pkt.dts = av_rescale_q(pkt.dts, Ifcx->streams[index]->codec->time_base, Ofcx->streams[index]->time_base);
  
  
  
            pkt.pts *= Ifcx->streams[index]->codec->ticks_per_frame;
  
            pkt.dts *= Ifcx->streams[index]->codec->ticks_per_frame;
  
  
  
            av_interleaved_write_frame(Ofcx, &pkt);
  
          }
  
        av_free_packet(&pkt);
  
        av_init_packet(&pkt);
  
      }
  
  
  
    // Now we stopping
  
    av_free_packet(&pkt);
  
    av_read_pause(Ifcx);
  
  
  
    av_write_trailer(Ofcx);
  
  
  
    avio_close(Ofcx->pb);
  
  
  
    avformat_close_input(&Ifcx);
  
    avformat_free_context(Ofcx);
  
  
  
    AddEndClipToDb();
  
  
  
    Ifcx = NULL;
  
    Ofcx = NULL;
  
  
  
    return 0;
  
  }

  • Input stream :
    ’rtsp ://192.168.0.15:554/axis-media/media.amp ?videocodec=mpeg4&fps=25&resolution=800x600&audio=0’
  • Output file : test_out.mkv

  I’m trying various output format but result was fully equal - very big duration and very small fps.

  Please tell me in what direction I need seek ?

  Thanks a big !

  P.S. dump_format() :

  Input #0, rtsp, from 'rtsp://192.168.0.11:554/mpeg4/media.amp?resolution=800x600&audio=0':
  
    Metadata:
  
      title           : Media Presentation
  
    Duration: N/A, start: 0.133344, bitrate: N/A
  
      Stream #0:0: Video: mpeg4 (Advanced Simple Profile), yuv420p, 640x480 [SAR 1:1 DAR 4:3], 100 fps, 100 tbr, 90k tbn, 100 tbc
  
  Output #0, matroska, to '/me':
  
    Metadata:
  
      encoder         : Lavf53.32.100
  
      Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 640x480 [SAR 1:1 DAR 4:3], q=2-31, 100 fps, 100 tbr, 1k tbn, 90k tbc