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• 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

• Filter out voice frequency with FFMpeg

  9 août 2022, par shrw

  Using ffmpeg can i filter out the voice frequency ?
I checked the voice frequency is somewhere in 300 Hz to 3000 Hz.
i just want the music from a mp3 file !

  


• Imprint an Image above a video's canvas [duplicate]

  25 août 2021, par ichthyocentaurs

  I want to add an image strip above/below a video using ffmpeg, but currently it overlaps the video content.

  


  The command I was using

  


  ffmpeg -i ./image_path.png -filter_complex \"[1:v][0:v]scale2ref=(3000/200)*ih/8/sar:ih/8[wm][base];[base][wm]overlay=0:0\" -pix_fmt yuv420p -c:a copy output.mp4

[wm]overlay=0:-200 Does not imprint anything

"pad=height=ih+40:color=#71cbf4,overlay=(main_w-overlay_w)/2:main_h-overlay_h" places at the bottom of the video canvas


  


  I want to place my image strip either above or below the video canvas.