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• Video recorded with ffmpeg not showing up at all in android (Oneplus 7T)

  15 juin 2021, par ppengy

  I'm trying to render a video using a program called "danser", which uses ffmpeg. The video comes out fine, but when I transfer the video to my phone to upload to a social media platform, the phone does not see the video at all. I've used USB and Google Drive to transfer videos. Videos uploaded to Discord show up fine, which I assume is because of compression. I can't use discord to transfer because the video is over 100MB limit. I've also tested it on BlueStacks and it doesn't show up either.

  


  Running ffmpeg with options: [-y -f rawvideo -vcodec rawvideo -s 1920x1080 -pix_fmt rgb24 -r 60 -i - -vf vflip -profile:v high -preset slow -an -vcodec h264_nvenc -color_range 1 -colorspace 1 -color_trc 1 -color_primaries 1 -movflags +write_colr -pix_fmt yuv420p -rc constqp -qp 18 videos\420eb0fce66c010c71553949ac611eeb.mp4]


  


  Is there anything i can change here that allows for better compatibility ? I can share some video examples too if you request.

  


      "Recording": {
        "FrameWidth": 1920,
        "FrameHeight": 1080,
        "FPS": 60,
        "Encoder": "h264_nvenc",
        "EncoderOptions": "-rc constqp -qp 18",
        "Profile": "high",
        "Preset": "slow",
        "PixelFormat": "yuv420p",
        "Filters": "",
        "AudioCodec": "aac",
        "AudioBitrate": "128k",
        "AudioFilters": "",
        "OutputDir": "videos",
        "Container": "mp4",
        "MotionBlur": {
            "Enabled": true,
            "OversampleMultiplier": 16,
            "BlendFrames": 24,
            "BlendWeights": {
                "UseManualWeights": false,
                "ManualWeights": "1 1.7 2.1 4.1 5",
                "AutoWeightsID": 27,
                "GaussWeightsMult": 1.5
            }
        }
    }
}


  


• Get Total number of frames and FPS faster than with OpenCV library in C++

  20 juillet 2018, par daniels_pa

  I need to check which video can be analyzed and which cannot given the total number of frames in a video and the fps of the video. I created a c++ program to do the checking. Analyzing each video is not an option since analyzing is time consuming.

  I used the OpenCV library for starters :

      cv::VideoCapture vid_to_analyze;
  
      vid_to_analyze.open( me_vid.vid_path.string() );
  
      me_vid.total_frames= static_cast<int>(vid_to_analyze.get(CV_CAP_PROP_FRAME_COUNT));
  
      me_vid.fps=vid_to_analyze.get(CV_CAP_PROP_FPS);
  
  
  
      if (!vid_to_analyze.isOpened())
  
      {
  
          std::cout &lt;&lt; "Skipping vid: "&lt;&lt; me_vid.vid_path.string()&lt;&lt;", couldn't open it" &lt;&lt; std::endl;
  
      }
  
      if (me_vid.fps != me_vid.fps || me_vid.fps &lt;= 0)
  
      {
  
          std::cout &lt;&lt; "For video " &lt;&lt; me_vid.vid_path.string() &lt;&lt; std::endl;
  
          std::cout &lt;&lt; "FPS of the video file cannot be determined, assuming 30"&lt;&lt; std::endl;
  
          me_vid.fps = 30;
  
      }
  
  
  
      vid_to_analyze.release();
  
  </int>

  However when debugging it becomes painfully slow (the program is faster running without the debugger attached but still very slow given the number of videos it needs to cover). I think that has something to do with 4 threads being created and deleted each time a video is opened (released).

  How to get total number of frames and fps in a faster manner ( without actually creating 4 threads !!) if i am not interested in actually grabbing frames from the video just the number of frames and fps.

  Is there a way to use ffmpeg library from c++, would that be faster and where to start ?

  EDIT : Valgrind seems to agree since (Ir=)91.66% of time spend in the vid_to_analyze.open phase

• setting cpu thread in ffmpeg

  2 novembre 2024, par Amy Bomer

  I have a PC 24 Thread and when I use ffmpeg. It only uses 25% of my CPU. So, how can all of these 24 threads be used ? So my CPU usage reaches 100%, because if it's 25% it's still a slow process

  


  example :

  


  ffmpeg -i video01.mkv -i watermark.png -filter_complex "overlay = 10: 10" output01.mkv


  


  how to set 24 cpu threads ?