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• How to use NReco ffmpeg ConvertMedia with filter_complex

  12 décembre 2015, par AlbertoGmx

  I’m currently converting a mov video to a mp4 video and applying a filter_complex, and it’s working :

      var ffMpeg = new NReco.VideoConverter.FFMpegConverter();
  
      ffMpeg.Invoke("-y -i \"" + input/ + "\" -filter_complex \"[0] yadif=0:-1:0,scale=iw*sar:ih,scale='if(gt(a,16/9),1280,-2)':'if(gt(a,16/9),-2,720)'[scaled];[scaled] pad=1280:720:(ow-iw)/2:(oh-ih)/2:black \" -c:v libx264 -c:a mp3 -ab 128k " + output + ".mp4");

  However, I would like to do the same thing, but using the ConvertMedia method of the class FFMpegConverter, in order to use the ConvertProgressEventArgs available, as stated here.

  My first bet is to use the ConvertSettings parameter to add the filter_complex in the CustomOutputArgs. I’m trying the following, but it’s not converting properly the video (it can’t be played).

      ffMpeg.ConvertMedia(this.Video /*+ ".mov"*/, NReco.VideoConverter.Format.mov , outPutVideo1 + ".mp4", NReco.VideoConverter.Format.mp4, new NReco.VideoConverter.ConvertSettings()
  
                          {
  
                              CustomOutputArgs = " -filter_complex \"[0] yadif=0:-1:0,scale=iw*sar:ih,scale='if(gt(a,16/9),1280,-2)':'if(gt(a,16/9),-2,720)'[scaled];[scaled] pad=1280:720:(ow-iw)/2:(oh-ih)/2:black \" -c:v libx264 -c:a mp3 -ab 128k " + outPutVideo1 + ".mp4"
  
                          });

  Do you have any ideas on how to achieve this ? Or do you know if it’s possible to use the ConvertProgress when using the Invoke method ?

  Thank you !

• Direct3d Color space conversion in GPU

  12 juin 2019, par eruslu

  Creating direct3d surface inYV12 format and rendering video frames in yuv420 format causes a blur video. Seems like there is a smog on video. I think this is because yuv 420 color space format’s data range is in 16-235 for Y planes and 16-240 for U and V planes. They are not in range of 0-255.

  I changed color format to BGRA in CPU by using ffmpeg’s sws_scale() function and I created direct3d surface in BGRA format and then displayed video is OK. But cpu consumption is very high due to color space conversion. Is there any way to make color conversion in GPU or is there another way to have sharp video display ?

  This is how I create YV12 surface

  m_pDirect3DDevice->CreateOffscreenPlainSurface(_srcWidth, _srcHeight, (D3DFORMAT)MAKEFOURCC('Y', 'V', '1', '2'), D3DPOOL_DEFAULT, &m_pDirect3DSurfaceRender, NULL);

  Here I copy yuv planes of camera’s video frames data to direct3d surface

          BYTE* pict = (BYTE*)d3d_rect.pBits;
  
          BYTE* Y = pY;
  
          BYTE* V = pV;
  
          BYTE* U = pU;
  
  
  
          for (int y = 0; y < _srcHeight; y++)
  
          {
  
              memcpy(pict, Y, p1);
  
              pict += d3d_rect.Pitch;
  
              Y += p1;
  
          }
  
          for (int y = 0; y < _srcHeight >> 1; y++)
  
          {
  
              memcpy(pict, V, p3);
  
              pict += d3d_rect.Pitch >> 1;
  
              V += p3;
  
          }
  
          for (int y = 0; y < _srcHeight >> 1; y++)
  
          {
  
              memcpy(pict, U, p2);
  
              pict += d3d_rect.Pitch >> 1;
  
              U += p2;
  
          }

  I appreciate your help, thank you.

• How to process video stream ?

  27 avril 2016, par sharpener

  I would like to ask some experienced multimedia professional how to proceed with following task :

  Given URL provides video stream and we would like to get access to decoded frames (byte stream in memory) in managed Win7+ application (C#). We don’t want to render/present the frames the standard way. The video format is known but not fixed (might get changed between two successive sessions, but we will know the parameters).

  So far, I have found there are several methods and I have build following picture in my mind :

  1. ffmpeg wrapper
     • Pros
       1. Self contained (no dependency to windows technologies)
       2. Powerful
     • Cons
       1. Little more complex to understand
       2. Lot of different wrapping variants (FFmpeg.NET, ffmpeg-sharp, ffmpeg-shard, FFmpeg.AutoGen, ...)
  2. DirectShow wrapper
     • Pros
       1. Widely used/supported technology (variaous filters freely available)
       2. Nice/detailed documentation on MSDN
     • Cons
       1. Quite old
       2. Considered obsolete from the point of author’s view (available only for desktop model on runtime >= Win8)
  3. MediaFoundation wrapper
     • Pros
       1. Theoretical successor of DirectShow, so should be available in the future
     • Cons
       1. Seems to be not as good as DirectShow
       2. Not very popular, limited "community" support
  4. FFmpegInterop wrapper
     • Pros
       1. Microsoft’s open source wrapper alternative
     • Cons
       1. Not available for runtime < Win8