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• ffmpeg : Computing PSNR on RGB channels

  21 janvier 2016, par Mike

  I have 2 rgb48le tif images that I want to compare with ffmpeg to compute the PSNR

  ffmpeg automatically computes the PSNR on YUV channels instead of RGB.
  This is the command that I’m using on "ffmpeg-20160119-git-cc83177-win64-static" :

  ffmpeg -y -an -i image1.tif -i image2.tif -filter_complex "psnr" output.tif

  and this is the output :

  [tiff_pipe @ 045b36a0] Stream #0: not enough frames to estimate rate; consider increasing probesize
  
  Input #0, tiff_pipe, from 'image1.tif':
  
    Duration: N/A, bitrate: N/A
  
  Stream #0:0: Video: tiff, rgb48le, 7680x4320 [SAR 1:1 DAR 16:9], 25 tbr, 25 tbn, 25 tbc
  
  [tiff_pipe @ 045c53a0] Stream #0: not enough frames to estimate rate; consider increasing probesize
  
  Input #1, tiff_pipe, from 'image2.tif':
  
    Duration: N/A, bitrate: N/A
  
      Stream #1:0: Video: tiff, rgb48le, 7680x4320 [SAR 1:1 DAR 16:9], 25 tbr, 25 tbn, 25 tbc
  
  Output #0, image2, to 'output.tif':
  
    Metadata:
  
  encoder         : Lavf56.40.101
  
  Stream #0:0: Video: tiff, rgb48le, 7680x4320 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc (default)
  
  Metadata:
  
    encoder         : Lavc56.60.100 tiff
  
  Stream mapping:
  
    Stream #0:0 (tiff) -> psnr:main
  
    Stream #1:0 (tiff) -> psnr:reference
  
    psnr -> Stream #0:0 (tiff)
  
  Press [q] to stop, [?] for help
  
  frame=    1 fps=0.3 q=-0.0 Lsize=N/A time=00:00:00.04 bitrate=N/A
  
  video:195568kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
  
  [Parsed_psnr_0 @ 045cf760] PSNR y:46.00 u:49.32 v:50.34 average:48.14 min:48.14 max:48.14

  Is this normal ?
  Is there a way to force the PSNR to compute on RGB48 each channel ?

• lavfi/vf_vpp_qsv : scale_mode can be applied to color conversion

  28 novembre 2022, par Haihao Xiang

  lavfi/vf_vpp_qsv : scale_mode can be applied to color conversion
  Reviewed-by : Soft Works <softworkz@hotmail.com>
  
  Signed-off-by : Haihao Xiang <haihao.xiang@intel.com>
  

  • [DH] libavfilter/vf_vpp_qsv.c

• FFmpeg Fade Out Audio Filter (afade) not being Applied to Track Clipped Iteratively

  4 juin 2016, par Juan Carlos Farah

  I am trying to split a track into multiple fixed-sized (30-second) clips, each with a (5-second) fade-in / fade-out at the beginning and end, respectively. I’m using node-fluent-ffmpeg to interface with ffmpeg and saving each of the ffmpeg commands in an array of ES6 Promises that I later execute using Promise.all().

  I am able to clip the tracks and add the fade-in filter successfully, but for some reason the fade-out filter is only applied to the first clip of the track. I have looked around for answers both in the ffmpeg and node-fluent-ffmpeg documentation (here and here), but there is no mention of issues arising from applying fade-out filters to a track that is being clipped multiple times.

  My code is very similar to the snippet below, with the audio filters being applied in sequence using the audioFilters method. Note that I have tried leaving only the fade-out filter, but the problem persists. Any pointers would be greatly appreciated.

  var promises = [];
  
  const duration = track.duration;
  
  const interval = 30;
  
  const fade = 5;             
  
  const bitrate = 128;        
  
  
  
  for (var i = 0; i <= Math.floor(duration) - interval; ++i) {
  
      const start = i;            // Start second.      
  
      const end = start + interval;
  
      const mp3 = `${new ObjectId().toHexString()}.mp3`;
  
  
  
      var command = new Promise((resolve, reject) => {
  
          ffmpeg(path).setStartTime(start)
  
                      .audioBitrate(bitrate)
  
                      .audioFilters([
  
                          {
  
                              filter: 'afade',
  
                              options: `t=in:ss=${start}:d=${fade}`
  
                          },
  
                          {
  
                              filter: 'afade',
  
                              options: `t=out:st=${end - fade}:d=${fade}`
  
                          }
  
                      ])
  
                      .duration(interval)
  
                      .on('error', (err) => {
  
                          reject("An error occurred while clipping.");
  
                      })
  
                      .on('end', () => {
  
                          resolve(`Finished processing ${output}.`);
  
                      })
  
                      .save(mp3);
  
      });
  
      promises.push(command);     
  
  }

  And here is my ffmpeg version information :

  ffmpeg version 2.8.6 Copyright (c) 2000-2016 the FFmpeg developers
  
  built with Apple LLVM version 7.0.2 (clang-700.1.81)
  
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.8.6 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libvo-aacenc --enable-libxvid --enable-vda
  
  libavutil      54. 31.100 / 54. 31.100
  
  libavcodec     56. 60.100 / 56. 60.100
  
  libavformat    56. 40.101 / 56. 40.101
  
  libavdevice    56.  4.100 / 56.  4.100
  
  libavfilter     5. 40.101 /  5. 40.101
  
  libavresample   2.  1.  0 /  2.  1.  0
  
  libswscale      3.  1.101 /  3.  1.101
  
  libswresample   1.  2.101 /  1.  2.101
  
  libpostproc    53.  3.100 / 53.  3.100