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• Batch execute (ffmpeg) command on multiple sets of images at once [Novice]

  23 septembre 2021, par Ethan Kendrick

  I'm relatively new to navigating Python libraries, Windows batch processing, and coding as a whole. Here is my situation :

  


  I have multiple folders each with n images in them, where n is a number divisible by 7.
In each folder, the images are in sets of 7, grouped by their name. If one set of these images was named "apple", I would have the following seven images with the following naming structure :

  


  Apple.0_aspect-gigapixel-art-scale-4_00x.png,
Apple.1_aspect-gigapixel-art-scale-4_00x.png,
Apple.2_aspect-gigapixel-art-scale-4_00x.png,
Apple.3_aspect-gigapixel-art-scale-4_00x.png,
Apple.4_aspect-gigapixel-art-scale-4_00x.png,
Apple.5_aspect-gigapixel-art-scale-4_00x.png
Apple_aspect-gigapixel-art-scale-4_00x.png
(Please note that that order matters, the numberless file should be the last, but if the files are sorted by alphabetical/date, that should already be the case.)

  


  For each one of these sets of images inside of one of the folders, I am using ffmpeg to make a video file with the guidelines outlined in this post. On that post I received great help from the user Gyan, who gave me this command : ffmpeg -framerate 10 -i %d.png -vf "split=2[head][loop];[head]trim=end_frame=4[head];[loop]trim=start_frame=3,setpts=PTS-STARTPTS,loop=6:4:0,shuffleframes=1 2 3 2[tail];[head][tail]concat=n=2:v=1:a=0" out.mp4. I am wanting to batch execute this command in each of my folders of images, having it create a video file for each one of the groups of 7.

  


  TLDR ; How can I batch execute a ffmpeg command (above) on multiple sets of images at once ?

  


  Thank you all so much. I very much appreciate the help I've received so far.

  


• mlpenc : Working MLP/TrueHD encoder

  30 août 2016, par Jai Luthra

  mlpenc : Working MLP/TrueHD encoder
  * Multichannel support for TrueHD is experimental
      There should be downmix substreams present for 2+ channel bitstreams,
  
      but ffmpeg decoder doesn’t need it. Will add support for this soon.
  * There might be lossless check failures on LFE channels
  * 32-bit sample support has been removed for now, will add it later
      While testing, some samples gave lossless check failures when enforcing
  
      s32. Probably this will also get solved with the LFE issues.
  Signed-off-by : Jai Luthra <me@jailuthra.in>
  

  • [DH] libavcodec/Makefile
  • [DH] libavcodec/allcodecs.c
  • [DH] libavcodec/mlp.c
  • [DH] libavcodec/mlp.h
  • [DH] libavcodec/mlpenc.c

• Getting a poster frame(thumbnail) with ffmpeg

  3 juillet 2012, par Tyler

  I am trying to get a poster frame from a video file, using ffmpeg.

  I have been following this tutorial and come up with the following code(which is taken/adapted from the link I gave) :

  public bool GetVideoThumbnail(string path, string saveThumbnailTo, int seconds)
  
          {
  
              string parameters = string.Format("-i {0} {1} -vcodec mjpeg -ss {2} -vframes 1 -an -f rawvideo", path, saveThumbnailTo, seconds);
  
  
  
              if (File.Exists(saveThumbnailTo))
  
              {
  
                  return true;
  
              }
  
              else
  
              {
  
                  using (Process process = Process.Start(pathToConvertor, parameters))
  
                  {
  
                      process.WaitForExit();
  
                  }
  
                  return File.Exists(saveThumbnailTo);
  
              }
  
          }

  At the moment this code is successfully creating a file in the correct destination (saveThumbnailTo) only the picture is completely black. I have tried changing the seconds value in the code to ensure that I am not just getting a blank picture from the start of the video. The path refers to where my video is stored, by the way.

  I am currently calling the above code like so :

  GetVideoThumbnail(videoPath, folderPath + "/poster.jpg", 100)

  ..and then passing it out to my view to display the picture. I just wonder whether ".jpg" is the extension I should be giving to this file as I am not entirely sure ?

  Edit : When I run the same command from the command line I get the following errors :

  Incompatible pixel format 'yuv420p' for codec 'mjpeg', auto-selecting
  format 'yuvj420p'

  which appears in yellow, and

  [image2 @ 02S96AE0] Could not get frame filename number 2 from pattern
  'poster.jpg' an_interleaved_write_frame() : Invalid argument

  which appears in red.

  Could anyone help me with getting this working properly as I am completely unfamiliar with the ffmpeg command line and not sure what I am doing wrong. I have tried removing the vcodec parameter and get the same error message.