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• How do i create a batch file that iterates through the files in a folder and executes another .bat on them ?

  1er mai 2013, par El Guapo

  i have a folder full of .avi files and i want to use ffmpeg to convert them to .mp4 files. I followed an online tutorial to create a batch file that does just this, here is the code :

  "C:\ffmpeg\ffmpeg.exe" -y -i %1 -sameq -ar 22050 -vcodec libx264 "C:\videos\Series 1\S01E01.mp4"

  This works fine if i just drag and drop the .avi files onto the createmp4.bat file containing the above code. However i want to be a little bit smarter about this and use another batch file that will iterate through the .avi files in the folder and run createmp4.bat on all of them and copy them to the C :\videos\Series 1\ directory.

  I would also like to change the name of the files if possible to S01E01.mp4, S01E02.mp4 and so on if possible.

  Any help on this would be greatly appreciated. Oh and just in case you hadn't guessed i am fairly clueless about writing batch files !!

  Thanks

• ffmpeg decode one video frame at a time

  28 juillet 2014, par Krishna

  Most ffmpeg examples online show video decoding using a while () and the entire sequence is decoded in one attempt. For example,

  while(av_read_frame(pFormatCtx, &packet)>=0) {
  
      if(packet.stream_index==videoStream) {
  
  
  
          // Decode video frame
  
          avcodec_decode_video(pCodecCtx, pFrame, &frameFinished,
  
                       packet.data, packet.size);
  
  
  
          // Did we get a video frame?
  
          if(frameFinished) {
  
               ... do something   
  
          }
  
       } 
  
  
  
    // Free the packet that was allocated by av_read_frame
  
    av_free_packet(&packet);
  
  }

  Is there a technique to (1) create a function that will decode only one frame and (2) then call that function repeatedly (how many ever times needed).

  I wrote such a function and tried to decode an HEVC stream and I always get this error "Could not find ref with POC xx", where xx stands for some integer. Looks like it can’t find references — how do I get around this ?

  Thanks !

• Python Youtube-dl convert to mp4

  27 mars 2021, par Church.exe

  (if it matters, I'm on windows)

  


  So I am trying to download a Youtube video in an Mp4 format (the program I am putting it into has limited compatibility) with audio but whatever I find online either doesn't work how people are saying it does (leading me to believe it is either outdated, missing context, or for a different OS) or is formatted in a way that doesn't make sense.

  


  My current code is :

  


  if PreferredOutput == 1:
    with youtube_dl.YoutubeDL({'format' : 'bestvideo+bestaudio[ext=m4a]/bestvideo+bestaudio/best', 'merge-output-format' : 'mp4'}) as ydl:
        ydl.download([url])


  


  but when I test it, it just seems to output the file as normal.(which I am guessing is the format the video file was uploaded to youtube as though I could be mistaken) What should I do/am I missing to make this only output (final) Mp4s ? (after the fact ffmpeg conversion or something similar is fine for my purposes)