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• Adding an Overlay Using FFMPEG With Minimal Re-Encoding

  9 décembre 2015, par spaceman

  FFMPEG is really useful for cutting a part of a video, without re-encoding the video.

  I know it is also possible to use FFMPEG for adding an Overlay Image to a video, in a certain part of the video (for example from 10secs till 20secs).

  My question is : If I do this overlaying of an image, will the whole video get re-encoded because of that ? Or just the relevant duration will be encoded ?

  Also are there any options that I can use to make the re-encoding minimal ?
  The purpose if of course to keep the quality of the video like the original one..
  (I would ask for no re-encoding at all, but I don’t see how that might be possible...)

  Thank you

• How to cut multiple parts of audio with ffmpeg ?

  27 septembre 2022, par Groovie

  How can i cut a multiple parts of single audio and save it with ffmpeg ?
I have tried -ss -to command, but instead of cutting selected part its saves it, how can i reach the result when selected part will be removed ? I want to do that for a multiple parts of audio.

  


• Best way to have 2 youtube-dl input with ffmpeg and php

  8 janvier 2021, par Baraque Obahamas

  I'm trying to find the best way to combine a youtube-dl link in mp4 format with another youtube-dl link in m4a format to get an mp4 file through ffmpeg & php and to have an output in stdout in order to download the file directly.

  


  With only one file to convert to another format, I managed to do it easily, for example from m4a to mp3 :

  


  $cmd = "youtube-dl -f bestaudio[ext=m4a] --no-part --no-cache-dir --no-warnings --no-progress -o - https://www.youtube.com/watch?v=6Dh-RL__uN4 | ffmpeg -i - -f mp3 -ab 192k -";


  


  But with 2 inputs, it doesn't work :

  


  $cmd = "cat <(youtube-dl -f bestvideo[ext=mp4] --no-part --no-cache-dir --no-warnings --no-progress -o - https://www.youtube.com/watch?v=6Dh-RL__uN4) <(youtube-dl -f bestaudio[ext=m4a] --no-part --no-cache-dir --no-warnings --no-progress -o - https://www.youtube.com/watch?v=6Dh-RL__uN4) > ffmpeg -i - -movflags frag_keyframe+empty_moov+faststart -frag_duration 3600 -c:v copy -c:a copy -f mp4 -";


  


  In this case I get a "said into stderr : "sh : 1 : Syntax error : "(" unexpected")" error.

  


  I guess there must be a better way to do it.
I notice another problem is that on the ffmpeg command there is only one input "-i -". Now there are 2 inputs, there should be I guess "pipe:3" in addition, but so far my tests have not been conclusive.

  


  Full code :

  


  <?php
header('Content-Description: File Transfer');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header("Content-Disposition: attachment; filename=\"ok.mp4\"");
header("Content-Type: application/octet-stream");

$cmd = "cat <(youtube-dl -f bestvideo[ext=mp4] --no-part --no-cache-dir --no-warnings --no-progress -o - https://www.youtube.com/watch?v=6Dh-RL__uN4) <(youtube-dl -f bestaudio[ext=m4a] --no-part --no-cache-dir --no-warnings --no-progress -o - https://www.youtube.com/watch?v=6Dh-RL__uN4) > ffmpeg -i - -movflags frag_keyframe+empty_moov+faststart -frag_duration 3600 -c:v copy -c:a copy -f mp4 -";
$cmd = passthru($cmd, $status);