Recherche avancée

Sur d’autres sites (8578)

• ffmpeg use complex_filter only for a part of the video

  7 mars 2019, par Andy P

  I am trying to apply a filter to only the first few seconds of a video clip - and leave the rest of the video unchanged.

  why ?
  I got some video clips that I wanted to put on a website - unfortunatelly those clips are starting with a black background, which does not fit the website’s design. Therefor I was changing the background to transparent.

  I got that filter working from many of the great answers here (thanks to Gyan) and those videos are playing fine in common browsers :

  ffmpeg -i ${1} -filter_complex "[0]split[m][a];
  
  [a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
  
  [m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 ${1}.webm

  the problem now : of course this replaces all black pixels during the video, which leads to many artefacts later on. Therefor I am searching for a way to apply that filter only to the first 5-ish seconds.

  I think I need a second split and a crop or a trim and a concat filter with a timestamp - but I can’t make it work :(

  ffmpeg -i ${1} -filter_complex "[0]split[f][s];
  
  [f]trim=start=0,duration=5[ft];
  
  [s]trim=start=6[st];
  
  [st]split[m][a];
  
  [a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
  
  [m][al]alphamerge,format=yuva420p[mal];
  
  [ft][mal]concat" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 ${1}.webm

• Adobe connect video : FLV to MP4 (export, convert)

  4 mai 2022, par Guillaume Chevalier

  I would like to convert an adobe connect video from .flv in the downloaded zip to .mp4. I have already done the steps explained in this question and answer, however I get .flv files organised like this inside the .zip :

  



  

  



  Moreover, I know that ffmpeg can merge video and sound files together as well as concatenating resulting clips directly from the command-line which could be quite useful : https://www.labnol.org/internet/useful-ffmpeg-commands/28490/

  



  I can't ask the owner of the video to make it available as an .mp4 from within the adobe connect admin interface. Briefly, I would like to listen to those videos in x2 speed in VLC (just like what I do when listening to random math classes on YouTube - I put ON the x2 speed). The amount of time I would gain to watch adobe connect videos in x2 speed is MASSIVE.

  



  I think I am not the only one that would like to do this. There are a lot of questions on forums about downloading adobe connect videos, but the .flv format mixed with some .xml is generally a killer when the host does not make the videos properly available in .mp4.

  



  Dealing with the order of the .flv files is a puzzle. At least, I would not care to flush the chat away and leave some details like that behind, that would help to reconstruct the videos. Any scripts to automate the process would be useful.

  


• How do you include ffmpeg in a php enviroment

  6 février 2019, par Joseph Williamson

  So looking through documentation and answers on stack overflow all leave out one detail thats throwing me off and thats how to actually include the library

  Following along the code listed here ffmpeg-php to create thumbnail of video

  class VideoTile
  
  {
  
      public static function createMovieThumb($srcFile, $destFile = "test.jpg")
  
      {
  
          // Change the path according to your server.
  
          $ffmpeg_path = 'D:\\ffmpeg\\bin\\';
  
  
  
          $output = array();
  
  
  
          $cmd = sprintf('%sffmpeg -i %s -an -ss 00:00:05 -r 1 -vframes 1 -y %s', 
  
              $ffmpeg_path, $srcFile, $destFile);
  
  
  
          if (strtoupper(substr(PHP_OS, 0, 3) == 'WIN'))
  
              $cmd = str_replace('/', DIRECTORY_SEPARATOR, $cmd);
  
          else
  
              $cmd = str_replace('\\', DIRECTORY_SEPARATOR, $cmd);
  
  
  
          exec($cmd, $output, $retval);
  
  
  
          if ($retval)
  
              return false;
  
  
  
          return $destFile;
  
      }
  
  }

  The ffmpeg path is D:\\ffmpeg\\bin\\ I have downloaded the latest release for ffmpeg(4.1) and the uncompressed file does not contain any directory for bin

  I am very confused as to actually use this even with detailed code saying how to if I do not even know how to dictate the proper path

  I also realize that the link is almost 5 years old but as there are no post outlining how to do this in so long I figure its about time for some clear,concise, detailed solutions