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• Concat three videos with one audio [duplicate]

  26 septembre 2018, par Михаил Безуглый

  This question already has an answer here :

  • FFmpeg concatenation, no Audio in Final Output
    
    1 answer
    
  • FFmpeg : concat multiple videos, some with audio, some without
    
    1 answer
    
  • Vertically or horizontally stack several videos using ffmpeg ?
    
    2 answers
    

  Thank you for coming here.
  I have three video clips (the first is 3 seconds, the second is 20 seconds, the third is 2 seconds), I connect them using the following command :

  ffmpeg -i opening.mp4 -i middle.mp4 -i ending.mp4 -filter_complex "[0:v] [1:v] [2:v] concat=n=3:v=1 [v]" -map "[v]" output.mp4

  Since all three videos do not have audio tracks, I do not need to include [a]. And then the day came when I needed it. I have an audio track,
  duration of 35 seconds(which is much larger than the output.mp4 video) and I need this audio to be connected to the whole video.
  1) Do I need to crop the video to the length that is obtained by merging all three videos ?
  2) Is it possible to do this with one command, or i need first have to concatetate all together with my command, and then merge video and audio track ?

• Is there a way to convert uploaded videos to browser MP4 using most basic ffmpeg ?

  22 janvier 2016, par PeterTheLobster

  I am trying to convert videos uploaded to my website to browser friendly mp4 using ffmpeg.

  The Problem : the website is hosted by a company and it seems like it does not have the codecs I need (the ones I’m aware to be browser-friendly.) I have learned that h264 and libx264 are the codecs I would want to encode the mp4 videos to, but libx264 is not present and h264 is decodable only. Doing :

  exec("ffmpeg -codecs", $output);

  tells me that :

  D V D h264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10

  I have tried converting the videos using mpeg4 codecs, but those are not supported natively in browsers it appears :

  $command ="$ffmpeg -i $target -b 1500k -vcodec mpeg4 -pix_fmt yuv420p -acodec aac -strict experimental $converted2 2>&1";
  
  exec($command, $output);

  The videos converted using the method above play only audio in chrome for example (the mpeg4 codec encoding is supported).

  Edit : I was able to convert videos to ogg and webm, but those won’t cover all browsers as far as I’m aware. Especially not the mobile ones anyway.

  Question : is there another type of basic ffmpeg, browser friendly mp4 codecs that I am not ware of or was there something wrong with my conversion $command above ? Or would I have to somehow try to install libx264 codecs and libraries ? (My guess is, that I probably cant do that to their servers, right ?)

• How do I use ffmpeg to bulk scale videos of different sizes to the same size (some potentially with black bar padding) ?

  9 décembre 2020, par Tumbleweed53

  I have a bunch of videos I want to stitch together. I want to scale them all to the same size, maintaining aspect ratio (thus adding black bar padding if necessary). Some videos will be downscaled, but most upscaled.

  


  Does anyone have a clever ffmpeg scale formula to accomplish this ? My alternative is to iterate through every video and calculate the scale formula based on its size, but I'd prefer not to do that if I don't have to.