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• What is ffmpeg, avcodec, x264 ? [closed]

  26 février 2016, par onmyway133

  From wiki, I read that

  FFmpeg is a free software project that produces libraries and programs
  for handling multimedia data. The most notable parts of FFmpeg are
  libavcodec, an audio/video codec library used by several other
  projects, libavformat, an audio/video container mux and demux library,
  and the ffmpeg command line program for transcoding multimedia files.

  So ffmpeg is a wrapper of avcodec ? And I often hear that people encode video with x264 using ffmpeg. So ffmpeg is also a wrapper of x264 ?

  How are they related ?

• 'ffmpeg' or 'handbrake cli' for video conversion on server ? [closed]

  18 juin 2013, par AaronJiang

  I want to convert videos on my server using command line, maily mp4 -> flv or flv -> mp4. I googled and found these two products 'ffmpeg' and 'HandBrake cli'.

  http://ffmpeg.org/ffmpeg.html

  https://trac.handbrake.fr/wiki/CLIGuide

  Which one is better ?

  Plus I am running on ubuntu server.

• How to put a png onto an mp4/gif using imagemagick ?

  24 juillet 2022, par Harrison

  TLDR : How do I convert an MP4 to GIF without sacrificing quality ? How can I lay a PNG on a GIF without sacrificing quality ? And how to get rid of the flicker from combining them ?

  


  So I have an MP4 that is 3000x3000 and a PNG that is 1000x1000.

  


  The end result that I want is a GIF that is 1000x1000 where the PNG is layered on top of the MP4 as a background.

  


  These are the step I tried and the issues I am running into. Mainly the issues I am running into are a loss in quality.

  


  MP4 to GIF :

  


  


  1. I have converted the MP4 to a gif with ffmpeg -i background.mp4 background.gif. Result : A major loss of quality in the gif.

     


  


  2. Instead of that - I tried an online converter. Works better but would like to do it on my own. But I will use this GIF from the online converter in the next examples. Still a slight loss of quality but not near as bad.

     


  


  3. I have sized down my gif using convert temporary.gif -coalesce -resize 1000x1000 smaller.gif. (Have also tried with specifying the -size 3000x3000 but no difference really.) Another minor loss of quality there.

     


  


  


  PNG ontop of GIF - Trial 1

  


  

  1. I have converted my PNG to a single page GIF with convert front.png front.gif (Along with some other options). Loses quality, anything that fades or is semi see through gets turned into a solid pixel.

  


  2. Duplicated this page a bunch of times to match number of pages in my background gif using convert front.gif front.gif front.gif multiple times.

  


  3. Merged background and front together with convert background.gif -coalesce null: front.gif -layers composite both.gif. Little more lose of quality and some flickering on the foreground..? Tried some other variations but thats the best I got.

  


  


  PNG on GIF - Trial 2

  


  

  1. Instead of making a GIF of the PNG, I am just using the original PNG with the background.gif like this convert smaller.gif -coalesce null: front.png -layers composite -layers optimize both.gif. This one comes out weird. The from image is very different looking in color and flickery. Not gonna work.

  


  2. Tried without optimization. convert smaller.gif -coalesce null: front.png -layers composite test.gif. This on is closer. The foreground looks great, but is just flickery still ! Again the background is not great but it doesn't seem to have much more impact from after the original mp4 conversion. Did this without -coalesce and still get the same output.

  


  


  The best I can get is a decent front image with details preserved - but flickery. On top of a lossy background.

  


  How can I go about doing this with imagemagick or some other library ?