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• FFmpeg library in WPF

  20 avril 2022, par MikeTMG

  I am building a softwere that can decode and encode using Wpf and c#, and I want to do that using, FFmpeg libary. I saw the ffmpeg autogen warpper but I couldn't find any documantion for its function.
Can someone please find me one ? Or better, give me better warrper.

  



  I already tried FFMpegCore, its working but very slow. For Exaple it takes 20 seconds to decode a specific frame.(And i have monstruos computer)
If will be happy if ou could give me better warpper, or a guide for ffmpeg.autogen.
Thanks in advance.

  


• rails / streamio-ffmpeg - How to execute 2-pass encoding ?

  20 mars 2017, par R4ttlesnake

  I’m using streamio-ffmpeg to encode videos uploaded to my Rails application via ffmpeg. I want to encode the videos to .webm-format using the VP9 coding format and the VP9 Encoding Guide of the WebM Project recommends using 2-pass encoding. I managed to get the videos encoding via streamio-ffmpeg using 1-pass encoding, but I can’t figure out how to handle the 2-pass encoding.

  Here my setup so far :

  # create two tempfiles for the video and a still
  
  video = Tempfile.new(["video", ".webm"], binmode: true)
  
  still = Tempfile.new(["still", ".jpg"], binmode: true)
  
  
  
  # new FFMPEG
  
  movie = FFMPEG::Movie.new(original.path)
  
  
  
  # extract still from video
  
  movie.screenshot(still.path)
  
  
  
  # encode video
  
  options = %w(-c:v libvpx-vp9 -b:v 1000K -threads 8 -speed 4 -tile-columns 6 -frame-parallel 1 -auto-alt-ref 1 -lag-in-frames 25 -c:a libvorbis -b:a 64k -f webm)
  
  movie.transcode(video.path, options)

  The command to do a 2-pass encoding with ffmpeg would be :

  ffmpeg -i <source> -c:v libvpx-vp9 -pass 1 ... -f webm /dev/null
  
  ffmpeg -i <source> -c:v libvpx-vp9 -pass 2 ... -f output.webm
  
  </source></source>

  In particular, I don’t get how to pass the file of the first encoding step to the second step with streamio-ffmpeg. How would I apply these two steps to the syntax of movie.transcode(output, options) ?

  Thanks !

• Decrypt or decode ultraviolet videos

  29 mai 2017, par argetlam5

  I was on Vudu because I have some Ultraviolet movies in my collection and I saw you could download them from their site for offline usage.

  The files on the computer from that download are an h264-2000.mp4 file and aac-256.mp4 file (along with a json subtitle file and some other meta data stuff). When I try to run them individually however nothing happens and when I try to convert to m4v with ffmpeg it fails.

  • Are these files encrypted so that only their video player can play it ?
  • Is there a way to combine all of these files that I’m just not aware of ?

  Vudu uses Adobe Air if that gives you any more information.

  Also, if it is encrypted, does that mean it’s illegal for me to try to be messing with these ? I thought since I bought the movie it would be fine to try. I know I could rip the movie with something like handbrake but the quality from Vudu & other Ultraviolet sites is really nice and my computer doesn’t have a bluray reader to try and rip from a bluray.