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• C api on capturing video stream from webcam using ffmpeg

  14 juillet 2013, par Tanjim Hossain Sifat

  I am a new user of ffmpeg. Ffmpeg has a good documentation on using it in command-line, but i am looking for some C API code.

  I want to make a software using C, that would capture video stream from webcam and give me the video stream in raw format, that I would encode in a codec later.

  I have visited this given link, but it provided only the command-line use, not the use of libraries provided by ffmpeg :
  http://ffmpeg.org/trac/ffmpeg/wiki/How%20to%20capture%20a%20webcam%20input

  I also visited this link, which gave me good idea on using the libavcodec, but no other tutorial is available :
  ffmpeg C API documentation/tutorial

  Please someone help me finding C api on video stream capturing from webcam using ffmpeg's library. Thanks in advance.

• Performant AV1 encoding, does it exist ?

  29 novembre 2022, par V O

  I'm developing a VoD application as a white label product that runs in a SaaS context using K8s. To enable streaming, I take the input video and re-convert it into HLS segments in multiple version and codecs to reach maximum compatibility.

  


  Yesterday I started implementing AV1 as codec, as it will in near future detach h264 as it's more efficient with the same level of compatibility across all the available browsers.
That was the point where things started to get strange, as I want to have this codec instead of h264 ^^.

  


  If you take a look at the following doc pages from ffmpeg : https://trac.ffmpeg.org/wiki/Encode/AV1

  


  You will notice that there are 3 main encoders available to handle encoding to av1. These are : libaom, SVT-AV1 and rav1e. No matter which one of these I try, the performance is slow, even slower than with HEVC. Recently I came along a news article about Netflix and that they are upgrading their library to AV1. If I take a look at the numbers of media elements Netflix offers, the amount is just huge, and I really don't understand how they did it. From what I know, SVT-AV1 is developed by Netflix in cooperation with Intel, So I assume they somehow rely on hardware encoding using an Intel CPU extension.

  


  Does somebody maybe know more and how they did it ? I really can't imagine that they just do CPU only encoding. A movie would take days to get encoded.

  


  Thanks in advance

  


• Bash script to convert music from one directory into another

  26 octobre 2014, par SinTrans

  I’ve modified this script from the arch forums : https://wiki.archlinux.org/index.php/Convert_Flac_to_Mp3#With_FFmpeg

  I’m trying to find specific file types in a directory structure, convert them to another music file type, and place them in a "converted" directory that maintains the same directory structure.

  I’m stuck at stripping the string $b of its file name.

  $b holds the string ./converted/alt-j/2012\ an\ awesome\ wave/01\ Intro.flac

  Is there a way I can remove the file name from the string ? I don’t think ffmpeg can create/force parent directories of output files.

  #!/bin/bash
  
  # file convert script
  
  find -type f -name "*.flac" -print0 | while read -d $'\0' a; do
  
      b=${a/.\//.\/converted/}
  
      < /dev/null ffmpeg -i "$a" "${b[@]/%flac/ogg}"
  
      #echo "${b[@]/%flac/ogg}"