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• avcodec/mediacodecdec : restructure mediacodec_receive_frame

  24 avril 2018, par Aman Gupta

  avcodec/mediacodecdec : restructure mediacodec_receive_frame
  The new logic follows a recommendation by @rcombs to use
  
  dequeueInputBuffer with a timeout of 0 as a way to detect
  
  whether the codec wants more data. The dequeued buffer index is
  
  kept in MediaCodecDecContext until it can be used next.
  A similar technique is also used by the Google's official media
  
  player Exoplayer : see MediaCodecRenderer.feedInputBuffer().
  Signed-off-by : Aman Gupta <aman@tmm1.net>
  
  Signed-off-by : Matthieu Bouron <matthieu.bouron@gmail.com>
  

  • [DH] libavcodec/mediacodecdec.c
  • [DH] libavcodec/mediacodecdec_common.c
  • [DH] libavcodec/mediacodecdec_common.h

• What is the most suitable H265 setting converting from H264 on ffmpeg ?

  9 juin 2017, par minion007

  Currently, I was trying to convert my videos no matter personal videos or movies from H264 to H265. But that was much harder than what I expected.

  Firstly, it took me over 10 hours to build ffmpeg on Linux and I believe I’m still having some problems on dealing with this.

  Secondly, I notice there is degradation after converting by using the setting or parameters from Internet or ffmpeg official website. On the other hand, the video size would be the same or even bigger than the original video size if I use small crf like 23 or 28.

  For instance, sudo ffmpeg -i input.mp4 -c:v hevc -x265-params lossless -preset medium -crf 30 -c:a copy output.mkv

  sudo ffmpeg -i input.mp4 -c:v libx265 -x265-params lossless -preset medium -crf 30 -c:a copy output.mkv

  the above two settings give me the very small video size (between 21% 23% of the original video) which is the main reason why I want to convert my videos to H265 but drawback would be the quality of converted video is worse than the original video (I would may be between 30% 35% degradation).

  Thirdly, the size of video would be much bigger than the original size of video if I use the lossless parameter.

  sudo ffmpeg -i input.mp4 -c:v libx265 -x265-params lossless=1 -preset medium -crf 30 -c:a copy output.mkv

  the above setting can keep the quality of the original video but size would be huge (above 200% of original video).

  Is there any suggestion ?

• OpenFaas. Write python function with FFmpeg using

  11 août 2021, par Валентин Никин

  I need to write OpenFaas function which can accept binary file as parameter. This function will extract some data from that binary file. Based on that data function will generate ffmpeg command. And finally function must be call ffmpeg to process generated command and return file as output.

  


  Function language must be python, because I need to use some python modules to process input binary file.

  


  The main questions :

  


  

  1. Can I accept binary a file as function parameter (in python function) ?

  


  2. Can I call ffmpeg from python function, and return binary file as output ?

  


  


  I have already met with alexellis official example (https://github.com/alexellis/openfaas-streaming-templates) but that example used bash language.

  


  I have one idea, but I don't know is it correct.
Maybe I can use example with bash, to accept binary file as parameter, then I call python script, after that I call ffmpeg, and return file as output as described in the example.
But I need some python modules available with pip. So, I don't know how I can got this.

  


  I'm newest in OpenFaas, so any idea would be appriciated