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• How to install libx265 for ffmpeg on Mac OSX

  20 octobre 2019, par Spencer

  I have tried multiple guides here (search for "Building libx265") and here with no success. Both times I made sure I uninstalled ffmpeg first, went through the guides, then ran

  brew install ffmpeg --with-fdk-aac --with-freetype --with-libass --with-libvpx --enable-libx265

  No matter what when I go to run a command like

  ffmpeg -i source.mkv -c:v libx265 test1.mkv

  I get the error :

  Unknown encoder 'libx265'

  Has anyone had success building libx265 for use with ffmpeg on OSX and can you please share how you did it ?

  P.S. I am running OSX 10.11.3

• ffmpeg usage to encode a video to H264 codec format

  2 avril 2024, par goldenmean

  I have a *.mp4 video file(MPEG4 video codec) and I am trying to convert this to a H264 video codec format(raw h.264 format) using ffmpeg on Linux(Version - FFmpeg version SVN-r0.5.1-4:0.5.1-1ubuntu1, Copyright (c) 2000-2009 Fabrice Bellard,) using command line as shown below,

  



  ffmpeg -i input .mp4 output.h264 


  



  but I get an error saying -

  



  Unsupported codec for output stream #0.0


  



  Then when i try this option :

  



  ffmpeg -i input .mp4 -formats h264 output.h264 


  



  it still does not work, and gives -

  



  Seems stream 0 codec frame rate differs from container frame rate: 59.94 (5994/100) -> 29.97 (30000/1001)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Rapture.mp4':
  Duration: 00:02:06.44, start: 0.000000, bitrate: 26574 kb/s
    Stream #0.0(eng): Video: h264, yuv420p, 1920x1080, 29.97 tbr, 29.97 tbn, 59.94 tbc
    Stream #0.1(eng): Audio: aac, 48000 Hz, stereo, s16


  



  And then it prints out help on the formats which we get when we do ffmpeg -formats

  



  When I checked the help, ffmpeg -formats, I see below information related to H264 file format and codec :

  



  File format : 

DE h264            raw H.264 video format

Codecs:

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


  



  My questions :

  



  


  1. How can I convert the video to a H264 encoded video (raw H264 video format)

  


  2. When I do ffmpeg -formats, I see many acronyms for the codecs supported, I see many acronyms before the codec name/type such as - D V D S E A, what do they stand for ?

  


  3. How to use the ffmpeg options -vcodec and -formats ?

  


  


• finding speed and tone of speech in an audio using python

  1er février 2018, par kRazzy R

  Given an audio , I want to calculate the pace of the speech. i.e how fast or slow is it.

  Currently I am doing the following :
  
   convert speech to text and obtaining a transcript (using a free tool).
  
   count number of words in transcript.
  
   calculate length or duration of file.
  
   finally, pace = (number of words in transcript / duration of file).

  However the accuracy of the pace obtained is dependent purely on transcription , which I think is an unnecessary step.

  Is there any python-library/sox/ffmpeg way that will enable me to

  • to calculate, in a straightforward way,the speed/pace of talk in an audio
  • dominant Pitches/tones of that audio ?

  I referred : I referred : http://sox.sourceforge.net/sox.html and https://digitalcardboard.com/blog/2009/08/25/the-sox-of-silence/