Recherche avancée

Sur d’autres sites (11000)

• FFmpeg eq filter brightness vs. CSS brightness

  21 juillet 2022, par Yoz

  I would like to achieve similar results with FFmpeg eq=brightness and CSS brightness filter. However both processes the image differently :

  


  

  


  This has been partially discussed in Difference between FFMPEG eq ... and CSS filters ? & FFmpeg eq filter complex : Contrast. There are multiple topics discussed, i.e. :

  


  

  1. CSS filter: contrast(c) saturate(s) can be achieved with FFmpeg eq=contrast=c:saturation=c*s

  


  2. CSS filter: brightness(b) somehow matches FFmpeg colorlevels=rimax=...

  


  3. FFmpeg eq filter alternative routine

  


  


  


  The eq filter has two routines that operate upon the pixel data. One
of them is mathematically equivalent to CSS but is only activated if
the user supplies an expression to change gamma

  


  


  I wonder if there is a way to achieve similar results, by modifying ffmpeg eq filter values as mentioned in point 1. or 3. ?

  


  Can someone provide more insight into the second eq routine as mentioned in point 3. , how exactly this can be activated in my case ?

  


• This program is only provided for compatibility and will be removed in a future release. Please use avconv instead [duplicate]

  1er septembre 2014, par Reshma R Panicker

  This question already has an answer here :

  • Who can tell me the difference and relation between ffmpeg, libav, and avconv
    
    1 answer
    

  I am using ffmpeg for uploading videos.

  While uploading some mp4 files, it shows an error :-

  ffmpeg version 0.8.10-6:0.8.10-0ubuntu0.12.10.1, Copyright (c) 2000-2013 the Libav      developers
  
  built on Feb  6 2014 20:56:10 with gcc 4.7.2
  
  *** THIS PROGRAM IS DEPRECATED ***
  
  This program is only provided for compatibility and will be removed in a future release.     Please use avconv instead.

  Please help me to find some solution.

• Why the number of samples given by `ffmpegio` differs using 2 methods ?

  24 septembre 2024, par Julien Larget-Piet

  I have an mp3 file at a sample rate value of 44100, let's name it a.mp3.

  


  Using python library ffmpegio with the following code, i get a total amount of sample equal to 290704.

  


  with ffmpegio.open(file, 'ra', blocksize = 16, sample_fmt = 'dbl') as file_opened:

        for i, indata in enumerate(file_opened):

            do some stuff
    print((i + 1) * 16)


  


  But,

  


  ffmpegio.probe.audio_streams_basic('a.mp3')[0]['nb_samples']

  


  gives me 292608

  


  How the difference between 292608 and 290704 could be explained ?

  


  I search in ffmpegio documentation, but found nothing that trigered my attention :

  


  https://python-ffmpegio.github.io/python-ffmpegio/

  


  Thanks.

  


  I tried to get more information about how the total number of samples was calculated in ffmpegio.probe.audio_streams_basic()

  


  Also, the difference does not seem to increase with increasing the length of the mp3 file.