Recherche avancée

Sur d’autres sites (8148)

• How to use audio volume data to affect other filters in FFMPEG ?

  14 septembre 2019, par Dan Weaver

  Is it possible to use the audio level to affect other filter parameters in FFMPEG ?

  Use case would be to use the audio level of a video file to affect the zoompan filter so the video stream is scaled up and down with changes in the audio level.

  I looked at the audio filters but can’t find anything so far that outputs the audio level as data.

  Example : extract the audio level at each frame (assuming audio level is output 0.0-1.0)

  level = [0, 0.01, 0.03, 0.07, 0.1, 0.4, 0.35, 0.2, 0.05, 0.01, 0.0]

  then use level in as a parameter in a video filter like scale or zoompan.

• How to normalize the volume of an audio file in python : any packages currently available ?

  17 décembre 2019, par Luke Davis

  I have a bunch of AAC (.m4a) audio files that need to be normalized, and was hoping to find a way to do it with a simple python script using some package. I found this thread on superuser where someone has written an ffmpeg command-line utility in python, and it works well, but was wondering if there is some currently available package with a pip install that would be up to the task.

• FFMPEG amix filter volume issue with inputs of different duration

  2 août 2016, par cupuyc

  I noticed that ffmpeg amix filter doesn’t output good result in specific situation. It works fine if input files have equal duration. In that case volume is dropped in constant value and could be fixed with ",volume=2".

  In my case I’m using files with different duration. Resulted volume is not good. First mixed stream resulted in lowest volume, and last one is highest. You can see on image that volume is increased linearly withing a time.

  

  My command :

  ffmpeg -i temp_0.mp4 -i user_2123_10.mp4  -i user_2123_3.mp4  -i user_2123_4.mp4  
  
  -i user_2123_7.mp4  -i user_2123_5.mp4  -i user_2123_1.mp4  -i user_2123_8.mp4  
  
  -i user_2123_0.mp4  -i user_2123_6.mp4  -i user_2123_9.mp4  -i user_2123_2.mp4  
  
  -i user_2123_11.mp4 -filter_complex "[1:a]adelay=34741.0[aud1];
  
  [2:a]adelay=18241.0[aud2];[3:a]adelay=20602.0[aud3];
  
  [4:a]adelay=27852.0[aud4];[5:a]adelay=22941.0[aud5];
  
  [6:a]adelay=13142.0[aud6];[7:a]adelay=29810.0[aud7];
  
  [8:a]adelay=12.0[aud8];[9:a]adelay=25692.0[aud9];
  
  [10:a]adelay=32143.002[aud10];[11:a]adelay=16101.0[aud11];
  
  [12:a]adelay=40848.0[aud12];
  
  [0:a][aud1][aud2][aud3][aud4][aud5][aud6][aud7]
  
  [aud8][aud9][aud10][aud11]
  
  [aud12]amix=inputs=13:duration=first:dropout_transition=0" 
  
  -vcodec copy -y temp_1.mp4

  That could be fixed by applying silence at the beginning and end of each clip, then they will have same duration and volume will be at the same level.

  Please suggest how I can use amix to mix many inputs and ensure constant volume level.