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• How to Mute audio after 10 Seconds for 2 seconds with ffmpeg filter volume ?

  19 août 2020, par vinico2532

  I am using this command to mute audio :

  


  ffmpeg -i input.mp4 -af "volume=enable ='between(t,10,15)':volume=0, volume=enable ='between(t,20,25)':volume=0, volume=enable ='between(t,30,35)':volume=0, volume=enable ='between(t,40,45)':volume=0, volume=enable ='between(t,50,55)':volume=0" -c:v copy -c:a aac -b:a 192K output.mp4


  


  How can I repeat or loop this filter without writing it again and again ?

  


  For example, this commands zooms video after specific seconds :

  


  ffmpeg -i input.mp4 -vf "zoompan=z='if(lte(mod(time,6),3),zoom+1.5,zoom-3)':x='iw/2-(iw/zoom)/2':y='ih/2-(ih/zoom)/2':d=1:fps=24" -c:v libx264 -crf 20 -preset:v ultrafast -profile:v high -g 60 -threads 2 -c:a aac -b:a 192K output.mp4


  


  How can I use volume filter like this to mute audio after specific seconds ?

  


• FFmpeg amix + volume filters create saturated output ?

  1er septembre 2021, par Sonia Seddiki

  


  First of all, this is a question asked more out of curiosity than desperate need of fixing. I seem to have "fixed" it by upgrading from FFmpeg 3.4.6 to FFmpeg 4.3.1. Or so I think, at least the result is much better.

  


  


  I'm trying to mix 2 audio files (of the same length, so no scale variation here) using FFmpeg amix filter :

  


  

  • A music which starts pretty loud in the beginning and then is almost quiet until the end,

  


  • An audio that starts with silence (basically as long as the music is loud), then continues with a person speaking at an "average" volume

  


  


  Now, I learnt that the filter will divide each input volume by 1/nb_active_inputs (by 2 in my case then), so I added a volume filter on the output to multiply its volume by 2. My command basically looks like this :

  


  ffmpeg -i music.mp3 -i voice.mp3 -filter_complex amix=inputs=2:duration=first[mix];[mix]volume=2[out] -map [out] output.mp3


  


  After that complex filter, my final output is completely distorted. The voice sounds overall very loud and saturated.

  


  I'm not an expert with audio nor with FFmpeg so I assume I'm missing something. I'm trying to understand what is going on and why I am having this result since I use the same inputs, filters and filter options in both cases. Only the FFmpeg version differs.

  


  I've tried to read the code of af_amix.c for both versions but can't seem to find any explanation for that difference. I've seen that the 4.3.1 has a weights option for inputs but from what I understood, they default to 1.0 if not specified. Any clue would be much appreciated.

  


• Increase volume of multiple mp3 files in a directory [closed]

  6 mai 2022, par kojow7

  I am looking for a way to increase the volume of a number of sound bytes in a directory without clipping. I have seen that I can use ffmpeg to pass it through a filter and set volume to a certain level such as 1.5x etc.

  


  However, I would like each file to be moved up to its maximum volume without clipping. How do I do this ?

  


  Some examples show how to do it in 2 passes, by taking values from first pass and manually using them in 2nd pass. But I am trying to automate this in a bash script with hundreds of sound clips.

  


  What is the best way to do this ?

  


  I am ultimately trying to put this into a Bash script on MacOS and preferably using ffmpeg.