Increase Volume of an MKV Video from Linux Terminal
Solution 1:
It isn't very well documented, but FFmpeg has a -vol switch which will allow you to increase volume output.
Example:
ffmpeg -i vid.mkv -vol 512 -vcodec copy output.mkv
Some things to take note of:
- the
-volswitch uses "byte percent", so you can't just specify a 200% volume increase, 100% = 256 so specifying 256 would leave the volume as is, 512 would double it and so on.
Solution 2:
The -vol switch is deprecated I've found this method to be useful currently:
ffmpeg -i input.mkv -vcodec copy -filter:a "volume=5.000000" output.louder.mkv
Adjust the number after volume= to suit your needs.
You can also use decibel measures. To increase the volume by 15dB:
ffmpeg -i input.mkv -vcodec copy -filter:a "volume=15dB" output.louder.mkv
The -vcodec copy simply copies the video as is and -filter:a tells ffmpeg to filter the audio. Note that -vcodec can be shortened to -c:v
Sources:
https://trac.ffmpeg.org/wiki/AudioVolume
Testing.