A quick note on how to boost the audio stream in a video using the volume filter in ffmpeg
#;For newer versions of ffmpeg ffmpeg -i input.mkv -filter:a "volume=4.0" output.mkv; #For older versions of ffmpeg (we use multiples of 256) ffmpeg -i input.mkv -vol 1024 -vcodec copy output.mkv;
Using the above command we were able to make the audio LOUDER!
This post is also available in: Greek
How do you do it whilst using filter_complex to boost the volume of a mix?
If you are processing multiple streams, we would advise you not to make an overly complex command that does everything in one go. To boost the audio, it is better to use one of the two commands listed above (depending on which version of FFmpeg you are using) and then proceed with the mix.
Suppose you are doing a lot of audio processing. In that case, you could extract the audio from the video files (https://bytefreaks.net/gnulinux/bash/ffmpeg-extract-audio-from-mkv-to-mp3) before processing to make individual steps faster.