ffmpeg: How to make audio stream silent

By adding

-af "volume=-60dB"

to your ffmpeg command, you can make the audio stream essentially silent. This command reduces the volume of the audio stream by 60 decibels, which is a reduction by 99.9%.

Remember that you cannot use -c:a copy when applying audio filters like -af. Instead, you need to re-encode the audio stream using e.g. -c:a aac -b:a 128k or any other codec and bitrate of your choice.

Full example command:

Reencoding a video to baseline and silencing the audio stream:

ffmpeg -i video.mkv -threads 8 -c:v libx264 -profile:v baseline -level:v 4.0 -af "volume=-60dB"  -c:a aac -b:a 128k video.mp4