Shell – Remove silence from audio files while leaving gaps

audioffmpegshell-scriptsox

Currently we're using this command within a shell script to remove silence from audio files:

ffmpeg -i $INFILE -af silenceremove=0:0:0:-1:1:${NOISE_TOLERANCE}dB -ac 1 $SILENCED_FILE -y

This works fine except that it removes all the silence, causing the remaining audio to be squeezed together.

How can this be done while leaving two or three seconds between each piece of audio?

The solution needs to be very efficient as we'll be processing a lot of audio and should use a tool that can be fairly easily installed on both Linux and OSX, such as ffmpeg or sox.

Best Answer

The best way that I've seen is by adding the -l flag to silence as follows:

sox in.wav out6.wav silence -l 1 0.1 1% -1 2.0 1%

I've copied this command from Example 6 of this very useful blog post called The Sox of Silence

Related Solutions

Sox: splitting audio on silence but leaving tails

To add some silence, you need a chunk of silence and append it to your file

sox -n -r 44100 -c 2 silence.wav trim 0.0 3.0

and

sox filetopad.mp3 silence.wav output.wav

as described Padding an audio file with silence using sox.

How to use sox or ffmpeg to detect silence intervals in a long audio file and replace them by zeros (aka suppress background noise)

Use sox silence option:

sox [input] [output] silence 1 1 2% -1 0.5 2%

will trim silence at front to 1 second and reduce gaps to half a second in the file. 2% in my case ignores noise floor. 0% might work for you.

-1 tells sox to deal to each instance.

Best Answer

Related Solutions

Sox: splitting audio on silence but leaving tails

How to use sox or ffmpeg to detect silence intervals in a long audio file and replace them by zeros (aka suppress background noise)

Related Question