Bash script to split an mp3 file from silent sections

split_by_silence.sh

#!/bin/bash

# file name to be split
input=$1
# text to prepend to the file name of the slices
prepend=$2
# counter for the slices
slice_counter=1
# current start 
start=0
# current end
end=0

# saves a parsed section between silences
split () 
{
	local offset=`echo "$start" | bc`
	local length=`echo "$end - $start + 0.25" | bc -l | awk '{printf "%.3f\n", $0}'`
	local output=`echo $prepend$slice_counter.mp3`
	echo 'output: ' $output

	ffmpeg -ss $offset -t $length -i $input $output
}

# create info file from input
echo `ffmpeg -i $input -af silencedetect=noise=-30dB:d=0.5 -f null - 2> _silenceinfo_.txt`

# filter info file for silence breakpoints
echo `cat _silenceinfo_.txt | grep silencedetect > _breakpoints_.txt`

echo "CREATED TEMP FILES"

# Link filedescriptor 10 with stdin
exec 10<&0
# stdin replaced with a file supplied as a first argument
exec < '_breakpoints_.txt'

# read breakpoints line by line
while read LINE; do

	if [[ $LINE = *"silence_start"* ]]; then

		end=`echo $LINE | awk '{print $5}'`
		
		split
		
		((slice_counter++))
	fi
	
	if [[ $LINE = *"silence_end"* ]]; then
		start=`echo $LINE | awk '{print $5}'`
	fi
    
done

# restore stdin from filedescriptor 10
# and close filedescriptor 10
exec 0<&10 10<&-

# clean up, delete files
echo `rm _silenceinfo_.txt`
echo `rm _breakpoints_.txt`

echo "DELETED TEMP FILES"


###########################################
# Inspired by this answer on SO:
# https://stackoverflow.com/a/36077309
###########################################

Just wanted to say thank you for sharing this- helped me a lot!

If you ever come back to it, you might want to change L18 to the following, or else it will fail with sub-second slices:

local length=`echo "$end - $start + 0.25" | bc -l | awk '{printf "%.3f\n", $0}'`

@thomasmichaelwallace ✌️thanks, appreciate the feedback. just updated it.