Download only part of a youtube video precise by the millisecond - linux

Question

I used this bash script here to download only short parts of long yt videos:
#!/bin/bash
#taken from https://unix.stackexchange.com/a/388148/48971
if [ $# -lt 4 ]; then
echo "Usage: $0 <youtube's URL> <HH:mm:ss.milisecs from time> <HH:mm:ss.milisecs to time> <output_file_name>"
echo "e.g.:"
echo "$0 https://www.youtube.com/watch?v=T1n5gXIPyws 00:00:25 00:00:42 intro.mp4"
exit 1
fi
echo "processing..."
from=$(date "+%s" -d "UTC 01/01/1970 $2")
to=$(date "+%s" -d "UTC 01/01/1970 $3")
from_pre=$(($from - 30))
if [ $from_pre -lt 0 ]
then
from_pre=0
fi
from_pre_command_print=$(date -u "+%T" -d #$from_pre)
from_command_print=$(date -u "+%T" -d #$(($from - $from_pre)))$(grep -o "\..*" <<< $2)
to_command_print=$(date -u "+%T" -d #$(($to - $from_pre)))$(grep -o "\..*" <<< $3)
command="ffmpeg "
for uri in $(youtube-dl -g $1)
do
command+="-ss $from_pre_command_print -i $uri "
done
command+="-ss $from_command_print -to $to_command_print $4"
echo "downloading with the following command:"
echo "$command"
$command
but the problem is its only precise to the full second.
I want to use it to download a bunch of very short clips (only one word long mostly) those are often below 1 second long.
I tryed to fix this by using milliseconds in the date.
But then i found out bash can only subtract with integers.
Here is what i tryed:
from=$(date "+%s.%3N" -d "UTC 01/01/1970 $2")
to=$(date "+%s.%3N" -d "UTC 01/01/1970 $3")
function diff {
diff="$(echo $from - 5 | bc)"
echo $diff
}
from_pre=$diff
echo $diff
but the workaround using bc didnt work because later in the script its again throwing errors because bash dosnt know what to do with non integers.
a sample command would look like this:
sh download_youtube.sh https://www.youtube.com/watch?v=dH3auOKyxio 00:06:28.230 00:06:28.740 clip004.mp4
and this works...if the the timeframe is more than 1 second.
Sadly i am out of knowlage here how to make it more precise.
This all is part of a project to make automated compilations of specific word from a youtube channel more on that here:
https://github.com/moeC137/video-recutter
I am very thankfull for every help
edit:
after a bit try an error i found out that this seams to work for me:
#!/bin/bash
#taken from https://unix.stackexchange.com/a/388148/48971
if [ $# -lt 4 ]; then
echo "Usage: $0 <youtube's URL> <HH:mm:ss.milisecs from time> <HH:mm:ss.milisecs to time> <output_file_name>"
echo "e.g.:"
echo "$0 https://www.youtube.com/watch?v=T1n5gXIPyws 00:00:25 00:00:42 intro.mp4"
exit 1
fi
echo "processing..."
from=$(date "+%s" -d "UTC 01/01/1970 $2")
to=$(date "+%s" -d "UTC 01/01/1970 $3")
from_pre=$(($from - 20))
#to_post=$(($to + 20))
if [ $from_pre -lt 0 ]
then
from_pre=0
fi
from_pre_command_print=$(date -u "+%T" -d #$from_pre)
from_command_print=$(date -u "+%T" -d #$(($from - $from_pre)))$(grep -o "\..*" <<< $2)
to_command_print=$(date -u "+%T" -d #$(($to - $from_pre)))$(grep -o "\..*" <<< $3)
#to_post_command_print=$(date -u "+%T.%3N" -d #$to_post)
command="ffmpeg "
for uri in $(youtube-dl -g $1)
do
command+="-ss $from_pre_command_print -i $uri "
done
command+="-ss $from_command_print -to $to_command_print $4"
echo "downloading with the following command:"
echo "$command"
$command
But i starting to think the orginal script actually works with milleseconds.
Because this:
sh download_youtube.sh https://www.youtube.com/watch?v=dH3auOKyxio 00:06:28.230 00:06:28.740 clip004.mp4
works, but when try to combine it with the script from here How to repeat a command for every line in a textfile with given arguments from the textfile (Bash?) it dosent use the milliseconds anymore.
Solved
The orginal Script worked. It just didnt like the "," in the timestamps, i replaced them with "." and now its working.

Answer 1

solved by replacing "," in timestamps with "."