Re: working with mp3 files

[davidson <davidson@freevolt.org>]

On Thu, 29 Oct 2020 Nicolas George wrote:
> Siard (12020-10-29):
> > > ffmpeg -f concat -safe 0 -i <(for f in ./*.mp4; do echo "file '$PWD/$f'"; done) -c copy output.mp4
> >
> > The method that I know is slightly different. I once took it from
> > https://medium.com/abraia/basic-video-editing-for-social-media-with-ffmpeg-commands-1e873801659
> > but that site has apparently been simplified now and concatenation has been
> > removed.
> > I found that it works fine for mp3's as well.
> >
> > Create join.txt file that contains the exact paths of the files that you
> > want to join. All files should be same format (same codec). The path name
> > of all files should be mentioned one by one like below.
> >   file /home/xx/myvideos/part1.mp4
> >   file /home/xx/myvideos/part2.mp4
> >   file /home/xx/myvideos/part3.mp4
> >   file /home/xx/myvideos/part4.mp4
> > Now, join all files using command:
> > $ ffmpeg -f concat -i join.txt -c copy output.mp4
> > If you get an error something like below;
> >   [concat @ 0x555fed174cc0] Unsafe file name '/path/to/mp4'
> >   join.txt: Operation not permitted
> > add "-safe 0":
> > $ ffmpeg -f concat -safe 0 -i join.txt -c copy output.mp4
>
> That's exactly the same method, you are just using a file instead of a
> shell pipe substitution.

Also known as "Process Substitution". See the subheading, with that
name, in bash(1) under EXPANSION section.

Briefly review the effects of doing s/buster/bullseye/g on some file:

$ diff /etc/apt/sources.list <(sed 's/buster/bullseye/g' /etc/apt/sources.list)

--
Ce qui est important est rarement urgent
et ce qui est urgent est rarement important
-- Dwight David Eisenhower