[FFmpeg-user] Replace part of the audio

[Reino Wijnsma]

Hello Michael,

On 2023-01-22T18:50:20+0100, Michael Koch <astroelectronic at t-online.de> wrote:
> This command line works with asendcmd and astreamselect:
>
> ffmpeg -i audio1.wav -i audio2.wav -lavfi asendcmd="4 astreamselect map 1",asendcmd="6 astreamselect map 0",astreamselect=map=0 -y out.wav
>
>
> However with amix filter I have no idea what's the syntax for the string inside the string. It doesn't work.
>
> ffmpeg -i audio1.wav -i audio2.wav -lavfi asendcmd="4 amix weights '0 1'",amix=weights='1 0' -y out.wav

You've got your quotes all wrong. Always surround the complete filter-chain with double quotes and use single quotes for the individual filters.

ffmpeg -i audio1.wav -i audio2.wav -lavfi "asendcmd='4 astreamselect map 1',asendcmd='6 astreamselect map 0',astreamselect=map=0" -y out.wav

ffmpeg -i audio1.wav -i audio2.wav -lavfi "asendcmd='4 amix weights '\\\'0 1\\\',amix=weights='1 0'" -y out.wav

See: http://ffmpeg.org/ffmpeg-all.html#Quoting-and-escaping and http://ffmpeg.org/ffmpeg-all.html#Notes-on-filtergraph-escaping.

On 2023-01-22T19:21:53+0100, Paul B Mahol <onemda at gmail.com> wrote:
> there is way to escape stuff

Can't you for once make a useful post?!

-- 
Reino