[FFmpeg-user] Filter just the 1st audio channel of the input.

[Paul B Mahol]

On Wed, Feb 3, 2021 at 7:48 PM Nicolas George <george at nsup.org> wrote:

> Marco Mircoli (12021-02-03):
> >    wandering if it is possible to process just the 1st audio channel of
> an
> > input.
> > I don't know how many channels I will have as input, but I know that I
> have
> > to process just the 1st and the others I have not to considerate.
> >
> > INPUT from mono to multichannel
> > filters.....
> > OUTPUT just one channel (mono)
> >
> > I've tried this but doesn't works
> >
> > ffmpeg -i FILE_FROM -map_channel 0.0.0 -af
> > highpass=f=70,adeclick,loudnorm=I=-16.5:TP=-1.5:LRA=7 FILE_TO
>
> Just use pan=mono|c0=c0 to extract the channel you want wherever you
> want in the graph.
>
> No need to completely split the channels, it was meant for versions that
> lack the pan filter.
>


You missed fact that user needs all channels again, not just first.


>
> Regards,
>
> --
>   Nicolas George
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