[MPlayer-users] correct syntax for combining filters

[Erik Auerswald]

Hi,

On Thu, Apr 15, 2021 at 12:48:23PM -0400, The Wanderer wrote:
> On 2021-04-15 at 10:08, Christian wrote:
> > I´m looking for the right way to combine filters in *mplayer*.
> > 
> > I want to achieve the following:
> > 
> > I´d like to play a .wav-file with the *equalizer*-option set and the 
> > *higher-speed*-option (plus: *not altering the pitch* when playing
> > faster).
> > 
> > Man-pages say:
> > 
> > -af <filter1[=parameter1:parameter2:...],filter2,...>
> >                Setup a chain of audio filters.
> > 
> > Seems that´s what I´m looking for.
> 
> Notice the comma in the above, before 'filter2'.
> 
> > This command however doesn´t work:
> > 
> > mplayer -af scaletempo=scale=1.2:speed=pitch -srate 44100 -af 
> > lavcresample=44100 -af equalizer=0:0:0:0:0:0:0:0:7:7 test.wav
> > 
> > I.e.: the equalizer option does work (audio is much crisper) but it´s 
> > all played back at normal speed (not with the factor of "1.2").
> > 
> > Could anybody help me with the correct syntax?
> 
> I haven't tried this myself, and don't have much experience with using
> filters, but I'd suggest you see what you get from:
> 
> mplayer -af
> scaletempo=scale=1.2:speed=pitch,lavcresample=44100,equalizer=0:0:0:0:0:0:0:0:7:7
> -srate 44100 test.wav

I don't think I've ever combined _audio_ filters in MPlayer, but _video_
filters can be combined with commas between individual filters, e.g.,
-vf yadif,crop=720:320:0:128 to use both the yadif and crop video filters.

> My guess is that each time you specified the '-af' option, it was
> overriding the value you set with the previous time, so that in the end
> only the equalizer filter was being applied.

Seems plausible. :)

Thanks,
Erik
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