[MPlayer-dev-eng] [PATCH] set/get equalizer slave mode commands

[Reimar Döffinger]

Hi,
On Sat, Jul 23, 2005 at 03:47:21PM -0400, kiriuja wrote:
> I started coding something like this myself just a few weeks ago. In my
> version the set command took three arguments: gain, band and channel.
> It would change the gain of just one band of a channel, which would've
> been more useful imho when the user would drag a slider for example.

But more effort if you want to set everything and you need additional
code because the equalizer supports only setting all bands at once.
Also I can't see how this would make things any easier, you know all 10
values anyway (if e.g. programming a GUI). Only advantage I can see is
actually that you don't have to increase the maximum argument define.

[...]
> did. I didn't have a get command for it's fairly useless.

Well, to find out if it worked maybe?

> But anyhow, I abandoned that project after I discovered how horribly
> af_equalizer distorts the sound. It tries to hide the distortion by
> divinding the output volume level by 40, but that doesn't completely
> eliminate the distortion, and of course it makes the output volume 40
> times lower when using the filter than when running without it.

Are you sure? It uses float as data type, and if you output that reduced
volume directly as ints, you will be using only maybe 12 instead of 16
bits, maybe that's what you hear? Try something like -af equalizer,volume=10

> Is it a problem of af_equalizer itself or libaf as a whole?
> 
> Having filter loading/removing commands is a good idea. I wonder if
> that would also be possible with video filters.

Not without rebuilding the whole filter chain, reiniting the vo etc. I
think, whereas for audio it is already done in e.g. mixer.c and seems to
work well.

Greetings,
Reimar Döffinger