[LAD] [EPAMP] an effect plugin API for media players: anyone interested?

Stefano D'Angelo zanga.mail at gmail.com
Mon Jun 2 14:45:01 UTC 2008

2008/6/2 Arnold Krille <arnold at arnoldarts.de>:
> Am Montag, 2. Juni 2008 schrieb Stefano D'Angelo:
>> 2008/6/2 Arnold Krille <arnold at arnoldarts.de>:
>> > Am Montag, 2. Juni 2008 schrieb Fons Adriaensen:
>> >> On Mon, Jun 02, 2008 at 01:39:26PM +0200, Stefano D'Angelo wrote:
>> >> > It would work like this:
>> >> > stereo input -> hosts converts to 5.1
>> >> What do you mean by 'converts to 5.1' ?
>> >> That's actually what the plugin is supposed to do,
>> >> and the only reason why it's being used. If the host
>> >> is doing this sort of thing then you don't need plugins
>> >> at all.
>> > @Stefano: Without having seen anything from your spec, when you don't
>> > allow different numbers of input- and output-channels your spec is
>> > absolutely worthless.
>> Because...?
> Because:
> Either your plugins are all stereo in and stereo out. Too bad that no one can
> use your plugin-format to do 5.1-downmixing or converting stereo/5.1 to
> stereo-for-headphones. Bummer, won't be used.
> Or all the plugins are 5.1 (= six channels). Neither the stereo-only crowds
> will adopt your interface nor the 7.1 cineastics.

What about this: 5.1 stream and you have an effect doing low-pass
filtering on one channel. You use 6 instances and you're done with it,
and a clever host (not too much) could let you control their
parameters together at the same time.

(Anyway, I forgot to put the channel number on which to operate in the
run() callback.)

> And if you answer that conversion between numbers of channels should be done
> by the host and not by different plugins, what need for plugins do remain for
> the average media-player? EQ? That can be done by the host too, no need to
> add a plugin-infrastructure for that.

I take audacious as an example, here's a list of effects implemented
for its API:
- compressor
- "crystalizer"
- echo
- time stretching and pitch shifting
- voice removal
- freeverb3
- pole-zero plot filter

> You don't have to listen to me. But there are some good folks in this list
> with _lots_ of knowledge and experience with plugins (Paul Davis, Fons
> Adriansen, Lars Luthman(n?), Nedko Arnaudov to name just a few). and while
> they might have different views each other, you should _really_ listen to
> them...

When you discuss something you usually listen. That's what I'm doing.


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