make_it_cool: kdelibs/kdemm

[Thomas Wilczek]

Am Mittwoch, 23. März 2005 10:00 schrieb Matthias Kretz:

> alsa, jack, polypaudio and MAS, I'd say. Looks like quite some work. I
> believe alsa and jack are the two most important PlaybackNodes to have
> (though they're pretty much Linux only).

well, oss support is already there :) so basiclly *bsd should be covered, too. 
btw, marco what about win32 output in nmm? 

> Yes and no.
> Thomas' idea was to use effects in the "soundserver". I don't think we
> really need that. It should be enough if you can insert those effects into
> the media player and save the settings there.

not quite, it was just an example of a customized backend, not a "final 
design" ;) i'm aware of the fact that you are able to use those "effect 
nodes" (e.g. ladspa) nearly everywhere in a session graph (== your app).

> To use effects from a KDE API without deciding on the media framework we
> need some common interface to work with. One common interface we could use
> is LADSPA. Every media framework should support it - AFAIK only gstreamer
> and NMM support it at this point.

ladspa sounds pretty good - as long as you don't want to go "fully 
crossplatform" when setting up a session using network transparency like nmm 
is capable of now (since cebit, right marco?)

> But I'm planning on using special interfaces for effects that we know are
> usefull to media player developers. So we would at least define interfaces
> for a Fader and an Equalizer effect.

very essential in every mm app, imho 

> This way you could integrate the EQ into your application's skin and 
implement crossfading.

you "just" need a decent qt/kde frontend which talks to 1..* node interface 
class(es) where then the gory details for the underlaying subsystem (nmm, 
gstreamer etc.) are handled.

> BTW, if you have more effect interfaces that a media app might need let me
> know.

ok, that question was primary directed at marco, but what about pitch and 
tempo for an beginning? (i'm pretty sure you can already do it with arts - 
and it's sometimes pretty funny esp. on mic-in)


one example (or use case - for those sw engineering dudes):
one could setup a nice "dual player + battle mixer" combo for the casual 
dj... ;) so, what would such an "installation" require:

mixer: 5-band eq and a simple fader for each channel, then a x-fader with 
selectable inputs combined with a trigger for automatic fades when reaching 
"end-of-input" on one of the active channels.   

player(s): first of all some eye candy :P - fft analyzer, scope, etc. maybe a 
beat counter in combination with pitch and tempo. i'll leave out those basic 
parts like seek and play controls. a generic playlist would be nice, too.

so, every mentioned feature needs 1. a counterpart in your mm subsystem of 
choice and 2. some generic wrapper class in front of it + gui.

...and now get me that guy over there jumping up and down, waving hands and 
screaming "I WILL DO IT!" *ggg*

Thomas

p.s.: and don't get me started about those vj setups - could be even more 
fun ;)