On Sun, 2009-08-09 at 23:10 +0100, james morris wrote: > On 9/8/2009, "Fons Adriaensen" <f...@kokkinizita.net> wrote: > > >2. The situation is already different for e.g. a compressor > >or limiter. In that case you would expect the same gain profile > >on all channels, probably determined (but not always) by the one > >with the highest level. In other words the channels *do* interact. > ... > >Clearly at least (2) requires the plugin to be aware of the situation, > >and to be designed to handle it. That in turn is possible only if the > >plugin interface can represent this case. But also case (1) would > >benefit from being aware of the multichannel use: in many cases the > >bulk of the work is not the real signal processing but things like > >limiting the rate of change of parameters, computing and interpolating > >internal parameter values etc. and all of that can be shared if the > >plugin standard is designed for it. It's not possible to 'retrofit' > >this to existing mono plugins by an extension. And finally, a plugin > >that would do the right thing in case (2) would fail if used in case > >(3) - it again needs to be aware of being used in this role. > > some probably bad ideas: > > rather than trying to get a number of instances of the same plugin > sharing data, is there any way for having a dynamic number of ports > created within one plugin depending on the context (noof channels) it is > placed in?
That is almost certainly the way to go IMO. I see no advantage to trying to make several separate instances of a single plugin work this way, and it's quite a bit more complicated, and raises some ugly realtime issues, and generally breaks the whole LADSPA/LV2 model when you consider static/shared control ports and such. This way probably has a ton of optimisation issues as well (bunch of process calls instead of one, plugin code doesn't have direct access to all inputs/outputs, etc. It's a mess) Dynamic number of ports, though, is simpler, more efficient, fits well with static/shared ports, and useful in cases other than this one (i.e. we need it anyway). I can't think of any cons. The way AU handles it is analogous to dynamic numbers of ports as well. -dr _______________________________________________ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev