2009/6/19 Stefan Kost <[email protected]>: > Stefano D'Angelo schrieb: >> 2009/6/13 Jörn Nettingsmeier <[email protected]>: >>> hi everyone! >>> >>> >>> sorry if this has been discussed before, but i didn't find anything in >>> the archives... >>> consider the case of periodic control values of LADSPA plugins, for >>> instance the azimuth in a horizontal panner or the phase shift in a phaser. >>> currently, they are usually marked as BOUNDED_BELOW and BOUNDED_ABOVE, >>> but the host has no way of knowing that the upper bound is next to the >>> lower bound, so that it can chose the shortest path to the next value >>> when interpolating automation control points. >>> >>> take ardour, for example: if i want to spin a source 360 degrees, i have >>> to start at 0, set a control point at 180, set another control point at >>> the exact next sample to -180 and then onwards. if there is even a >>> single sample between the control points, the interpolation will cause >>> the image to jump in weird ways, because it doesn't know that 180 == -180. >>> >>> does it make sense to add a new hint to LADSPA, something like >>> LADSPA_HINT_PERIODIC? it would mandate LADSPA_HINT_BOUNDED_BELOW and >>> LADSPA_HINT_BOUNDED_ABOVE as well as the respective port range hints, >>> *and* imply that LowerBound is equivalent to UpperBound in the port >>> range hint structure. >>> >>> this would enable hosts to do the Right Thing(tm). >> >> Hi, >> >> I think it makes no sense nowadays to do something like that, for two >> reasons: >> >> * LADSPA is old, hence old LADSPA hosts will not support that and >> new/maintained ones are not likely to support that, since many are >> focusing on newer APIs; >> * An LV2 extension would allow you to do that quite easily in LV2, >> which is probably preferable these days. >> >> That said, I can already hear people who disagree with me shouting and >> screaming. > > I disagree. I would not mind adding support for more hints to the gstreamer > ladspa wrapper. Its not a lot of work and its good to have that now even if > lv2 > takes over in the long run. > > The other think I'd like to have is hints for audio-port channel > grouping/mapping. That is describe that a port is the left-channel of stereo > pair named <xyz>, Even if this goes to the rdf. > > Stefan
Stefan, once again, I originally misunderstood the post by Jorn thinking he wanted to add that stuff outside of the LADSPA header, the discussion went and is still going on. Stefano _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
