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 > > Stefano > _______________________________________________ > Linux-audio-dev mailing list > [email protected] > http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
