l?rdagen den 25 oktober 2003 05.42 skrev Jesse Chappell: > Mathias Lundgren wrote on Sat, 25-Oct-2003: > > l?rdagen den 25 oktober 2003 01.10 skrev Paul Winkler: > > > On Fri, Oct 24, 2003 at 06:44:31PM -0400, Paul Winkler wrote: > > > > seems to be building now, thanks! > > > > > > and it runs. > > > damn, hydrogen is fun. wish i had this years ago. > > > > Yes, it's neat. The things you don't do to run bleeding edge... > > One thing that I think is a little sad is that it's not realtime safe... > > (at least it wasn't last time I checked). I'd really love to have the > > possibility to use it from a sequencer and get the output via Jack. > > Okay, it works, but in case you need to increase jack's period things > > get shaky and unsynced. Hydrogen and zynadd running realtime safe > > together with jack and MusE, that would be something. Oh, and the > > possibility to have ladspa send effects in hydrogen. Then I'd be happy > > as a bee. > > You can turn on JACK ports for each instrument, then run them > through jack-rack or similar (or into ardour). Neat, is this one of the latest features? I haven't found it (honestly, I haven't looked very hard for it). But doesn't that require one specific effect for each channel? I guess it's possible to do it in ardour (one jack-channel for each instruments and then using send-effects on them through ardour), but I think it's a bit of overkill. I would love to have a couple of internal send-channels in hydrogen, so that you can share f.ex. one reverb amongst all your drums. Those send effects could just be sent out to a jack port, and then connected via f.ex. jack-rack (or even better through ladspa effects loaded in hydrogen, but maybe ladcca will solve this issue). Yes, there will probably be some overhead mixing and routing the send-outputs, but that'll be very little compared to running 5 reverbs.... Zynadd does this in a very nice way IMHO. Well, I'm just dreaming... :-) > Can you be more specific about the problems with increased periods? > I would like to further contribute to hydrogen's realtime safeness > (although precision and accuracy problems you seem to be describing). I've run hydrogen feeding it midi via MusE and jack as audio output. When using -p 512 it sounds OK, even though it's possible to hear that the timing isn't accurate. When increasing the period, -p 2048, it's really horrible. I've glanced at the midi input thread sources in hydrogen and noticed there are a few mutex thingies there. I've tried increasing the real time priority of the midi thread, with no luck. I guess jack's callback function (audio processing) and midi input thread are locking each other out, and when the buffer gets bigger it results in greater inaccuracy. When running hydrogen with alsa output in the same scenario as above, there's no timing problems (but then I can't use it together with any other apps). The above scenario applies to Zynadd as well. /Mathias
