From: Mark K. <mar...@at...> - 2002-12-31 06:22:48
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On Mon, 2002-12-30 at 15:04, Chris Cannam wrote: > On Monday 30 December 2002 22:54, Mark Knecht wrote: > > 1) While this was interesting, the nature of the MIDI in that file > > is one note at a time, whereas my file is multiple notes on every > > channel at the same time. Do we have an example that you think > > might be better? > > Try mandolin-sonatina.rg, which is written for mandolin and piano and > will suffer being played entirely on piano. It has simple chords in > the piano right-hand, but if you select all segments and Collapse > them then you can get serious counterpoint in a single instrument. > The timing is very precise -- it's entirely quantized. Hi. Did it. Same results as my tune, but I think some more info: 1) I posted the some recordings online at: http://www.controlnet.com/~makeMusic/Linux/Rosegarden a) Beethoven1.mp3 - This is the Rosegarden/Ardour session for the standard .rg file. For the first 20 second I play only the mandolin line. I think the timing is fine, or at least good enough that it's not obviously out of time. There's a little break while I set up all 3 channels playing the same data over again. It's obvious that there's a problem again, just like my session. This tells me the problem is not in the import of my MIDI data. b) PT_Beethoven1.mp3 - I took the exported MIDI data from Rosegarden over to Pro Tools and built a session there. The timing is dead on, again using the HDSP with RME supplied drivers. While I was in Windows making this very bounce, Windows did a spontaneous reboot, I lost my session and had to build it and bounce all over again! Let's fix this so I never have to deal with that piece of c%@p operating system again, OK? ;-) This tells me the problem is not specifically in the way RG deals with MIDI data internally since it exports cleanly. 2) The MIDI timing of Rosegarden seems just fine if I only play the mandolin line. However, if I add the piano lines to the mix, then the whole thing starts getting behind. It gets further and further behind as the song goes on. 3) I think I listen closely I can actually hear the individual piano notes in the chords being struck at different times. It's more like the chord gets slightly arrpegiated. (sp?) If I had to guess, I'd really say it sounds like Rosegarden isn't actually sending all the notes that belong at the same time, but must be sort of sending individual notes and hoping they are closely spaced. It sounds that way to me anyway, just listening with my ears to the piano. I understand that MIDI only really sends one note across the buss at a time. This is why I depend on multiple MIDI interfaces to different synths to keep the MIDI choke problem to a minimum. However, a chord is only three notes, and I think I can actually hear the time between them. It would be interesting to try and record this in Ardour and measure the delays. (!!) ;-) What is the process for outputting MIDI events that are supposed to be played together to Alsa and eventually the hardware? How do they get buffered and sent out? 4) I ran the same sessions, except I ran Rosegarden as root. There was no appreciable difference in this problem. I could swear the app loaded faster though. No big deal. ;-) 5) I updated to Fernando's new Jack rev 0.44. Again, no appreciable difference in the problem. 6) I am convinced at this point that there's nothing really wrong with the MIDI data since I can export from RG and get good results in Pro Tools. > > > 2) Assuming that Pro Tools is still good, then I'm wondering if > > testing this with soft synths would provide valid data? (I.e. - > > skipping the hardware part of Alsa, I think...) > > It would almost certainly be worth trying playback through iiwusynth > without Ardour or jackd running, and listening to the output through > headphones (_surely_ your soundcard has a headphone socket...?) > I went down a path to do this and then wondered about sound fonts and wasted time looking, but not finding them. Maybe later tomorrow. I have two days off for New Years, so I'll keep plugging away at it. If you have some online somewhere that can be legally shared, please point me in that direction. I also have the USB MidiMan 2X2 which I will dig out tomorrow and try, checking the possibility the this problem is really in the HDSP MIDI driver implementation. If the MidiMan runs well, that points at the HDSP driver. If it runs badly, then it points either at Alsa in it's entirety, or at Rosegarden in some way. We'll just have to wait and see... |