OT regarding to Spectrum3d. On Fri, 2011-05-06 at 11:03 +0200, Victor henri wrote: > I t seems that having a rt kernel working is already very difficult; I > believe there is already really hard work behind this... Furthemore, > in my humble opinion, the preempt kernel becomes more and more > interesting...
Building the kernel-rt ourself isn't difficult! AFAIK the only known issue is regarding to the proprietary nvidia driver, which anyway could cause issues for harder real-time. It's correct, that more and more of the rt-patch occupies the vanilla kernel, anyway, it's untrue that a real-time kernel can be replaced by a preemtion only kernel. It's correct, that just doing audio work with Ardour2 is without problems, regarding to hard real-time issues, but if you wish that MIDI event recordings should have a proper timing, like an analog recording of a really good musician, than you need a kernel-rt + jack from svn etc.. A lot of people think that it's impossible that a MIDI event recording could preserve the groove of a very gifted musician, well, that's a half-truth. MIDI nearly is possible to do that. Most people aren't able to hear that MIDI isn't able to do it perfectly. What people are able to hear, as a less good timing, is jitter. They guess that the sequencer does play too correct, human touch should be missing, but that's wrong. You don't need to quantize MIDI events and if hard real-time works, it's very close to a real musician or an audio recording. Unfortunately most of the PCs are unable to do hard real-time and jitter will break the groove. For less gifted musicians it might sound like the timing is to perfect, but this is wrong, it's bad timing caused by jitter, that makes MIDI breaking grooves. I don't like the statement that a PREEMPT kernel could replace a PREEMPT RT. Even the PREEMPT RT should do harder real-time. Note that on multi-tasking OS real-time seldom is real-time. The kernel-rt, ASIO etc. don't do, what's called hard real-time. Hard real-time usually is done by old computers and stand alone sequencers, e.g. the C64, Atari ST. Btw. JACK2 from svn is able to do MIDI hard real-time, when using the kernel-rt. Without JACK2 from svn, there's no chance to get this! Of cause, I'm talking about hw MIDI and not about soft synth (Or do you guess Hexter does sound like an old DX7 in the brown metal case? Any analog synth emulation does sound like e.g. an Oberheim Matrix-1000? I do use those and other old faithful synth. Btw. I'm a guitarist not a keyboarder ;). 2 cents, Ralf -- Ubuntu-Studio-users mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-studio-users
