--- On Wed, 5/20/09, Louis B. <[email protected]> wrote: > From: Louis B. <[email protected]> > Subject: [fluid-dev] What is the best way start fluidsynth with zero/low > latency? > To: [email protected] > Date: Wednesday, May 20, 2009, 8:57 PM > Hi all, > > I am the developer of Piano Booster and I have written > some > instructions on how to start fluidsynth see this link. > > http://pianobooster.sourceforge.net/faq.html#how-do-i-hear-the-sound-on-linux-ubuntu > > > However I cannot get fluidsynth to run with zero/low > latency. I > estimated the latency delay is about 100msec. I > can hear a delay > when I play on the Piano which is always a bad sign. I do > not get a > noticeable delay when I play using an external synth. See > this link > for more info on my set-up. > > http://n2.nabble.com/Poll---What-system-are-you-running--td2595879.html > > Please tell me what I have to do to get fluidsynth to > run as close to > real time as possible so that I can improve the > instructions on the > PianoBooster web site. Please bear in mind that > PianoBooster also uses > the CPU fairly heavily and that I and other users are using > a netbook > which sits on top of the piano nicely so we also want > reduce > fluidsynth CPU usage (as well as Piano Booster CPU usage). > > Do you have an examples page for non technical users on how > to run > fluid synth? If there is not one, may I suggest it would be > very > useful addition. > > > Thanks > > L o u i s J a m e s B a r m an
to control latency you can use audio driver jack, or alsa directly. With Jack is quite easy to control de latency. Go to Setup in Jack Audio Connection Kit and tune periods, period size and sample rate. 5msec latency must be fine. You can see how fluidsynth create the alsa driver with your settings: $ fluidsynth -a jack -m alsa_seq AI-APiano02trans.sf2 ... creating alsa driver ... hw:0|hw:0|1024|2|44100|0|0|nomon|swmeter|-|32bit ... configuring for 44100Hz, period = 1024 frames (23.2 ms), buffer = 2 periods ... to calculate latency: (1024/44100)*2 = 46.4 msec if you avoid Jack and use alsa directly, I have my doubts in setting latency (help is appreciated): $ fluidsynth -a alsa -m alsa_seq -l AI-APiano02trans.sf2 > settings audio.periods 16 audio.period-size 64 synth.sample-rate 44100.000 -> 64 * 16 / 44100 = 23.2 ms these are default values. But if I try my own settings, I find the same settings. $ fluidsynth -m alsa_seq -a alsa -o synth.sample-rate=44100.000 audio.periods=2 audio.periods-size=32 -l AI-APiano02trans.sf2 > settings audio.periods 16 audio.period-size 64 synth.sample-rate 44100.000 How can I tune and control real latency using -a alsa? Another question is: If pianobooster is gonna be used by normal users... how to explain them all this staff? Of course, pianobooster needs low latency, and it will be necessary to use an rt kernel. I needed about six months to be confident with all these subjects, understand latency and XRuns... Joan Quintana http://wiki.empresalibre.org/index.php/P%C3%A0gina_principal#Inform.C3.A0tica_musical _______________________________________________ fluid-dev mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/fluid-dev
