Re: [fluid-dev] MIDI stutters when I move windows

[Josh Green]

On Thu, 2003-11-20 at 12:29, Florian Schmidt wrote:
> On Thu, 20 Nov 2003 16:37:58 -0300
> Menteco <address@hidden> wrote:
> 
> > I still don't what for do you suggest to run jack. Do the low latency 
> > kernel patches depend on or work just while jack is running?
> > I have installed jack and jackd. Should I need to load/run any of them
> > 
> > at startup of my gnome session?
> 
> i suggest that because fluidsynth runs beautifully here together with
> jack. I suppose running fluidsynth as root will work pretty good to. I
> like the jack solution, because fluidsynth doesn't need to run as root
> then and because i use jack for other stuff so it integrates nicely..
> 
> Flo

You shouldn't really need Jack though to stop stuttering or clicks in
audio. Jack is nice for routing audio, but not necessary for low latency
response (although it does help achieve that). In fact Jack won't solve
your problem with MIDI anyways. In the case of using a separate program
to generate the MIDI, that program needs to have low latency capability
as well. If you are just running FluidSynth stand alone, then its just
sufficient to run it as root, or SUID it as root if you want to run it
as a normal user (a security hole BTW, if you are concerned about
security make it only executable by you by changing the group of the
binary to be your personal group "chgrp yourgrp /path/to/fluidsynth" 
and turn off rwx permissions for everyone else "chmod o-rwx
/path/to/fluidsynth", I usually don't worry about this on my systems
though). To play a MIDI file with FluidSynth you can do:
fluidsynth [options] [soundfonts] [midifiles]

With 2.4.x kernels these days, you can usually get fairly good response
without applying any low latency patches, but if you want that real
hardcore professional feel, it makes sense :) I imagine if you are just
trying to play a MIDI file for web pages, you probably don't need lowlat
patches.

On a some what unrelated note I'm just realizing right now that there
isn't a way to set the interpolation algorithm. This has a drastic
effect on CPU consumption and the like. There should probably be a
settings parameter for it. I believe the default is 4th order
interpolation, but I suppose linear could be used for much less CPU
usage, I haven't tested it much myself. Cheers.
        Josh Green