[fluid-dev] Re: SWAMI and fluidsynth (on OS X)

[Josh Green]

On Sat, 2004-03-20 at 06:59, Ebrahim Mayat wrote:
>         I'll dedicate some time to this in the next couple days,
>         andlet you
>         know how it goes. What is your impression of the 2 different
>         audio
>         drivers supported on OS X, Jack and CoreAudio?  Do you feel it
>         is worth
>         requiring Jack with FluidSynth? 
> 
> Hey Josh
> 
> Well, if you're using fluidsynth as the sole audio source then I
> wouldsay that CoreAudio is just as good as Jack and that there is no
> needfor Jack. On the other hand, in a studio setup, you would most
> likelybe using other music software in addition to fluidsynth. In this
> case,Jack is essential for routing the different audio
> signalssimultaneously. (Microprocessor use is about the same for both
> Jack(fluidsynth + Jack) and CoreAudio (fluidsynth by itself): see the
> twofiles attached with this message.)
> 

Thats a bit of CPU usage (~ 60%), were you pushing the synth during
those tests?

> I also applied Stéphane's patch to the fluid_midishare.c source filein
> FS, recompiled and re-installed. Now I am able to triggerfluidsynth
> from my external MIDI controller in addition to the"noteon"
> command-line and computer keyboard options. However, when Itry to play
> chords or even play fast passages for synth pads(SYNTH.SF2), Iget
> severe distortion on some notes while other notes do not sound.


This was actually what I was experiencing as well when I tested
FluidSynth on OS X (except I don't think I was having troubles with the
notes not sounding, they just sounded bad). Does it make a difference
whether you are using CoreAudio or Jack? Sometimes the FluidSynth gain
setting is too high, which causes clipping and you then need to turn it
down. You can find the gain parameter in Swami on the FluidSynth Control
dialog (Plugin menu -> "FluidSynth Control"). Or in FluidSynth directly
you can "set synth.gain 0.4" replacing 0.4 with different values.

>  IfI try the FMDreams.sf2 soundfont, no problem for playing
> fastpassages. So, I think that the latency between note triggering
> that Iexperience when playing SYNTH.SF2 is probably due to the long
> releasetimes in the envelopes of the synth sounds. I could probably
> edit thatusing SWAMI. Also, how does one control the degree of
> polyphony influidsynth and SWAMI for that matter?
> 

Latency can be caused by a number of things. If, like you said, you
experience the latency on only certain instruments, then it could very
well be the instrument. If its for all instruments then your audio
buffer size and count could be set high.
Unfortunately Swami is lacking in the FluidSynth settings area, so you
can't currently set the polyphony. In FluidSynth you can do a "set
fluidsynth.polyphony 256" for example, 256 is the default (not that your
machine can necessarily handle that).

> A new problem has now appeared in SWAMI. I am unable to launch
> SWAMIwhether Jack is running or not (see below):
> 
>         % swami
>         Message: Parsing config file
>         "/Users/ebrahimm/.swami/swami.cfg"
>         Message: Parsing config file
>         "/Users/ebrahimm/.swami/swami_state.cfg"
>         Message: Parsing config file
>         "/Users/ebrahimm/.swami/plugins.cfg"
>         Message: Parsing config file
>         "/Users/ebrahimm/.swami/plugin_state.cfg"
>         Message: Loading plugins from /usr/local/lib/swami
>         Message: Loading
>         plugin"/usr/local/lib/swami/samplelib_libsndfile.so"...
>         Message: Plugin "/usr/local/lib/swami/samplelib_libsndfile.so"
>         loaded
>         Message: Loading plugin
>         "/usr/local/lib/swami/wavetbl_fluidsynth.so"...
>         Message: Plugin "/usr/local/lib/swami/wavetbl_fluidsynth.so"
>         loaded
>         Message: Loaded 2 plugins
>         fluidsynth: debug: Using 'coreaudio' audio driver
>         
>         cannot connect to jack server
>         cannot connect to default JACK server
>         fluidsynth: debug: sampleRate 44100
>         fluidsynth: debug: mFormatFlags 0000000B
>         fluidsynth: debug: mBytesPerPacket 8
>         fluidsynth: debug: mFramesPerPacket 1
>         fluidsynth: debug: mChannelsPerFrame 2
>         fluidsynth: debug: mBytesPerFrame 8
>         fluidsynth: debug: mBitsPerChannel 32
>         fluidsynth: debug: Using 'midishare' midi driver
>         
>         dyld: swami Undefined symbols:
>         _MidiOpen
>         Trace/BPT trap
> 
> Could you explain the above diagnostic to me. It probably hassomething
> to do with enabling fluidsynth for external MIDI controllertriggering?

Actually, I'm not quite sure whats going on there. It seems MidiOpen is
part of MidiShare, and is used by the FluidSynth MidiShare driver.
FluidSynth is loaded into Swami as a plugin, and apparently its unable
to resolve the _MidiOpen symbol. The question becomes is the MidiShare
library getting loaded when the FluidSynth plugin is loaded but there is
some sort of library mismatch causing that symbol to not be found, or is
the MidiShare library not being loaded at all. I'm not sure really what
to tell you there since I don't know how to debug dynamic library issues
on OS X. Make sure you re-compile and install Swami (the plugins in
particular) if you change FluidSynth.

> I removed, recompiled and re-installed. The problempersists. By the
> way, in which source file could I find the "MidiOpen"function: can't
> seem to find it anywhere? Is there some kind ofdeveloper documentation
> for SWAMI: like the definitions of routines,classes, objects etc.?
> 

For Swami 1.x there is, for 0.9.x there isn't, so for this case, no.

> (By the way, the soundfont file VintageDrums.sf2 that I downloadedfrom
> <http://www.geocities.com/SiliconValley/Campus/8645/sf2.html> doesnot
> work.) 
> 

No sound from it?? Make sure you are playing notes in the 3rd octave,
since thats where all the drums are situated.

> What is the e-mail address for the SWAMI developer's mailing list? 
> 

Its in the CC, its address@hidden You'll need to
join the list to post:

http://lists.sourceforge.net/lists/listinfo/swami-devel


> Greetings.
> Ebrahim

Cheers,
        Josh Green