Re: [fluid-dev] Windows Fluidsynth with PortAudio driver - Fails to create multiple instances of the PortAudio driver

[Pedro Lopez-Cabanillas]

On Monday 11 April 2011, Graham Goode wrote:
> Hi Guys,
> 
> I have finally been able to compile the SVN of fluidsynth with the
> recent SVN of the PortAudio WDMKS branch (with WDMKS and ASIO) [go
> cmake!!]. This is a great achievement for me as I have not been able
> to complete this without getting errors before...
> 
> Now this is my problem:
> 
> I use the Jack Audio Connection Kit as my ASIO source (which in other
> ASIO programs allows me to have multiple instances of ASIO all
> connecting to JACK). With Fluidsynth using the PortAudio ASIO
> interface I can only get one instance of fluidsynth to use the
> portaudio driver. If I attempt to load the PortAudio driver in a
> second instance in Qsynth then I get the "Failed to create audio
> driver (portaudio)..." error.
> 
> As there are situations where people have multiple ASIO devices
> (hardware or software), is there a way to overcome this situation? If
> so, is it a fluidsynth issue or a portaudio issue? From what little I
> know I would assume this was a fluidsynth driver loading issue...

I usually don't use PortAudio myself, and I am not interested in accepting the 
ASIO license terms, so I can't test a scenario similar to yours. Sorry if my 
answer doesn't help you too much.

Anyway, a similar problem happens when running two instances of FluidSynth with 
Jack or ALSA sequencer drivers, if you are using the same audio or MIDI client 
name for both instances. In both ALSA sequencer and Jack FS drivers there are 
settings allowing you to include the process number (pid) as part of the client 
name, exactly to avoid this problem. 

In Linux is not possible to run two instances of FluidSynth using the PortAudio 
driver with its Jack backend, because PortAudio creates a client simply named 
"PortAudio" in Jack. When you try to start a second FluidSynth instance, it 
fails to create the driver; maybe this is similar to your problem?

Regards,
Pedro