[fluid-dev] Fluidsynth stops playing when stdout is piped

[John O'Hagan]

As I mentioned in a recent post ("Stopping fluidsynth via a socket"), I'm 
starting fluidsynth as a python subprocess and sending midi commands via either 
a socket or stdin. In either case there is a lot of unwanted screen output 
interspersed with my input, which I have tried to pipe like this:

subprocess.Popen(["fluidsynth", "-sli","-a", 'alsa', "-j", 
'/usr/share/sounds/sf2/FluidR3_GM.sf2'], stdout=subprocess.PIPE, 
stderr=subprocess.PIPE)

This renders the screen output invisible, but if I have a number of 
simultaneous connections sending commands, after a short time the audio stops, 
and when the program exits, all the missing notes are played at once!

The output of the pipes when the audio crashes is no different from the unpiped 
screen output. 

I really have no idea whether the problem is with (my understanding of) 
fluidsynth or pipes, but the reason I ask here first is this clue: if the audio 
crashes as above, but I leave the same instance of fluidsynth running, 
subsequent instances of my program which connect to it do not crash. I'm at a 
loss as to what that means.

Does anyone have any clues as to what might be happening?

Thanks,

John