Re: [fluid-dev] What is the best way start fluidsynth with zero/low latency?

[David Henningsson]

Louis B. skrev:
> 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. 

The recent Ubuntu versions will try to route things through pulseaudio,
which introduces some latency. I would suggest you add the following
options:

-a alsa -o audio.alsa.device=hw:0

Selecting the right alsa device could be a jungle for the novice, but
shortly: where "hw:0" is the suggested sound output, it is "hw:0" for
your first soundcard, "hw:1" for your second etc. If that fails with a
message "could not find a suitable audio format", you can try "plughw:0"
 instead of "hw:0", although that will increase the CPU consumption a bit.

// David