Re: [fluid-dev] Small CPU stuttering fluidsynth

[David Henningsson]

On 2011-01-27 23:04, Carma Trepp wrote:
> Thank you for your support. I`m fighting right now compiling FS with
> all the dependencies. Solved many. Now I have to find pkg-config.
>
> 2011/1/27 David Henningsson<address@hidden>:
> > On 2011-01-27 00:02, Carma Trepp wrote:
> > > Hi Element
> > >
> > > Thank you for your answer. I checked the device specifications from
> > > the ARM Cortex A8. And it have two Floating Point Units, a
> > > non-pipelined VFP-lite conforming to the IEEE754 standard for floating
> > > point arithmetic and a pipelined SIMD NEON coprocessor. Source:
> > > http://www.pandorawiki.org/Floating_Point_Optimization
> > > Its interesting that fluidsynth use CPU at 34% when nothing plays. The
> > > CPU itself is powerful. It runs PSX and N64 Emulation at fullspeed.
> >
> > Interesting. I think the 34% might be due to the reverb and/or chorus
> > engines still running although nothing plays. Assuming you're running Linux
> > on this device, can you provide perf output?
> >
> > As for 1.0.8, that's pretty ancient, please try upgrading to 1.1.2. Also, if

That should have been 1.1.3, which is the latest version.

Btw, on x86, what takes the most time is the interpolation, so you could 
try changing the interpolation method - this is a trade-off between CPU 
and sound quality though.

Also increasing the buffer sizes can help in some cases. Unless you need 
low latency, I recommend a buffer size of e g 4096 or 8192 instead of 
the default of 64.

Some people have also suggested lowering the sample rate.

// David