What Parts of Linux Audio Simply Work Great? (was Re: [linux-audio-dev] Best-performing Linux-friendly MIDI interfaces?)

[Florian Schmidt]

On Thu, 16 Jun 2005 20:20:41 +0200
fons adriaensen <fons.adriaensen at skynet.be> wrote:

> > The price for this is afaik an extra period worth of latency. I'm not
> > sure this is the way to go. Sure it makes handling of devices easier
> > that do not generate irq's like pci soundcards do (all this USB and
> > IEEE1394 stuff), but isn't the price too high?
> 
> Why should this take a extra period of latency ? 

Ah, i remembered slightly incorrectly. Thanks Paul, for setting me
straight in #ardour. The thing is that the DLL based client thread
wakeup has the ever so slight possibility to do its thing too early.
Thus coreaudio waits a bit more (the "safety offset"). 

It seems this safety offset is driver specific but usually ranges from
64 to 32 frames (i have no definite source for this, just a bit of
googling). And with a sufficiently low period size used this accounts
for pretty much an extra period of latency..

Flo

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