Minimum reasonable latency Was: Re: ZynAddSubFX was: Re: [linux-audio-dev] some new soundfiles on-line

[Florian Schmidt]

On Thu, 19 May 2005 17:40:41 +0200
Alfons Adriaensen <fons.adriaensen at alcatel.be> wrote:

> You shouldn't check for events int jack_process(), but in a separate
> thread, linked to jack_process() using a lock-free circular buffer for
> the [event+timestamp] data.

Of course. I assumed that you assumed that i know this :) But this is
not the problem. I still insist: To get constant latency you have to
take 2 periods worth latency into account. I cannot spell it out more
clearly than i have done. 

> To get really accurate timing in all cases, this thread should even have
> higher priority than the one created by jackd (*), otherwise all events that
> occur while a jack_process() is running will be delayed until the end
> of all processing for the current cycle.

Exactly.

> (*) but lower than jackd's master thread. This is currently not possible
> since the difference in priorities is just 1.

Flo

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