linuxaudio.org

On 07/12/2010 09:47 PM, fons@kokkinizita.net wrote:

quoted text
> On Mon, Jul 12, 2010 at 09:30:05PM +0100, Rui Nuno Capela wrote:

>

>> problem is that input buffers are always read before any output signal

>> is produced, while on the same process period cycle. iow, you're

>> consuming what hasn't been produced yet. that's why you'll probably get

>> silence, at best.

>

> This should still work, you should get the output from the

> previous cycle. Unless

>

> 1. you clear outputs before reading inputs, and

> 2. Jack is using the same buffer for the feedback input

> and the output that connects to it.

> 

yep, all outputs are zeroed at each cycle. i suspect some potential

garbage could be injected in the process otherwise...
> (2) is an Jack bug wich I reported at least a year ago.

quoted text
> Don't know if it has been fixed. You can work around it

> by connecting a second (silent) output to the feedback

> input - this stops Jack sharing the buffer. Or insert

> a dummy client as you suggested.

> 

i think that's the "zero-copy" optimization that jack pursues when ports

are single connected?
byee

--

rncbc aka Rui Nuno Capela

rncbc@rncbc.org

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