Re: [Alsa-user] Output latency

2008-06-12 Thread Alexander Carôt
Hola Jochen and all, > yes, of course it is a trade-off between xruns and delay, but i do > that adaptively as well - start with a quite low framing, measure the > drop-out rate and reopen the soundcard in case of too much drop-outs. > this only impacts the quality of the start-up phase and

Re: [Alsa-user] Output latency

2008-06-11 Thread Alexander Carôt
Hi Jochen, > 2. use a lower frame size, than my codec/systems framing. (e.g. 128 > instead of 256, but still transmit 256 in one pass) Yes - a good idea, however, sometimes depending on the actual machine and OS (or even low-latency patches) problems might occur when running below 256 samples

Re: [Alsa-user] Output latency

2008-06-11 Thread Alexander Carôt
en" <[EMAIL PROTECTED]> > An: "Clemens Ladisch" <[EMAIL PROTECTED]> > CC: alsa-user@lists.sourceforge.net, "Alexander Carôt" <[EMAIL PROTECTED]> > Betreff: Re: [Alsa-user] Output latency > Did you try the settings in /etc/security/limits.conf sugges

Re: [Alsa-user] Output latency

2008-06-11 Thread Helge Fredriksen
Did you try the settings in /etc/security/limits.conf suggested on the Frinika front page? (http://frinika.sourceforge.net). I noticed quite some difference in delay for Terratec Aureon 5.1 Fun cards using JavaSound. Helge F. On Wed, Jun 11, 2008 at 10:11 AM, Clemens Ladisch <[EMAIL PROTECTED]> w

Re: [Alsa-user] Output latency

2008-06-11 Thread Clemens Ladisch
Alexander Carôt wrote: > 3.) Rather than using a double buffer for the playout wouldn't it be > possible to choose only one physical playout buffer and parse the > captured data in right at the interrupt. It's unlikely that any code could be fast enough to write the entire buffer before the hardwa

Re: [Alsa-user] Output latency

2008-06-11 Thread Clemens Ladisch
stan wrote: > Florian Faber wrote: > > You want hardware monitoring - there are sound cards that support > > hardware mixing. With good converters you have latencies down to 5 > > samples at 192kHz, that would be 0.026ms for each way, 0.052ms over > > all. > > I'm not the original poster, but I'm c

Re: [Alsa-user] Output latency

2008-06-10 Thread stan
Alexander Carôt wrote: >> If I understand your question correctly, it is because they use two >> different buffers. If you aren't trying to play the capture buffer, it >> would wreak havoc to try to use it for playback while capture is going >> on. So there is a buffer for capture and a buffer

Re: [Alsa-user] Output latency

2008-06-10 Thread Alexander Carôt
> I think you would have to customize the driver to do this. In the > special case that you are playing back the recorded input, you write the > input buffer directly to the output buffer every time the input buffer > interrupts because it is time to empty it. Adds an extra branch in the > dr

Re: [Alsa-user] Output latency

2008-06-10 Thread stan
Florian Faber wrote: > Alex, > > >> The idea is the following : >> >> 1.) Of course there has to be an input double buffer which generates >> the desired block of samples. >> > > You want hardware monitoring - there are sound cards that support > hardware mixing. With good converters you

Re: [Alsa-user] Output latency

2008-06-10 Thread Alexander Carôt
Hej, thanks for getting back to me. > What do you want to do? Realtime monitoring/mixing? As subject of my PhD research I am working on realtime network music performances. In other words : I am bassplayer and I play livemusic via the Internet with people in different locations. http://www

Re: [Alsa-user] Output latency

2008-06-10 Thread Florian Faber
Alex, > The idea is the following : > > 1.) Of course there has to be an input double buffer which generates > the desired block of samples. You want hardware monitoring - there are sound cards that support hardware mixing. With good converters you have latencies down to 5 samples at 192kHz, t

Re: [Alsa-user] Output latency

2008-06-10 Thread Alexander Carôt
> If I understand your question correctly, it is because they use two > different buffers. If you aren't trying to play the capture buffer, it > would wreak havoc to try to use it for playback while capture is going > on. So there is a buffer for capture and a buffer for playback. And > each

Re: [Alsa-user] Output latency

2008-06-09 Thread stan
Alexander Carôt wrote: > Hi all, > > can anyone give me an explanation why the blocking delay of a soundcard > appears twice using the ALSA driver ? E.g. with 48 kHz at 128 samles / frame > I understand that the capturing process requires 2,6 ms to actually fill one > block of audio samples (= b

Re: [Alsa-user] Output latency

2008-06-09 Thread Mark Knecht
On Sun, Jun 8, 2008 at 5:12 AM, "Alexander Carôt" <[EMAIL PROTECTED]> wrote: > Hi all, > > can anyone give me an explanation why the blocking delay of a soundcard > appears twice using the ALSA driver ? E.g. with 48 kHz at 128 samles / frame > I understand that the capturing process requires 2,6