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 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 curious

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 hardware

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]

Re: [Alsa-user] Output latency

2008-06-11 Thread Alexander Carôt
] 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 suggested on the Frinika front page? (http://frinika.sourceforge.net). I noticed quite some

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

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 has

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, that

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.

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 have latencies

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 driver

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 for

[Alsa-user] Output latency

2008-06-09 Thread Alexander Carôt
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 (= blocking delay of 2,6 ms).

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 ms to

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 (=