It turns out I am doing something very wrong, and i *can* get much lower latency’s even with the large buffersize.
I could not get jack_delay itself to work (it wouldn’t connect to any ports no matter what i tried), but i did use jack rather than my own alsa implementation and with a period size of 32 samples @ 48KHz I measured a roundtrip delay of around 169 samples (3.5 ms), which is very reasonable. The method I used was perhaps a bit crude, so it could be off by a few samples. But it seems accurate enough. (I used another soundcard on a different machine, and plugged one output straight back in, and the other went through the converter /madi fx / jack and then back in. The difference in timing should be the rtd). So now i am a but confused how to get the same kind of latency in my own code (using alsa directly rather than through jack) Basically what happens is when i have a buffersize of 8192 and a period of 32 is that snd_pcm_avail_update(capture_handle), will keep returning 0 until i have played back the full 8192 samples. After that I will start receiving input samples, but obviously the latency is now more than 8182 samples… How can i make alsa not wait until the entire buffer is full? best, Fokke > On Feb 3, 2016, at 15:40 , Jörn Nettingsmeier <[email protected]> > wrote: > > On 02/03/2016 02:54 PM, Fokke de Jong wrote: >> Hi Adrian, >> >> I could’ve guessed you were on this list as well :-) >> I’m going to try this tomorrow when back in the studio, or maybe I can even >> do it remote if I have left everything patched up correctly :-) >> >> I will come back with the results. >> Thanks for your input! >> >> fokke > > watching this with interest, keep us posted about your results and > longer-term experience with this card! > > > best, > > > jörn > > > > > -- > Jörn Nettingsmeier > Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 > > Meister für Veranstaltungstechnik (Bühne/Studio) > Tonmeister VDT > > http://stackingdwarves.net > > _______________________________________________ > Linux-audio-dev mailing list > [email protected] > http://lists.linuxaudio.org/listinfo/linux-audio-dev _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
