On 02/20/2016 03:46 AM, Markus Seeber wrote: > On 02/19/2016 11:46 PM, Robin Gareus wrote: > [...] > >> >>> Usually I use 48KHz p256 n2: >>> [rocketmouse@archlinux ~]$ jackd -dalsa -dhw:0 -r48000 -p256 -n2 >>> jackdmp 1.9.10 >>> Copyright 2001-2005 Paul Davis and others. >>> Copyright 2004-2014 Grame. >>> jackdmp comes with ABSOLUTELY NO WARRANTY >>> This is free software, and you are welcome to redistribute it >>> under certain conditions; see the file COPYING for details >>> no message buffer overruns >>> no message buffer overruns >>> no message buffer overruns >>> JACK server starting in realtime mode with priority 10 >>> self-connect-mode is "Don't restrict self connect requests" >>> audio_reservation_init >>> Acquire audio card Audio0 >>> creating alsa driver ... hw:0|hw:0|256|2|48000|0|0|nomon|swmeter|-|32bit >>> configuring for 48000Hz, period = 256 frames (5.3 ms), buffer = 2 periods >>> ALSA: final selected sample format for capture: 32bit integer little-endian >>> ALSA: use 64 periods for capture >>> ALSA: final selected sample format for playback: 32bit integer little-endian >>> ALSA: use 64 periods for playback >> >> and 64. >> >> I dimly recall seeing some message on LAU fly by about some RME devices >> requiring 16K buffers. >> >> If you have such a kernel/card, Ardour/ALSA won't currently support it >> directly, sorry. >> > > That is correct, the AIO, same as the RayDAT has a fixed buffer of 16K. > This means that regardless of the requested number of periods and frame > size, it will always report a buffer size of 16K and a number of periods > equal to buffersize divided by framesize. Thanks for confirmation. > Never the less, if requested 2 > periods with framesize of 64 samples, the card will still work correctly > and have a latency that corresponds to 2 frames of 64 samples. What is the case for exposing those this to userland? I ask for two, I get behavior of two, but when checking the parameters the value is 16. That sounds like a bug to me. Did anyone flag this up at ALSA-dev, or report a bug? > As said before, there are applications that make (most likely too many) > assumptions about these numbers and therefor break with these cards. Ardour is not as forgiving as JACK. if a call to a snd_pcm_hw_params_* fails or if the requested value does not match the one reported by the card, it constitutes hard failure. best, robin _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
