[linux-audio-user] JACK samplerate stuck at 48000

[Lee Revell]

On Wed, 2006-06-21 at 02:02 +0000, Cesare Marilungo wrote:
> Lee Revell wrote:
> 
> >On Tue, 2006-06-20 at 10:24 -0700, Mark Knecht wrote:
> >  
> >
> >>Many built-in/inexpensive sound cards are stuck at 48K. Possibly this
> >>one is also?
> >>
> >>    
> >>
> >
> >It's still a bug for JACK not to report any error.
> >
> >Does aplay report any errors with a 44100Hz file?
> >
> >  
> >
> In fact it happens on my laptop (it has a VIA AC97 chip). Jack does 
> report the sample rate you choose but the other applications connect to 
> it at 48000Hz.
> 
> I guess it is because they're designed to play dvds (which are at 
> 48000Hz) and they don't have a built-in sample rate converter. Maybe 
> JACK assumes they always have one since it is designed for high end cards?
> 

I think cards defaulted to 48000Hz before DVDs existed.  I believe the
AC97 spec requires it and it's cheapest to support a single sample rate
and rely on a software sample rate converter for everything else.

Lee

> >>- Mark
> >>
> >>On 6/20/06, Link Swanson <link at sumerianbabyl.com> wrote:
> >>    
> >>
> >>>After removing my Multiface II and switching back to my nVidia onboard
> >>>audio, qjackctl will not run at 44100. I can set it in the setup window
> >>>and it reports starting 44100 in the messages:
> >>>
> >>>11:07:46.232 Patchbay deactivated.
> >>>11:07:46.322 Statistics reset.
> >>>11:07:46.498 MIDI connection graph change.
> >>>11:07:46.528 MIDI connection change.
> >>>11:07:47.580 Startup script...
> >>>11:07:47.580 artsshell -q terminate
> >>>11:07:47.861 Startup script terminated with exit status=256.
> >>>11:07:47.861 JACK is starting...
> >>>11:07:47.862 jackd -R -dalsa -dhw:1,0 -r44100 -p512 -n2 -S
> >>>11:07:47.870 JACK was started with PID=3071 (0xbff).
> >>>jackd 0.101.0
> >>>Copyright 2001-2005 Paul Davis and others.
> >>>jackd 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
> >>>JACK compiled with System V SHM support.
> >>>loading driver ..
> >>>Enhanced3DNow! detected
> >>>SSE2 detected
> >>>apparent rate = 44100
> >>>creating alsa driver ... hw:1,0|hw:1,0|512|2|44100|0|0|nomon|swmeter|-|16bit
> >>>control device hw:1
> >>>configuring for 44100Hz, period = 512 frames, buffer = 2 periods
> >>>nperiods = 2 for capture
> >>>nperiods = 2 for playback
> >>>11:07:49.953 Server configuration saved to "/home/bozone/.jackdrc".
> >>>11:07:49.954 Statistics reset.
> >>>11:07:49.979 Client activated.
> >>>11:07:49.980 Audio connection change.
> >>>11:07:49.981 Audio connection graph change.
> >>>Enhanced3DNow! detected
> >>>SSE2 detected
> >>>11:10:21.095 MIDI connection graph change.
> >>>11:10:21.123 Audio connection graph change.
> >>>11:10:26.482 Audio connection graph change.
> >>>11:10:26.504 MIDI connection graph change.
> >>>
> >>>But then both qjackctl and Ardour report 48000 as the samplerate.
> >>>
> >>>All help is appreciated.
> >>>
> >>>Link
> >>>
> >>>
> >>>--
> >>>e-mail is . . .
> >>>
> >>>      
> >>>
> >
> >
> >
> >  
> >
> 
>