24 Dec
2004
24 Dec
'04
9:43 p.m.
On Fri, 24 Dec 2004 14:29:46 -0500, Lee Revell <rlrevell(a)joe-job.com> wrote:
On Fri, 2004-12-24 at 12:15 -0700, Mark Knecht wrote:
Maybe we cannot distinguish it but RME drivers can. I can set one to
auto sync and then on the other card tell it to be the master and
switch between 44K and 96K. The autosync end indicates the correct
frequencies.
I think it's certainly easier to know in advance which way you want to
run though.
- Mark
On 23 Dec 2004 21:53:34 -0800, Fernando
Lopez-Lezcano
<nando(a)ccrma.stanford.edu> wrote:
I also seem to recall there was some kind of an issue where you cannot
distinguish an incoming 44.1 stream for an 88.2 (or 48 from 96) stream
with half the number of channels, or something. This was either
discussed on the list, or maybe in the comments in the driver source.
Lee On Thu, 2004-12-23 at 20:11, Kevin Ernste wrote:
Hi,
Yes - there have been two or three threads about this, I think. The
number of 'user visible' channels does change between the two ranges.
RME 'binds' two channels running at 44.1K to make an 88.2K ADAT
channel. The ADAT interface itself does not run at 88.2K. It's just a
logical combination of the data on both channels to make it look like
the card is runnign 88.2K. (Or 2x48K to make 96K)
Unfortunately this is not a globally supported mode of operation
for ADAT devices. None of the Pro Tools hardware I have supports this.
It does work fine between RME cards though. > Range 1 - 44.1K/48K
> Range 2) 88.2K/96K
>
> Jack can switch between either rate in each range, but for whatever
> reason it cannot switch between the two ranges themselves.
Aha, this is precicely the behaviour I was looking for _across_ the
two ranges! As you say, sampling rates change happily within each
range, just not to/from rates in the other. In any case, I'm relieved
to know that it's not my setup (things are working remarkably well
now).
I may contact the developer (if only to thank him) and inquire about
this, it seems to me that ALSA or JACK should be able to inform
HDSPconf of a rate change regardless of speed/range. It is
particularily painful at the command line where I'm jumping back and
forth between rates all the time meaning HDSPconf is always open ;)
There was a thread long ago about this. I think the issue is that the
number of channels that the device supports change with the switch
between the two ranges of sampling rates. I don't remember why this was
a problem.
-- Fernando