[linux-audio-user] emu10k1 multichannel support

[Lee Revell]

On Tue, 2005-01-25 at 15:52 +1100, Shayne O'Connor wrote:
> hi lee,
> 
> well, things are going *absolutely magnificently* with your emu10k1
> patch - i haven't really tested it at 128 frames, but it works
> brilliantly at 256 (i've tested it running ardour, hydrogen, muse, and
> two vst plugins + vkeybd at the same time - incredible!).
> 

Great!  I have found it's usable at 128 frames on my slow (600Mhz) box.
64 frames "works" in that there are no xruns but the sound is completely
distorted.  Maybe this would sound good on a faster machine or maybe
that's the lower limit of the hardware.  Interestingly 128 frames is the
lowest latency the kX driver supports, although 256 seems to be the
lowest usable latency under  Windows.

> my only problem, now that i've sort of got the hang of things, is
> recording - i don't seem to be able to isolate the ac97 input as before
> ... when i try to record guitar or vocals over other tracks in ardour,
> it keeps mixing the pre-recorded stuff with the line input stuff!! i'm
> sure it's just a mixer setting i have to adjust, but i don't know which
> .... it certainly doesn't seem to be the same adjustments i had to make
> before the patch?
> 
> so, can you tell me how to isolate the ac97 channel?
> 

Known problem.  Currently it captures the 16 channels which correspond
to physical outputs, so you can't isolate an input for capture.  This
setting is good for testing, you can connect meterbridge to all 16
outputs and monitor your output levels, which is handy if you want to
see which FX buses go to which outputs.  But it's not practical.  There
are 16 other channels that don't map to physical outputs, these only
record what you connect to them in the DSP manager.  This are the
channels the kX driver uses for ASIO capture.

The next version will capture these channels by default, but this
requires an update to the default DSP configuration, because the current
DSP config doesn't connect anything to them.  This way the multichannel
functionality will be usable without requiring ld10k1 to be installed.

Lee