[linux-audio-user] emu10k1 multichannel support

[Shayne O'Connor]

Lee Revell wrote:

>QuickStart:
>
>$ jackd -R -v -d alsa -P hw:0,3 -C hw:0,2 -S
>  
>
here's what i get here:

[mrmachine at localhost mrmachine]$ jackd -v -d alsa -P hw:0,3 -C hw:0,2 -S
-i 2 -o 4
getting driver descriptor from /usr/lib/jack/jack_oss.so
getting driver descriptor from /usr/lib/jack/jack_alsa.so
getting driver descriptor from /usr/lib/jack/jack_dummy.so
jackd 0.99.36
Copyright 2001-2003 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.
server `default' registered
loading driver ..
creating alsa driver ...
hw:0,3|hw:0,2|1024|2|48000|2|4|nomon|swmeter|-|16bit
ALSA: Cannot open PCM device alsa_pcm for playback. Falling back to
capture-only mode
control device hw:0
configuring for 48000Hz, period = 1024 frames, buffer = 2 periods
ALSA: cannot set channel count to 2 for capture
ALSA: cannot configure capture channel
cannot load driver module alsa
registered builtin port type 32 bit float mono audio
required capabilities not available
capabilities: = cap_ipc_lock,cap_sys_nice,cap_sys_resource+e
new client: alsa_pcm, id = 1 type 1 @ 0x805e040 fd = -1
starting server engine shutdown
freeing shared port segments
stopping server thread
last xrun delay: 0.000 usecs
freeing engine shared memory
max usecs: 0.000, engine deleted
no message buffer overruns
cleaning up shared memory
cleaning up files
unregistering server `default'
[mrmachine at localhost mrmachine]$

i patched alsa 1.0.8 with your updated patch, and it compiled and
installed ok ... then i just rebooted the computer. thing is, i merely
installed it over the already existing planetccrma alsa-driver - would
that be ok, or should've i removed the existing one first?

in any case, the wavetable synth still doesn't seem to be working ... at
least, the tables are loaded with the default sf banks, but no sound is
output if i program a midi line in muse.

i'm not sure i get what's happening using hw:0,2 and hw:0,3 instead of
plain old hw:0 ?

 anyway, this might all be a bit overwhelmingly confusing for me ...
without an interface like the kx-audio dsp manager, i'm a bit lost as to
routings etc ... (i've tried installing ld10k1, but the
init_soundblaster script fails to complete or load ... would the
capabilities your patch provides be accessible/routable through the
ld10k1 interface? that would indeed be good, and would encourage me to
get ld10k1 happening ...).

the *primary* capability i needed (seperation of the front and rear
channels for dj cueing) was solved while i was investigating how to
apply patches to source code and how to configure .asoundrc - all i
needed was this:

ctl.jack40 {
    type hw
    card 0
}

pcm.jack40 {
    # "asym" allows for different handling of in/out devices
    type asym
    playback.pcm {
        # route for mmap workaround
        type route
        slave.pcm surround40
        ttable.0.0 1
        ttable.1.1 1
        ttable.2.2 1
        ttable.3.3 1
    }
capture.pcm {
        # 2 channels only
        type hw
        card 0
    }
}

now i can have headphone cueing in mixxx/djplay ... now to figure out
how to get gdam cued up (it doesn't use jack, so i guess it might be a
slightly different .asoundrc configuration).

basically, what i'm hoping to achieve is:

*ability to access a kx-audio-style dsp routing interface that can load
dsp filters/effects (like the noise-gate in kx dsp that, in windows, i
would put between the ac97 in-port and the mixer input to reduce noise
when recording guitar). i'm guessing that ld10k1 would provide this ...

*ability to simultaneously access and route multiple audio/effect/synth
channels. i'm guessing your multi-channel patch would provide most of
the capabilities here?

i must apologise for my lack of technical knowledge in helping you test
this patch - my audio work has, i guess, pretty humble requirements:

*record guitar/bass/vocals into either ardour or muse.
*use soundfonts (preferably loaded into soundcard memory)
*i have no midi keyboard, so all my midi stuff is either doodling with
vkeybd, more complex doodling with zynaddsubfx, or - when
composing/recording - programming into muse/rosegarden.
*independent front/rear channels.

as a result, i'm not too hip with some of the more advanced linux audio
options ...


i'll let you know if i progress any further.

shayne