AC100 USB Soundcard support using the AC100 2.6.29 Kernel

These instructions enables USB soundcard support so that various USB headsets can be used. This are currently work in progress, feel free to test it and report to the #ac100 IRC channel on irc.freenode.net if it work for you. Thanks!

It makes sense to install ubuntu-restricted-extras so that you can play some common audioformats
sudo apt-get install ubuntu-restricted-extras
(12.30.03) ogra_ac: xranby, usb soundcards work with some hacking
(12.30.49) ***ogra_ac listens to rhytmbox radio

ogra@ac100:~$ cat /etc/udev/rules.d/70-private-alsa.rules 
KERNEL=="controlC[0-9]*",       NAME="snd/%k"
KERNEL=="hw[CD0-9]*",           NAME="snd/%k"
KERNEL=="pcm[CD0-9cp]*",        NAME="snd/%k"
KERNEL=="midi[CD0-9]*",         NAME="snd/%k"
KERNEL=="timer",                NAME="snd/%k"
KERNEL=="seq",                  NAME="snd/%k"
ogra@ac100:~$ cat /etc/pulse/default.pa 
#!/usr/bin/pulseaudio -nF
#
# This file is part of PulseAudio.
#
# PulseAudio is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# PulseAudio is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with PulseAudio; if not, write to the Free Software Foundation,
# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

# This startup script is used only if PulseAudio is started per-user
# (i.e. not in system mode)

.nofail

### Load something into the sample cache
#load-sample-lazy x11-bell /usr/share/sounds/gtk-events/activate.wav
#load-sample-lazy pulse-hotplug /usr/share/sounds/startup3.wav
#load-sample-lazy pulse-coldplug /usr/share/sounds/startup3.wav
#load-sample-lazy pulse-access /usr/share/sounds/generic.wav

.fail

### Automatically restore the volume of streams and devices
load-module module-device-restore
load-module module-stream-restore
load-module module-card-restore

### Automatically augment property information from .desktop files
### stored in /usr/share/application
load-module module-augment-properties

### Load audio drivers statically (it's probably better to not load
### these drivers manually, but instead use module-hal-detect --
### see below -- for doing this automatically)
load-module module-alsa-sink device=hw:1
load-module module-alsa-source device=hw:1
#load-module module-alsa-source device_id=1
#load-module module-oss device="/dev/dsp" sink_name=output source_name=input
#load-module module-oss-mmap device="/dev/dsp" sink_name=output source_name=input
#load-module module-null-sink
#load-module module-pipe-sink

#### Automatically load driver modules depending on the hardware available
#.ifexists module-udev-detect.so
#load-module module-udev-detect
#.else
#### Alternatively use the static hardware detection module (for systems that
#### lack udev support)
#load-module module-detect
#.endif

### Automatically load driver modules for Bluetooth hardware
.ifexists module-bluetooth-discover.so
load-module module-bluetooth-discover
.endif

### Load several protocols
.ifexists module-esound-protocol-unix.so
load-module module-esound-protocol-unix
.endif
load-module module-native-protocol-unix

### Network access (may be configured with paprefs, so leave this commented
### here if you plan to use paprefs)
#load-module module-esound-protocol-tcp
#load-module module-native-protocol-tcp
#load-module module-zeroconf-publish

### Load the RTP reciever module (also configured via paprefs, see above)
#load-module module-rtp-recv

### Load the RTP sender module (also configured via paprefs, see above)
#load-module module-null-sink sink_name=rtp format=s16be channels=2 rate=44100 description="RTP Multicast Sink"
#load-module module-rtp-send source=rtp.monitor

### Load additional modules from GConf settings. This can be configured with the paprefs tool.
### Please keep in mind that the modules configured by paprefs might conflict with manually
### loaded modules.
.ifexists module-gconf.so
.nofail
load-module module-gconf
.fail
.endif

### Automatically restore the default sink/source when changed by the user during runtime
load-module module-default-device-restore

### Automatically move streams to the default sink if the sink they are
### connected to dies, similar for sources
load-module module-rescue-streams

### Make sure we always have a sink around, even if it is a null sink.
load-module module-always-sink

### Honour intended role device property
load-module module-intended-roles

### Automatically suspend sinks/sources that become idle for too long
load-module module-suspend-on-idle

### If autoexit on idle is enabled we want to make sure we only quit
### when no local session needs us anymore.
load-module module-console-kit

### Enable positioned event sounds
load-module module-position-event-sounds

### Cork music streams when a phone stream is active
#load-module module-cork-music-on-phone

# X11 modules should not be started from default.pa so that one daemon
# can be shared by multiple sessions.

### Load X11 bell module
#load-module module-x11-bell sample=bell-windowing-system

### Register ourselves in the X11 session manager
#load-module module-x11-xsmp

### Publish connection data in the X11 root window
#.ifexists module-x11-publish.so
#.nofail
#load-module module-x11-publish
#.fail
#.endif

### Make some devices default
#set-default-sink output
#set-default-source input
ogra@ac100:~$ 


(12.32.03) ogra_ac: thats what i needed
(12.32.51) ogra_ac: i think there is still some finetuning needed, but genrally sound seems to work fine with that over usb
(12.32.59) ogra_ac: (inozt and output)
(12.33.58) ogra_ac: oh, also sudo rm /usr/bin/pulseaudio; sudo cp /usr/bin/pulseaudio.orig /usr/bin/pulseaudio
ogra ogra_ac 
(12.34.24) ogra_ac: there are still some distortions, i guess i need to adjust default.pa a bit still
(12.34.44) xranby: ogra_ac: heh whats the difference between the pulseaudio.orig and pulseaudio    and wheree did the .org come from?
(12.34.49) ogra_ac: but with ubuntu-restricted-extras installed i can listen to radio just fine
(12.35.24) ogra_ac: its a diversion i added in the image, pulse eats 100% CPU if it tries to attach to the tegra soundcard
(12.35.58) xranby: ah
(12.36.09) ogra_ac: which it does because it wants to attach to the default interface (silly fallback igf it cant detect anything)
(12.38.15) ogra_ac: ok, distortion sorted too
(12.38.18) ogra_ac: load-module module-alsa-sink device=hw:1 tsched=0
(12.38.18) ogra_ac: load-module module-alsa-source device=hw:1 tsched=0
(12.38.32) ogra_ac: add the tsched=0 to these lines in default.pa
(12.39.12) ogra_ac: hmm, no, they seem to return
(12.40.08) ogra_ac: buut they dont stay
(12.40.09) ogra_ac: weird

(12.44.18) ogra_ac: try if it works for you first ;)
(12.44.22) xranby: have to test it when i get access to a usb soundcard, dont have any here at my office
(12.44.28) ogra_ac: ah
(12.45.13) ogra_ac: i recompiled my kernel with phh's patch, built tegra sound as modules to block the tegra modules from loading
(12.45.33) ogra_ac: so i'm not sure how pulse behaves if you still have them compiled in
(12.46.18) ogra_ac: the default.pa should prevent it from autodetection and it should fall back to the dummy device, but i havent tested