[alanwww1]

PART 2: SETTING UP THE SYSTEM THE ALSA WAY

Note once again that you loose software mixing if you choose this way.
When coming back from reboot, we create a custom virtual alsa device because in nvidia driver, speaker channels are wrongly set up, so we need to change the speaker channel configuration. For this i created a "remap-surround71" virtual device in this file:

Code:

sudo wget http://pastebin.com/pastebin.php?dl=f5f9654bb -O /etc/asound.conf
sudo dos2unix /etc/asound.conf

To tell the system to actually use this as a default digital output leaving the predefined hdmi device alsa definition. I created a custom HDA-Intel conf file for alsa. With this file we achieve that all ubuntu playback applications (including xbmc-tested, vlc-tested) will use default,hdmi,surround51,surround50 etc. vitrual devices as remapped channel configurations directed to your hdmi output without mixing.

Code:

sudo cp /usr/share/alsa/cards/HDA-Intel.conf /usr/share/alsa/cards/HDA-Intel.conf_backup
sudo wget http://pastebin.com/pastebin.php?dl=f2e38265 -O /usr/share/alsa/cards/HDA-Intel.conf
sudo dos2unix /usr/share/alsa/cards/HDA-Intel.conf

We will unmute the needed channels and store these settings:

Code:

/usr/bin/amixer -q -c 0 sset 'Master',0 unmute && /usr/bin/amixer -q -c 0 sset 'Master',0 100
/usr/bin/amixer -q -c 0 sset 'IEC958 Default PCM',0 unmute
/usr/bin/amixer -q -c 0 sset 'IEC958',0 unmute && /usr/bin/amixer -q -c 0 sset 'IEC958',1 unmute
sudo alsactl store

Now we can test if everything went ok. First let's check out the Alsa Driver version and the available playback devices:

Code:

cat /proc/asound/version
aplay -l
alsamixer

The alsa driver version should be 1.0.21
aplay -l should show a HDMI device on card 0 device 3
alsamixer should show three iec devices, all has to be unmuted.

For gnome-desktop users who want to have this feature, knowing that they loose software mixing of system sounds set up sound configuration like this:



We'd better have a reboot now and after we can start testing sound. For speaker test to work it is needed to have the xserver started. So you need to type these commands into an xterminal (or gnome terminal) or you need to start the xserver (maybe with xbmc) and ssh over another machine to run these commands. First er test a basic 2 channel 48/16 configuration, than we jump to the most advanced 192/32 6 channel configuration. (You can stop testing with crtl+c)

Code:

speaker-test -Dhdmi -c2 -r48000 -FS16_LE
speaker-test -Dhdmi -c6 -r192000 -FS32_LE

With these command you can easily test your speak configuration if all channels sound in the right speaker.

XBMC SETUP ALSA WAY

If everything is ok now we just have to set up xbmc to use our tuned hdmi device. It will be very easy with one little trick. On sound settings just set it like this (note that looks like in the latest SVN and probably will be in 9.10)

Note that in older xbmc revisions just type "hdmi" for both devices.

As we lost software mixing capabilities (just like we wanted) we need to disable crossfading in xbmc's music settings like this:


There is one trick which has to be done to keep navigation sound all the time. There is a bug (xbmc or alsa) that when you play ac3, dts track and press spacebar to pause 2-3 secs and start playback again, you loose navsounds until restarting xbmc. See ticket: http://trac.xbmc.org/ticket/7338

To correct this do as follows:

Code:

cp /usr/share/xbmc/system/keymaps/remote.xml .xbmc/userdata/keymaps/remote.xml
cp /usr/share/xbmc/system/keymaps/keyboard.xml .xbmc/userdata/keymaps/keyboard.xml
nano .xbmc/userdata/keymaps/*.xml

In both files at global settings change "Pause" to "Play"

That's it, now it is all done !!

As a help here are a lot of test files (audio and video)
With for ex. the dts file you can test pass through with hdmi.
With the aac file you can test the multichannel LPCM capability of your setup etc.

Dedicated server with testfiles

It was a bit rough isn't it, but it is worth it. It will be more and more simpler as we go in time. I will try to update this guide to keep up to date as kernels, xbmc, alsa changes. Any suggestions, contributions wellcome. I hope it will work for everyone.


REVERT CHANGES FROM ALSA WAY

If you would like to revert back what we've don just do it as follows:

Code:

rm /etc/asound.conf
sudo cp /usr/share/alsa/cards/HDA-Intel.conf_backup /usr/share/alsa/cards/HDA-Intel.conf
cd ~
sudo ./Alsa_upgrade-1.0.21_hd.sh -r
sudo rm -rf /usr/src/Alsa*

And of course set pulseaudio in gnome sound settings as it wes.

RECOMPILE THE KERNEL MODULE AFTER KERNEL UPGRADE

If you regulary upgrade ubuntu packages you can run into kernel upgrades from time to time.
These overwrites our custom hda kernel modules. To recompile do as follows:

Code:

cd /usr/src/Alsa* && cd alsa-driver*
sudo make clean
sudo ./configure --with-cards=hda-intel --with-kernel=/usr/src/linux-headers-$(uname -r)
sudo make
sudo make install
sudo reboot

Or alternatively you can re-run the upgrade script.