[mythtv-users] RE: Configuring SPDIF digital out.

[Marius Schrecker]

> I finally got it working.
>
> Here is what I did to enable spdif output to my amp when I switched from a
> SB Live! 5.1 analog surround card to the on-board audio on my Asus
> motherboard.
>
> The obvious first step was to remove the SB Live! Card from the PC. During
> the Power On Self Test (POST), I entered the BIOS settings and enabled the
> on-board audio. Saved the settings ant continued with the boot up.
>
> KDE informed me that the default audio device was missing. I went to the
> Start menu --> System Settings --> Soundcard Detection. KDE found my
> Soundcard and played a test tune. The analog sound was coming out of my TV
> Speakers and nothing was coming out of my Receiver.
>
> I opened up a terminal and typed alsamixer.  I was given an error message
> :
>
> alsamixer: function snd_ctl_open failed for default: no such file or
> directory.
>
> Googling for that error led me to believe that my modprob.conf file was to
> blame so. . .
>
> # (any text editor) /etc/modprob.conf
>
> -----Before------
>
> alias eth0 sk98lin
> options snd-emu10k1 index=0
> remove snd-emu10k1 { /usr/sbin/alsactl store 0 >/dev/null 2>&
> 1 || : ; }; /sbin/modprobe -r --ignore-remove snd-emu10k1
> alias char-major-81 cx8800
> alias usb-controller ehci-hcd
> alias usb-controller1 uhci-hcd
> alias ieee1394-controller ohci1394
> # nvidia kernel module
> alias char-major-195 nvidia-1_0-7174
> alias nvidia nvidia-1_0-7174
> options snd-intel8x0 index=1
> remove snd-intel8x0 { /usr/sbin/alsactl store 1 >/dev/null 2>&1 || : ; };
> /sbin/modprobe -r --ignore-remove snd-intel8x0
> alias snd-card-0 snd-intel8x0
> options snd-card-0 index=0
> options snd-intel8x0 index=0
> remove snd-intel8x0 { /usr/sbin/alsactl store 0 >/dev/null 2>&1 || : ; };
> /sbin/modprobe -r --ignore-remove snd-intel8x0
>
> The intel8x0 is my on-board audio device, and the emu10k1 was my old card.
> I
> commented out the lines referencing my old sound card and made a few
> number
> changes in the file. This is my file after editing it.
>
> -------After--------
>
> alias eth0 sk98lin
> #options snd-emu10k1 index=0
> #remove snd-emu10k1 { /usr/sbin/alsactl store 0 >/dev/null 2>&
> 1 || : ; }; /sbin/modprobe -r --ignore-remove snd-emu10k1
> alias char-major-81 cx8800
> alias usb-controller ehci-hcd
> alias usb-controller1 uhci-hcd
> alias ieee1394-controller ohci1394
> # nvidia kernel module
> alias char-major-195 nvidia-1_0-7174
> alias nvidia nvidia-1_0-7174
> #changed index=1 to index=0 and ... store 1 to store 0
> options snd-intel8x0 index=0
> remove snd-intel8x0 { /usr/sbin/alsactl store 0 >/dev/null 2>&1 || : ; };
> /sbin/modprobe -r --ignore-remove snd-intel8x0
> alias snd-card-0 snd-intel8x0
> options snd-card-0 index=0
> options snd-intel8x0 index=0
> remove snd-intel8x0 { /usr/sbin/alsactl store 0 >/dev/null 2>&1 || : ; };
> /sbin/modprobe -r --ignore-remove snd-intel8x0
>
> I rebooted and still no dice. Same error message from alsamixer. I tried
> creating a .asoundrc file like like the example on the ALSA website.
>
> $ vi /home/mythtv/.asoundrc
>
> pcm.intel8x0 {
>    type hw
>    card 0
> }
>
> ctl.intel8x0 {
>    type hw
>    card 0
> }
>
> Still no digital sound. I attempt to run alsamixer and receive this error
> message:
>
> alsamixer: relocation error: alsamixer: symbol
> snd_mixer_selem_get_playback_dB, version ALSA_0.9 not defined in file
> libasound.so.2 with link time reference
>
> After a few Google’s, I find out what needs to be done.
> It is time to update drivers and such. But first a little house cleaning.
>
> # mv /usr/lib/libasound.so.2 moved.libasound.so.2
> # mv /usr/lib/libasound.so.2.0.0 moved.libasound/so/2/0/0
>
> --- I later went back and deleted them but you can’t be too careful ---
>
> # yum install alsa-utils
> # yum install alsa-lib
> # yum install alsa-driver
>
> I tried alsamixer again and it worked.
> In alsamixer I un-muted IEC958, turned ICE958 Playback all the way down,
> set
> ICE958 Playback source to [AC-Link], un-muted External Amplifier, turned
> <PCM> and <Master> up to 90%. ESC to exit.
>
> --- I don’t know if all of this was necessary, but it worked for me. ---
>
> I started up mythfrontend, and navigated to Utilities/Setup -> Setup ->
> General. On the 3rd page I selected “Enable AC3 to SPDIF passthrough” and
> “Audio output device” was already on “/dev/dsp”.
> Finish going through the menu’s in order to make the settings take effect.
> After I verified that it worked, I spent a few minutes patting myself on
> the
> back, and then decided to save my settings.
>
> #  /usr/sbin/alsactl store
>
> --  That’s it. I hope someone can find this information useful. -Mat
>
Thanks! I may well find the last bit very useful! I have the libasound2
libs installed and have been banging my head tyrying to det spdiff out
working (and it was working fine on the same box in a previous
incarnation).

Will try doing what you suggested with the libasound libraries.

Cheers

Marius