[mythtv-users] SPDIF Audio = no sound, Myth FE lockup in speaker test

[Kingsley Turner]

Greetings Earthlings,

A few weeks ago I basically replaced the inside of my HTPC. Reinstalled form 
Mythbuntu 12.04.2, Mythtv 0.27 + updates

The new motherboard did not have an SPDIF output port, (just a header) so I 
had to rely on HDMI output until the SPDIF rear panel bracket arrived.

Aside: Gigabyte lists this part as "optional", but their support said they 
don't sell them anymore.  HDMI audio worked poorly (in stereo). If the 
monitor went into power-save mode I had to reboot or logout for it to start 
working again.  Perhaps this is because I had to hardcode the EDID into 
X11/xorg.conf since the monitor would not be detected by the video card 
(Nvidia 610, with nvidia drivers) after it went into power-save.  Ho-hum.

So, the bracket is installed, the header connected.  I have the red light 
coming out of the Toslink(sp?) port, so I assume it's OK.  If I had the 5V 
or Ground miss-connected, this would not be the case, and the only remaining 
wire is the signal.

The amplifier has basically been sitting idle, so I just plugged the link 
back in to the new port.  I did check the volume, and amplifier settings.

I un-muted SPDIF in alsamixer.  Interestingly (confusingly) there's 3x SPDIF 
entries: "S/PDIF", "S/PDIF Default", "S/PDIF 16".  The first one defaults to 
being muted. FWIW: I also disabled "Auto-Mute Mode", whatever that is.

I went into Mythfrontend [Setup]->[Audio], then [ReScan].
The Audio Output Device defaulted to:  ALSA:iec958:CARD=PCH,DEV=0
Which looks good.  This is what it was set to with my old motherboard.
Dolby Digital and DTS are checked.
Speaker Config = 5.1
Upconvert Stereo to 5.1 sound is checked
Upmix Quality = Best

Which seems to match aplay -L and -l :
# aplay -L
[...]
iec958:CARD=PCH,DEV=0
     HDA Intel PCH, ALC887-VD Digital
     IEC958 (S/PDIF) Digital Audio Output
[... plus a truckload of others]

# aplay -l
card 0: PCH [HDA Intel PCH], device 0: ALC887-VD Analog [ALC887-VD Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 1: ALC887-VD Digital [ALC887-VD Digital]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
[... plus the NVidia HDMI]

If I then go into [Test]

The mythfrontend.log gets the messages:
    Nov  5 12:37:27 mediabox mythfrontend.real: mythfrontend[1536]: I 
CoreContext audio/audiooutputbase.cpp:792 (Reconfigure) AOBase: Opening 
audio device 'iec958:CARD=PCH,DEV=0' ch 2(6) sr 48000 sf signed 16 bit reenc 0
and
    Nov  5 12:37:47 mediabox mythfrontend.real: mythfrontend[1536]: E 
AudioOutputBase audio/audiooutputalsa.cpp:623 (WriteAudio) ALSA: WriteAudio: 
Write failed, state: 3, err: Input/output error

If I select [Center] nothing happens.  If I select it again, mythfrontend 
locks up.
(there's no additional mythfrontend.log)

I can kill the process, and it restarts OK.

Playing any sort of video results in no audio.

The only thing I can think of is that "aplay -l" says the digital output 
device is device 1, not 0.
But trying to use iec958:CARD=PCH,DEV=1 just fails.


Any ideas?