[mythtv-users] Audio not working via coax/spdif

[Alen Edwards]

Mir Islam wrote:
> Hi just got a new sound card Diamond extreme with coax output. The sound 
> is working fine outside of MythTV in regular desktop but not in MythTV.
>
> In MythTV I have audio setup as following:
>
> Audio Output Device: ALSA:spdif
> Passthrough: ALSA:IEC958{AES0 0x02}
> Max Audio Channels: 5.1 Upmix: Passive
> Enable AC3/DTS to SPDIF passthrough checked
>
> But no sound comes out of my AV receiver. I can start mplayer and play 
> DVD or recorded programs from hard disk fine and AV receiver correctly 
> identifies number of channels etc. In MythFrontend log I see this error:
>
> 2008-06-29 14:33:54.596 AFD: Opened codec 0x138f550, id(MPEG2VIDEO) 
> type(Video)
> 2008-06-29 14:33:54.596 AFD: codec AC3 has 2 channels
> 2008-06-29 14:33:54.597 AFD: Opened codec 0x13d3150, id(AC3) type(Audio)
> 2008-06-29 14:33:54.599 Opening audio device 'spdif'. ch 6(2) sr 48000
> 2008-06-29 14:33:54.599 Opening ALSA audio device 'iec958:{ AES0 0x02 }'.
> 2008-06-29 14:33:54.698 AudioOutput Error: Channels count (6) not 
> available: Invalid argument
> 2008-06-29 14:33:54.698 AudioOutput Error: Unable to set ALSA parameters
> 2008-06-29 14:33:54.698 NVP: Disabling Audio, reason is: Unable to set 
> ALSA parameters
>
>
> Some other info:
>
> In mplayer config I have ac=hwac3.
>
> mislam at neptune:~$ aplay -l
> **** List of PLAYBACK Hardware Devices ****
> card 0: CMI8768 [C-Media CMI8768], device 0: CMI8738-MC8 [C-Media PCI 
> DAC/ADC]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> card 0: CMI8768 [C-Media CMI8768], device 1: CMI8738-MC8 [C-Media PCI 
> 2nd DAC]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
> card 0: CMI8768 [C-Media CMI8768], device 2: CMI8738-MC8 [C-Media PCI 
> IEC958]
>   Subdevices: 1/1
>   Subdevice #0: subdevice #0
>
>
> Thanks
> Mir

Have you tried "default" as the audio output device?  Keep your bypass 
device as is and you should get spdif out.

Allen