[mythtv-users] Digital Audio Passthrough not working Mythtv 0.24-fixes

[David Knight]

On Wed, November 10, 2010 8:38 pm, Jean-Yves Avenard wrote:
> Hi
>
> On 11 November 2010 03:21, David Knight <dlknight at sdf.lonestar.org> wrote:
>
>>
>> When running the scan process "ALSA:default" isn't detected however
>> "ALSA:default:CARD=Nvidia" is detected but shows "No digital
>> passthrough"
>> under Audio capabilities. I have been manually entering "ALSA:default"
>> as
>> the audio output device.
>
>
> What does the audio device description shows in the settings (bottom
> of the page). It probably is showing as analog and is reporting a
> maximum of 6 channels support.
> I'd like to get that information please.

With "ALSA:default" = Device support up to 5.1 (AC3,DTS,)

With "ALSA:default:CARD=NVidia" = HDA NVidia, ALC1200 Analog, Default
Audio Device, Device supports up to 2.0.

With "ALSA:iec958:CARD=NVidia,DEV=0" = HDA NVidia, ALC1200 Digital, IEC958
(S/PDIF) Digital Audio Output, Device supports up to 5.1 (digital output,
AC3,DTS,)

I have other configurations available for HDMI and analog outputs (2.0 up
to 7.1).

>
> Unfortunately, your particular use isn't supported.
> Myth relies on the capabilities reported by ALSA on the primary device
> to determine what your system can do.
>
> My guess is that your card reports 6 channels support, and be an
> analog interface, so DTS and AC3 are disabled in the settings.
>
> By manually entering ALSA:default you are effectively overriding all
> the settings and prevent myth of doing its job as it is designed to
> do. To verify that it is indeed the case, after entering ALSA:default,
> press the Scan devices , and see at the bottom what the device report.
>
> That it worked before was a matter of luck really and now that it is
> more tightly controlled you can't do it anymore.
>
> Will have to think on how to enable a use case for your particular usage.
>

Well I've set the Audio output device to S/PDIF now and audio output is
working fine. I guess I need to enable the software mixer if I want to
regain volume control from within Myth?

Only time I use Analog is if I just want to output audio to the TV
speakers rather than the surround sound speakers. But I really should sort
out the HDMI output for that. Is there a possibility of enabling both
S/PDIF and HDMI output simultaneously for Myth?

Cheers

Dave