[mythtv-users] MythTV 0.24 HDMI audio problem

[Jean-Yves Avenard]

Hi

On Friday, November 19, 2010, Steven Adeff <adeffs.mythtv at gmail.com> wrote:
> On Wed, Nov 17, 2010 at 6:11 PM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:
>> On 18 November 2010 06:28, Mr. Duncan McDonald
>> <duncan.john.mcdonald at gmail.com> wrote:
>>> Hi folks,
>>>
>>> Upgraded to 0.24 from 0.23 and it was nearly seamless! :-)
>>>
>>> I'm using Mythbuntu 10.4 with Alsa 1.0.23 (not Pulse Audio because for some reason I could never get this to work with 10.4) - the connection is over a Nvidia GT220 card using HDMI to a surround sound receiver.
>>>
>>> The problem is that when I first boot the machine I don't get audio out of MythTV until I run something like Mplayer (which does output audio straight away) - once I've run a video using Mplayer and  go back into MythTV audio works within it again! My audio device in MythTV has correctly been discovered as 'ALSA:hdmi:CARD=NVidia' and outputs Dolby Digital no problem.
>>>
>>> Has anyone come across this before or have any suggestions for how to fix this? (audio worked perfectly using this setup in 0.23 but I realise there's been a lot of great audio changes from 0.23 to 0.24). I'm using revision 27251. I understand getting PulseAudio to work is the correct solution but unfortunately I've had no luck with 10.4 (especially since I have a slightly different setup and am using Alsa 1.0.23) - maybe upgrading to 10.10 would help?
>>
>> The ALSA drivers for the newer hdmi nvidia card is far from perfect yet.
>> It detects several hdmi audio device, and only one works.
>> It's a bit of a try&test to find out which one work.
>>
>> XBMC has a good wiki on the matter:
>> http://wiki.xbmc.org/?title=HOW-TO_set_up_HDMI_audio_on_nVidia_GeForce_G210%2C_GT220%2C_or_GT240
>>
>> It has a list of cards, what is known to work for both which device to
>> use and the speaker configuration.
>>
>> Myth relies on ALSA to provide the correct information to test devices
>> capabilities ; so until the values returned by alsa are correct, you
>> will have to manually set it.
>
> JYA, the issue I have with manually setting it is that the features
> like AC3/DTS passthrough, and multichannel LPCM don't appear. I think
> this may be why when I try and play 24bit/96KHz FLAC files from
> HDTracks that all I hear is static. Last night I figured I'd try and
> play the same through my bedroom system which doesn't have HDMI, only
> S/PDIF and it played fine.
>

If you manually enter ALSA:hw:1,7 etc, and you do not press the scan
button, you are in manual mode, and you can enter any settings you
want.

The only way to have some fields greyed out is if you press the scan button.