[mythtv-users] Issues with audio over HDMI

[Owen Townend]

2009/1/23 Erik de Jong <erik at and.li>:
> Hi Phil, and others experiencing problems ;-)
>
> (apologies for not responding inline, working with outlook for the moment)
>
> I have different hardware (onboard AMD) yet suffered from similar issues. I
> documented the shortest route that worked for me and that I suspect may give
> you clues in the right direction on different hardware as well. Here's what
> I did:
>
> $ sudo alsactl names
>
> This will output a list of audio/alsa devices into /etc/asound.names
>
> Going through /etc/asound.names, the two relevant entries for me were:
>
> alsactl19 {
>        name 'hw:1,3'
>        comment 'Physical Device - ATI HDMI (Playback)'
> }
> alsactl20 {
>        name 'plughw:1,3'
>        comment 'Physical Device With Conversions - ATI HDMI (Playback)'
> }
>
> I found that the first one worked sometimes and the second one always, I
> suspect this to depend on the format of the audio.
>
> In mythfrontend -> Utilities/Setup -> Setup -> General -> page 3 I used
>
> ALSA:plughw:1,3
>
> for both "audio output device" and "passthrough audio device".
>
> Unchecked "use internal volume controls"
>
> Lastly, make sure sound over HDMI is not muted:
>
> $ sudo alsamixer -c 1
> (-c 1 to select the second device, see device name from asound.names)
>
> Choose the right channel and press 'm' to unmute if needed.
>
> Hope this helps. For me being able to actually go through the list of my
> devices in /etc/asound.names was the break-through.
>
> Erik.

I have a similar setup (AMD, HDMI is 1,3)
By putting this stanza in asound.conf I found I could leave myth to
alsa:default and have mplayer et al all output through HDMI without
explicit instruction.

# Default to HDMI out
pcm.!default {
        type hw
        card 1
        device 3
}

Unfortunately using this I have the issue reported earlier whereby it
_mostly_ works but the occasional mute/unmute is required.

Perhaps plughw gets around this...

cheers,
Owen.