[mythtv] AC3 playback mangled until timestretch activated

[Matt W]

On Thu, Feb 11, 2010 at 3:02 AM, Jean-Yves Avenard <jyavenard at gmail.com> wrote:

>> latest version where this occurs.. trunk Revision: 23531
>>
>> any guidance appreciated. thanks!
>
> When you disable the mixerx (look like you're using "software" mixer).
> Does this still happen?
>
> Are you certain your sound amp can handle either AC3 or DTS and that
> you have checked passthrough?

Hi, Jean-Yves--

yes definitely the amp is capable, Denon AV-1602, connected via
optical S/PDIF to the port on the motherboard.  The display goes to
'DOLBY DIGITAL', the proper LED lights up, and the VFD on the amp has
a box that lights up: "DIGITAL" so I'm covered there :-)  In most of
the DD-enabled broadcasts that I play back, it's fine (e.g. in
playback, my local station's broadcast of Lost in 720p goes DD sans
problème).

but i'm a newbie with regard to sound driver usage/configuration in
the linux world.  In Myth, I have passthrough enabled, and I'm not
doing any volume controls via the General setup.  Am I looking for
particular settings in alsamixer, perhaps?