[mythtv-users] AC3 audio problems

[Eric Sharkey]

I have some problems playing some recordings that have AC3 audio tracks.

I know that my hardware is working ok.  If I use mplayer to play a
file I get 2 channel PCM sound output using the default settings, but
with -ac hwac3 I get 5.1 channel Dolby Digital on my stereo receiver
(which is hooked in to my mythtv's optical spdif port) and it sounds
great.

If I play the same file through MythTV, with "Enable AC3 passthrough"
turned on in the configuration, then all I get is noise.  It sounds a
bit like a baseball card in a bicycle wheel, just a choppy clicking
sound.  With this option turned off, I can hear the left and right
audio channels only.  The center channel which carries most dialog is
missing.  (I have 5.1 as the setting for max audio channels.)

This happens with video from multiple sources.  (DVD rips, firewire
capture from cable box, etc.)

Is anyone else on this list have success or trouble with these kinds
of files/recordings?  Ideally, I'd like to have AC3 passthrough
working in myth as well as it does in mplayer.

Eric Sharkey