[mythtv-users] 32khz AC3 Streams was: Sound problem with AC3 passthrough

[Rob Baumstark]

> Disregard the request, I'm reading out of order.
>
> Will get to it first thing tomorrow noon. Question for you in prep: Are
> you passing '-ao alsa:device=default -ac hwac3' without the comma to
> mplayer while playing the 32k clip?

I had been just running '-ac hwac3' with no comma and no -ao option.
But to make sure all the bases are covered I just ran a slew of
experiments.  The results don't really make sense to me, but I have
very little linux experience, and what I have is on servers at work
and doesn't involve audio.  Anyways - a few different options, and
their results.

No options
  Plays perfectly fine.  Audio is in sync and at the right pitch/speed.

'-ac hwac3'
  Both the audio and the video play back at high speed - they stay in
sync.  The audio is also quite high pitched.  Here I'm assuming it's
just speeding the AC3 up to 48khz (and the video along with it)
instead of resampling it properly.  This is what MythTV does.

'-ac hwac3,'
  Same as without the comma.

'-ao alsa:device=default -ac hwac3'
  The video plays fine, at the proper framerate.  My receiver
indicates it's receiving a 48khz PCM stream, and outputs a very loud
popping kind of sound, so I didn't let it play for long.

'-ao alsa:device=default -ac hwac3,'
  Same as without the comma.