[mythtv-users] 0.20, bad audio, HD-5500

[noah at bonfire.homelinux.org]

Hi, I am slowly getting a couple of HD-5500 cards to work under Mandriva 2007 
with Myth 0.20 but am having audio probs (also tried svn rev 11570-- no 
improvement). This is on an ASUS P5W DH board with a Conroe 6600 and a 
GeForce 7600GT.

My current problem is that the NTSC audio in MythTV is awful-- it sounds like 
compressed streaming audio on a very low bandwidth connection. I know the 
captured audio from the HD-5500 cards is ok, because I can listen to it 
using:

sox -t ossdsp -w -c2 -r 48000 /dev/dsp1 -t ossdsp /dev/dsp

and they both sound fine.

[Also, the audio from ATSC channels is completely fine as long as long as AC3 
passthough is disabled-- otherwise I get (undecoded?) static. I'll worry 
about that after I get the NTSC audio working.]

I've tried everything I can find or think of. Extra audio buffering has no 
effect on the bad NTSC audio. I have the following settings:

Audio output device = ALSA:default
Passthrough output device = default
mixer device = default

In the backend, the audio capture devices for the HD-5500 cards are /dev/dsp1 
and /dev/dsp2, which are created when the cx88-alsa module is loaded.

Under ALSA, my capture devices look like this:
----------------
$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 0: Intel [HDA Intel], device 0: ALC882 Analog [ALC882 Analog]
  Subdevices: 1/2
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
card 0: Intel [HDA Intel], device 1: ALC882 Analog [ALC882 Analog]
  Subdevices: 2/2
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
card 1: CX8801 [Conexant CX8801], device 0: CX88 Digital [CX88 Digital]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 2: CX8801_1 [Conexant CX8801], device 0: CX88 Digital [CX88 Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
---------------

I'm hoping someone else has had this problem, though I couldn't find it in the 
archives or elswhere. I'd be grateful for any suggestions. Please let me know 
if there's more info that I could provide that would help diagnose this.