[mythtv-users] AC3 and/or S/PDIF (again)

Mario Limonciello mario.mailing at gmail.com
Tue Jan 24 04:01:58 UTC 2006


> > A quick question if I may. Am I right in thinking that if I buy a new 
> > sound-card with 6 analogue channels on the output it will drive my 5.1 
> > amp (it has 6 channel input) for surround sound.
> Yes (assuming you mean by 6-channel input that you have at least 6 RCA 
> connectors or 3 headphone connectors for input).
> 
> Note, though, that many cards use line in for surround output in 
> surround modes, so if you've got a software encoder that requires a 
> sound card for audio, you may have to keep your on-board card enabled as 
> well for sound capture.
> > i.e. I guess I am asking does myth decode the 5.1 happily from DVDs 
> > and from DVB-T broadcasts?
> Yep.  It's been doing this for a long time--just disable AC-3 pass 
> through.  Mark Spieth recently created a patch to support timestretch 
> with multi-channel streams.  He did the analog patch in no time, but 
> it's the re-encoding to AC-3 that's taking some time.  I don't think the 
> patch has been put in SVN, yet, though, so it may not make it into 0.19.
On this exact note - I was having trouble just today with a recent SVN
release attempting to do 5.1 native from myth the analogue route.

I have a HD5000 that records a few streams with 5.1.  I also have xine
setup to use the analogue 5.1 outputs to drive my receiver for dvds.
Now in myth, when I change from ALSA:default to ALSA:surround51 (which I
use for xine), I get no audio in myth.  If I try to force it to the
exact pcm available for my card, ALSA:hw:0,3 I also get no audio.  Is
there something else I'm missing here?

Here is relavent info from my mythfrontend console output:
2006-01-23 21:59:58.595 Opening audio device 'hw:0,3'.
2006-01-23 21:59:58.637 Access type not available: Invalid argument
2006-01-23 21:59:58.637 Unable to set ALSA parameters
2006-01-23 21:59:58.637 NVP: Disabling Audio, reason is: Unable to set
ALSA parameters

And relavent info about my card:
supermario at supermario ~ $ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Audigy2 [Audigy 2 Platinum [SB0240P]], device 0: emu10k1 [ADC
Capture/Standard PCM Playback]
  Subdevices: 32/32
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
  Subdevice #8: subdevice #8
  Subdevice #9: subdevice #9
  Subdevice #10: subdevice #10
  Subdevice #11: subdevice #11
  Subdevice #12: subdevice #12
  Subdevice #13: subdevice #13
  Subdevice #14: subdevice #14
  Subdevice #15: subdevice #15
  Subdevice #16: subdevice #16
  Subdevice #17: subdevice #17
  Subdevice #18: subdevice #18
  Subdevice #19: subdevice #19
  Subdevice #20: subdevice #20
  Subdevice #21: subdevice #21
  Subdevice #22: subdevice #22
  Subdevice #23: subdevice #23
  Subdevice #24: subdevice #24
  Subdevice #25: subdevice #25
  Subdevice #26: subdevice #26
  Subdevice #27: subdevice #27
  Subdevice #28: subdevice #28
  Subdevice #29: subdevice #29
  Subdevice #30: subdevice #30
  Subdevice #31: subdevice #31
card 0: Audigy2 [Audigy 2 Platinum [SB0240P]], device 2: emu10k1 efx
[Multichannel Capture/PT Playback]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 0: Audigy2 [Audigy 2 Platinum [SB0240P]], device 3: emu10k1
[Multichannel Playback]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Audigy2 [Audigy 2 Platinum [SB0240P]], device 4: p16v [p16v]
  Subdevices: 1/1
  Subdevice #0: subdevice #0




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