[ALSA - driver 0001651]: ac3 passthrough not really work with ac3dec

[bugtrack@alsa-project.org]

The following issue requires your FEEDBACK.
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<https://bugtrack.alsa-project.org/alsa-bug/view.php?id=1651> 
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Reported By:                tycordinal
Assigned To:                jcdutton
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Project:                    ALSA - driver
Issue ID:                   1651
Category:                   PCI - emu10k1
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     feedback
Distribution:               
Kernel Version:             2.4.31
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Date Submitted:             12-14-2005 09:44 CET
Last Modified:              07-23-2006 18:45 CEST
======================================================================
Summary:                    ac3 passthrough not really work with ac3dec
Description: 
using the following from alsa-tools to play ac3 as passthrough:
ac3dec -C oneac3file.ac3 


the ac3dec is able to "open" the spdif device "iec958:{AES...}" and did
not report any error and keep on running, but the ac3 decoder (creative
ddts-100), connected to the "spdif output" from the card, did not switch
to dolby mode, and no sound come out from speaker.

one interesting thing is, when I run this:
ac3dec -6 oneac3file.ac3 

As this is software decoding to PCM, I can hear the left/right channels
from the front stereo jacket, as they also output on the "spdif output".
Therefore, I believe the "spdif output" on the card is indeed working,
just that for this card we might need to write some different AES command
to open the spdif output?

I am not sure if the alsa config files in /usr/share/alsa have to change
or maybe some "switches" in emu10k1_main.c needs to apply for the "spdif
output" to  really behave as "iec958" device to passthough ac3 stream to
external decoder.

Thanks.





======================================================================

----------------------------------------------------------------------
 jcdutton - 07-23-06 18:44 
----------------------------------------------------------------------
Which sound card are you using?
cat /proc/asound/cards
cat /proc/asound/version

----------------------------------------------------------------------
 jcdutton - 07-23-06 18:45 
----------------------------------------------------------------------
Please provide the requested feedback.


Issue History
Date Modified  Username       Field                    Change              
======================================================================
12-14-05 09:44 tycordinal     New Issue                                    
12-14-05 09:44 tycordinal     Kernel Version            => 2.4.31          
12-14-05 10:05 tycordinal     Note Added: 0007031                          
12-14-05 10:15 tycordinal     Note Added: 0007032                          
12-14-05 10:16 tycordinal     Note Added: 0007033                          
12-14-05 10:30 pzad           Note Added: 0007034                          
12-14-05 10:31 tycordinal     Note Added: 0007035                          
12-14-05 10:53 pzad           Note Added: 0007036                          
07-18-06 14:43 jcdutton       Status                   new => assigned     
07-18-06 14:43 jcdutton       Assigned To               => jcdutton        
07-23-06 18:44 jcdutton       Note Added: 0011196                          
07-23-06 18:45 jcdutton       Note Added: 0011197                          
07-23-06 18:45 jcdutton       Status                   assigned => feedback
======================================================================



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