[ALSA - driver 0001210]: Exaudio produces noise on all speakers for 5.1 channels

[bugtrack@alsa-project.org]

A NOTE has been added to this issue.
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<https://bugtrack.alsa-project.org/alsa-bug/view.php?id=1210> 
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Reported By:                andersin
Assigned To:                Clemens Ladisch
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Project:                    ALSA - driver
Issue ID:                   1210
Category:                   USB - usb-audio
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     assigned
Distribution:               
Kernel Version:             
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Date Submitted:             06-23-2005 23:54 CEST
Last Modified:              06-24-2005 17:22 CEST
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Summary:                    Exaudio produces noise on all speakers for 5.1
channels
Description: 
I am using a soundblaster extigy with ALSA ver. 1.0.9b and am happy to say

that stereo sound works find and that all 6 speakers can produce some
sound.

With more than 2 channel output, I experience problems. speaker-test,
which 
works for 1 and 2 channels, results in a hissing/crackling for 3,5,6 
channels, which changes in pitch depending on the number of channels. For
4 
channels, it loops, producing the following output


speaker-test 0.0.8

Playback device is extigy
Stream parameters are 48000Hz, S16_LE, 4 channels
Using 16 octaves of pink noise
Rate set to 48000Hz (requested 48000Hz)
Buffer size range from 96 to 8192
Period size range from 48 to 4096
Periods = 4
Buffer time size 2525
To choose buffer_size = 8192
To choose period_size = 2048
was set period_size = 2048
was set buffer_size = 8192
Unable to set hw params for playback: Invalid argument
Setting of hwparams failed: Invalid argument
Rate set to 48000Hz (requested 48000Hz)
[ The "Rate set to ..." part is repeated continuously ]


Setting my capture device to mixer, I was able to record the output with 
arecord -c 6 -f dat -r 48000 /root/speaker-test-6ch.wav . The distortion
is 
still present when playing the file, forcing 2 channels in aplay.

In addition to using speaker test, I tried using the route plugin to
isolate 
the rear channels. When I route to any channel, I can hear the same output
on 
all 5 (not sure about Woofer) channels, no matter which channel I route
to. 
Here is the relevant setup:

pcm.route1      {
type            route;
slave.pcm       "extigy";
slave.channels  6;
ttable.0.0      1.0;
}

The music that I played had similar distortions like the one for speaker
test 
and played considerably slower than when player with 2 channels. Again I 
could record and replay the effect. The setup was slightly different in
order 
to route the stereo channels to all 6 speakers.

For routing with 4 slave channels, I get a failure (as expected), this
time 
with the output:

Playing WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 48000 Hz,
Stereo
aplay: set_params:910: Unable to install hw params:
ACCESS:  RW_INTERLEAVED
FORMAT:  S16_LE
SUBFORMAT:  STD
SAMPLE_BITS: 16
FRAME_BITS: 32
CHANNELS: 2
RATE: 48000
PERIOD_TIME: (42666 42667)
PERIOD_SIZE: 2048
PERIOD_BYTES: 8192
PERIODS: 4
BUFFER_TIME: (170666 170667)
BUFFER_SIZE: 8192
BUFFER_BYTES: 32768
TICK_TIME: 1000

This is all the relevant bits that I can think of at the moment. Thank you
for 
reading this far. If anybody thinks it is important to get the recorded 
files, I am happy to sent them. I am grateful for any nudge on what I am 
doing wrong with my setup.

Christoph Burger-Scheidlin
======================================================================

----------------------------------------------------------------------
 andersin - 06-24-05 15:23 
----------------------------------------------------------------------
Sorry, I did not mention it. Everything with 2 speakers works fine.
Playback and Recording.

I assumed that the card did not support 4 speakers. As far as I understand
it, the channel routing mode can be used to select only 4 channels for
playback (and for that matter the routing plugin). If I run speaker-test
then the channel routing mode does turn off certain speakers when I cycle
through the different values (don't know if this is relevant though).

As far as the recording is concerned, I recorded from the "mixer" capture
setting and that should work no matter how many channels I set, shouldn't
it?



----------------------------------------------------------------------
 Clemens Ladisch - 06-24-05 17:22 
----------------------------------------------------------------------
When you're recording with the "mixer" setting, you probably get the two
front channels.

What I meant to say above was:  if you record two channels while playing
more than two channels, the distortion should still be present in the
first two channels you've recorded.  Is it?  Could you upload a _small_
test file?

Issue History
Date Modified  Username       Field                    Change              
======================================================================
06-23-05 23:54 andersin       New Issue                                    
06-24-05 09:21 Clemens LadischFile Added: alsa-lib-start-threshold-check.diff   
                
06-24-05 09:22 Clemens LadischFile Deleted: alsa-lib-start-threshold-check.diff 
                  
06-24-05 09:23 Clemens LadischNote Added: 0005205                          
06-24-05 10:14 andersin       File Added: stream0.txt                      
06-24-05 10:16 andersin       Note Added: 0005208                          
06-24-05 10:25 Clemens LadischNote Added: 0005209                          
06-24-05 13:38 andersin       Note Added: 0005218                          
06-24-05 15:23 andersin       Note Edited: 0005218                         
06-24-05 17:22 Clemens LadischNote Added: 0005239                          
======================================================================




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