[ALSA - driver 0001044]: Heavily distorted audio

[bugtrack@alsa-project.org]

A NOTE has been added to this issue.
======================================================================
<https://bugtrack.alsa-project.org/alsa-bug/view.php?id=1044> 
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Reported By:                jefferai
Assigned To:                
======================================================================
Project:                    ALSA - driver
Issue ID:                   1044
Category:                   PCI - intel8x0
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     feedback
Distribution:               Gentoo
Kernel Version:             2.6.16
======================================================================
Date Submitted:             04-11-2005 17:41 CEST
Last Modified:              07-15-2006 15:33 CEST
======================================================================
Summary:                    Heavily distorted audio
Description: 
I have a laptop that is fine by itself, but when plugged into my docking
station I get heavily distorted audio when something plays either
directly to hw0:0 or through the OSS emulation. The problem seems to be
with sample rate conversion -- if I create my own dmix-based device that
resamples audio to 48KHz and then plays it to hw0:0, and I have an
ALSA-aware app that lets me define which device to use and set it to
that device, the audio is beautiful both on and off of the docking
station.  Unfortunately, not all apps allow these settings, so things such
as RealPlayer and Flash (in Firefox) sound horrid if I'm on my docking
station, which is most of the time.

I've seen this same problem through three Linux distributions now
(Gentoo, SuSE, and Fedora Core 3) on the same laptop so I know it's an
ALSA issue (or configuration issue) and not distribution-specific.

I've hard-set the ac97 clock option in the snd-intel8x0 module to 48000
but this
doesn't help, and my clock is detected as being 48000Hz anyways.  I
don't know what to do.  Some people have said to point OSS apps to
/dev/adsp but apps complain it's not a valid device, and anyways pointing
to anything but /dev/dsp doesn't seem to be an option for all apps. 
Besides, I'd still have the ALSA issues for apps that don't let you define
which device to use.

Following are relevant snippets of files.  I'm on up-to-date Gentoo
linux using the Gentoo alsa-driver, alsa-tools, alsa-headers, alsa-lib,
and alsa-oss ebuilds, all 1.0.8.  Configuration files are the defaults
(I added the extra device with a .asoundrc).

TIA,
Jeff
======================================================================

----------------------------------------------------------------------
 jefferai - 07-15-06 15:32 
----------------------------------------------------------------------
The exact model of the laptop is a Dell Inspiron 8600.  I have a port
replicator for it.  I only see this behavior if my speakers are connected
to the audio out jack in the port replicator; if they are connected to the
audio out in my laptop, then I do not have this problem.  And again, I
only see the problem when connected to the port replicator and something
uses OSS, or uses ALSA without allowing me to select my device that forces
a sample rate conversion to 48000.  I also see other behavior, like the
Headphone mixer only having an effect when plugged directly into the
laptop, not the port replicator (the PCM mixer always has an effect).

I'm using the following ~/.asoundrc:


pcm.jeff {
        type plug
        slave.pcm {
                type dmix
                ipc_key 8888
                slave {
                        pcm "hw:0,0"
                        period_time 0
                        buffer_time 0
                        period_size 2048
                        buffer_size 32768
                        rate 48000
                }
                bindings {
                        0 0
                        1 1
                }
        }
}

ctl.jeff {
        type hw
        card {
                @func getenv
                vars [
                        ALSA_CTL_CARD
                        ALSA_CARD
                ]
                default {
                        @func refer
                        name defaults.ctl.card
                }
        }
}

pcm.dsp0 {
    type plug
        slave.pcm {
                type dmix
                ipc_key 8888
                slave {
                        pcm "hw:0,0"
                        period_time 0
                        buffer_time 0
                        period_size 2048
                        buffer_size 32768
                        rate 48000
                }
                bindings {
                        0 0
                        1 1
                }
        }
}

----------------------------------------------------------------------
 jefferai - 07-15-06 15:33 
----------------------------------------------------------------------
Oh, also, I'm now using ALSA 1.0.11 built as a module with with kernel
2.6.16.

Issue History
Date Modified  Username       Field                    Change              
======================================================================
04-11-05 17:41 jefferai       New Issue                                    
04-11-05 17:41 jefferai       Distribution              => Gentoo          
04-11-05 17:41 jefferai       Kernel Version            => 2.6.11-ck3      
04-12-05 16:32 tiwai          Note Added: 0004448                          
04-12-05 18:13 jefferai       Note Added: 0004457                          
04-12-05 18:39 tiwai          Note Added: 0004458                          
12-30-05 04:42 rlrevell       Note Added: 0007219                          
03-01-06 01:02 rlrevell       Status                   new => closed       
03-01-06 01:29 jefferai       Kernel Version           2.6.11-ck3 => 2.6.15
03-01-06 01:29 jefferai       Status                   closed => feedback  
03-01-06 01:29 jefferai       Resolution               open => reopened    
03-01-06 01:29 jefferai       Note Added: 0008258                          
03-01-06 01:34 rlrevell       Note Added: 0008260                          
03-01-06 01:35 rlrevell       Note Added: 0008261                          
04-14-06 03:31 Ensnared       Issue Monitored: Ensnared                    
07-15-06 01:58 Adrian Bunk    Status                   feedback => closed  
07-15-06 01:58 Adrian Bunk    Resolution               reopened => unable to
duplicate
07-15-06 15:32 jefferai       Kernel Version           2.6.15 => 2.6.16    
07-15-06 15:32 jefferai       Status                   closed => feedback  
07-15-06 15:32 jefferai       Resolution               unable to duplicate =>
reopened
07-15-06 15:32 jefferai       Note Added: 0011023                          
07-15-06 15:33 jefferai       Note Added: 0011024                          
======================================================================




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