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* [ALSA - lib 0000496]: nearest-neighbor downsampling causes noise
@ 2004-11-09 15:33 bugtrack
  0 siblings, 0 replies; 4+ messages in thread
From: bugtrack @ 2004-11-09 15:33 UTC (permalink / raw)
  To: alsa-devel


The following issue has been CLOSED
======================================================================
<https://bugtrack.alsa-project.org/alsa-bug/view.php?id=496> 
======================================================================
Reported By:                grabner
Assigned To:                tiwai
======================================================================
Project:                    ALSA - lib
Issue ID:                   496
Category:                   pcm - digital audio
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     closed
Resolution:                 fixed
Fixed in Version:           
======================================================================
Date Submitted:             09-10-2004 22:06 CEST
Last Modified:              11-09-2004 16:33 CET
======================================================================
Summary:                    nearest-neighbor downsampling causes noise
Description: 
The rate-conversion plugin in ALSA-1.0.7rc1 uses the nearest-neighbor
method for downsampling (function snd_pcm_rate_shrink in
src/pcm/pcm_rate.c), which causes considerable noise.
======================================================================

----------------------------------------------------------------------
 grabner - 09-16-04 11:24 
----------------------------------------------------------------------
Ok, here is the required information:

-----
Summary: Fix the downsampling noise problem
 
Description: The patch replaces the nearest neighbor downsampling method
in the sample rate conversion plugin by linear interpolation of the
closest two samples, thus significantly reducing the resampling noise.
 
Signed-off-by: Markus Grabner <grabner@icg.tu-graz.ac.at>
-----

Regards,
Markus

edited on: 09-16-04 11:24

----------------------------------------------------------------------
 tiwai - 09-16-04 12:02 
----------------------------------------------------------------------
Thanks, applied to CVS now.

Issue History
Date Modified  Username       Field                    Change              
======================================================================
09-10-04 22:06 grabner        New Issue                                    
09-10-04 22:06 grabner        File Added: downsample_interpolate.patch          
         
09-10-04 22:08 grabner        Issue Monitored: grabner                     
09-15-04 18:18 tiwai          Note Added: 0001763                          
09-16-04 11:24 grabner        Note Added: 0001768                          
09-16-04 11:24 grabner        Note Edited: 0001768                         
09-16-04 12:02 tiwai          Status                   new => resolved     
09-16-04 12:02 tiwai          Resolution               open => fixed       
09-16-04 12:02 tiwai          Assigned To               => tiwai           
09-16-04 12:02 tiwai          Note Added: 0001771                          
11-09-04 16:33 tiwai          Status                   resolved => closed  
======================================================================




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^ permalink raw reply	[flat|nested] 4+ messages in thread

* [ALSA - lib 0000496]: nearest-neighbor downsampling causes noise
@ 2004-09-16  9:24 bugtrack
  0 siblings, 0 replies; 4+ messages in thread
From: bugtrack @ 2004-09-16  9:24 UTC (permalink / raw)
  To: alsa-devel


A BUGNOTE has been added to this bug.
======================================================================
https://bugtrack.alsa-project.org/alsa-bug/bug_view_page.php?bug_id=0000496
======================================================================
Reported By:                grabner
Assigned To:                
======================================================================
Project:                    ALSA - lib
Bug ID:                     496
Category:                   pcm - digital audio
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     new
======================================================================
Date Submitted:             09-10-2004 22:06 CEST
Last Modified:              09-16-2004 11:24 CEST
======================================================================
Summary:                    nearest-neighbor downsampling causes noise
Description: 
The rate-conversion plugin in ALSA-1.0.7rc1 uses the nearest-neighbor
method for downsampling (function snd_pcm_rate_shrink in
src/pcm/pcm_rate.c), which causes considerable noise.
======================================================================

----------------------------------------------------------------------
 tiwai - 09-15-2004 18:18 CEST 
----------------------------------------------------------------------
The patch looks fine.

Could you provide the summary, description and signed-off-by
for the patch to apply to ALSA CVS tree?

thanks.

----------------------------------------------------------------------
 grabner - 09-16-2004 11:24 CEST 
----------------------------------------------------------------------
Ok, here is the required information:

-----
Summary: Fix the downsampling noise problem
 
The patch replaces the nearest neighbor downsampling method in the sample
rate conversion plugin by linear interpolation of the closest two samples,
thus significantly reducing the resampling noise.
 
Signed-off-by: Markus Grabner <grabner@icg.tu-graz.ac.at>
-----

Regards,
Markus

Bug History
Date Modified  Username       Field                    Change              
======================================================================
09-10-04 22:06 grabner        New Bug                                      
09-10-04 22:06 grabner        File Added: downsample_interpolate.patch                    
09-10-04 22:08 grabner        Bug Monitored: grabner                       
09-15-04 18:18 tiwai          Bugnote Added: 0001763                       
09-16-04 11:24 grabner        Bugnote Added: 0001768                       
======================================================================


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^ permalink raw reply	[flat|nested] 4+ messages in thread

* [ALSA - lib 0000496]: nearest-neighbor downsampling causes noise
@ 2004-09-15 16:18 bugtrack
  0 siblings, 0 replies; 4+ messages in thread
From: bugtrack @ 2004-09-15 16:18 UTC (permalink / raw)
  To: alsa-devel


A BUGNOTE has been added to this bug.
======================================================================
https://bugtrack.alsa-project.org/alsa-bug/bug_view_page.php?bug_id=0000496
======================================================================
Reported By:                grabner
Assigned To:                
======================================================================
Project:                    ALSA - lib
Bug ID:                     496
Category:                   pcm - digital audio
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     new
======================================================================
Date Submitted:             09-10-2004 22:06 CEST
Last Modified:              09-15-2004 18:18 CEST
======================================================================
Summary:                    nearest-neighbor downsampling causes noise
Description: 
The rate-conversion plugin in ALSA-1.0.7rc1 uses the nearest-neighbor
method for downsampling (function snd_pcm_rate_shrink in
src/pcm/pcm_rate.c), which causes considerable noise.
======================================================================

----------------------------------------------------------------------
 tiwai - 09-15-2004 18:18 CEST 
----------------------------------------------------------------------
The patch looks fine.

Could you provide the summary, description and signed-off-by
for the patch to apply to ALSA CVS tree?

thanks.

Bug History
Date Modified  Username       Field                    Change              
======================================================================
09-10-04 22:06 grabner        New Bug                                      
09-10-04 22:06 grabner        File Added: downsample_interpolate.patch                    
09-10-04 22:08 grabner        Bug Monitored: grabner                       
09-15-04 18:18 tiwai          Bugnote Added: 0001763                       
======================================================================


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^ permalink raw reply	[flat|nested] 4+ messages in thread

* [ALSA - lib 0000496]: nearest-neighbor downsampling causes noise
@ 2004-09-10 20:06 bugtrack
  0 siblings, 0 replies; 4+ messages in thread
From: bugtrack @ 2004-09-10 20:06 UTC (permalink / raw)
  To: alsa-devel


The following bug has been SUBMITTED.
======================================================================
https://bugtrack.alsa-project.org/alsa-bug/bug_view_page.php?bug_id=0000496
======================================================================
Reported By:                grabner
Assigned To:                
======================================================================
Project:                    ALSA - lib
Bug ID:                     496
Category:                   pcm - digital audio
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     new
======================================================================
Date Submitted:             09-10-2004 22:06 CEST
Last Modified:              09-10-2004 22:06 CEST
======================================================================
Summary:                    nearest-neighbor downsampling causes noise
Description: 
The rate-conversion plugin in ALSA-1.0.7rc1 uses the nearest-neighbor
method for downsampling (function snd_pcm_rate_shrink in
src/pcm/pcm_rate.c), which causes considerable noise.
======================================================================

Bug History
Date Modified  Username       Field                    Change              
======================================================================
09-10-04 22:06 grabner        New Bug                                      
09-10-04 22:06 grabner        File Added: downsample_interpolate.patch                    
======================================================================


-------------------------------------------------------
This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170
Project Admins to receive an Apple iPod Mini FREE for your judgement on
who ports your project to Linux PPC the best. Sponsored by IBM. 
Deadline: Sept. 13. Go here: http://sf.net/ppc_contest.php

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2004-11-09 15:33 UTC | newest]

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