Bug 23322

Summary: Small resolution video tearing problem with open source radeon drivers
Product: xorg Reporter: Jānis Jansons <janhouse>
Component: Driver/RadeonAssignee: xf86-video-ati maintainers <xorg-driver-ati>
Status: RESOLVED INVALID QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: high CC: christopher.m.penalver, hramrach, tobias.pal
Version: git   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
xorg.0.log
none
Possible fix none

Description Jānis Jansons 2009-08-14 19:18:48 UTC
Created attachment 28642 [details] [review]
xorg.0.log

I get some sort of screen tearing for small resolution videos (dvdrip etc.) when watching them in maximized or fullscreen mode. (As if there would be problem with resizing video up.)
Bug looks like lines tearing video in places where fast color changes happen (watching action movies is allmost impossible)
Here you can see how it looks: http://www.youtube.com/watch?v=wdaXRo17lv4

The weird part is that I don't get this problem when watching dvd movies or HD video (720p and up).
Users from irc suggested that it was problem with codec, so I converted video to theora but the problem stayed. (Same video on my other computer plays just fine.)

I am using Ubuntu Jaunty with xserver-xorg-video-radeon drivers from xorg-edgers ppa. At the moment version 1:6.12.99+git20090807.cd99d9f0-0ubuntu0sarvatt~jaunty.

I am running video in Xv mode (guys in #radeon irc channel suggested to do this to reduce CPU usage and lags).

My laptop has "01:05.0 VGA compatible controller: ATI Technologies Inc RS690M [Radeon X1200 Series]"

Linux 2.6.30-02063004-generic
 
Xorg.conf - http://pastebin.com/m4c37d00c

Xorg.0.log is attached
Comment 1 Michel Dänzer 2009-08-22 17:01:40 UTC
'Tearing' is a term which refers to non-smooth animation due to parts of several source frames being visible in a single output frame, which isn't what this is about.

This is a problem with the bicubic filter, you can work around it by disabling the bicubic filter with something like

xvattr -a XV_BICUBIC -v 0
Comment 2 Jānis Jansons 2009-08-22 17:54:56 UTC
(In reply to comment #1)
> 'Tearing' is a term which refers to non-smooth animation due to parts of
> several source frames being visible in a single output frame, which isn't what
> this is about.
> 
> This is a problem with the bicubic filter, you can work around it by disabling
> the bicubic filter with something like
> 
> xvattr -a XV_BICUBIC -v 0
> 

Thank you Michel Dänzer. You helped solve me problem I had form months! :)
Comment 3 Michel Dänzer 2009-08-22 18:00:55 UTC
There is a bug which needs to be fixed, disabling the bicubic filter is just a workaround.
Comment 4 Michel Dänzer 2009-08-23 04:13:43 UTC
Created attachment 28864 [details] [review]
Possible fix

(In reply to comment #1)
> 'Tearing' is a term which refers to non-smooth animation due to parts of
> several source frames being visible in a single output frame, which isn't what
> this is about.

Actually I misinterpreted the problem - it does look like tearing. This probably means one of two things:

* The textured video blit takes too long to finish before the next output frame
  is scanned out.

or

* The textured video blit doesn't finish before the next source frame is
  uploaded to VRAM.

If it's the first case, it boils down to 'the GPU is too slow to handle bicubic filtering without tearing, you need to disable it'.

If it's the second case though, this patch may fix the tearing, though it may introduce frame skips instead.
Comment 5 Alex Deucher 2012-04-25 05:55:47 UTC
Is this still an issue with a newer driver/kernel?
Comment 6 Christopher M. Penalver 2016-02-25 21:26:07 UTC
Jānis Jansons, Ubuntu Jaunty reached EOL on October 23, 2010. For more on this, please see https://wiki.ubuntu.com/Releases .

If this is reproducible on a supported release, it will help immensely if you filed a new report with Ubuntu by ensuring you have the package xdiagnose installed, and that you click the Yes button for attaching additional debugging information running the following from a terminal:
ubuntu-bug xorg

Also, please feel free to subscribe me to it.

For more on why this is helpful, please see https://wiki.ubuntu.com/ReportingBugs.

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