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displaying waveform distortion

Posted: Fri Sep 17, 2010 7:30 pm
by unixland
O/S: FreeBSD 8.1-STABLE amd64
Audacity Version 1.3.12_4

Hi,

When opening a music file (wav,mp3,ogg,whatever), the waveform appears garbled on the display. It plays good though, it's just that the waveform is so distorted that it's not possible to work with.
I have attached a screenshot of the distortion, so that you see what I am talking about.

Any idea's how to resolve this ?

Cheers,

Rick
screenshot-s.jpg
screenshot of waveform distortion
screenshot-s.jpg (976.84 KiB) Viewed 1081 times

Re: displaying waveform distortion

Posted: Sat Sep 18, 2010 8:31 am
by Gale Andrews
This problem happens a lot on Linux if you use an open source driver for ATI graphics instead of the intended proprietary driver manufactured by ATI. On Linux, the solutions if you don't want to use the ATI driver are to disable UMS (user mode setting) and use KMS instead (kernel mode setting). Or, disable "EXA solid" acceleration.

You can read about the bug as xorg tracked it here.



Gale

Re: displaying waveform distortion

Posted: Sat Sep 18, 2010 1:52 pm
by unixland
Gale Andrews wrote:This problem happens a lot on Linux if you use an open source driver for ATI graphics instead of the intended proprietary driver manufactured by ATI. On Linux, the solutions if you don't want to use the ATI driver are to disable UMS (user mode setting) and use KMS instead (kernel mode setting). Or, disable "EXA solid" acceleration.

You can read about the bug as xorg tracked it here.
Hi Gale,

Unfortunately on FreeBSD we don't have such thing as KMS.
Disabling the EXA Solid acceleration ? I am using XAA Acceleration, so it shouldn't apply...

Rick

Re: displaying waveform distortion

Posted: Sat Sep 18, 2010 2:05 pm
by unixland
Gale Andrews wrote:You can read about the bug as xorg tracked it here.
hmm...looking at the xorg bugtrack, discovered that someone said to put the option:

Option "MigrationHeuristic" "greedy"

in /etc/X11/xorg.conf

This worked and the waveform is displayed correctly.
However, not sure what features I am breaking or disabled now in the radeon driver...

Anyway, cheers for helping out!

Rick