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saa7134 image distorted at certain capture sizes



HI, Dan

Dan Sandberg wrote:
Hi Everyone,

At very specific capture sizes ( including unfortunately QCIF ), I am
getting distorted looking images.  It looks like the last vertical
column of the picture is repeated for the last 20 or so columns of the
image.

The problem happens in xawtv as well as in other programs.

The problem happens with the linux 2.6.16.11 kernel ( as well as earler
kernels, such as 2.6.15.3 ).

I played around with capturing different image sizes and the problem
goes away if the image is made at least 4 pixels wider or narrower than
QCIF ( 176x144 ).

Here is a captured image in a resolution that works well ( a bit bigger
than QCIF ):

http://headthere.com/saa7134/room-good.png

Here is a captured image in a resolution that shows the problem ( QCIF
size ):

http://headthere.com/saa7134/room-bad.png

Anyone have any ideas what is going on?  I've explored the code and
tried different things ( like capturing as RGB as opposed to YUV ) to no
avail.

This sounds like a rounding problem in the scaler setup. Funny that nobody
noticed this yet.
Lets see whether i can reproduce this tomorrow.

Hartmut

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