[mythtv] [PATCH] Patch to fix rounding errors from Aspect Ratio settings

[Terry Barnaby]

This patch fixes problems with rounding errors caused by the X-Servers
rounding of the DisplaySize configuration parameter.

The patch also adds a new Aspect setting "Fill" which will take the 
incoming Video and "fill" the display with the picture cropping as 
necessary.

In the current MythTv, the Aspect rounding errors, cause the display 
size to not exactly match the incomming picture size, even when the 
display has the same aspect and number of pixels as the Video being 
displayed. This results in some scaling being applied to the Video
stream even when un-necessary.

On my system I am trying to set MythTv to not scale the incoming 720x576
DVB DTV image when displaying on my 720x576 TV display to improve the 
display quality. This is especially necessary as an interlaced TV is 
being used for output and if any scaling is used motion artifacts start
to appear.

For information the XServer rounds the DisplaySize configuration 
parameter as thus:

     Displaysize is set in mi/miscrinit.c
        pScreen->mmWidth = (xsize * 254 + dpix * 5) / (dpix * 10);
        pScreen->mmHeight = (ysize * 254 + dpiy * 5) / (dpiy * 10);

After using this patch the xorg.conf file's DisplaySize parameter can be
set to: "300 225" for 4:3 and "400 225" for 16:9.

Could someone check this code to make sure it will not break anything ?
The patch works well for me, I now have a good quality picture on my
Via EPIA M10K box with a digital TV source.

Cheers

Terry

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