Hello forum,

I am using MythTV on my wide screen TV using Nvidia's TV out and all works great except for a little overscan when watching movies using Mplayer. Since I am using HD1040i for the TV standard, I have little control over the overscan in Nvidia's control panel.

I came across a parameter while googling called -vf expand that can shrink the picture on all four sides using it as follows:

-vf expand=-30:0:22:0 (This will shrink the picture on all four sides, but how?)


The man pages for Mplayer says this in part:

expand[=w:h:x:y:a:r]
Expands (not scales) movie resolution to the given value and places the unscaled original at coordinates x, y. Can be used for placing subtitles/OSD in the resulting black bands.

<w>,<h>
Expanded width,height (default: original width,height).
Negative values for w and h are treated as offsets to the original size.

<x>,<y>
position of original image on the expanded image (default: center)



I would like to tweak it to make the picture fit more exact but I don't understand how it works. For instance, the command I am using has a zero for the H (height) coordinate and it seems like it should have a negitave value like the W (width) coordinate does since I am shrinking the picture. And I am at a total lose about what the X and the Y coordinates do.

Can anyone show me how to use this command properly and explain how it works better than the man pages do?

Thanks,
Roy