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Overscan Fix for Intel on a Cheap TV

I got a rea­ll­y, rea­lly cheap 24" 1080p TV to use as a mo­ni­to­r.

On­ce I fi­na­lly got hold of the mi­cro­-HD­MI->HD­MI adap­ter and plu­gged it in, of cour­se, I ran in­to overscan is­sues.

What's overscan?

When TVs get a fu­ll re­so­lu­tion feed over HD­MI, then zoom it a bit and trim the edges be­cau­se tv sig­nals usua­lly ha­ve gar­ba­ge the­re.

Ho­we­ve­r, com­pu­te­r's do­n'­t. In fac­t, be­cau­se of Fi­tt's law, the edges are so­me of the most in­te­res­ting bi­ts of the screen.

The usual so­lu­tion for this is to set a spe­ci­fic mo­de in the TV me­nus, like "1:1" or "Just scan" whi­ch di­sa­bles overscan. But this is a ve­ry cheap TV and has no su­ch things.

The se­cond usual so­lu­tion is to use nvi­dia uti­li­ties and con­fi­gu­re "un­derscan". But I ha­ve an in­tel board and can't do su­ch things.

The third usual so­lu­tion is to use "x­ran­dr --­trans­for­m" to tweak the screen. But that makes the ri­ght and bo­ttom edges be hi­dden.

The four­th usual so­lu­tion is to se­tup a cus­tom mo­de that does­n't tri­gger the TV's overscan, but that means you are not doing 1:1 pixels and things look ugly

The fi­fth usual so­lu­tion is to use a VGA in­pu­t, whi­ch has no overscan. But my VGA adap­te­r/­ca­ble com­bi­na­tion pro­du­ces fu­z­zy ima­ge and the TV can't qui­te sync it, so I lo­se the le­ft edge.

The sixth (not quite usual solution) is to use xrandr --ou­tput HD­MI --set au­dio for­ce-­d­vi because that will trigger some random combination of side effects in the intel driver and make the TV believe it's getting DVI input (the TV even says DVI on its mode info!?!) and not overscan.

But that ma­de my screen look pur­ple.

So, seventh solution, which worked for me: xrandr --ou­tput HD­MI --set au­dio for­ce-­d­vi --­mo­de 1920­x1080i

UP­DA­TE: The ima­ge qua­li­ty in 1080i is not as good as 1080­p, and the pur­ple tint is pro­ba­bly fi­xa­ble using xran­dr's --­ga­m­ma op­tio­n.

And no, I ha­ve no ex­pla­na­tion for it.


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