[mythtv-users] Two Pixel Offset at Top of Screen With git Version as of 2 Feb 2013

[Paul Gardiner]

On 04/02/2013 18:28, Jim Stichnoth wrote:
> On Sun, Feb 3, 2013 at 8:00 PM, Paul Gardiner <lists at glidos.net> wrote:
>> Do we really scale 1088 to 1080? Surely we should truncate to avoid the detrimental effects of scaling. I know a lot of us have gone to some effort to buy a true 1080 display with defeatable overscan. Don't we lose any advantage of doing so if myth performs an unnecessary scaling?
>>
>> I'd always assumed 1088 was really a misreported 1080 with no intention that the bottom 8 lines be displayed. Is that not the case?
>
> This is probably the case.  However, when I study the HD-PVR sample,
> it appears that the bottom two lines (out of 1088 total lines) have
> the green line garbage, and 6 lines above have legitimate picture
> information.

Interesting, although I'd imagine that - even when there are legitimate
looking pixels beyond 1080 - the overall picture would be improved by
having < 1% missing, and > 99% as crisp as is possible.

> In any case, the scaling trick to hide the green line only works on a
> 16:9 aspect ratio display, so I will try to get the code to truncate
> the source before it gets to the scaling step.

That would be great, although failing that, to change the scaling to be
vertically pixel to pixel would be a win for typical use.

I think myth used to truncate long ago. Here's a post from someone
claiming it did back in 2005:
http://www.mythtv.org/pipermail/mythtv-users/2005-May/089090.html
Maybe code to do so got lost in a rewrite of a module at some stage.

Cheers,
	Paul.