[mythtv-users] HDTV modeline frustrations

[Brian Foddy]

Thanks Jim and Doug for the feedback...

On Sunday 30 November 2003 12:17 pm, Jim Paris wrote:
> > 720p.  This will probably be my eventual goal.
> > stable, but much more overscan than I'd like.
>
> You won't be able to adjust the overscan, at least not for the
> top/bottom.  You're giving the TV 720 lines and it's up to the TV
> where to display them.
>
> > 1.  My primary question is about Dot Clocks.  As I work through
> > the adjustments and formulas, most sites seem to assume the
> > clock is constant.  Its nearly impossible to make significant
> > improvements in overscan (720p) keeping the clock constant.
>
> Dotclock doesn't matter, only horizontal and vertical refresh.  Keep
> those constant if you want your TV to be happy.  Adjust dotclock to
> adjust the total horizontal resolution in a given scanline.
>

You both seem to agree.  So I guess its safe to increase the dotclock
enough to reduce the horizontal overscan, as long as I compensate
the horiz and vert frequencies in range.

> > I don't think my HDTV tuner at 720p has this much overscan?
>
> Check.  With a proper input signal, overscan is a function of the TV,
> not the signal.

I'm not sure how I can prove one way or the other, its not like I can
control the content of the hd tuner image...  I know the network 
watermarks in the lower right show up fine, and I haven't noticed
anything not displayed like bottom scrolling text or anything.

I guess I just need to take things slow, make small/slow adjustments.
A very hair-raising process...

Thanks again.
Brian