[mythtv] 4:3 content on 16:9 HDTV & Black bars - revisited

[John Patrick Poet]

On Tue, 14 Sep 2004, Moasat wrote:

>
>
> > -----Original Message-----
> > From: mythtv-dev-bounces at mythtv.org
> > [mailto:mythtv-dev-bounces at mythtv.org] On Behalf Of Isaac Richards
> > Sent: Tuesday, September 14, 2004 6:25 PM
> > To: Development of mythtv
> > Subject: Re: [mythtv] 4:3 content on 16:9 HDTV & Black bars -
> > revisited
> >
> > On Tuesday 14 September 2004 07:06 pm, Moasat wrote:
> > > I've done a version of a non-linear horizontal image
> > scaling function
> > > that would stretch the edges of the video to the edge of the TV but
> > > keep the center more or less at 1-to-1.  My Hitachi HDTV
> > has this mode
> > > built-in, as do many other HDTV's I imagine.  The problem with the
> > > code right now is that it is written in C and only has MMX code for
> > > Intel assembly syntax and I assume it needs to be AT&T
> > assembly.  The
> > > C code would most likely not be fast enough, even on the fastest
> > > systems right now.  If someone would like to convert it, I
> > could make
> > > it available.  Otherwise, I'll continue to work on
> > converting it to AT&T.
> > >
> > > Besides that, I currently have no idea how it would get integrated
> > > into MythTV or MythVideo.  I planned to jump off that
> > bridge when I got to it.
> >
> > If your TV has the mode built in, why not simply send 4:3
> > content and let your TV stretch it?
> >
> > Isaac
> > _______________________________________________
> > mythtv-dev mailing list
> > mythtv-dev at mythtv.org
> > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-dev
> >
>
> I haven't worked out the optimum setup yet but with a modeline of 960x540, I
> get a great looking picture but my TV locks into widescreen and the
> smooth-wide mode is not an option any longer so I end up with black bars
> when watching 4:3 content.  Not that I understand why but I've been warned
> not to leave the black bars on the screen for more than about 10% of the
> viewing time or burn-in will occur.  I kind of figured that sort of thing
> wouldn't happen with newer TVs but I'm not an engineer so I'm taking other
> people's word for it.  For my setup though, I figured a software version of
> the smooth-wide mode in Myth would solve the problem for me.
>

What is the resolution of the source 4:3 material?  Is it 704x480/720x480
or is it upconverted by your tv station to an HD resolution?

If it is not upconverted by your tv station, you could configure Myth to
send it to your TV in it's "native" resolution, thus allowing your TV to
scale/stretch it.

My local stations which broadcast in HD, upconvert all 4:3 material.  This
results in a nice picture, but I end up with black bars all the way around
the image, with some content.  I have not decided how to handle the problem.

John