[mythtv-users] Remember Aspect Ratio?

Peter Schachte schachte at csse.unimelb.edu.au
Thu Apr 13 01:16:47 UTC 2006


On Wed, Apr 12, 2006 at 04:05:36PM -0400, Steven Adeff wrote:
> On 4/12/06, Jason Sharpe <mythtv.list at gmail.com> wrote:
> > I have 2 TVs both are 16:9. I have the setting of the frontend to play back
> > content in 16:9 so if I record something from DishNetwork on my PVR-250 it
> > stretches the picture properly to fill the 16:9 TV. If I record The Simpsons
> > via an OTA antenna on my HD-3000 it records the 4:3 show in a 16:9 format,
> > which I would expect it to do.
> >
> > The problem is on playback of 4:3 content recorded OTA on the HD-3000. If I
> > start to watch the Simpsons I hit W 3 times to take the screen to 16:9
> > Stretch so it fills my 16:9 screen.

> I don't think playback groups support aspect ratio's, but this would
> be the way to do it if it did...

That would be better than nothing, but not ideal, because aspect ratio
has nothing to do with the other things you set in playback groups.
So you'd wind up having to double the number of playback groups you
define.  For example, I have playback groups for news and information
programming, which I time stretch to 1.35x normal speed, and for
French programming set to .85x speed, and so on.  If aspect ratio were
part of play groups, I'd need separate play groups for 16:9 news and
info, 4:3 news and info, 16:9 French, 4:3 French, etc.  Worse still, I
believe play groups are per recording, so this would get the aspect
ratio wrong if you had both 16:9 and 4:3 frontends.

I think myth must know, or can somehow figure out, the actual aspect
ratio of the program it's playing, because the 'Fill' aspect ratio
setting automatically zooms letterboxed programming to fill a 4:3
display.  So I would expect myth could recognize a pillarboxed program
and zoom or stretch it to fill a widescreen display.  Perhaps 'Fill'
mode should do this:  automatically zoom a letterboxed program on a
4:3 display, as well a pillarboxed program on a 16:9 display.  Or
maybe there should be a new 'Widescreen fill' mode.

The other thing that would be nice would be if Myth had a smarter kind
of zooming.  Zooming tends to lose a bit too much of the edge of the
program, and stretch distorts the image too much.  My widescreen TV
has a mode that stretches the display a bit, zooms it a bit, and
pillar boxes it a bit, as a compromise.  Works pretty well.  If you
horizontally stretch a pillarboxed program by 10% and zoom it by 10%,
it would be 90% of the width of the TV, and if you zoom and stretch by
12% each, it would be 94%.  I guess you'd have to play with the zoom
and stretch percentages to find the best compromise.  Of course, this
could also be done when myth is fitting a letterboxed program to a 4:3
display, and could even be done when showing a 2.21:1 widescreen movie
on a 16:9 (1.7777:1) widescreen TV.

-- 
Peter Schachte              What use is magic if it can't save a unicorn?
schachte at cs.mu.OZ.AU            -- Peter S. Beagle, "The Last Unicorn" 
www.cs.mu.oz.au/~schachte/  
Phone: +61 3 8344 1338      


More information about the mythtv-users mailing list