[mythtv] s-video input / widescreen tv ?

[Erik Arendse]

At 20-1-03 15:04, Bruce Markey wrote:
>If mythTV knows which format a recording has and could control your TV, it 
>can turn the TV in 4:3 for all menus, and show normal pictures as 4:3, 
>while showing pictures from anamorphic sources squashed into 16:9.
>>>
>>>Do not attempt to adjust your set. We control the vertical.
>>>We control the horizontal. The best approach would be to
>>>leave the TV, and thus the X screen, at 16:9 then set the
>>>dimension of the Xv output to the desired aspect ratio.
>>
>>Nope.
>>That's just when you have a _real_  physical anamorphic 16:9 display.
>
>I thought Laurent was referring to a physical 16:9 display.
>I didn't realize you had something different...

>>home I have a TV (CRT tube) which can switch over to 16:9. It does that 
>>by deflecting the rays less in the vertical direction, so I still have 
>>the same amount of lines.
>
>So it is physically 4:3? In the US, all I've ever seen are
>16:9 for high definition. I'd prefer a 4:3 screen that could
>compress the raster lines for HDTV. What brand/model do you
>have? I assume it isn't compatible with US TV but I'm curious
>to see any sets that work this way.

Short story:

Philips, don't know the model but nearly every non-portable newer 4:3 can, 
most upper models are compatible with NTSC but not HDTV.

Long story:

At the moment half of the TV's for sale over here (Netherlands) are 16:9 
displays, half are 4:3.
All use the PAL 625 lines, 25Hz interlaced source. Some have a frambuffer 
and interlacer on board, and end up with 50Hz non-interfaced, 100Hz 
interlaced, or 100Hz non-interlaced.
Some have interpolation (most notably plasma and TFT screens) and scale up 
from 625 to whatever.
We have a special broadcast norm being introduced (since 1995)  which uses 
PAL to transmit a letterboxed image, but in the black bars below/above the 
picture extra lines are hidden (in such a way to be below the blacklevel on 
a normal TV). Using a framebuffer a PAL-Plus TV can use these to 
reconstruct a 16:9 image with a higher resolution compared to the 
letterboxed one visible on the 4:3 TV.

HDTV is not really available here, there were some experiments but the 
equipment was very hard to get and the norm used (D2MAC) was more-or-less 
discarded . And even I believe some of the available equipment was just a 
converter to degrade the digital HDTV to an analog PAL to display on a 
normal 4:3 set.

Back to the question:
My TV (Philips, branded Aristona, Philips brand is originally Dutch (but 
now just another global company) available everywhere - but mostly Europe 
and Asia - under several names, most models country specific) can lower the 
vertical deflection so all horizontal lines squeeze in the leterboxed 
needed to show a 16:9 image with the width of the physical 4:3 tube (Phew, 
mouthfull...). This is only useful for DVD (or PC's)  as they are the only 
16:9 sources here, packing a 16:9 image anamorphic into a transport 
developed for 4:3. A theroetical "PAL-Plus to anamorphic PAL" converter 
could be used as well, but I have never heard such a beast existing.
By the way: the set does support NTSC the manual says, so if you send some 
money my way I could put it in a box and ship it your way :-)

The benefit of all this is based on the fact that that most of the 
tranmissions here are 4:3, slowly moving to 16:9.  Most commercial channels 
here will never transmit 16:9 yet out of fear some viewers will run away 
when they see a set of black bars.

If you watch 16:9 on a physical 4:3 you end up with a letterboxed image. 
The other way around you end up with a vertical "leterboxed" image. As most 
material is 4:3 I have to watch the smallest hours of black bars this way.
Other issue is that although on paper the 16:9 tubes are bigger, that is 
only because the diagonal is cited. The final size of a 16:9 picture is 
comparable within the same price-range for both 16:9 and 4:3, but the size 
of a 4:3 image will be a lot bigger on the 4:3.

Finally a weird tale (to me at least): As we sell so many 16:9 tubes, and 
as there are so few 16:9 transmissions, everybody puts their TV in some 
sort of "stretched" mode which deforms the 4:3 picture to 16:9...
And everybody thinks this is neat, except for a handful of people who use 
their eyes, including yours truly.

Erik