Optimising Blanking For Overscan

[meldavid]

Wow it's amazing how much of the sides of the video don't get displayed on my widescreen TV. I have been experimenting with blanking sizes and I found that in order to see the pillarbox on the sides I had to have the video width as 640 pixels with the rest made out of black borders to make it 720.

So I estimate probably from an mpeg2 of 720 pixels wide, you will only see about 656 pixels (before converted to its real-size).

I've noticed that most commercial DVDs only have black letterboxing on the top and bottom and they prefer to use the full width of the 720 pixel DVD width resolution - if they do have black borders on the side it's actually very thin.

Too bad you can't zoom out on your DVD player or your LCD TV. I didn't think an LCD TV would bother with overscan and just display the whole picture.

If you have a VGA input on your LCD TV and you use that to play back a DVD movie from say an Xbox 360, you will get the full picture. Likewise playing the DVD on your computer as monitors don't have overscan.

Do you think it's silly to encode MPEG2 video as 656 pixels wide with 32 pixels pillarboxing on each side so you don't lose any of the picture watching the DVD?

Is there a specification in the DVD format where you can instruct the DVD player not to overscan the video? It would be good to actually be able to encode using the full 720 pixel-width resolution but not loose any of the sides when watching the movie.


What are your thoughts about this subject?

[Case]

Do you think it's silly to encode MPEG2 video as 656 pixels wide with 32 pixels pillarboxing on each side so you don't lose any of the picture watching the DVD?

It could be considered silly, because it isn't future-proof. Your next digital tv will show the whole picture, and then you're stuck with a black border on the DVDs you made today.
It could be considered silly, because tvs have a different amount of overscan. When you show your DVD on someone else's tv, they'll suddenly see black borders, because their overscan might be half the amount of your tv.
I suppose you could tune your tv, or let some technician do it for you, to minimize the amount of overscan, especially with digital sources (signals) and digital tvs. Overscan is just a way to hide analog artifacts.

[meldavid]

Well right now I am using the component inputs on the LCD tv. If I upgrade to a DVD player with HDMI outputs do you think that will show the whole picture?

[meldavid]

If I have an avi fie that is 640 x 360, I could just resize it like so:

LanczosResize(640,512) # PAL Widescreen
AddBorders(40,32,40,32)

And I would only see tiny borders on the side. I mean if your source material wasn't really high-res to begin with would it be silly to do it like this. I doubt we would be replacing our TV for another 5 years. I just feel like I am missing out on detail when the picture is overscanned.