Changing the aspect ratio while you watch a DVD title (DVD-Video).
 

Hi:

This is a serious question. When you watch a DVD title (that's a disc) you usually have the option to change the screen aspect ratio (AR). Suppose the DVD title does not give you that option but the DVD player does. Can you still change the AR?

Is this on a computer or on a DVD player ? Obviously you can on a computer, I mean mplayer and other media players support changing the aspect ratio. For a particular DVD player it varies. I have some that can and some that can't. It's best to buy a DVD with the right aspect ratio for your screen.

There is no DVD that will give you "the option to change the screen aspect ratio (AR)". That's simply not something that a DVD can do. Some DVDs do let you choose between different video tracks that were encoded with different aspect ratios (widescreen and full-frame), but that's not the same thing.

I know there are two-sided DVDs with widescreen on one side and letterbox on the other. For most DVDs, however, they come in one aspect ratio. The only real adjustment the DVD player does is to play it at the stated aspect ratio and add black bars if needed, or stretch to fit the screen (but not all have this option).

OK. But when you say DVD, what do you mean? A DVD disc or a DVD player?

Disc.

It's proper to say "player" if you mean "player", since the last letter of DVD stands for "disc".

Thank you. So the ability to make one watch in AR= AR1 or AR= AR2, to put them a name, is it on the disk or on the dvd player? Well, you've already answered the disk can have to tracks, one for AR1, the othe for AR2. Now suppose the disk does not have a second track forthis purpose. Can the DVD player offer the option anyway?

My goodness, in fact there are four possibilities, two for the disk and two for the dvd player itself. This greatly complicates matters.

My answer is the same as H_TEXMEX_H's.

Yes, the player can offer the option to play the video in a square or rectangular aspect ratio. This is so that the player will work on both square and rectangular TVs.

If you have a rectangular TV, you set the player to output video in a rectangular aspect ratio. If the video was encoded to use a square aspect ratio, then the player will put black bars on the sides.

If you have a square TV, you set the player to output video in a square aspect ratio. If the video was encoded to use a rectangular aspect ratio, then the player will put black bars on the top and bottom.

And these black bars are a bit of an annoyance. I always had thought they were some result of a bad quality product! For the record: all squares a rectangles. Thanks a lot.

Would you rather the player scale/stretch the video frame to fill the screen, regardless of the aspect ratio? This results in horizontal stretching when playing 4:3 ("standard") content on a 16:9 ("widescreen") display. Letter/pillarboxing exists to prevent such stretching from occuring either way; it always scales the video frame to the nearest possible horizontal or vertical resolution to fit the TV while maintaining the aspect ratio (or in the case of choosing between "widescreen" and "standard" format on a disc, the "standard" video has (often) been pre-encoded with letterboxing).

Ahhh, I now realize what the definitio of black bar is: and certainly not what I thought. No. When certain cable TV channels radiate a picture (movie) a line of dot or dashes can be seen separating the usable are from the black areas (black bars). And these dot/dashes are not static but moving along the border all the time. That's certainly annoying. I do not remember if in DVD discs the same is true. Anyway, perhaps in the US things are done another way, I mean better and such a phenomenon as I'm describing takes not effect. Thanks for your post.