[MacDV] Size and position of subtitles/subpictures in a DVD

[Aaron]

Both to clarify what I'm trying to find out and share what I already know or think I know, I'm going to first summarize the latter:

* Subtitles/subpictures are encoded as images of a special kind (with, among other things, a restricted pallette) in separate data tracks, one for each language. (They are NOT encoded as text!)

* These tracks are multiplexed with the various audio tracks and the main video track in a single MPEG-2 file which appears on the DVD as a sequence of .VOB files.

* There is nothing to prevent a hardware or software DVD player from displaying the subtitles anywhere the programmer and user choose to display them. A software DVD player on a computer could, for instance, display several different language subtitle tracks at the same time in different windows! (Whether such a player already exists or not I don't know!)

My questions are the following:

? Is the subtitle/subpicture restricted to a relatively small area of the screen?

? If it is restricted, is it restricted in such a way as to appear only at the bottom when displayed with ordinary commercial DVD players?

 - Aaron

P.S. Regarding the following: Is closed captioning even implemented in DVD technology? Isn't it replaced by subtitles?

>Date: Tue, 3 Jan 2006 10:40:50 -0500 (EST)
>Subject: Re: [MacDV] Size and position of subtitles/subpictures in a DVD
>From: rgb at ellerbach.com
>To: "A place to discuss digital video on Macintosh." <macdv at listserver.themacintoshguy.com>
>
>On Tue, January 3, 2006 10:07 am, Michael Winter said:
>>
>> On Jan 1, 2006, at 7:34 PM, Aaron wrote:
>>
>>> He said it was because he needed to have the words describing the
>>> various interviewees in the different languages as well, and that
>>> subtitles could only be in a limited area at the bottom of the screen.
>>
> > I can only say that I've seen subtitles at the top of the screen on a
>> couple commercial DVDs when the opening credits were being displayed
>> near the bottom. I have no idea how that is done though. Something
>> else I've noticed is that while viewing widescreen movies on my
>> regular TV, sometimes subtitles appear in the black area beneath the
>> image (which I think is great), though most of the time the subtitles
>> appear over the bottom part of the video. Just pointing out that
>> there must be different ways of doing subtitles.
>
>Closed captioning is a completely separate technology from simple
>subtitles. It requires special hardware to encode the captions into the
>video signal and isn't just a video overlay encoded into the video images.
>
>Rich