Posted by Jukka Aho on 10/18/06 19:34

Linea Recta wrote:

> However, playng the DVD in the stand alone player, I cannot display
> the closed captions, although I have the option for closed caption
> activated in the players setup menu. What a shambles of standards
> eh...?

"Closed captioning" is an American subtitling standard where digital
subtitling data is embedded in the VBI (vertical blanking interval) of
analog video signals.

Decoding this digital data and displaying the CC subtitles as text
superimposed on the video typically requires a TV set with a built-in CC
decoder. Built-in CC decoders are required by law in the US as they are
seen as an important accessibility feature.

(As far as I know, American CC subtitles are typically intended first
and foremost for the hard of hearing and may contain textual
descriptions of sounds [such as "PHONE RINGS"]. Those learning English
as a second or additional language are probably another large group that
uses them. This is different from some other countries which primarily
use subtitles/captions as means of language translation for the "normal"
viewers.)

A DVD player _could_ have an option for displaying the Closed Caption
data as text on the screen. As far as I know, they usually don't.
Instead, the CC data, if present, is embedded in the VBI and it is up to
the tv set to decode it. If the tv set does not have a CC decoder...
well, though luck.

Since the email address in your signature points to the Netherlands, I
believe you might be using a PAL tv set. The PAL tv sets do not support
the American CC standard. There is a similar VBI-based
subtitling/captioning feature in the Teletext standard (Teletext
decoders are common in European tv sets), but I'm not sure if there are
any DVD players that would convert the American CC data to the European
Teletext subtitling format. There is nothing that would technically
prevent doing that, but the manufacturers of DVD players probably do not
bother with these kind of neat-but-little-needed features.

As you already noted, the DVD standard has a subtitling feature on its
own. If you encounter a(n NTSC?) DVD with Closed Caption data that you
can't view, it would be technically possible to extract this data with a
computer, convert it to DVD subtitles, and reauthor the DVD. Might
require learning some obscure tools and investing some time in it,
though.

--
znark

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