I was watching the DVDs of a TV show when I decided to turn on the captioning to be sure I caught everything - there were some lines I missed and I wanted to get it all.
I did what I always do when watching TV: I grabbed the TV remote and hit the “Caption” button. Nothing happened. I checked again that I’d turned it on properly. Still nothing. No words on the screen.
“That’s odd,” I thought. “I thought all DVDs were supposed to be captioned for the hearing impaired.”
I continued watching for a few minutes when I remembered the “Subtitles” option on the DVD menu. :smack:
Okay, I turned that on with the DVD remote and it worked.
The question: Why didn’t the regular TV captioning option work? With other DVD movies (and even other DVD TV shows), I can turn it on with the subtitles option or with the TV captioning, but not this certain show. Is it just the way this one show’s DVDs are formatted?
The closed captions on TV programs are transmitted as part of the TV signal in the “blanking interval,” which is the portion of the signal between the end of one frame and the start of the next. When you turn captions on with your TV remote the circuitry in your set looks for this specific signal and attempts to decode it.
When you are playing a DVD and turn on the subtitles, they are electronically displayed as part of the picture signal, in the same way that titles and other information are superimposed over the picture.
Was it a Universal Studios DVD? For some reason, Universal does not use the regular captioning, only the subtitle kind, unlike most other studios, which use both.
I’ve found that a lot of the BBC DVDs aren’t captioned, which is also true for a bunch of their movies, so I suspect the same goes for their TV show collections. Apparently in the UK, they go in more for having an inset with an interpreter doing her thing in the corner. (UK Dopers, correct me if I’m wrong)
Any road, this makes me sad because it’s just not worth it to watch some awesome movies like Neverwhere if you can’t understand the dialogue. I still remember that a bunch of us CC-dependent Americans emailed Neil Gaiman and begged him to ask the BBC (?) to make Neverwhere captioned. Unfortunately his response didn’t sound like he had much control over the production.
All DVDs can have subpictures (aka subtitles), which are overlays that your DVD player combines with the video as it plays. You can turn them on yourself with your DVD player’s controls, or the disc can force them on. These are usually just transcriptions of the dialogue, but they can be any simple images: Not Another Teen Movie has a playback mode where message boxes pop up to point out all the references to other movies, and subpictures are used in Ray and The Matrix to indicate when extra scenes are available. Since they’re just pictures, these subtitles will look the same no matter which DVD player you have, and different discs might have different fonts or colors of subtitles.
NTSC (US/Japanese) DVDs can also have closed captions, which (like subpictures) are stored separately from the video on the disc, but a DVD player that understands closed captions will automatically encode them into a hidden part of the video signal and send them to your TV, whether or not you’ve told it to show subpictures. Closed captions are decoded by your TV, so they’ll have the same appearance on the same TV, no matter which DVD player or disc you’re using.
If you don’t see closed captions, either (1) the disc has no closed caption information, (2) your DVD player isn’t capable of reading the closed caption info and encoding it for the TV, or (3) your TV isn’t capable of decoding the captions. Since you see captions on other discs, we can rule out 2 and 3.
Fat Bald Guy basically nailed it. To put things in as simple a nutshell as possible:
Closed captioning is stored in what’s called the Vertical Blanking Interval, or VBI, on standard NTSC video (what we use in North America).
DVDs store the video in MPEG (a digital format) rather than NTSC. MPEG has no VBI, hence the captioning must be stored in a separate file on the DVD.
When your DVD player converts the video from MPEG to NTSC, it has to find that file and create new VBI data from it. Most, but not all, DVD players know how to do this.
The law in the U.S. requires closed captioning on broadcasts only. There is no legal requirement for captions on DVDs. There are some production houses that consider the DVD subtitles (these are the “subpictures” that Mr2001 referred to) equivalent to captions, so they leave the captions off.
Captioning and subtitling are not actually equivalent, for quite a few reasons.
If you want all of the straight dope on the subject, see The Closed Captioning Handbook, by Gary Robson. The link takes you to Robson’s bookstore, but you can also get the book on Amazon. If you’re a member of the National Association of Broadcasters, their store has it at a discount.
I missed the last question before my post. Modern captioning software can create the standard VBI closed captioning and DVD subtitles all at once from the same data file. There’s no extra work and no extra cost (although some captioning service providers have an extra charge for generating the DVD subpicture files).
Companies that use “do it yourself” subtitling may not understand how to do closed captioning, or they may have software that’s not capable of doing it.
I still remember that a bunch of us CC-dependent Americans emailed Neil Gaiman and begged him to ask the BBC (?) to make Neverwhere captioned. Unfortunately his response didn’t sound like he had much control over the production.