Looking back at the bugs we've fixed over the last several months, we certainly have had a good share of captioning issues, especially with regards to the size of the codebase compared to the "video" code. Surprisingly, we don't hear from users a ton when captions don't work properly, but maybe that's because a minority of the users actually use them in the first place.
I'm not usually so negative, but I'm just annoyed at captioning today. The following is a poorly thought-out rant on the subject.
[donning my asbestos underwear]
I happen to be one of those users, so it drives me up the wall seeing poor-quality captions, time-delay issues, and glitchy behavior. In the U.S. it isn't so bad, but that is mainly because the only thing available here is dumb-as-a-rock Closed Captioning over VBI. In PAL countries they have Teletext, which tried to learn from the limitations of CC, and DVB goes even farther with MHEG support and all sorts of other interactive goodies. Not that we support those (yet), but they're there. Even with our CC support, though, the results are not what I would consider stellar. Whether the fault lies in poor VBI support at the tuner card, our VBI capture filter, or the CC decode itself, the end result is often missing or incorrect characters, bad timing, and the decades-old CC text look-and-feel.
I suffer from a mild hearing impairment that makes it a little more difficult for me to pick out conversations against background noise than the average Joe, so I turn captions on pretty often. The experience is not good on any American TV, ATSC or NTSC, only marginally better on European sets, and worse in Media Center. I admit I have not tested out TiVO or other PC-based systems to see if their support is any better (if you have, let me know how it goes for you). Mainly it's a low-level nuisance to parse words around the junk that crops up on the screen, and the "white text on a black/gray bar" color scheme with fixed font sizes is so 1970s. Come on! It's the 21st century... can't we do better than Lucida Sans fixed-width fonts? The DVD implementation, in contrast, is fantastic in most cases, with bigger, clearer captions and no noise/dropped words (yes, it's because it's a low-loss streaming medium, not like TV, but still).
Lest I put too much blame on the software or hardware on the user side of things, I also want to point out that broadcasters and content producers are often shoddy in their support of captioning features on their shows and networks. You'd think they want to get the captions in as close to perfect shape as possible, but between dialog inconsistencies (perhaps they used a pre-release script to make the captions?) and transmission problems, it's too often that captions come out unusable or barely usable. I count my blessings that most times I do not have to depend on the captions alone to track the storyline or news story. Maybe the hearing-impaired market isn't big enough to justify spending more resources on the problem to the boards of directors.
I wonder if I am a member of a small group of people that use these features and find them annoying. Almost deal breakers, in my case, if I didn't love the rest of it. Well, not almost, but damn it, I'm annoyed. Nobody seems to get this stuff right, and it almost seems like the folks implementing decoders and renderers nowadays put in captioning support as a legally-required afterthought. TVs do it poorly, we do it poorly, everybody does it poorly. If it's just me, I'll shut up.