Closed Captioning: An Overview

Just got to reading the description of this video. I like the "(nice)" next to my name!

Sonic the Anonymous Hedgehog

I bet a Sony PVM or BVM would make showing the HBlank lines easier for demo purposes, since it's HDelay would move the image half down on screen showing the HBlank in a stable location.

Matthew Holder

I love your videos, keep up the good work! Great to see your videos are going to be more accessible to those not fluent in English. Unfortunately there is no way to disable translated video titles in the mobile app. They confuse me :P

Was that a clip from Raise the Titanic at 11:17?

I never thought about the etymology of "stay tuned" until this video. similarly, until I actually dialed a phone for the first time in my life (I had to buy a rotary phone to do it), I didn't realize where dial originated. I wonder how many more common phrases like this have similarly forgotten or lost origins.

adcurtin

Don‘t use past tense when talking about teletext: It’s still being broadcast, at least in German speaking countries (DE, AT, CH). It now lives as a separate stream within the MPEG-TS container on DVB broadcasts. Some broadcasters even put it on webpages <a href="https://www.ard-text.de/" rel="nofollow noopener" target="_blank">https://www.ard-text.de/</a> or — even weirder — in an app <a href="https://itunes.apple.com/de/app/ard-text/id1026666292" rel="nofollow noopener" target="_blank">https://itunes.apple.com/de/app/ard-text/id1026666292</a>

Reemt Rühmkorf

In case you need a source of teletext content for your next video, the Raspberry Pi's composite video output can be hacked to output Teletext. Google for "Raspberry Pi teletext" and you should find what you need to get it working.

Tyler Knott

As a Dane, I am looking forward to the episode about teletext, which we still use. When I was a child we had a board changed in our TV and suddenly the danish characters æøå were turned into their sweedish counterparts. Talk about baking a text format into hardware.

Simon Mikkelsen

Love the episode. As a Dane I only stumbled across captions on Laserdiscs, and a Danish store had their own made, it used the RGB input on the TV for the captions and just let the composite picture pass through, so the captions didn't interfere with the picture. but used scart, so modern tvs can't use it. Had to buy a new one from eBay that uses composite. But I totally love the technical details in your video, o going behind the scenes of the captions 😊

Because Why-Nerd

Sweet, I'm in there now :)

Benjamin Kier

Can you do a video on S-video vs composite?

Awesome. You should do one about DVS (descriptive video service). I use it often. (I'm legally blind)

Brad Wilmot

Great video. I remember as a child wondering what the "CC" meant that appeared in the corner of the screen when Star Trek:The Next Generation started. I presume that was hard coded into the video as it was the same font as the episode titles. For us this side of the pond, the numbers "888" appeared in the corner of the screen indicating that subtitles were available, as they were accessed by navigating to teletext page 888. I don't know if closed caption decoders ever worked for tv broadcasts here, but I know that they were available, as a message telling you about them appeared at the beginning of most pre recorded video tapes.

Brian Condron

Great video. I didn't realise Teletext wasn't big in the US. In the UK I don't know what we would have done without Ceefax (the BBC) and Oracle (ITV and Channel 4) - it was like the precursor to the internet, especially for live news and sport.

Mark Wayt

I really like all of the WGBH/PBS nods in this video. As someone who grew up with out cable, PBS was my variety channel and I was a huge fan of Mystery. I still consider Jeremy Brett to be the best Sherlock Holmes actor.

Kajico

Cool, and definitely worth the effort for the CRT "entrapment" for sure. Would have liked to have a small bit about the actual data encoding like you did for the CD!

Kilrah

Ahh yes. Mode 7; I remember it well! In fact I was playing with it again just a few weeks ago. Seriously. There is a simple but perfectly useable browser-based Model 7 editor here: <a href="https://zxnet.co.uk/teletext/editor/" rel="nofollow noopener" target="_blank">https://zxnet.co.uk/teletext/editor/</a> and there are quite a few downloadable editors to run on Windows. Another super video Alec. You're back to your old form obviously. The time and effort that goes into a video like this is obvious - but it pays off.

Stephen Bell

There also seems to be multiple options for CC texts, although I'm not sure I've seen any differences or alternate uses. Slightly related: Also, some videotape studios used that blanking interval to put their name, sort of a watermark. CBS FOX was one. So if you made a copy of one of their tapes that ID mark would go with it, I guess enabling the studio to know if it came across a blank video with their content they could tell it came from one of their tapes. A TV we had decades ago when I was growing up developed a fault where some of the content of that blanking interval was reflected back down onto the top of the picture in an elongated fashion. That CBS FOX trick was especially annoying on this set because we had an upside down CBS FOX white text in separated out scan lines superimposed onto the picture. It was only when the horizontal hold failed at one point that I spotted the CBS FOX text in the black bar and finally understood where that ghost text was coming from.

Arthur Robillard

Now that's the kind of content I used to really appreciate when I first notice your channel! Nice that you're back on track! Very good work! :) I just love those nostalgic anecdotes!

Jean Lefebvre

Great episode! Great prequel for the teletext one too. Can hardly wait for that one... but I patiently will!

Compuart

That turned out amazingly well. Definitely worth the effort to put yourself on the CRTs again — as someone else said it added a lot of visual benefit over just a talking head. Hopefully more people find out how closed captions work/came about through this fun video. Ewen

Ewen McNeill

Another awesome video. Thanks! I grew up in the UK and am familiar with teletext if you have any questions. BTW, you should check out the BBC Micro (<a href="https://en.wikipedia.org/wiki/BBC_Micro)." rel="nofollow noopener" target="_blank">https://en.wikipedia.org/wiki/BBC_Micro).</a> Mode 7 provides the same graphics mode as teletext, and indeed had a teletext adapter available (<a href="http://www.heyrick.co.uk/software/ttx/ttxouse.html)." rel="nofollow noopener" target="_blank">http://www.heyrick.co.uk/software/ttx/ttxouse.html).</a> Also, Prestel used the same graphics mode, which was a UK BBS (like Compuserve).

Big Car

On one hand the switching between the different TVs got me distracted, but on the other hand, it’s a reason to watch the video more than once - I am and have been in TV Business at a Broadcaster in Europe for the last 15 Years and for me watching your videos is like a narrated journey through my past - thank you very much

Really enjoyed this--definitely worth waiting for. Please accept the imaginarily attached certificate of total awesomeness.

Mark Hesse

Huh, I always thought they were "Closed Captions" because they were enclosed by a box, rather than just text on top of the video. Learn something every day I guess.

Jesse G. Donat

Thanks, great video. Can't wait for the Teletext video!

Paul Schuur

Cool, as a European, I never knew that in the USA, they used a much simpler system than our Teletext. As simpler, it seems also to be more robust, as I have never been able to decode Teletext very well from a VHS cassette...

MrHammond

Thanks for the nice feedback! I thought a lot about the placement of the captions at 12:38--I decided that they should just stay at the bottom where they would usually appear in a broadcast. People using captions might miss them, but that was more of an Easter egg than anything else. For the open captions that slide from the bottom earlier in the video--I'm gonna be shutting off the YouTube captions at that time so they don't interfere. And as I had remarked--I wish you could specify the position of YouTube captions! That would be very helpful.

Technology Connections

Great work! The sections where you are on CRT's helps break up the large section of talking. If you do something similar in the future it would be nice if the captions you added (12:38 for example) were not at the bottom as they run under the YouTube CC's so look messy can can be missed. Maybe top right corner or some other dead space Thanks!