New video time!

A whole lot of folks keep forgetting about closed captions on DVDs, and as time has marched on this means they're getting less accessible.

https://www.youtube.com/watch?v=OSCOQ6vnLwU

Closed captions on DVDs are getting left behind

YouTube
@TechConnectify i actually found that some of my DVDs don't even have captions! and it's not like some unheard of show, i noticed it on House MD!
@dysfun Ah, but they might! There's a good chance they don't have a subtitle track, but they may have closed captions.
@TechConnectify oh boy, i thought closed captions was just what you call subtitles in america

@dysfun @TechConnectify At least in the US, subtitles are meant for hearing folks who don't understand the language the film (or particular scene) is in.

Captions include not just spoken words, but descriptions of sounds important to the film/TV (knocks on doors, music, etc) and are for Deaf & hard-of-hearing folks.

If they're open, they're burned right into the main screen. If they're closed captions, they need to be selected to be seen.

@meganL @dysfun @TechConnectify Huh. I call those "hard" versus "soft" subs (if I had enough media with both subtitles and captions to need to distinguish them, I'd say "hard" or "soft" captions by analogy, but since there's usually only one such track per language I don't mind calling them all "subs").

The distinction between those groups is not so clear cut. I understand English fairly well even though it’s not my native language. My hearing isn’t perfect, but it’s good enough in most everyday situations.

When I watch a movie I often want subtitles due to a combination of those two factors and one more factor: On many movies the volume of the voices is too low compared to all the other sounds. (It would be so nice if a DVD player would have separate volume controls for speech and everything else.)

If I watch a movie in English I want the subtitles in English, and I want them to match perfectly with what is being said. Even without subtitles I will understand a large part of what’s being said, and I will hear even more. Proper subtitles will help me understand the parts I would otherwise hear, but not hear clearly enough to understand.

But if the subtitles differ from what’s actually being said, it will confuse me a lot. The closed captions which include descriptions of every sound effect in the movie are quite distracting to me, but I understand that they will be helpful to people with worse hearing than me.

@kasperd I was simply defining how those terms are used in US English. Not demanding that hard-of-hearing people use captions rather than subtitles.

Not every sound is described in captions. Sounds that hold meaning that is important for a story or for context (in non-fiction) are what are described.

It is sadly common in mainstream Anglophone productions to censor or approximate what is said. In the case of captions, that's due to audism/ableism. Also capitalism "extra cost".

@meganL @kasperd My X-Files set certainly approximates what’s being said, which is very confusing because I still have some hearing left and I use the captions to have clarity — when the captions are substantially different that defeats the purpose.

@dysfun just to expand on what Megan Lynch said, in the US, "closed captioning" almost exclusively refers to EIA-608 or "Line 21 captions." These were broadcast with the rest of a television signal. Since this was a genuine part of the signal, they worked automatically with VCRs, and including them in video cassettes was easy.

DVDs don't store a native analog signal, so the closed captioning has to be injected into the analog output - analog output that doesn't exist, on many modern devices.

@dysfun @TechConnectify

Homicide: Life on the Street also has no captions and I’m really unhappy about that.

@TechConnectify
Gods I remember how cool all the little special features on DVDs used to be. Blueray too. It is so strange how far we've allowed our media to degrade.

Now we have to fight tooth and nail just for basic closed captions... :<

@TechConnectify And alas they’re going to get even harder to obtain because the current *ahem* thinks being accommodating to people with accessibility requirements is unamerican.
@TechConnectify hmmm, I was thinking that all DVDs have awful bitmaps as subtitles.
@burak @TechConnectify I remember when I "backed up" some of these that the dumping program retrieved the bitmap characters, OCRed and created a SRT file.
@TechConnectify I don't know anybody that actually buys DVDs any longer!
@3dcandy @TechConnectify I do, because I like to own my media. But then, you still don't know me 😂
@the_grue @TechConnectify Oh it was not a dig or anything - streaming is taking over the world. We still have some Blurays but.... very rarely I get them out
I did until the shops where I bought them ceased to exist.

@TechConnectify I learned things!

Things that I have zero use for.

But then again, I know how DOS interrupts work.

@TechConnectify ooo accessibility things? Love learning stuff about that! <3
@TechConnectify That is actually my favorite video of yours so far, very fascinating! And that's saying something because your videos are generally great.
@TechConnectify This video inspired me to buy the Perry Mason box set. I’ve seen just about all the episodes available on streaming, but there are so many missing episodes!
@nwd i bought the Yes Minister boxset for the same reason
@TechConnectify with age, we will all become hard of hearing, and we will all need captions.
at least the tik toks are making sure that short video content has open captions (i.e. captions that are in the video stream) we should keep that going
@TechConnectify this reminds me about how much worse BluRay subtitles are to dvd captions
@dat The few bluray discs I own are really enshittyfied... I bought a few and they're a pain to watch through a BD drive and VLC.
@TechConnectify
@dat Technology-wise they should be better as, IIRC, they are more like PNGs than simple bitmaps with a color to represent alpha. At the same time, seems the additional possibilities mostly made it easier to companies make worse subtitles.
@qgustavor only I really don't think having images if you want to display text is better in any way

they should instead have embedded a font and fixed encoding to utf8

that would solve more problems and would enable different usages of that data

maybe add images too - but never only images!
@TechConnectify Bonus Points for using a film that's famously unavailable for streaming in a video about physical media.

@TechConnectify thank you for that video. And OMG, all this time I had assumed that HDMI actually provisioned some kind of auxiliary data channel for a counterpart to the line 21 data. But a quick glance over the standard, and… it does in fact not. What the heck?

Goes to show, that I'm not a very active consumer of "television" and alike content.

@TechConnectify
I've always hated the stupid video overlay style of closed captions. How much easier it would've been if all DVD and Blu-ray players rendered text captions instead.
@sloanlance Considering the state of web subtitling is a mess - some websites use WebVTT because browsers should support it, others prefer ASS with libass-wasm because it supports more features, and others (like YouTube) even have their own formats - I guess if those formats had a textual format either it would be as simple as WebVTT (and people would be complaining that it lacks features) or the compatibility mess from ASS and the other formats (well, as Alec showed, some players have issues even with the basic Line 21 rendering). Then, there are fonts (and their formats) and Unicode and all of its issues (from garbled text, right to left rendering, top to bottom rendering, ♪ and even emoji), which are non-existent issues with image-based formats. 
@sloanlance To be fair, I spent a lot of time working with those formats. One of my projects consisted partly on taking those subtitles (doesn't matter which format) and converting into a common format (I chose PNG, in hindsight it was a bad choice) as part of the processing pipeline, which wasn't as easy as I thought. BTW two of my gripes with subtitling is that MP4 (which I will not name if after it's official name) supports a subtitle format which has more features than SRT (like positioning, which Alec surely likes), yet, like Line 21, is far forgotten in time. MKV doesn't support it and many players just render it as if it was a SRT, skipping support for it's additional features, and, AFAIK, that browsers often don't support inline styles in WebVTT files.
@TechConnectify It's great to see some TV technology again. House appliances just don't excite me much.

@TechConnectify And this is where everyone outside the US is discovering that closed caption isn't just a US linguistic term for what we call subtitles in the rest of the world...

Great video, as always.

@quixoticgeek @TechConnectify Except for those who were unfortunate enough to rely on such technology in the VHS era. There were about three PAL VCRs that could do it, and at least one of them was SVHS.
@kim @TechConnectify i did find myself wondering if there's a pal Vs ntsc difference in here too ...
@quixoticgeek @TechConnectify There's certainly a teletext vs closed captions difference. If you wanted to record with captions in the UK you either needed enough bandwidth to preserve the teletext stream (iffy, even with SVHS), or a machine that would decode the teletext subtitles and convert them to closed captions.

(Playback would require a CC decoder that would overlay the captions. This was available as a stand-alone unit.)

There's a reason all the deaf people had that Philips VCR.
@TechConnectify An accessibility feature that is not accessible? How novel! I'm glad someone is trying to raise awareness for this, especially since we still have a long ways to go before physical media disappears despite what the young'uns and Silicon Valley folks seem to think.
@TechConnectify I'd say it might be worth a message to whatever government ministry is in charge of accessibility, but at this point I'd be afraid that it would just get upper management to speed up the demise of optical media.

@TechConnectify You sent me down this rabbit hole too. I've written several MPEG2-TS decoders in my career, and when I was watching this video, I assumed they'd used another PID in the TS stream on the DVD. Turns out it is stored in the video stream. And not in line 21. There is additional data in the MPEG2 elementary video stream that has the EIA-608 data in it. To prove this, I got an old DVD, decrypted the VOBs, used ffmpeg to extract ONLY the video stream, and then passed that to ccextractor to see if it could find captions, and it worked!

I also tried MakeMKV (A popular archiving tool) to see what it thinks. Even though you can see in the screenshot it recognizes the CC stream separate from the subtitles, it strips them from the MPEG2 ES stream it puts into the mkv file (proved by extracting the m2v from the mkv, passing that to ccextractor, which finds no closed captioning)

@TechConnectify I tried to run MakeMKV with the following settings, and the resulting MKV file plays in VLC with a subtitle track! So, there is hope for MakeMKV for DVDs that ONLY have EIA-608 closed captions. In the bit of research I did about MakeMKV, it seems like it's using ccextractor under the hood to convert these to SRT.

Try MakeMKV on your Perry Mason DVDs and see how the subtitles look.

@keiko @TechConnectify

SRT does not support text positioning, so the positioning of EIA-608 CC is lost in this conversion.

Having tested the same Perry Mason DVD's with MakeMKV (I coincidentally ripped them for someone last month) I don't see any text transcription errors but the missing positioning is definitely a bit of a downgrade.

@UntaggedTransmitter @TechConnectify Yeah, that's a shame, but at least they're not lost completely. Sounds like it could be worth coming up with a better output format that does preserve the positioning (not SRT)
@TechConnectify My parents' dvd player from 2003 can display line 21 captions on screen. However, the option is hidden-- you must press a button labeled navi which brings up a large menu of options separate from the normal settings menu, including the one to display closed captions. Also, some disks' closed captions are decoded incorrectly, so that captions are never erased from the screen, and new captions layer on top of older ones.

@TechConnectify I wonder if there’s a different handling on this depending on the region - I’m in Brazil and pretty much all content here (local or foreign) includes subtitles - didn’t check CCs, will take a look at this later.

Also: I’m currently working on archiving our home DVD collection to our NAS - approx. 200 titles, cloning the discs using Brasero on my Linux laptop - then I’ll replace Plex with Jellyfin to be able to watch them via streaming.

@UnderEu @TechConnectify only US DVD had legal requirements to provide captions. Other countries/regions didn't.

@TechConnectify The current episode of @radiolab is a fun accidental companion piece to your video.

https://radiolab.org/podcast/the-echo-in-the-machine

The Echo in the Machine

The story of our attempts to make the spoken visible.

Radiolab Podcasts | WNYC Studios
@TechConnectify No one seems to have mentioned Youtube Subtitles hacking yet: https://youtu.be/NEDFUjqA1s8 If you want to actually do cool stuff with Youtube subtitles, the video is well worth a watch.
Poisoning AI with ".аss" subtitles

YouTube
@TechConnectify Just finished it, excellent video thanks!

@TechConnectify
Thanks for giving attention to often ignored accessibility features! Love to see it.

What are the episodes and timestamps where VLC had issues for you?

After seeing @rcombs comment on YouTube I got motivated to try replicating your issue to report it to the VLC devs. I have copies of the same DVDs available but don't see the same rendering problems in VLC in Linux or Windows, although in Windows I do see it using the same worse looking fallback font as shown in the video.

@TechConnectify interesting

My experience with DVB-SUB is that VLC sucks at that too. Even teletext rendering, which to be fair it does support, it doesn’t do all that well…

As for preservation, it is absolutely possible to put CTA-708 (which can wrap CTA-608) into an H.264 NAL unit in a similar way to how it can be embedded in MPEG-2 but I have no clue if people are doing this!

The good news is that guess is that I still work with CTA-608/708 quite a bit when writing software for broadcasters so… the knowledge is at least still out there

(Yes, EIA-608 got renamed to CTA-608 a while ago - it’s a bit of a rabbit hole!)

@TechConnectify I usually whenever I rip a DVD on MakeMKV try to include the captioning data from the disc which has the closed captioned data enclosed in the file, so I can stream the files on Plex which will show the CC data in the subtitles function on an HDMI TV with no problem.

@TechConnectify I can confirm that WinDVD supports captions.

I don't know how correct they are though as all my DVD players are computers

It has an option to not show the black background and seems to be moving them around the screen

@TechConnectify Looking forward to watching this one. I still buy DVDs, and I make them into MKV files with captions included, so it's of interest to me (especially when I need subtitles, e.g. non-English films).

One irritating thing is that VLC (which I use on my Android TV) keeps glitching the video stream whenever it has a new caption to display.

I hate smart TVs. I'm now looking to get a dumb display and build my own media server to feed it!

@TechConnectify I can confirm the PlayStation 5 has perfect closed captioning. (Please ignore my phone's inability to take decent photos of my TV.)

@TechConnectify I see that VLC has a few open issues on CC rendering, and I wonder how many of those derive from having a lot of devs in region 2 or, well, anything that is not region 1?

code.videolan.org/videolan/vlc…

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