DVD RB and Closed Captions (CC)

[quantum]

Thought I'd give this a thread in case anyone wants to keep an eye on it.

Background: What are closed captions?
Captions (CC) are text that is displayed on the TV screen. It is stored in the video stream and activated by the TV remote. CC works on television programs and VCR tapes as well as DVD. They are not the same as subtitles that are on most DVD's and activated by the DVD remote.

[UPDATE: Now DVD RB does retain CC]

Why would you care about CC on a DVD when you usually have subtitles? The answer is a number of disks, particularly episodic TV disks like Farscape, and some older movies, don't have subtitles at all, but they do have CC. Another example is some disks have subtitles but only foreign languages, leaving CC as the only option for english text.

Some technical details
http://forum.doom9.org/showthread.php?s=&threadid=32646

[quantum]

@jdobbs: Any further info, either good or bad on this?

[Joergen]

Oh so thats what CC is, kinda like Teletext in the PAL region, where you can enter a specific page number into the Teletext system and it will show subtitles instead of a page, drawn by the digital overlay chip thingie. A similar system is used for DVB-S subtitling but the sub page is automatically selected and the different subtitle pages are shown as simple language choises. But DVB-T/C uses bitmap subtitling much like DVD, but somewhat smoother/higher palette.

CC isnt used for PAL discs at all though. Never seen any mention of it.

[wmansir]

Recently, jdobbs wrote here (http://forum.doom9.org/showthread.php?s=&postid=504424#post504424) that he just became aware that you can retain CC info using a CCE method, and needs to research it.

[quantum]

Thanks for the link ;)

[Video Dude]

(CC) Closed Captions differ from subtitles in that they not only display text speech, but they also display sounds that are in the background. For example, "water dripping", "fire crackling", etc.

They are stored on the GOP of the MPEG video stream.

[Joergen]

So thats the usual "for the hearing impaired" subtitles that we have on every PAL disc practically. But it still makes me wonder why they use this CC method instead of normal subtitles.. what is the benefit?

[quantum]

CC came before DVD. It works on TV programs, such as the news and sporting events as well as VCR tapes. It's not better, but it's probably more available to some disk authors in some situations.

Consider Farscape for example. It's a TV program so you can bet they already have CC ready to go. Adding subtitles would probably have cost more money. In any case, Farscape comes with CC only.

Almost all new mainstream movies have subtitles. But I have seen some recent movies that have subtitles, but only in non-english languages. So in that case we're back to resorting to CC.

[Joergen]

Thanks for the info.

We have a somewhat similar system here in scandinavia where all programs are properly subtitled with nice large white letters with antialiased black edges and its in the picture itself (usually, though DVB-T/C transmissions use a floating bitmap of the same subtitle), so if you want to see other subtitles, you have to enter a teletext page, and it then draws the other subtitles in a simpler low rez version with black bars hiding the original under them.

I can see some situations where CC could be cost-effective, but then again I bet it doesnt cost too much to buy software that converts the CC material to proper bitmap subtitles.

Also I'd expect the standard for subtitling is lower in countries where subs are not used all the time (and a common standard/guideline has not formed). Rare a hollywood studio yet comes up with the kind of subtitles that I expect of them. Sometimes the white subs have such a small black border (1px) that its almost hard to read them.

BTW. I have always wondered, is there a Teletext system in use in the USA? I never see mentions of it, and even channels like CNN Europe adopted Teletext (or Text TV) only a few years ago, but it has been available since the late 80's.

Take a look at an internet version here:
http://www.yle.fi/teksti-tv/

For instance, you can enter page 173 to see currencies. Some pages have subpages (173, page 1/4).

I remember as a kid when we got our first Text TV capable TV. It was lost in the pages for an hour, my first Internetish experience :)

[Video Dude]

@Joergen
We don't have a Teletext in the USA. I guess the closest thing to it is "Interactive TV". If you watch a station that uses Interactive TV, you press a button on your remote and it brings up info about the show. You can also play trivia games or vote in polls. It was more popular years ago, but you hardly hear about it today. People got sick of it when advertisers started to use it to sell products.

The reason CC is so big in the USA is that there is a law that requires broadcasters to include it for the hearing impaired. If you press the CC button on your remote (or the mute button), CC subtitles are shown on TV broadcasts. When these TV shows are then transfered to DVD, most companies will use them instead of subtitles. Less work for them.


Example of CC: http://ktwu.wuacc.edu/journeys/images/captioned.jpg

[maksa]

I have managed to extract it from Resrvoir Dogs and insert it as a subtitle stream.

It is not easy, but if you want to do it link is here:

http://forum.doom9.org/showthread.php?threadid=75987

[harpseal]

I know this is in the known issues thread but I was curious if it's been looked at lately. Obviously jdobbs has had (or always has) his hands full with bug fixes and such but I personally would kill, or at least slightly mame, to have closed captions retained with RB. I back up a LOT of episodic TV discs and they are played in an environment where the sound isn't played (and the discs end up very mistreated!!) so subtitles and CC are the only thing viable, but unfortunately a lot of discs still don't have the English CC duplicated as subtitles.

Is this something that would take a lot of work to accomplish? It seems that the whole seemless branching thing is on everyones list but personally I have not once had an issue with multi-angle but have many discs without subtitles. I can understand my use may be a bit more unusual though so I am probably an exception. I looked into changing CC to subtitles but there doesn't seem to be any way that's even close to easy to do, but if someone has some ideas I'd greatly appreciate them.

Thanks to jdobbs for the great program and all the rest of you for the awesome support on this board.

[harpseal]

any comments? sorry to pester.... :o

[maksa]

Read above your post. I did it with reservoir dogs and VobSub.

[harpseal]

Right, I did read it, but it seemed way too much to do on a regular basis. Plus the fact that some of that stuff seems over my head.

I do a lot of sets of episodic discs such as the 5 disc per season Stargate SG-1 series' or the original Outer Limits seasons. I was hoping for a bit more practical of a way, or to know if this was still on jdobbs' list of "to do's" in the near future.

[str8]

At long last v1.09 added CC support. Kudos to jdobbs.

[BobZhome]

First test was a success, with CC lining up perfectly :)

:thanks:

[quantum]

Better late than never.

Nice work jdobbs :)

[jdobbs]

I always keep my promises...

:cool:

BTW, killer system you have there.

[harpseal]

hooray!!! hooray!!!!

:thanks:

:D :p

[maksa]

:thanks: :thanks: :thanks:
Gratefull ESL community...

[DocDragon]

:thanks: jdobbs! i was waiting for this a looooong time :D.

i did a batch run last night, and unfortunatly, i came across some "weird" behavior. playing a scene from SG-1 using the media player classic and playing from my stand-alone sony ns715, i get "ghost" images -- pictures from another scene overlap the current. my sony did stutter quite a bit as well, ie. the timer went back and forth, the pictures were constantly freezing, and there were a bunch of macroblocks...:confused: . once in a while CC would show up, though.

i attached a picture of the original scene and the one that was processed by DVD-RB.

DD

ps: i'm doing some more tests right now and will report back.

[jdobbs]

??????

I don't see how any of that could possibly be related to closed captions.... Closed captions are just a user data stream that is independent of the pictures.


It looks really artistic, though. Are you sure you don't have "make this picture surreal" mode checked?


Are you using any filters?

[DocDragon]

addendum:

i should mention that during the batch run, the first converted movie (Star Trek 5 - The Final Frontier) was running smooth without any pixelations, but it did not display CC on my sony.

the following 2 conversions in this batch (SG-1 Season2 Vols. 1 + 2) exhibited the above-mentioned symptoms.

DD

[DocDragon]

??????

[...]
It looks really artistic, though. Are you sure you don't have "make this picture surreal" mode checked?

Are you using any filters?

*hehehe* i would certainly try to sell my "artistry"... but no, no filters were used, only menu encoding was checked, and i'm using CCE basic if that is of any importance.

i will run another test, and if necessary, will re-boot my computer just to make sure things are fresh. it's been running 24/7 for more than a week now. windows has been known for very "strange" behaviors after awhile...

also, before i discovered that the "closed_captions=1" parameter had to be inserted into rebuilder.ini to ACTIVATE CC, the conversions were fine (they just didn't display CC).

DD

[jdobbs]

What happens if you do them without CLOSED_CAPTIONS=1 in the INI file?

Also, I assume these are NTSC? I'd like to run them and see what happens on my system.

[DocDragon]

What happens if you do them without CLOSED_CAPTIONS=1 in the INI file?

Also, I assume these are NTSC? I'd like to run them and see what happens on my system.

yes, like i mentioned above, before i discovered the "closed_captions" parameter, conversions ran without any issues. it's only AFTER the insertion of the parameter line and redoing the same DVDs that i got those weird pixelations. all DVDs are NTSC.

i'll report more when i'm back home. my machine is currently converting in "single" mode (ie. no batch mode used).

DD

addendum: i just read another thread about preprocessing. the only thing i did with the SG-1 S2 V1+2 was to kill the playback of the "MGM" logo with pgcedit. nevertheless, conversions without activation of CC were always fine until the insertion of the "closed_captions" parameter.

[jdobbs]

I'll pick those discs up tomorrow and run them. Maybe there is something unique about them.

[DocDragon]

I'll pick those discs up tomorrow and run them. Maybe there is something unique about them.
i'll do some tests with SG-1 s2 vols. 3 + 4 as well. let's see if the same problems appear.

i'm only curious, why "ST5-final frontier" was converting fine, but on the other hand did not display CC...

so, it has nothing to do with the way how CC info is re-multiplexed back into the vob stream?

DD

[jdobbs]

You never know... the CC should be separate from the video. It's positioned between the GOP header and the first picture header of the each GOP. But, if something is miscalculated and it overwrites something I suppose it could happen... I'll have to look at it.

This kind of unexpected result is exactly why I didn't enable it as the default this version. I've run it on about 20-30 titles without problems...

[DocDragon]

alrighty, new results:

attached are 2 pictures: again it's from SG-1 s2 v1. the original disc was encoded and rebuilt (once again... :p ).

test #1: pic is taken when "closed_captions=1" parameter was included in rebuild.ini -- very artsy ;).

test #2: no CC parameter -- result is absolutely normal. please note that i have used the SAME m2v files that were created to rebuild test #1, except that this time, i removed the CC parameter from rebuild.ini, restarted DVD-RB, and used the "Rebuild" button only (ie. i didn't do any new "Prepare" or "Encode"). so the source material is identical in tests #1 and #2 (but i guess re-multiplexed differently).

i hope this helps. i will start another conversion with ST5 final frontier.

DD

[jdobbs]

Could you send me your REBUILDER.INI so I can make sure I repeat your settings exactly? (dvd-rb@dvd-rb.com)

Thanks

[jdobbs]

Any chance you may have GOP size set to 18?

[jdobbs]

Ok... I was able to verify this problem. It happens on telecined streams when the GOP sizes are set to something other than default. Ugly...

[DocDragon]

Could you send me your REBUILDER.INI so I can make sure I repeat your settings exactly? (dvd-rb@dvd-rb.com)

Thanks

since you are able to verify this problem, do you still need my rebuilder.ini?

DD

[jdobbs]

No... I just want to verify, though... you have the GOP size set to either 15 or 18, right?

[DocDragon]

No... I just want to verify, though... you have the GOP size set to either 15 or 18, right?

GOP size is at "Default (Auto)" -- i haven't touched it ;).

DD

[jdobbs]

What encoder are you using?

[DocDragon]

What encoder are you using?
CCE Basic 2.70.01.10.

DD

[str8]

My GOP also says "default" in DVD-RB.

CCE 2.70.01.05.

[jdobbs]

I've found two problems that I've corrected related to CC.

First, as mentioned, is one in which using a non-default GOP size can cause corruption of the picture -- this one is obvious to those who experience it. The second is a failure to properly assert the CC flags in the IFO generated by DVD-RB when selecting "Movie-Only" mode. This one acts differently with different players... but generally it simply doesn't show CC.

I'm still doing testing on these fixes and checking out a couple of other reports, but as soon as I'm sure they are stable I'll release v1.09.1

Also note that this has no effect on any encodes for which the CLOSED_CAPTIONS=1 flag hasn't been specifically set in the REBUILDER.INI file for beta testing of CC.

[BobZhome]

I did a backup of The Brothers Grimm and got the nice looking art work at the end on the movie.
My GOP was at default and I'm using CCE SP Version: 2.70.2.4
I did a "full backup (menus, movie, extras)"

As a side note: I have completed 5 backups with CC that came out perfect, they were all cartoons :)

Thank you for not giving up on CC :thanks:

[jdobbs]

The "non default" could also happen occasionally if the encoder ever gives you telecined output that has more than 12 frames... a little more tweaking and we'll get it working and out of beta. I can tell you it was quite a bit harder than I first imagined. Also the documentation for CC on DVD is really scarse -- and what you can find is often wrong.

I don't think I would have ever figured some parts out if old trusty MPUCODER wasn't around with the right answers. That guy is a genious.

[str8]

You're not slouch yourself. Thanks again for the CC support.

[DocDragon]

You're not slouch yourself. Thanks again for the CC support.

yep, thanks for working so hard, jdobbs! :thanks:

just curious: i just finished converting "serenity" using Rejig (b/c it's FAST). i did not see any CC files (*.CC1, *.RCC) in DVD-RB's working directory -- is that normal? i know the movie has CC b/c i watched it.

let's see how my DVD players will play this conversion -- i'm burning it right now.

DD

[jdobbs]

The CC1 files only show up in the version I sent you for testing -- I forgot to turn it off.

If no RCC file exists, that means that DVD-RB found no closed caption text or commands (something other than "empty" field indicators) in that segment. If you select ReJig or "No Compression" you will never get one (because they are already there).

Using ReJig will always have CC (even before v1.09) because ReJig is a transcoder. The CC doesn't need to be remultiplexed back in because it was never reencoded.

[DocDragon]

The CC1 files only show up in the version I sent you for testing -- I forgot to turn it off.

If no RCC file exists, that means that DVD-RB found no closed caption text or commands (something other than "empty" field indicators) in that segment. If you select ReJig or "No Compression" you will never get one (because they are already there).

Using ReJig will always have CC (even before v1.09) because ReJig is a transcoder. The CC doesn't need to be remultiplexed back in because it was never reencoded.

thanks for the info!

i did a boo-boo: "serenity" does NOT contain CC -- i activated the subtitles when i watched it :o .

back to converting...

DD

[DocDragon]

update:

interesting, although rejig supposedly retains the CC stream, my result with a quick "Star trek V - the final frontier" conversion is even worse than with CCE basic. CC text only shows up sporadically and most of the time, emptiness roams the screen (meaning nothing gets displayed). RCC files ARE present in the working directory...

DD

[jdobbs]

Hmm... that's really interesting, because the captions are unchanged from the original. I'll have to check about the RCC files.... maybe I left the extraction code on -- it may be just in the test version I sent you.

[jdobbs]

I just tested that title using ReJig. As is true with the CCE encodes, it plays perfectly on both my standalone player and through PowerDVD. There is obviously something about your players that don't like this... but what is really confusing is the report of playback problems with the ReJig stream. :confused: The Closed Captions are unmodified from the original stream...

I'll look at it more tomorrow.