OT: Can MPEG2 display Closed Captioning?

xjasonxisxdeadx wrote on 3/19/2005, 1:01 AM
OK.....Here's the deal...

I work at MTV so you'd figure the building would be overflowing with people with a definitive answer....but unfortunately...suits get in the way. Here's the issue.....

After encoding about 1600 music videos to both MPEG2 files and WMV files with FlipFactory....someone came into the fold and informed us that they NEEDED to have Close Captioning and had to be redone with different comp reels. The thing is....several of us have tested the files we KNOW had the "channel 21" CC track by burning it to a dvd and had no luck bringing up CC.

Is it possible to compress such a delicate string of information and have it still funtion correctly?

Originally we were told that the wmv files were to be used online...and the MPEG2s were strictly for archives. But now we're being told that somewhere down the line they're going to want to use the MPEG2s for broadcasting on MTV2.

So can anyone shed any light on this subject? I know it's way off topic but i also know that you guys are MORE than knowledgable.

thanks

Comments

filmy wrote on 3/19/2005, 1:58 AM
Not trying to offend here with this question but just making sure - when you tried to view the CC on the burned DVD were you using the TV's CC decoder or were you trying to view subtitles with the DVD? Some DVD players don't pass the CC info through to the TV either - so make sure the DVD player you are using does do that. On the PC side PowerDVD has CC ability. Just want to make sure we are on the same page.

If the info is still in the files you should have no issues decoding the CC info. If the TV or software doesn't decode it than chances are it is not there anymore. If you want to play around a bit you could create a graph in GraphEdit. Read about CC and GraphEdit at MSDN.

Since you're at MTV they might have CCaption already. But if not it might be worth looking into.

This is from the ATSC:
There are four ways that stations can originate DTV programming with closed captions. First, if programming arrives with DTV captions arrive already formatted and embedded in an MPEG-2 video stream or embedded in, or associated with, a baseband video stream, then the broadcaster is required to insure they are passed through and transmitted to receivers. Second, if the DTV program is being up-converted from an NTSC source, then the caption data in the NTSC program must be translated into CEA-708B format captions using CC types 10 and 11; the NTSC line 21 caption data must also be transcoded and broadcast with the DTV program using CC types 00 or 01 (also known as the 608 compatibility bytes). Third, if the program is locally originated (and not exempt) and captions are being locally created but are not in DTVCC, then again they must be translated into CEA-708B format captions and also carried as 608 compatibility bytes. Fourth, if the program is locally originated (and not exempt) and captions are being locally created as DTVCC, these must comprise the CEA-708B format captions and also 608 compatibility bytes.

If you want to read a good overview of the whole CC deal you might check out Closed Captioning FAQ. One of the things brought out is the fact that currently there is no standard for CC in MPEG files.
xjasonxisxdeadx wrote on 3/19/2005, 11:30 PM
please....no offense taken at all...

we were trying to view them with the TVs built in decoder. And we only tried it in a few DVD players. But I'll try a few more if it may work.

and I'll definitely try PowerDVD. I didn't even assume it would be such a common program. So thanks for that idea.

we're also gonna try viewing the files on an external monitor. The issue is....in those 1600 videos....there may be about 30% that actually DID capture the CC....so now I have to go through every one of them and figure out which ones they are.

and thank you for that link....i'm currently forwarding everything i find to my boss.