Closed Captioning Capture

[Jason Livingston]

Hi Darren,
Let’s focus on the “Beta -> Blackmagic” workflow since it is the most simple. (The DVCPRO deck might not be set up to pass thru CC data.)

If you have Final Cut Pro 7 and the latest Blackmagic drivers, then the line 21 data will get converted to a QuickTime CC track on capture. If you play the file in QuickTime Player and go to View > Show Closed Captions, they should appear just like the CC works on a TV. Now if you need to get those closed captions back out to tape, edit or convert to another format, or create new closed captions from scratch, that’s where CPC software can help.

Older Blackmagic drivers used to have the option to capture the line 21 VBI as part of the image. It only worked if you captured full raster 720×486 (not 720×480 and not DV codec). But I think this capability was disabled or removed in the recent drivers to make way for the new FCP7 workflow I mentioned above. So for FCP6 you might need to use an older version of the Blackmagic drivers which preserves the line 21.

Hope this helps,

Jason Livingston
CPC Closed Captioning

[Mark Suszko]

My tests of this were with an octo-core Apple mac, Grass 100 swircher, the original model IO with SDI and firewire into the Apple’s motherboard, and a beta SP deck. By using a capture setting of Uncompressed Composite, I was able to capture the original program with the line 21 cc signal, make simple cuts, play the timeline back out composite to the betacam deck, and that tape, checked on another deck hooked to a CC decoder, showed that the CC was preserved and readable.

What I end up doing mostly is, making a DVD using a stand-alone real-time DVD recorder, containing the same program with the CC turned off, and one with the CC turned on during the capture. Users can thus pick an open-captioned version or non-captioned version thru the DVD menu.

There’s a CC forum on the COW that can give you better advice than this, check them out directly.

https://forums.creativecow.net/closedcaptioning

[Jeff Carr]

Jason,

We have been trying to set up our workflow so that when we capture video from our archive which contains closed captions on line 21, we get the line 21 converted to a QuickTime CC track; in other words, we want to be able to open the resulting quicktime file using Quicktime Player and be able to display the captions. We are using FCP 7 on our Mac Pro workstations, Black Magic Decklink card/Multibridge Extreme, the latest drivers, and we have tried capturing to uncompressed as well as Apple ProRes. So far, we have not been able to convert line 21 to a quicktime CC track during capture–the “Show Closed Captioning” under the View tab of the Quicktime Player is greyed out. Line 21 is definitely showing up at the top of the video, both before and after capture. We can view the opened captions when we play back the freshly-captured file using FCP to a monitor with caption display turned on–but Quicktime is not getting the captions in a form it can see. Your Oct. 1, 2010 post seems to indicate this should be possible. Any Suggestions? Thank you for your help. –Jeff Carr

[Jason Livingston]

Hi Jeff,
I’ve been told by the other techs here that this did work. But I just tried it using the latest drivers 7.9.5 or something like that, and I couldn’t get it to work for me. I’m not sure if Blackmagic changed something in the driver or if something else is going on.

Our MacCaption software can extract the line 21 and convert it to QuickTime CC track even if the capture card is not doing it automatically during capture, so that is another option.

Best regards,

Jason Livingston
CPC Closed Captioning

[Carissa Mills]

Is there a way to capture a live feed with CC on line 22 (PAL) using FCP.

Footage will be placed within an embedded play as a H.264 file with CC enabled.

Thanks

[Jeff Carr]

Jason,

Thank you for confirming our experience. We are puzzled; the documentation we’ve found on both FCP7 and Black Magic seem to indicate that that we should indeed be able to get a quicktime caption track when we capture previously-captioned material.

You mentioned using MacCaption to extract the line 21 and convert it to QuickTime CC track; what would be the workflow for this? Can we test it using the MacCaption demo?

–Jeff Carr

[Jason Livingston]

It may have something to do with it working on the SDI input but not on the analog inputs.

And sure, you can try this on the MacCaption demo. If your captured file is 720×486 and you can see the “morse code” dots & dashes at the top of the frame, simply drag-and-drop the video into the right side (text area) of MacCaption and it will decode the line 21 CC into text & time codes.

Best regards,

Jason Livingston
CPC Closed Captioning

[Jeff Carr]

Jason, thank you for the guidance. The MacCaption demo confirmed that our captions are intact.

As far as capturing via SDI vs. analog–we tried it both ways. Neither way worked as far as FCP7 generating a Quicktime closed caption track. In looking over the documentation again, I’m thinking FCP7 may possibly generate a Quicktime caption track only if the capture setting is uncompressed and the source material is high definition with closed captions in the VANC.

Since both high definition and standard definition TV can contain “ancillary” information in the vertical blanking interval, I had the impression that both HD and SD had a “VANC.” But, in reality it seems that the term “VANC” really only applies to the HD world. So, it would appear that FCP7 will not generate a Quicktime closed caption track from standard definition material.

I would appreciate it if someone could prove me wrong. At any rate, if we capture our standard definition archived tape programs using a 720×486 capture setting, the closed captions are at least preserved at the top of the image; and, we know that MacCaption can open them. Thank you for your help!

–Jeff Carr

[Rafae; Parlatore]

Hi,

I’m from Brazil, i work in a company that do Closed caption live her. We do Closed Caption pre-recorded in Advertising also, but right now we are going to the prodcuer company with the encoder and the notebook to do it. Now we want to only send to then the Line 21 with the CC. Here in the company we have a Mac, Betacam SP(I know is old, but we still using here). Wich equipament i have to buy to do this? It’s simple to do in final cut? Many Thanks.

[Jason Livingston]

Hi Rafael,
To do this you need MacCaption. We have a patented technology to create the line 21 captions as a digital video file. It is very simple to bring this into Final Cut and print to BetaSP tape with closed captions.

You can read more about it here: https://www.cpcweb.com/nle/

Best regards,

Jason Livingston
CPC Closed Captioning