[Jean Lapierre]

Hi,

First let me confirm that SD Closed Caption (CC) is not very hard to capture, edit and playback. The CC information for SD is located in line 21. Line 21 is part of the picture you capture when capturing 486 lines of video. So you will require a full raster codec 720×486 uncompress works wonders.

In HD the CC data is located outside of the active video. In the Vertical Blanking Area. It is actually sent as a special block of data (packet) in the SDI signal. In order to be able to capture these packets you need a hardware and drivers that will be able to detect the packets and somehow put them in your file. Also when you playback your video file, you will need these drivers and hardware to retreive this CC info from your file and put it back in the output signal.

Currently there is no support in FCP to capture video and preserve the HD CC data. There is no support either for putting a clip on the timeline with CC data and playback that clip so you get a video + CC data out of your video card.

I work at Matrox and have been reading this thread. I would like to clear out some details that Shane can’t. I am one of the engineer that worked on MXO2 and the HD Close Caption support.

I would like to shed some light on Matrox 4VANC technology that is being refered to earlier in this thread. This is the technology used by the Matrox MXO2 line of products to Capture, Edit and Playback Hight Definition video containing Close Captioning.

Matrox MXO2s comes with drivers that transfer the HD CC information into the A/V clip. It is done by replacing one of the audio track in the file by Matrox 4VANC info. FCP is not aware that it is ingesting CC info. As far as FCP is concerned it is just capturing a video clip with some audio. The beauty of Matrox 4VANC is that it let’s you use any video codec you want.

You can edit your video clip, cut it, trim it, color correct it, it does not matter since the CC info is not in the video. With Line 21 files you have to restrict your manipulation of the video but not Matrox 4VANC.

Matrox 4VANC is a format that MacCaption supports. So you can edit the file you captured with MacCaption as well if you need to change the text in the CC.

You can also use MacCAption to generate HD CC from scratch. When your done, just save a Matrox 4VANC file and put it on the timeline in FCP.

You don’t need MacCaption if all you need to do is capture, trim and playback HD video that already has HD CC in it.

When you playback Matrox 4VANC files in FCP or any other application. The MXO2 drivers will detect the CC info in the Matrox 4VANC audio track and output the proper HD CC in the video signal at the output of the MXO2.

It will work with any application that can capture and playback Audio and Video(A/V)clips. It’s future proof since it will always be possible to capture, edit and playback A/V files. Matrox has a patent pending on the Matrox 4VANC technology.

Currently we beleive it is the only way to ingest, edit and playback HD video while preserving the close captioning.

For those that read all the way through here I hope you now understand better the HD CC issue and how we solve it.

Jean Lapierre
Matrox VPG Engineering.