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Please suggest capture and project settings to retain closed-caption data
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[walter biscardi] “Interesting, they can do something that Final Cut Pro can’t do. I’d have to see that in action to see how they can make software do something it can’t do. “
Thats because they are using a customized version of the CPC data component (Mac Caption) for the the captioning. I talked to a couple of people about this at NAB and it was my understanding that it is a software hack to get it to work in the current version of FCP. It is also my understanding that it will have to be completely rewritten for Quicktime X.
if someone from CPC sees this please advise.
gary adcock
Studio37
HD & Film Consultation
Post and Production WorkflowsCheck out
https://www.aja.com/kiprotour/Inside look at the IoHD
https://library.creativecow.net/articles/adcock_gary/AJAIOHD.php -
[Chris Borjis] “I’ve been capturing and outputting closed captioning on SD video for the last month with no problem at all. cc data is maintained.
HD closed captioning is another story though and only the mxo2 and the future kona
driver fixes that.
“OK,
let just confirm that we all understand that CC is standard def is different from CC content in HD.
In HD the data is written in a different manner, at a vastly different place in the metadata structure as part of the transport stream. Originally, CC information was included in the picture (“line 21”), but there is no equivalent capability in the HDTV 720p/1080i interconnect.
The HD-SDI closed caption and related data can be as much as 10x the amount of info used in a standard def CC schema and is carried in three separate portions of the HD-SDI bitstream. They are the Picture User Data, the Program Mapping Table (PMT) and the Event Information Table (EIT). The caption text and window commands are carried in the HD-SDI Transport Channel (which in turn is carried in the Picture User Bits).
Understand why it is harder to do CC in an HD stream?
gary adcock
Studio37
HD & Film Consultation
Post and Production WorkflowsCheck out
https://www.aja.com/kiprotour/Inside look at the IoHD
https://library.creativecow.net/articles/adcock_gary/AJAIOHD.php -
Yup…Matrox and CPC are now in kahoots.
MacCaptioning now creates files that can be imported directly into FCP and then played out of FCP and the MXO2 to tape, air, etc.. And maintain the CC data. They do this by making the CC into an AUDIO track that they can put on track 8. And this will play out from that track as well. Not being an engineer I don’t know all of the whys and hows of how this works, but it works.
Shane
GETTING ORGANIZED WITH FINAL CUT PRO DVD…don’t miss it.
Read my blog, Little Frog in High Def -
[Chris Borjis] “HD closed captioning is another story though and only the mxo2 and the future kona
driver fixes that. “HD CC is a big issue all around as I’ve been learning through some folks I’ve been working with. Seems to be some technical issues with the way it’s done in HD.
Walter Biscardi, Jr.
Biscardi Creative Media
HD and SD Production for Broadcast and Independent Productions.STOP STARING AND START GRADING WITH APPLE COLOR Apple Color Training DVD available now!
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[Shane Ross] “And maintain the CC data. They do this by making the CC into an AUDIO track that they can put on track 8. And this will play out from that track as well.”
Actually, now that you mention it, the broadcaster I’m working with is going to do the same thing with their FCP systems. I forgot about the channel 8 audio thing.
Walter Biscardi, Jr.
Biscardi Creative Media
HD and SD Production for Broadcast and Independent Productions.STOP STARING AND START GRADING WITH APPLE COLOR Apple Color Training DVD available now!
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[gary adcock] “let just confirm that we all understand that CC is standard def is different from CC content in HD.”
yes absolutely sir.
BUT the poster said he was working with DVCPRO SD not DVCPRO-HD.
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Mark there are issues with DV closed captioning. take a look here
https://www.cpcweb.com/dv/Kona cards will injest and output line 21 data no problem. we encode regularly.
I believe the issue with DV depends on the Deck
708 CC is only possible with hardware encoders, matrox MXO2, firewire DVCProHD to 1200 or 1400.
DVD closed captioning can be achieved using the specified file format in DVD SP. Mac Caption can read line 21 data and generate this file, or if MacCaption is being used to create CC data can export both a file to key over NLE footage and a file for DVD SP authoring
Doug Beal
Editor / Engineer
Rock Creative Images
Nashville TN -
Hi Doug,
I use automaticsynch to create my captioning files (a black .mov with line 21 data you crop to)
works great and no need for expensive gear.
they do say that DV compression makes it impossible to do reliable captioning with though
and so they don’t offer it. it kinda doesn’t make sense to me though since DV has full
luma raster.How are you retaining line 21 on your DVDS? compressor seems to crop out those extra lines
to 480 and line 21 is one of them.The Kona driver update will make HD captioning possible again. it has to do with some
trick of embedding an audio file within HD-SDI then getting that into the audio sub-carrier
of the HD 708 closed captioning protocol. (in a nutshell—so I’m told) -
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. -
Thanks for the informative info there Jean.
it is much appreciated.
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