What does the upcoming Blackmagic support mean to me?

dat5150 wrote on 4/7/2005, 5:44 PM
Can someone explain to me what having Blackmagic Design's Decklink support in Vegas 6 will mean to me? I'm capturing video just fine and able to make nice DVD's. Now all of a sudden, I have to investigate this upcoming feature and I can't figure out why I need it. Maybe I'm missing the obvious? Can someone get me up to speed or even excited about this new feature?

Comments

busterkeaton wrote on 4/7/2005, 6:00 PM
If you shoot DV and make DVDs, then it will probably mean nothing.

Blackmagic cards are SDI cards which allow inputting and outputting other digtial broadcast formats. For DV you can stick to firewire.

SDI Info
rmack350 wrote on 4/7/2005, 8:13 PM
Depending on the card, you can input and output in a variety of formats and color sampling types. For instance, you can output HD from some of the cards. You can aslo output to better color models than DV25.

DV25 definitely has very serious limitations because it smears colors so intensly. However, it's still pretty good and just because V6 may support BMD cards doesn't mean you have to use the cards.

In the bigger picture, this helps Vegas scale upwards. For example, in the shop I work in we originate everything in DV but all picture is transferred over SDI. Our DV deck doesn't even have 1394 ports. Really! So Vegas just wouldn't fit into the workflow there. Now, with an SDI capable card, we could conceivably use Vegas if we wanted to.

Rob Mack
musman wrote on 4/7/2005, 8:25 PM
Do you mean you shoot DV25 and transfer over SDI? Thought I read that actually is worse than using firewire.
p@mast3rs wrote on 4/7/2005, 8:26 PM
Scale meaning up-size/res?
rmack350 wrote on 4/7/2005, 8:56 PM
I personally don't do it. It's not my setup, it's my employer's.

If you look at Adam Wilt's site there's a fairly subjective scale on it that shows SDI as being slightly less than straight DV25. This makes total sense because DV25 over 1394 is just a straight bit-for-bit data transfer. SDI involves a conversion. However, from what I've seen, the conversion to SDI is just fine. Looks great.

The reason my shop does it is because the edit system is and has always been Media100. It's not a DV25 system at all. The owner moved from Betacam to a DSR500 several years ago thinking it would be transitional but we've yet to need to make the transition. We've never yet been asked for HD and we're only beginning to be asked for DVDs. Much of what we do goes to the web.

If you've been following the drama of Media100 lately you can guess that we're looking around for other systems that will scale up to HD and will fit in to our infrastructure-meaning SDI from a source, through a switcher and routed to various edit stations. Vegas has yet to be a consideration and the truth is that we could use the existing Media100 systems and the 844 for a few years yet.

The more useful thing about BMD cards is SDI output. For instance, we were able to output SD footage over SDI to a very nice HD upconverter. This was done from the 844 but could just as well have been done from Vegas. The end result looked great when I finally saw their finished film at Sundance. I was pretty damn impressed that the film could look as good as it did when projected.

Rob Mack
rmack350 wrote on 4/7/2005, 9:01 PM
No. When I say scale I mean that the system itself can be built up to handle higher resolution media. For instance, FCP is a DV25 editor that scales up to HD with the addition of hardware cards and disk arrays.

Vegas doesn't currently scale all that well into higher end production. Yes, you can do it, but it is an unnatural act for Vegas. One thing Vegas can't do is output better than DV25 images to a TV or studio monitor. This really shows when viewing text and graphic elements. The BMD cards will allow monitoring picture with better color sampling.

Rob Mack
farss wrote on 4/8/2005, 2:37 AM
Just to explain further about what Adam Wilt is saying.
SDI is a generic interface. You can connect any two decks and make a dub, say BetaSX to DVCPRO 50. Problem is that the SX data is converted to the generic data format and the DVCPRO deck has ro encode that into it's format.
As Rob Mack has said the loss can be very small but still cumulative. The plus is it makes routing and switching very easy.

SDTI on the other hand sends the data in its native format along with flags to tell the other end what it's getting. Problem then is that although this is lossless both ends have to use the same encoding system or at least know how to decode the sending decks data.

I'm not 100% certain of this but I think sending DigiBetcam over SDI is lossless.

The other nice thing about SDI is I think it allows for many audio streams as well as the video stream. No doubt we'll all be learning a bit more about this with V6.
Bob.
Jay Gladwell wrote on 4/8/2005, 3:49 AM
Bob, so if I'm understanding you and the others correctly (and I may not be), the SDI support will be primarily for the "larger, more diverse hardware oriented production houses" as opposed to those of us that are specifically using DV25.


Marco. wrote on 4/8/2005, 4:03 AM
>> I'm not 100% certain of this but I think sending DigiBetcam over SDI is lossless.

No, not really I think. Any format which is sent via SDI must be decompressed first and must be recompressed in the end again. DigiBeta is a very special kind of MPEG-compression which also must be decompressed and recompressed using SDI. This is at least my information.

Marco
farss wrote on 4/8/2005, 5:02 AM
To answer Jay first. Absolutely correct but not really! If you live in a world that's totally DV25 then SDI really has no benefit for you. However things like DigiBetacam are standard delivery formats for broadcast. You can always send your DV tapes out to a dub house. If that's all you need those formats for (final delivery ) then getting a dub house to do it is WAY cheaper.
On the ingest side there is some advantage to ingesting 4:2:2 SD even if your final delivery format is only DV25. An SDI card or a SD Connect box isn't terribly expensive and play only decks such as the J3 / J30 are a reasonable price, even cheaper if you can hire one. The advantages come to light in things like much better chroma keys and, having more data to start with color correction can work better. Of course if you cannot afford to acquire in 4:2:2 then this is all rather academic.
Having just had some footage shot by outside cameramen the overall cost difference between shooting in DV25 and 4:2:2 SD was around 20%, even downconverted to DV25 prior to ingesting the footage the images were 100% better, if I'd been able to ingest 4:2:2 (pull your finger out Convergent!) I'm certain the results would have been even better.
Again though Jay, to specifically answer your question, you're right, not a whole lot of interest if you're strictly DV25 and I add this, I doubt if many DV camcorders come close to what DV is capable of, probably much of the differences I was seeing had as much to do with a) a very capable lighting cameraman, b) the better optics on a >$100K camera.

Marco, you could be right, I think HDCAM uses a 2 frame GOP mpeg-2 format, don't know much about how DB is actually compressed. I'll try to find out more. Something about an all I frame mpeg-2 scheme comes to mind.
Bob.
Marco. wrote on 4/8/2005, 5:54 AM
>> Something about an all I frame mpeg-2 scheme comes to mind.

Yes, think so too. The DigiBeta compression seems to be a great big Sony secret. I often asked about some compression details in the broadcast area but knowbody could ever give me detailed information. Besides Sony no other company ever seemed to get a licence to handle DigitBeta, for example to use this compression in their own editing systems or to work on DB optimized interfaces.

So if there are further information available - I am very interested.

Marco
rmack350 wrote on 4/8/2005, 7:26 AM
Better glass, larger CCDs, more care in lighting, and possible a field engineer to help paint or shade the picture.

Man! When I was lighting full time I loved having a good engineer, a waveform monitor, paintbox, and a good production field monitor on the job. It just made a lot of difference.

Rob Mack