Dual Link HD-SDI
 

Dan and Mike,

Congratulations on the linked nanos for 3D recording. Quite a feat!

I was wondering — blue-sky, I don't really know much about the technical side of this — but does this have any implications for Dual Link HD-SDI recording?

Jeff

Hi Jeff, I also have a dual link SDI camera and I'm pretty sure that the Nano will not sync to a leg of a dual link output. I can test this tomorrow to be sure.

Cool. What I'm wondering is if a 3-D nano could be used to record both legs of a Dual Link HD-SDI signal.

Not that I have such a camera.

Just curious.

Jeff

Out of a Double Link you don't get 2 single Link. The stream you get, is nothing that the NANO can manage.
The 3D NANO is basically two NANOs in sync, recording from two different SDI.
rafael

I'd rather see the nano supporting the 3G HD-SDI than dual link with two nanos.

I am not quite sure how dual link works. Does it split a 4:4:4 stream into two complementary 4:2:2 streams? If so, you should probably be able to use two nanos to record the dual link into two single link recordings, each compressed separately. Though, combining the two separate 4:2:2 files into a single 4:4:4 file would be a challenge.

Adam, one stream 4:2:2 the other 0:2:2

Smpte 372m
 

FYI:

HD-SDI Standards
Standard Name Bitrates Example Video Formats
SMPTE 372M Dual Link HD-SDI 2.970 Gbit/s, and 2.970/1.001 Gbit/s 1080p

For very high-definition applications, requiring greater resolution, frame rate, or color fidelity than the HD-SDI interface can provide, the SMPTE 372M standard defines the dual link interface. As the name suggests, this interface consists of two SMPTE 292M interconnects operating in parallel. In particular, the dual link interface supports 10-bit, 4:2:2, 1080P formats at frame rates of 60 Hz, 59.94 Hz, and 50 Hz, as well as 12-bit color depth, RGB encoding, and 4:4:4 colour sampling.

Cheers—

Jeff

Thanks, Bruce.

This is pure science fiction.
rafael

Well on my camera single link 4:2:2 SDI is encoded with YCrCB, which the nano works fine with. My camera's 4:4:4 dual link is RGB encoded. I don't think that will work with Nano.

No need to be rude. I clearly stated I did not know how it worked. Bruce's reply was much more constructive and up to the point.

AJA Kona 3 does it...
 

...the AJA Kona 3 (I believe all Kona boards) could capture Dual Link HD-SDI. There are 2 SDI connectors on the BOB. I understand that the RED cameras are Dual Link HD-SDI capable.

Jeff

Dear Jeff,

We have not included Dual-Link HD-SDI recording in our current plans for nano3D.

For one, we had not thought of this.

Dan,

Pardon me for going off on such a tangent with this Dual-Link stuff, but the Nano 3-D got me thinking "blue sky." I would be very interested to hear from you or Mike as to whether or not this is even possible with a couple of Nanos. I was really impressed that you have them synchronized, and that got me started thinking...

I used to run a small software company, and we specialized in VTR control. If you ever control an RS-232, RS-422, or FireWire deck in Final Cut Pro, you're using our software. At one time (1996 or so), we had code that turned your desktop NLE into a DDR. We even had a 2 machine, frame-accurate, cuts-only editor waaaaaaaay back when. The last two products did not fly, but the knowledge gained in creating them was invaluable, and applied to other products.

All the best,

Jeff

Adam,
Sorry if I sound rude. Wasn't that my intention.

This is from Wikipedia:
"In the case of 1080p60, 59.94, or 50 Hz video over a dual link; each link contains a valid 1080i signal at the same field rate. The first link contains the 1st, 3rd, and 5th lines of odd fields and the 2nd, 4th, 6th, etc. lines of even fields, and the second link contains the even lines on the odd fields, and the odd lines on the even fields. When the two links are combined, the result is a progressive-scan picture at the higher frame rate".
If this is correct, with a 1080p60/50, each SDI could be recorded in a NANO.
The two stream could be recombined with the proper software.
Rafael