Red's high speed serial interface

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david farland

Member
I talking about the camera output that pumps out 4k raw video @ 60fps.

Can anyone give me more detail on this output?

Is it a dual HD-SDI link, fibre channel etc?

What capture device, computer i/o card etc is required to capture this raw video data from the camera's high speed serial interface?

Any examples of present devices/cards that can capture this 4k raw video signal?

Is this spec aligned to what AJA/Blackmagic already do, so it should only be time before AJA/BM make the jump from their 2k systems to 4k (and more)?

thanks a lot,

Dave Farland
 
It's not a video output, it's a data output, so it's not HDSDI or anything like that. The exact nature of the port is still TBD. I don't think you'd "capture" from it to a capture card, but just record the output direct to a big (very) hard drive.
 
Maximum is 4520 x 2540 x 2 (16-bit) x 60 (fps) = 1,377,696,000 bytes per second, or 1,28 GB/s (yes that is gigaBYTE and not BIT per second).

This is uncompressed RAW. No compression, not in RGB, not packed.
 
Hmm well according to this image on reds site that 1.28 GB/s isn't accurate It'll be more in the line of 807.5 MB/s for 60 FPS uncompressed linear RAW.

There are only a couple systems capable of putting out that data rate and it ultimatly depends on what format the red puts that data out as. Currently there are only 2 commercially available data interconnects that can perform at that speed Dual 4 GB fibre (and that is operating at the maximum of that standard) or infiniband which can handle that easily. In regards to the infiniband connection there are several interesting HBA's that can then go into a standard PC where the needed data speed can be achieved using SATA drives.

The big question is, will redcode be good enough to make hauling that kind of hardware around not worth it?
 
Jeff Brue said:
The big question is, will redcode be good enough to make hauling that kind of hardware around not worth it?
Click to expand...

Members of the RED development team have previously stated that in side-by comparisons REDCODE RAW looks very similar to 4k RAW. If that is the case, considering the increased mobility and decreased cost (storage) of shooting REDCODE RAW, I think only the very top end, stationary projects will use 4k RAW. REDCODE RAW 4k (28 MB/s) with S35mm lenses and 35mm lenses should be the cost-effective ticket for most projects...
 
Jeff Brue said:
Hmm well according to this image on reds site that 1.28 GB/s isn't accurate It'll be more in the line of 807.5 MB/s for 60 FPS uncompressed linear RAW.
Click to expand...

I think the figure there is for 4K. My calculation gives:

4520 x 2540 x 1.5 (12bit) x 60 = (about) 1 GB/s for full RedRaster
The precise answer depends on whether you use 1,000,000,000B or 1024x1024x1024B as 1GB.

Whatever, it's a lot of data!

Jim told me at IBC that they did not intend to be tied to one interface standard, but wanted to to produce an up-gradable (like all else Red) 'bridge' to connect to whatever was the most suitable high speed data link at any point in the future.

Nick
 
Personnaly I am interested to shoot 2k scaled uncompressed RAW at 24 fps or 25 fps. That would be something like 100 MBytes/sec, isn't it (based on 4k at 60fps would be 1GBytes/sec)
What hard drive would handle that?
 
There's no such thing as 2k scaled RAW - it's either RAW or 2k scale RGB and then it's now not RAW any more as it needs to be converted to RGB for the scaling process to work, and hence is no longer available on the RAW port.

Graeme
 
robl said:
I'm hoping the only ones using the RAW port are people who shoot 4(.5)K at 60 fps or 2K at 120 fps
Click to expand...

lol the problem is I've already been poised that question by several clients and friends. It's not even so much the 4(.5) k its the 2k at 120 FPS, that has a lot of people interested in that port. No matter what your're getting into an area outside of commodity hardware then.

Ah well I think it'll be done right, personally I'm hoping it's going to be infiniband as I've already had some success with that. If it's 4 GB fibre I can hear some of the screams of pain now.
 
Thanks Graeme for the updates.
But does it mean that the only format for shooting RAW is 4k, or is posible in an other format (such as 2K windowed)? If it it the only format for it, I guess the only afordable solution for (4k) RAW footage will be REDCODE then...
 
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Having heard lots of talk about refridgerator sized RAIDs, I'm wondering how large and how practical Red's solution, RED RAID, will be for 4k 60fps and 2k 120fps.

High speed shooting is of great interest to myself and everyone I tell about this camera. It would be a shame to have to drop from 4k Redcode Raw to 720p RGB just to record 120fps.
 
Thanks Graeme for your answear. You are really an amazing team at RED!

I guess you are write saying that 90-95 % of the user will use REDCODE. And I have to say that it reassure me that you are so sure of you, as for me, it sounds like REDCODE will be a very good and versatile codec.
Anyway 2k windowed RAW is possible, you do not get the S35mm DOF but you can go up to 120 fps if you have a fast enough HDD Raid array to record on.
Wait and see what the REDRAID has in the stomach...
But I was also interest to know if you could record directly to a computer, via for exemple REDCINE. Let's say you have already a very fast RAID array, and you are interested, mostly for studio work (because the computer:-), to record to that array, instead of using REDRAID, would it be possible?
 
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To record direct to a computer, you'd probably be going direct out of the high speed port or HD-SDI. I don't think you can send redcode direct to a computer.

Graeme
 
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