HDSDI Output -- 1080 to an External Deck?

[Paul Hazlett]

The ideal path from a high quality but simple filter point of view is a 2:1 scale from 4K to 2K (4096 x 2304 to 2048 x 1152) then a crop (pan/scan) to either 1920 x 1080 (HD) or 2048 x 1080 (DCI) pixels.

4096 x 2304 to 1920 x 1080 can be done, you just need a lot more filter taps, hence its more expensive in hardware and slower in software.

more filters and more taps also mean more processing and greater chance
to introduce noise, correct?

this scale and crop method seems like a good way to go without causing more work than is neccesary

 

[mezmo]

Nick and Mitch,

All the more reason to put RAW over HDSDI, enable 4K RAW to captured on dual link RGBA deck. Development will still be required, but with no quality loss.

Starting to see what you mean here David, this is a good idea
but does it fit the present 1080p industry standard workflow and what sorrt of development would be required?
Mezmo

 

[David Newman]

Starting to see what you mean here David, this is a good idea
but does it fit the present 1080p industry standard workflow and what sorrt of development would be required?
Mezmo

Nothing would need to happen on the capture equipment end, if it can handle 2048x1080 in RGB(A) (the A part is important), it can handle 4096x2160 RAW. Preview would occur with scaling, although there would be minor color fringing, due to the misaligned color primaries in a bayer sensor, but it would not be distracting for monitoring purposes. This color fringing would be removed by post demosaicing, just as it is in compressed RAW. When the is a RAW port, exactly the same work has to be done, all this would is allow the use of existing equipment for redundant, high quality 4K recording. The limitations are to use 4K resolutions and frame rate than match 2K RGBA equivalents. I.e. 4096x2160 not 4096x2304, at 24, 25 or 30p.

 

[TimPipher]

Nothing would need to happen on the capture equipment end, if it can handle 2048x1080 in RGB(A) (the A part is important), it can handle 4096x2160 RAW. Preview would occur with scaling, although there would be minor color fringing, due to the misaligned color primaries in a bayer sensor, but it would not be distracting for monitoring purposes. This color fringing would be removed by post demosaicing, just as it is in compressed RAW. When the is a RAW port, exactly the same work has to be done, all this would is allow the use of existing equipment for redundant, high quality 4K recording. The limitations are to use 4K resolutions and frame rate than match 2K RGBA equivalents. I.e. 4096x2160 not 4096x2304, at 24, 25 or 30p.

Hello David. This thread has moved past my limited technical "expertise".

Bottom line, do you (and anyone else here) forsee RED owners having the capability of recording 1080 live to an external deck such as the Wafian 2 in the near term (say next three months)?

Also, as a plan B, could RED add an option to switch off the data on the screen to allow for 720p output recording from the monitor output? If so, do you think this 720p recording would be at a similar quality to Panasonic Varicam recording?

 

[mezmo]

Hi David,
Thanks for the reply,
Your idea is more a method for recording 4KRAW to tape or
another 2048x1080 RGBa device for processing 4K RAW back to
1080p or another higher rez format all via existing Red HDSDI ports.
Hope I'm right with this.
So in Tim's case he could record out to an external deck if Red tweaked
the HDSDI ports to do this but 1080p would still need to be acquired after
processing the 4KRAW material in post.
This may solve many problems people have on this thread and be a great way to get a tape back-up from Red. But if I'm right, realtime on the fly
high quality debayer and processing from Red via onboard or outboard device to a 1080p rercorder seems like more of a challange.

Sorry Tim, high quality recordable 1080p's not looking an option anytime soon.
720p ??? over to the Red guys.
Mezmo

 

[David Newman]

Hello David. This thread has moved past my limited technical "expertise".

Bottom line, do you (and anyone else here) forsee RED owners having the capability of recording 1080 live to an external deck such as the Wafian 2 in the near term (say next three months)?

Also, as a plan B, could RED add an option to switch off the data on the screen to allow for 720p output recording from the monitor output? If so, do you think this 720p recording would be at a similar quality to Panasonic Varicam recording?

All up to Red. Technically I don't see any issues.

 

[David Newman]

Hi David,
Thanks for the reply,
Your idea is more a method for recording 4KRAW to tape or another 2048x1080 RGBa device for processing 4K RAW back to 1080p or another higher rez format all via existing Red HDSDI ports.
Hope I'm right with this. ...

Yes, that is what I'm suggesting. Let say the camera's FPGA hardware can only fit one scaler with a simple demosaic, and that is used up driving the LCD. This will make it difficult to provide a scaled 1080p with a nice demosaic needed for standard single link or dual link capture. Instead if dual link would to carry the RAW data without processing (just a curve via 1D LUT), basically the same data sent to the compressor (low FGPA requirements), you could record 4K to an SR-W1. 1080p preview is enabled, plus redundant 4K recording.

 

[Antoine Baumann]

Haven't seen this thread before, but I have to say that I am surprised that the 1080 HD-SDI output is only going to work if the camera is recording in this format. I understood that you could record 4k and get a 1080 out of the camera in the same time.

As for needs, I must have an option to record 720/1080 scaled with TC to a computer/HD deck in the same time the camera is recording either 4k or 2K.
I will only use the 720/1080 for offline editing, and export edl to REDCINE.
I really think it is the best and most efficient way for most of time.

A question to Mark L. Pederson. You wrote that FCP+Kona or ioHD would not record TC from the RED HD-SDI output, I haven't fully understand why.

thanks,
antoine.

 

[TimPipher]

I am surprised that the 1080 HD-SDI output is only going to work if the camera is recording in this format

I think a lot of people will be surprised when they find this out. In fact, if this had been made clear during Jim's "720p and 1020p...losers" poll from the summer, I bet a lot more people would've voted in favor of keeping 1080p.

 

[Michael Brennan]

RAW transmission

RAW transmission

Good thread.

Taking the concept of +4k remote debayer sideways a bit into outside broadcast, I believe that the concept of multicam operations where it is easier better and cheaper to ship raw data from the camera and then process it in the truck, rather than process in each camera in principle is sound but not without technical hurdles.

Indeed highly compressed RAW could be transmitted and debayer processing could take place once in the home 4k or ultra res HDTV.

Call it rawmitting

Mike Brennan

 

[Lauri Kettunen]

Instead if dual link would to carry the RAW data without processing (just a curve via 1D LUT), basically the same data sent to the compressor (low FGPA requirements), you could record 4K to an SR-W1. 1080p preview is enabled, plus redundant 4K recording.

David's suggestion is very clever. It meant one could easily add a RAW signal backup device in parallel with the CF-card/HD-disk storage.

David, assuming RED had such an output from the camera, would the HD-SDI version of the Cineform recorder be able to store the raw signal? If so, then we had a truly portable backup option.

 

[Mitch Gross]

This is an interesting thread, but I see it splitting in two directions, namely on set tools and post tools. This is a common problem to all of the Digital Cinema cameras with the elimination of the playback deck and the merging of what was production work into post.

I think the RED Box is a great idea but it might be a bit much for many people to have on set and a lot of what people are asking for can be dealt with more simply. Here's what I see as the three basic uses of a 1080p output on set.

1 - Focus assist. Get the highest resolution possible for judging focus.
2 - Framing & lighting judgement. This is how most professionals choose to work, even when they know that they have room to adjust in post. It is a basis from which to begin to judge the image.
3 - A clean 1080p output to send to a switcher, deck or whatever.

Here's how I would propose to attempt to deal with this in camera. For (1) Focus Assist, I would say a switchable 1-to-1 pixel or a magnified pixel window, say an 8x8 pixel square blown up to 80x80. It would be great to move this around the image. For (2) Framing & Lighting, I would suggest getting the entire 4K image down into 1080 and don't worry about the artifacts of remapping the image. This is just to see the frame. It might even be nice to show the full sensor image (beyond 4k) all within 1080 with a frameline indicating the 4k recorded image. For (3) a Clean 1080p, if option (2) yields artifacts that are unacceptable, I propose a frame that is a simple 2x zoom of 3840x2160 (double 1920x1080) which should be a very clean image. This would be good for those posting to a deck, feeding a switcher, etc.

If it is a problem for the RED One to output both one of these 1080p variants along with the 720p for the viewfinder/LCD, then I would suggest favoring the 1080p and offering a small crossconverter option for the 720p. This is a common enough circuit that shouldn't be particularly expensive.

Perhaps the finer points of these options could be open for change, but I think that they would answer most of the issues where people are calling for 1080p on the camera. The RED Box can serve as a lovely tool for post work, even the work that begins on set. But let the camera serve as a camera.

Mitch gross
Technical Director of Rental
Abel Cine Tech

 

[David Newman]

David's suggestion is very clever. It meant one could easily add a RAW signal backup device in parallel with the CF-card/HD-disk storage.

David, assuming RED had such an output from the camera, would the HD-SDI version of the Cineform recorder be able to store the raw signal? If so, then we had a truly portable backup option.

The Wafian HR-2 could do it (I think) but it would need an upgrade. Currently it doesn't record the alpha channel needed for this to work. It uses an AJA Xena 2K, which should handle this. We would of course pursue this change if Red where to output RAW over dual link HDSDI. This is why I mention the SRW1, as I know that can do it. While CineForm has a business interest for Red to be more flexible on it outputs (even a true 1080p 4:2:2 or 4:4:4 helps us) but the RAW output technically will work with a range of existing equipment. You just won't see Sony here making the same suggestion.

 

[TimPipher]

and have some other ideas to provide some form of 1080p capability.

There have been interesting ideas/solutions proposed on this thread. As the person who started the thread, I thank everyone.

I know I'm grasping at straws here, but is there any chance that RED has followed this thread all the way through, considered these ideas and their own ideas, and decided to activate HD-SDI output sooner rather than later?

 

[Mike Prevette]

Wow, Glad to see you on here Mitch! Your input is always great.

 

[Mitch Gross]

Wow, Glad to see you on here Mitch! Your input is always great.

Thanks, I've been lurking for awhile but a number of Red owners encouraged me to post. I've dealt with Red Ones a few times now and my dealings with other raw digital cinema cameras gives me a good grasp of what Red issues and ideas can be. I don't want to push Phantom or SI or anything else down anyone's throat; just hope I can be helpful in some way. It's all the same revolution in some ways.

Mitch Gross
Technical Director of Rental
Abel Cine Tech

 

[Mike Prevette]

You certainly have been down a lot of roads in the RAW world. I would think the lessons learned with Phantom are invaluable to us. In my mind the input, and collaboration with the cine world is going to make the difference with this second generation RAW Cine camera.

Not to be to nosy but is Abel going to pick up any Reds?

 

[Mitch Gross]

Not to be to nosy but is Abel going to pick up any Reds?

You can be nosy all you want my friend, but it doesn't mean that officially or not I can provide an answer right now!

Abel likes RED, and I'd like to think RED likes Abel.

Mitch

 

[MikeCurtis]

my thoughts on all this

my thoughts on all this

[QUOTE ] Do you mean the 1080p HD-SDI output will become available when 1080p recording becomes a reality?

Yes that is what I meant, if the camera is recording 1080p, then its easy to generate a 1080p HD-SDI output.

I'm still interested to understand what it is specifically everyone intends to do with 1080p HD-SDI outputs BTW .. to build up a check list for functions that would be necessary to support the intended applications.

Mark I understand yours...thanks for that concept.

Genlock (via tri-level sync) we have.[/QUOTE]


Jim Arthurs said:
"I'm surprised I overlooked this issue, as I check the boards daily, but it never occured to me that the loss of 1080 RGB recording would also mean the loss of any form of 1080 over HD-SDI live out. "

I feel the same way.

Mitch's comments about the difficulty point out that it is tough, but this is something that has been oftened described in the past as 'gonna happen' without the "Oh, only if you are shooting 1080p RGB" caveat.

ALL LIVE PRODUCTION will require this capability, and I'd be astounded if Red didn't deliver an at least decent looking 1080p out the single/dual link HD-SDI taps - that was the message they were giving in the past. All specs subject to change, right right right, but this is an "OH!" change, not a "Hmm...." change.

Since 1080p output has been deprioritized (that alternate build of the firmware was the last iteration of the concept I recall), that puts live production waaaaaay down the line from where we stand now.

The need is still high for 1080p60 (or p50) recording - any full aperture, broadcast bound work will require this - and some shows have a tape based workflow that they don't want to reinvent the wheel for - so HD-SDI based recording works for them.

Personally, if Red can't get high quality deBayer done in camera, or the cost is too high to fit within the current price point, in order of preference, I'd like to see:

1.) a plus cost option that DOES offer high quality, from in camera, to 1080p. Sucky PR to be dealt with, but hey, that's what it takes.

2.) Barring that, an outboard box that connects to the High Speed Port (or replaces it if it is small enough) that has two, full-size, HD-SDI taps on it, that outputs a high quality debayer, optimal 1080p, yadda yadda

3.) Variants on the above:
a.) there is a SMPTE spec for 2Kx1080 12 bit up to 24p - OK, we'll take that too!
b.) there is a spec and hardware for a single HD-SDI that can contain dual link signals (is on the HDLink Pro from Blackmagic already) that would allow for 1080i60 AND 1080p60 4:2:2 AND 1080p30 4:4:4. Use that.
c.) or, just two BNCs with the same options of 1080p23.976/24.0/25/29.97/30.0/50/59.94 in 4:2:2, and 1080p up to 30fps in 4:4:4, or two cloned outputs of the same 1080i or 1080p (up to 30p) in 4:2:2

My $0.02.

Otherwise, if they don't, Red becomes much more of a niche camera, not so much of an industry busting, genre crossing monster we hoped it would be. A low cost indie cinema/commercial/documentary camera is an AWESOME thing with the existing specs...I'm just sayin' it could be better, sell more, etc. if it had proper live and HD-SDI capabilities.

-mike

 

[MikeCurtis]

Red decks and metaphors

Red decks and metaphors

Solution?
1) Red builds THE RED BOX. A redcode "deck" - with "optimized" hardware decode - my latest obsession

2) Dirty Hack - Payback from the camera through ioHD - assuming TC is embedded in the preview out - last time I tested, it was not.

I have advocated, from the beginning, that if the Red were going to have HD-SDI ports on it, that it should have an RS-422 for virtual deck control purposes. It doesn't. OK. MAYBE some trickery can be done with a USB dongle adaptor plugged into the camea down the road, dunno - conjecture.

BUT...here's where we stand today:

1.) There is no hardware deck at this time since it is a data driven camera.

2.) What he have is software - Red Alert and Redcine.

3.) As the name Redcine alludes, it IS your deck.

4.) So I was thinking earlier today - Red Alert is like your small, cheap, portable field deck, and Redcine is like your big honkin' full featured studio deck.

5.) That said, we need to be able to do the kinds of things that Real Decks do - downconvert (check), aspect ratio (check), windowburn (check). All present, good so far. BUT....real decks can also do things like add 3:2 pulldown, which there is presently no provision for. Real decks can output to another deck with timecode maintained.

6.) So if Red Alert and Redcine are the decks for Red, they need to work. RIGHT. They need to be professionally supported as well, since that is THE tool, and the ONLY tool at present (excluding SCRATCH for the moment, see Mark's comments), to convert your footage to anything else. If Red were to stick to a policy of "it is a free beta, caveat emptor" with no professional heavy duty support...that would not suffice. Charge for a support contract, fine, but it is definitely something the market will need at the ongoing professional level.

7.) Red has announced that they'll have a partnership with AJA. I dream of a Kona Red product, that would have a compatible High Speed Port to take a feed from a Red camera (uncompressed Red RAW) or a Redcode RAW codec feed from camera or footage on media, and on-the-fly kick out dual link HDMI/component/HD-SDI in all the flavors we'd want, with 3:2 pulldown, downconversion, interlacing, windowburn, yadda yadda. Bundled with some virtual VTR software and you're good to go - card plus Mac Pro rig is still cheaper than most professional decks would be. Dunno, but I hope so.

8.) ....or, The Red Box as Mark describes. I had originally thought it could be as simple as a Red One with the sensor block sawed off and the buttons and readouts rearranged, but the current standing of HD-SDI conversation points out that it might need to be more than that.

-mike

-mike