4k Redcode vs Prores 422 vs 2k Redcode?

[Shawn Nelson]

I'm thinking through the logistics of media storage and have been reading a ton of the forum posts, Apple whitepapers, articles, etc. I am confused about a few things. Mainly my goal is to maximize my quality and minimize how many harddrives I must buy per project.

1. The RedDrive is 320gb and I've heard that it will last around 2 hours at 4k. But wait, the RedCode format is supposed to be 27MB. 27MB * 60s = 1660MB per minute. 1660/1024 = 1.582 GB/Min of 4k Redcode. So 3 hours should be only 285 GB, well within the RedDrive limit. So what's going on here?

2. It seems that by downrezzing to 2k or 1080p would be the sweet spot for now (as long as I'm not doing feature work). I've heard Graeme say that 4k->2k is not the 4:1 space saving you'd expect but it should still be good. If I downres my 4k Redcode RAW in Redcine to a 2k Redcode Raw, what is the data rate?

3. In comparison, 1920x1080p HQ Prores 422 is 1.32 GB/Min. Now if RedCode really is only 1.582 then that's now much of a saving. But, since we've heard that a 320gb HDD lasts for two hours, that's more like 2.67 GB/Min. So how much of a space savings would I get by downrezzing all my footage to a 1920x1080 Prores 422?

Thanks!

[Ralph Oshiro]

Maybe not the reply you were looking for, but I heard it explained by RED (or Apple--can't remember which) at NAB, that the big benefit of ProRes WASN'T saving drive space, since the ProRes file is only slightly smaller. The main benefit of ProRes is that it enables you to work with an FCP-friendly CODEC that makes a damn good-looking 2K 4:2:2 picture, that works optimally in an FCP environment.

[Shawn Nelson]

Ralph, that then works under the implication that RedCode will not work that well in FCP. To go from 4k 4:4:4 down to 2k 4:2:2 with marginal space savings, I'd expect to go from a clunky speed to blazing fast.

[Ralph Oshiro]

Well, Shawn, I suspect there are some well-thought out synergies between REDCODE and ProRes. And as you suggest, I would guess, some necessary ones. So, yes, I presume that ProRes is optimized to make things go as fast as possible in the FCP environment, whereas REDCINE was designed more to accomodate other, non-editing capabilities, in all of REDCODE's 4K glory. Thank god Apple stepped up to the plate and developed and released ProRes for RED. I'm sure ProRes will be a key factor in making 2K proxy editing much less painful for those editing on anything less than a supercomputer. I asked Ted at NAB how long had they been talking to Apple about the integration of REDCODE and ProRes. I think the answer was something like a year.

[Chris Kenny]

1. Red apparently hasn't completely decided on the data rate for REDCODE yet. They're probably saying two hours to be on the safe side. Note that they've also mentioned 4.5 minutes on an 8 GB CF card, which is a little under 30 MB/s.

2. You can't down-rez and still have RAW. You could down-rez to RECCODE RGB, but we don't know what the data rate on that is like. (RGB data is harder to compress than RAW data, because you're starting with three times as much -- three color channels instead of one.)

3. The main benefit to using ProRes vs. REDCODE probably isn't going to be file size, but performance. ProRes is optimized for (among other things) low CPU overhead. I would guess REDCODE is optimized with more weighting toward maximum quality. Also, ProRes will work for RT stuff in FCP in 6.0. REDCODE won't have RT support until a later update. ETA on that update is presently unknown.

[Ralph Oshiro]

Thanks, Chris. I was waiting for someone much smarter than me to comment on Shawns' questions.

[Shawn Nelson]

2. You can't down-rez and still have RAW. You could down-rez to RECCODE RGB, but we don't know what the data rate on that is like. (RGB data is harder to compress than RAW data, because you're starting with three times as much -- three color channels instead of one.)


But 2k RAW is a supported version of Redcode RAW, only when you go to 1080p and below to you have to go to Redcode RGB (per the Red website).

[Häakon]

But 2k RAW is a supported version of Redcode RAW, only when you go to 1080p and below to you have to go to Redcode RGB (per the Red website).
2K RAW is in windowed mode, however. You can't do any scaling of RAW images - it's either full frame 4K RAW or windowed 2K RAW. If you want to take images you shot in 4K and downsample them to a 2K size, you're going to have to enter the RGB domain.

[Shawn Nelson]

But Redcode Raw is wavelet based right? As such you should be able to extract the 2k proxy, save that as you would a windowed 2k RAW, and discard the 4k originals to save space. If this is not true, what am I misssing?

[david farland]

From this page (http://www.reduser.net/forum/showthread.php?t=1880&page=2) Deanan mentions they're still developing the 4K-> 2K/HD rgb down convert.
Graeme also says on the same page you can extract 500,1k, 2K files from a 4k raw master but doesn't explicitly say 4k raw to 1k raw, but that's what I'm guessing they used at Park Road?
Can someone point to a clearer statement from Red?

Cheers,

[Antoine Baumann]

A little bit out of topic, but keep a eye on CineForm codec, they have a 2k 4:4:4 codec, and have RT support as well (only in Premiere pro).

antoine.

[Jason Rodriguez]

A single 12-bit 2K 4:4:4 RGB CineForm stream will playback in RT in FCP . . . you just don't get access currently to the RT effects engine in FCP, but of course FCP doesn't support real-time RGB effects beyond 8-bits in the first place (only YUV), so you're not losing anything.

[david farland]

Graeme reckons he can do RGB->YUV conversions (http://www.xilinx.com/xlnx/xweb/xil_publications_display.jsp?iLanguageID=1&category=-1211226&sGlobalNavPick=PRODUCTS&sSecondaryNavPick=Design+Tools) all day for FCP and not get errors.

Cheers,

[Paul Leeming]

Actually, I'm still waiting to hear from the PC side of the fence, specifically about Premiere CS3's support of RedCode.

Don't get me wrong, I think it's great that Apple and Red have a close working relationship, but let's face it - the VAST majority of computers out there today (mine included) run some form of Windows, so it behoves Red to make sure that that type of working relationship straddles the divide to create a platform agnostic workflow that doesn't unnecessarily favour one architecture over another.

Plus, all the talk about ProRes422 neatly skips the part about how it is a proprietary codec built only for Final Cut - surely in this day and age software vendors realise that it is in EVERYONE'S interest to have a cross platform codec for once instead of these continual platform specific codecs everyone keeps pushing?!

I'm just hoping that Red are just sitting on the good news for the PC world until Adobe publically announce the new software as shipping....

[Steve Freebairn]

The other interesting thing is how Avid has had the same codec (DNxHD) for awhile now. I'm not quite sure why everyone is so excited about working with a second file instead of just with redcode with 1 and 2k proxies. That seems much better than transcoding to ProRes.

I agree though, if ProRes is only supported on Mac, it won't catch on like it could if they made it available on all platforms.

[Jeremy Newmark]

The other interesting thing is how Avid has had the same codec (DNxHD) for awhile now.

DNxHD is a good codec, but we really won't be able to compare the two until ProRes ships. While they are very similar in regards to the data rate, i don't think that you can call them the "same" codec. Already from what we've seen, ProRes supposedly holds up very well through multiple generations. DNxHD on the other hand does not. But like I said, we really just need to wait until everyone can compare the two.

[Antoine Baumann]

I'm not quite sure why everyone is so excited about working with a second file instead of just with redcode with 1 and 2k proxies. That seems much better than transcoding to ProRes.

I think as long as you do only editing plus color correcting in REDCINE you are fine with 4k REDCODE RAW all the way (just need to export to the delivery format). But if you want to do secondary color correction (unless you use Scratch) or compositing, then I think you better go 2k (or less) with a compressed codec. Or you going to face giant files (4k uncompressed) and huge rendering times (compositing 4k). That is why a 2k workflow with REDCODE RGB or CineForm 4:4:4 (or anything else) is very interesting and look promising.

antoine.

[david farland]

Where's your white point/color for color correction with Raw?

[Greg Voevodsky]

Plus, all the talk about ProRes422 neatly skips the part about how it is a proprietary codec built only for Final Cut - surely in this day and age software vendors realize that it is in EVERYONE'S interest to have a cross platform codec for once instead of these continual platform specific codecs everyone keeps pushing?!

Last time I looked, Avid's proprietary codec DNxHD doesn't play too well with other's either. However, at least its on both platforms!

[Robert Sanders]

I think as long as you do only editing plus color correcting in REDCINE you are fine with 4k REDCODE RAW all the way (just need to export to the delivery format). But if you want to do secondary color correction (unless you use Scratch) or compositing, then I think you better go 2k (or less) with a compressed codec. Or you going to face giant files (4k uncompressed) and huge rendering times (compositing 4k). That is why a 2k workflow with REDCODE RGB or CineForm 4:4:4 (or anything else) is very interesting and look promising.

antoine.

I've drawn the same conclusions. And since the best film-out rates from the labs are for 2K Arri, it makes sense to me to shoot 4K, down-res to 2K (or 1080P), and take advantage of the Apple ProRes RT Extreme features and Apple's "Color" app.

What's great is that you always have the 4K files (your neg so to speak) to go back to if your project is successful and you need a higher quality filmout or 4K digital cinema version.

[david farland]

sigh.

[Shawn Nelson]

I've drawn the same conclusions. And since the best film-out rates from the labs are for 2K Arri, it makes sense to me to shoot 4K, down-res to 2K (or 1080P), and take advantage of the Apple ProRes RT Extreme features and Apple's "Color" app.

What's great is that you always have the 4K files (your neg so to speak) to go back to if your project is successful and you need a higher quality filmout or 4K digital cinema version.

My thoughts exactly. I'll shoot in 4k, downres to 2k or 1080p and work with that, much more affordable and practical.

[Damien Molineaux]

Back to the drive issue raised by Shawn.


<cut>

1. The RedDrive is 320gb and I've heard that it will last around 2 hours at 4k. But wait, the RedCode format is supposed to be 27MB. 27MB * 60s = 1660MB per minute. 1660/1024 = 1.582 GB/Min of 4k Redcode. So 3 hours should be only 285 GB, well within the RedDrive limit. So what's going on here?

<cut>

Ever noticed how when you buy a drive indicated as X GB, once formatted you only end up with (X - 6 or 7%) GB. This happens for two reasons. HD vendors label their drives as 1 GB = 1000 Bytes while for your computer, 1 GB = 1024 Bytes. So you've already lost 2.4% right there. Then you have all the overhead of data handling and logging which requires around 4%. So, I don't have a 320 GB drive around to check precisely, but once formatted I would expect a Red drive to have about 297 GB of available space.

The second thing to take into account, is that as a drive gets full, it becomes slower. Mike from HD4indies raised that question a while back, will a Red drive be fast enough to record 4K Red Raw when it is nearly full. Which raises a couple questions, how much of a margin should be left aside ? And if you can, can you choose the amount you ? Trying to fill up a disk completely could kill it, what happens if you're recording and there's no space left ? Will there be a safe guard ?

Cheers,
Damien

[Adrian T.]

The second thing to take into account, is that as a drive gets full, it becomes slower.

The speed is only dependent on the following two factors, and not simply on "getting full":


If the used allocation blocks are fragmented, you have more random accesses as opposed to sequential accesses. And these are significantly slower. But when you start with an empty disk and just record, the disk will not become fragmented.

Access to the inner zone of the disk is somewhat slower than to the outer zone. The speed decreases linearly dependent on the radius. I could imagine a RAID 0 system where two disks are being filled in opposite directions. This would yield a more or less constant throughput.

[TimothyD]

I could imagine a RAID 0 system where two disks are being filled in opposite directions. This would yield a more or less constant throughput.



That is a DAMN good idea Lebowski...

I wonder if there is any way Red can force it to write that way? It seems like that would require getting at the innards of the drive? Who knows... Great idea anyway.

What we need is drives that are manufactured as RAID 0 that are already set up that way, where the RAID is built into the drive and it is writing to the platters like you mentioned, one from the inside, one from the outside. Then you wouldn't even need two drives...

Tim

[david farland]

I wouldn't worry too much!
If Red can't raid 0, two 2.5" drives with a continual sustain write of 35MB, somethings horribly wrong.
I'd be more worried about tracking your raw color corrections/rec 709 space (Prores). No one's explained that yet!
cheers,

[Nick Shaw]

I think somebody (could be Avid?) has already patented the idea of RAIDing a pair of drives which write in opposite directions.

[Antoine Baumann]

I'd be more worried about tracking your raw color corrections/rec 709 space (Prores). No one's explained that yet!
cheers,

Well I don't have the answear but Crossing the Line was color corected in rec 709 color space.

antoine