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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

100, 36, 28, Data rate question

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pablano

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Could someone give me a quick explanation on the advantages and disadvantages to higher and lower data-rates?

It would be much appreciated. I'd like to think that I'm pretty technologically minded but this confuses me somewhat. (By the way, I did do a search to no avail, but if this has been covered in a thread before, my apologies, please point me in the right direction).
 
pablano said:
Could someone give me a quick explanation on the advantages and disadvantages to higher and lower data-rates?

It would be much appreciated. I'd like to think that I'm pretty technologically minded but this confuses me somewhat. (By the way, I did do a search to no avail, but if this has been covered in a thread before, my apologies, please point me in the right direction).
Click to expand...

RED Raw uncompressed in 5K , 4K or even 3K ?

HDCAM 3:1:1 is less than 200mb/s and DVCPROHD is only 100mb/s

and RED is talking about 28/ 36 or 100 MB /s !!!!

2MB = 16mb/s

100MB = 800mb/s but not in just HD 444

HDCAM SR is not a RAW format and you do not have much space to enhance
in post.

Are you listening ?

STEWART
WOW Holdings
HKG
 
I also would be interested as redcode raw is, as told, visually lossless and no one showed me the quality diffenrence between redcode 28 and 36 (MB ratio are not quite different).

Thanks

Pat
 
Simply put, the higher the number the lower the compression...the lower the number the better playback you will get on slower machines.

btw-Red is not visually lossless w/ the current builds.
 
Thanks, digitalfx. And I assume less compression means better quality.
 
For your reference:
This is average industry standard storage size(DCI compliance)
RedCode is lower.
storage_bitrate.jpg

http://www.dcimovies.com/specification/index.tt2
 
Nerd alert

Nerd alert

Somebody correct me if I am wrong but I think with RedCode we are talking about MegaBytes not MegaBits. If I remember my computer classes from about a hundred years ago there are 8 bits in a Byte :shifty: . From what I have been told the DCI specs were created with hard drive sustained read speeds as the controlling factor.

In terms of the pros and cons of a higher bit rate I think it is safe to assume that with a larger bit budget Graeme (and the rest of the RedTeam) will be able to offer cleaner images. This will of course require more storage space, higher bandwidth, etc - however, IMHO smart client side decoding using GPUs and/or dedicated silicon, 64 bit or even 128 bit system architecture, multi-cores, parallel processing and other improvements should make 100MB/sec manageable on newer workstation class machines.

The crux of this argument is that there is a happy medium between the holy grail of uncompressed, and objectionable compression artifacting. It is my guess that part of the evolution of RedCode across various acquisition devices will include selectable compression rates.

The DCI spec (based on J2K for theatrical), MPEG-2 and MPEG-4 compression schemes for broadcast and optical discs are all targeted at various deliverables. RedCode, DVCPRO-HD, ProRes, HDV and many other codecs are ostensibly designed for production and post-production implementations with varying degrees of quality and system requirements.

What I am just fascinated to see is how RED scales a wavelet based scheme like RedCode from 100MBytes/sec in their EPIC camera to a small fraction of that in the Red Ray player. Exciting times.
 
Does higher bitrate hit the CPU harder or less?

Obviously it'll demand more from your storage array but if you already have a fast RAID it might actually reduce your processing... although I wager probably not since it'll just be more CPU intensive data to be decoded.

Someone wiht a fast Raid care to test?
 
digitalfx said:
15 doesnt do anything to picture quality...it adds multi monitor support.
Click to expand...

... Multi monitor support does do something to the picture quality, more pictures of more quality:shifty:
 
chosei said:
For your reference:
This is average industry standard storage size(DCI compliance)
RedCode is lower.
storage_bitrate.jpg

http://www.dcimovies.com/specification/index.tt2
Click to expand...

Um. The Mbit vs MByte issue again. It's a factor of 8, so a 28MByte/s codec is actually 224Mbit/s (although with parity and whatnot a factor of 10 isn't a bad basis). Either way, even the lowest bitrate in REDCODE is higher than the highest bitrate in that DCI table.

Of course those are delivery rates, not acquisition, you can get away with a lot more there. Although I'd be pretty pissed off to be watching a digitally projected film from a 28Mbit/s source (that's about DV rates, and DV is only 8bit for a start, and SD also).

As for RED's codec quality - I don't think it's possible to evaluate loss, as there's no uncompressed reference. However it's not lossless. It is however a very visually imperceptible loss in compression. There are none of the common compression symptoms you'd see in DCT-based compression.
 
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