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Transcoding from CinemaDNG to BlackMagicRAW

PostPosted: Thu Sep 20, 2018 3:35 pm
by Giordano Lu
Hi All,

Im very excited about start using BRAW, and indeed, one of the first things came to my mind was to transcode a cinemaDNG based project, expecting not actually get the benefits of BRAW, but simply having an exercise on using it, and maybe, hopefully, get some performance/space advantages.

I was surprised that in media management tool, there is no actually option to transcode to BRAW. Am I missing something ?

anyhow, this was a super nice move from BM. Congrats to the entire BM team !

Using DR15.1.0.023 btw...

Re: Transcoding from CinemaDNG to BlackMagicRAW

PostPosted: Thu Sep 20, 2018 10:07 pm
by Mark Foster
BRAW or proresRAW use the sensor information
no other codec has this information
so trancoding in one of this codec is not possible

only supported cameras can from there this codecs write

you should try understand was BRAW is

Re: Transcoding from CinemaDNG to BlackMagicRAW

PostPosted: Fri Sep 21, 2018 8:07 am
by Hendrik Proosa
Mark Foster wrote:BRAW or proresRAW use the sensor information
no other codec has this information
so trancoding in one of this codec is not possible

only supported cameras can from there this codecs write

you should try understand was BRAW is

Too much hype in what BRAW is. Reality is probably easier, encoder sales == money. I highly doubt there is anything that technically prevents encoding of other raw sources to braw. It might not be as clean because in-camera edge-preserving denoising (or whatever is exactly done there) is missing, but in the end it is just a bunch of data. One can always use some default settings for this supposed sensor information.

Re: Transcoding from CinemaDNG to BlackMagicRAW

PostPosted: Sun Sep 26, 2021 4:23 am
by Devon Stanczyk
Hendrik Proosa wrote:
Mark Foster wrote:BRAW or proresRAW use the sensor information
no other codec has this information
so trancoding in one of this codec is not possible

only supported cameras can from there this codecs write

you should try understand was BRAW is

Too much hype in what BRAW is. Reality is probably easier, encoder sales == money. I highly doubt there is anything that technically prevents encoding of other raw sources to braw. It might not be as clean because in-camera edge-preserving denoising (or whatever is exactly done there) is missing, but in the end it is just a bunch of data. One can always use some default settings for this supposed sensor information.


What is this “in-camera edge preserving denoising” you speak of? If the data is RAW sensor data, there shouldn’t be any processing like denoising applied to the recorded data. Can you explain further?

Re: Transcoding from CinemaDNG to BlackMagicRAW

PostPosted: Sun Sep 26, 2021 5:23 am
by Hendrik Proosa
Braw is not raw sensor data anymore, it is processed and lossily compressed. If braw image is stretched a bit, specific DCT compression patterns emerge (16x16 pixel macroblocks). Processing like denoising on one hand allows better compression and on the other helps prevent problems with the RED patent of in-camera compressed raw recording: if it ain’t raw anymore, it doesn’t violate the patent. What the exact denoising algorithm is, don’ know, it isn’t public afaik.

Re: Transcoding from CinemaDNG to BlackMagicRAW

PostPosted: Sun Sep 26, 2021 6:40 am
by Uli Plank
Exactly. It's not RAW in the sense of Red's patent (remember, in the US you can get a patent on nearly anything).
But it's very efficient, if you compare file sizes and quality vs ProRes and it's easy on the decoding power needed.
Try to decode Red's new DCT based Komodo version in 8K on a weak machine and you'll know what I mean.

Re: Transcoding from CinemaDNG to BlackMagicRAW

PostPosted: Mon Sep 27, 2021 3:16 am
by Devon Stanczyk
Got it! I did some further reading, now I think I’m up to speed.

From what I’m gathering, BRAW is debayering, processing, and compressing the data. But still stored at a high bit depth. If I had to put it simply, it’s basically a container of TIFF images with an audio stream.

If the data is debayered, how does it achieve RAW-like white balance corrections? Are the images baked in a linear gamma? That’s the only effective way to have RAW-like white balance changes with non-RAW images yes?

I’m Davinci Resolve, when working with BRAW, can you change the decoding resolution?

Re: Transcoding from CinemaDNG to BlackMagicRAW

PostPosted: Mon Sep 27, 2021 6:09 am
by Hendrik Proosa
It is more like jpeg in a container (as is prores). DCT compression is very widely used in a lot of codecs, still and video.

White balance does not need raw data, none of the ”raw” color controls do. I don’t know why this idea keeps floating around. Only thing practically benefitting from actual raw data is debayering switching possibility (which affects sharpness, moire etc). It simply needs the gain on channels being done in proper colorspace with linearized values. Braw itself stores data in a pseudo-log curve for storage efficiency, the internal gamut is inknown.

Resolve changes decoding res behind the scenes automatically based on timeline resolution by default, which is why comments like ”my system plays 12k with ease” are frequently random noise, if it is on HD timeline it is decoded at 2K. You can override it in raw panel.

Re: Transcoding from CinemaDNG to BlackMagicRAW

PostPosted: Mon Sep 27, 2021 10:17 am
by antoine
Yes in theory ProRes 4444 12 bpc is as good as Blackmagic RAW .braw

In practice, BRAW is even better for workflow wise and with its official SDK color grading tools