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  1. #31  
    Senior Member Christoffer Glans's Avatar
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    Quote Originally Posted by Robert Hofmeyr View Post
    Not sure if this has changed, but Phil said he was getting 1 hour per TB in HQ and only 10 minutes more in MQ (and LQ was not yet enabled). I agree with Bjorn above that it would be nice to have ratios that make for easy runtime calculations. Eg. HQ = 1h, MQ = 2h, LQ = 3h.
    Yes, so because DSMC2 gives you around 50 minutes on a 512gb card at 4:1, Komodo has much less compression or uses a worse type of compression that gives the same kind of quality with larger files.
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  2. #32  
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    Maybe it has something to do with the global shutter? Having to compress the entire frame rather than line by line? Definitely an important consideration.
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  3. #33  
    Senior Member Bob Gundu's Avatar
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    Quote Originally Posted by Jon Dishler View Post
    Maybe it has something to do with the global shutter? Having to compress the entire frame rather than line by line? Definitely an important consideration.
    Could very well be the reason. I’m sure, horsepower, heating, and media write speed would be important factors.
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  4. #34  
    Senior Member Christoffer Glans's Avatar
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    Quote Originally Posted by Jon Dishler View Post
    Maybe it has something to do with the global shutter? Having to compress the entire frame rather than line by line? Definitely an important consideration.
    That only holds up if it was a fact that it compresses line by line. Why would it compress like that? The entire image is scanned, then put into a compressed form, otherwise, it would be compressed off the bayer sensor directly before put into r3d file format?
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  5. #35  
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    I have no idea, really, just trying to think why they would use a different method of compression, if in fact that is done. Line by line there would be a stream of data coming off the sensor continuously, whereas with a global compression it could be in large blocks? But again, I have no idea and would be perplexed since Red has just won a patent battle on their wavelet compression patent challenge against Apple, why would they do anything else if not needed? I apologize for making this guess which has no basis in fact, please disregard. I am in line for a white Komodo, and have a couple of DSMC2 cameras, so am keenly interested in any differences but should not speculate.
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  6. #36  
    Quote Originally Posted by Jon Dishler View Post
    I have no idea, really, just trying to think why they would use a different method of compression, if in fact that is done. Line by line there would be a stream of data coming off the sensor continuously, whereas with a global compression it could be in large blocks? But again, I have no idea and would be perplexed since Red has just won a patent battle on their wavelet compression patent challenge against Apple, why would they do anything else if not needed? I apologize for making this guess which has no basis in fact, please disregard. I am in line for a white Komodo, and have a couple of DSMC2 cameras, so am keenly interested in any differences but should not speculate.
    I think you are onto something. It is well beyond my full understanding but I found this technical paper (Link at bottom.) From my layman's understanding is, that it is like HDRx from the same time period read out going into two different memory caches. One memory slot is fired for the long exposure (the full time period), and the other is fired taking data samples through out the frame to prevent ghosting/double imaging. Then the two images are combine like HDRx. (It could explain why the low-ish frame rate limitation, the more data there is during compression and lack of an HDRx mode.)

    So the data heavy compression might be two different video streams rolled into one package. Each maybe compressed at two different levels themselves, if so the HQ, MQ, and LQ could be just affecting one of the streams, or both of them in different ways. (<<< All that is my imagination running wild with no real basis in fact.) Could you imagine trying to get the best quality picture by selecting two different compression ratios of what the camera could handle? So a factory preset at HQ, MQ and LQ makes a lot more sense. And Jarred's statement about "dialing" in the compression levels makes sense.

    Then again, we don't know RED is using this method, but it explains away the limitations of the Komodo.

    Link:
    https://iopscience.iop.org/article/1...47-4065/ab00f3
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  7. #37  
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    I don't think Red compresses any version of R3D line by line. It compresses the R, G, and B pixel patterns of a whole Bayer frame discretely so that higher compressions can be applied to the red and blue channels compared to green. Wavelet compression can be done in blocks or fractions of the whole frame up to the whole frame as a unit. Whole frame compression delivers highest quality results but requires the highest processing power per unit of time. Given the massive increases in available processing power vs power consumption and thermal envelopes with latest gen hardware, I would think it more likely that they are compressing larger block patterns or maybe even the whole frame pixel pattern for each primary at once. Whole frame compression could limit frame rates compared to small block compression schemes. Not a major change from past wavelet processes, but one that would require updated software to decode.
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  8. #38  
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    Quote Originally Posted by David Rasberry View Post
    I don't think Red compresses any version of R3D line by line. It compresses the R, G, and B pixel patterns of a whole Bayer frame discretely so that higher compressions can be applied to the red and blue channels compared to green. Wavelet compression can be done in blocks or fractions of the whole frame up to the whole frame as a unit. Whole frame compression delivers highest quality results but requires the highest processing power per unit of time. Given the massive increases in available processing power vs power consumption and thermal envelopes with latest gen hardware, I would think it more likely that they are compressing larger block patterns or maybe even the whole frame pixel pattern for each primary at once. Whole frame compression could limit frame rates compared to small block compression schemes. Not a major change from past wavelet processes, but one that would require updated software to decode.
    There was a mention of DCT based compression being used in the Komodo. That would explain the higher data rate for the same quality since Wavelet is more efficient. It would also explain the lower power consumption and lower price tag since DCT is much easier to do in hardware.
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  9. #39  
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    Quote Originally Posted by Christoffer Glans View Post
    Yes, so because DSMC2 gives you around 50 minutes on a 512gb card at 4:1, Komodo has much less compression or uses a worse type of compression that gives the same kind of quality with larger files.
    Just reviving this. Do we have a definitive answer on why this is happening? Or if it will change to match DSMC2 compression ratio > file sizes?
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    Yes I would like an update on this as well.... I thought the whole point of utilizing cheaper CFAST media in Komodo was not to require (2-4) times as much of it to get the same compression ratios as a DSMC2 cam. I currently have been getting by with 2 x 480gb mini mags on my Gemini and I do shoot 2:1 compression sometimes but there are times during long interviews that I borderline need more media and I have been having to offload my mags during long jobs. I am thankful minimags have finally come down in price but I was holding off on getting more as I was hoping Komodo would be at the very worst "on par" with DSMC2 data rates or hopefully better in which I could pick up more CFAST (2 x 512gb cards for Komodo to start) and just use Komodo intercut with my Gemini as B-CAM rather than investing in more DSCM2 mags at this time as they will probably be obsolete once DSMC3 comes around. Obviously, there are still a slew of many benefits to Komodo (form factor, global shutter, REDcode at an affordable B-Cam price point, etc.) that make it really worthwhile for my workflow but this definitely is a concern if I am going to need double the media storage for Komodo compared to an already data hungry DSMC2 cam. Not to mention such an increase in data rates affects requirements for longterm external storage and the required volumes for SSD editing drives as well as I already max out 1-2TB SSD editing drives fairly easily on certain projects just with my Gemini footage alone. So I cannot imagine adding Komodo into the mix if it has double the rates of my Gemini.

    Can anyone lock down data rates for sure on Komodo and how that translates into available storage / recording time on a 512gb CFAST card?
    Last edited by Andrew Reese; 07-14-2020 at 07:29 AM.
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