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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 :)

EPIC Dynamic Range...

Rick Burnett said:
I guess I am a bit confused on some of the terminology here.

If a compression is lossless, than why would you ever choose any different than the highest lossless compression ratio IF even in the worst circumstance the processor in the brain can handle the compression? (I could see if decompression is a later issue, but most algorithms are heavy on the encode). Like a zip file on a computer, I always want the highest compression I can get.

However, my previous question is on lossy compression. What I don't understand is what the situations would be where I'd use the lower compression compared to the higher compressions available. I've not enough knowledge of wavelet compression to know when the image will take a hit. Clearly there is something that has to be different or there would be no reason to run at a lower compression ratio. This is the kind of information someone would need to know to make that trade-off decision.
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Well if you think redcode 36 is acceptable for 4kp24, then you'll probably be perfectly happy with RC50 for 5kp24, excepting special cases like VFX work. I could see where you might want lossless for chroma key, because even the slightest pixel smear will make keying more difficult.
 
Stephen Gentle said:
I'd guess that it wouldn't be a standard sata connector - those connectors (and the power connectors SATA drives use as well) are really not at all durable. I've broken a couple on my computers after only a few mating cycles, (but mostly the cables thankfully).
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If this is the case then that means we have another propriety storage... no industry standard 1,8" SSD disks for EPIC...

The SATA interface is designed to be used like the SAS... which is hotplug... that is, if you slide the disk in a slot it simply can't break, it is being build for that purpose... if you referring to the free cable plug in then yes there mite be a problem... but with a slot driving the insertion its not possible to break the SATA connection...
 
It's totally logic that they won't allow standard 1,8'' discs:
The internal plug is designed for about 30 plugging-cycles. Would be terrible wrong to allow that as a switch-medium...

And IF they would - they would restrict the SSDs to Red-branded products only as they did with CF - a completely valid step to insure the high datarate needed for the cam.

BTW:
"no industry-standard SSDs"?! There is no SSD industry standard - at least not in the cine industry. And using standards that are designed for other industries isn't nesecarily a good thing. It surely wouldn't be in this case.
 
Steven Caesare said:
Mathematically lossless means an exact 1-to-1 preservation of the original data.
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Steven, the question was, why it is not then just called lossless. From the pragmatic point of view my question was hairsplitting. But technically I was interested in whether one can achieve genuine lossless compression without an infinite sequence. The other possible interpretation of term mathematical is that the sequence is limited to a finite amount of functions, but the error of cutting the sequence is within for instance the noise level. If so the compression-decompression map is not an identity but the difference is insignificant suggesting the additional adjective mathematically.
 
Lauri Kettunen said:
Steven, the question was, why it is not then just called lossless. From the pragmatic point of view my question was hairsplitting. But technically I was interested in whether one can achieve genuine lossless compression without an infinite sequence. The other possible interpretation of term mathematical is that the sequence is limited to a finite amount of functions, but the error of cutting the sequence is within for instance the noise level. If so the compression-decompression map is not an identity but the difference is insignificant suggesting the additional adjective mathematically.
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They have previously used the term "visually lossless" as meaning perceptible to the eye, but not on a literal level. Hence, they say "mathematically lossless" to distinguish when they mean truly lossless, and not just visually lossless.

It's kinda silly and confusing, but I think they wanted to emphasize the quality of their wavelet compression over other compression methods; they wanted to avoid being thrown in with other "lossy" codecs. (That just results in devolving into primitive ratio comparisons, though that ultimately happened anyway)
 
Lauri Kettunen said:
Steven, the question was, why it is not then just called lossless. From the pragmatic point of view my question was hairsplitting. But technically I was interested in whether one can achieve genuine lossless compression without an infinite sequence. The other possible interpretation of term mathematical is that the sequence is limited to a finite amount of functions, but the error of cutting the sequence is within for instance the noise level. If so the compression-decompression map is not an identity but the difference is insignificant suggesting the additional adjective mathematically.
Click to expand...

"Mathematically lossless" a a term that has been used in the video codec world for quite some time. (See: http://www.google.com/search?q=mathematically+lossless&sourceid=ie7&rls=com.microsoft:en-us:IE-SearchBox&ie=&oe==).

I've heard it used a number of times (particulalry in the recent audio and video wars as Blu Ray was duking t out with HD DVD) to emphasize the difference between lossy compressed, and uncompressed.

I suspect many poeple lose sight of what a "codec" really means, and automatically equate "lossless" with "uncompressed", and "compressed" with "lossy".

-sc
 
Deanan said:
No module necessary.
Gigabit ethernet is on the brain.
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mmmm. And GigE is on RED4K.
This could this allow real time RGB encoding if the hardware could be implemented on RedFork instead of upstream. Better than DVI recording for "those" jobs.
Or streaming of live events in 4k raw to....? instead of HD-DVI.

I'd like to hear more about the possible applications.
 
JD Holloway said:
mmmm. And GigE is on RED4K.
This could this allow real time RGB encoding if the hardware could be implemented on RedFork instead of upstream. Better than DVI recording for "those" jobs.
Or streaming of live events in 4k raw to....? instead of HD-DVI.

I'd like to hear more about the possible applications.
Click to expand...


Me too.

Streaming RAW sounds yummy. :bigear:
 
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Gigabit ethernet is on the brain.
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Why not an Infini band or a 10Gbit Ethernet or better a Fiber 4Gb or 8Gb? with a tactical fiber cable would be super..

As for the SATA connector... Yes I just took a closer look and its really not capable for field use... But a passive canister with a better connection system that will be able to host an 1,8" SSD drive that will cost few dollars will allow us to benefit from SSD technology advances and will make EPIC more flexible than the P2 style/cost storage...
 
Steven Caesare said:
"Mathematically lossless" a a term that has been used in the video codec world for quite some time. (See: http://www.google.com/search?q=mathematically+lossless&sourceid=ie7&rls=com.microsoft:en-us:IE-SearchBox&ie=&oe==). ...

I suspect many poeple lose sight of what a "codec" really means, and automatically equate "lossless" with "uncompressed", and "compressed" with "lossy".
Click to expand...

Steven, thanks for the links. Sounds like Jim really meant truly lossless.

Compression and lossy are obviously two different issues. Never had time to study wavelet compression techniques in details, but I know the basics from discrete wavelet techniques from mathematics and what the inventor Ingrid Daubechies has published. Based on that, cannot see immediately how the lossless compression is made. But will sort out the background when have a chance.
 
Evangelos Achillopoulos said:
As for the SATA connector... Yes I just took a closer look and its really not capable for field use... But a passive canister with a better connection system that will be able to host an 1,8" SSD drive that will cost few dollars will allow us to benefit from SSD technology advances and will make EPIC more flexible than the P2 style/cost storage...
Click to expand...

Yes, being able to screw the drive into an enclosure with a more robust connector would be ideal.
 
Lauri Kettunen said:
Steven, thanks for the links. Sounds like Jim really meant truly lossless.

Compression and lossy are obviously two different issues. Never had time to study wavelet compression techniques in details, but I know the basics from discrete wavelet techniques from mathematics and what the inventor Ingrid Daubechies has published. Based on that, cannot see immediately how the lossless compression is made. But will sort out the background when have a chance.
Click to expand...

I'm not sure I've seen anything that says the lossless algorithm will necessarily be wavelet based.

-sc
 
Kenneth Elkington said:
Jim said that it's redcode. I doubt the hardware is even capable of non-wavelet encoding.
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Well, lossless wavelet does exist, and is in fact included as part of JPEG2000, to which REDCode appears to be a cousin. Lossless compression rates of 2.0-2.6:1 are typical.

So while REDCode is a trademark name for a product that doesn't necessailry specify what's inside, if we take Jim's comments to mean "is wavelet based", then it sounds like what they could be using.

-sc
 
Stephen Gentle said:
Yes, being able to screw the drive into an enclosure with a more robust connector would be ideal.
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Jared has announced exactly that...!

Update: :blushing: :crying: I was wrong... its only the 2,5" that will be able to load bare drives... :cryin:
 
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