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Zak Ray
ARRIRAW Questions
on Jan 31, 2011 at 2:35:59 pm

If anyone happens to know the
-Bitrate
-Color space (RGB?)
-Supported audio channels
-Compression algorithm (DCT? Wavelet?)

of ARRIRAW, I'd appreciate it. Thanks!


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gary adcock
Re: ARRIRAW Questions
on Feb 1, 2011 at 1:40:48 pm

ARRIRAW bit rates for Alexa / D21 are similar to Uncompressed at 2880x1620.
The .ARI frames are 7MB each, DPX files from the same output are 19MB per frame.

ARRIRAW is recorded from the Tlink data stream over Dual Link HDSDI to specific recorders (Only Codex, Stwo and KG are supported today as far as I know)

the Color space is RGB.

ARRIRAW does not support audio, as it is captured as a sequence of frames just like DPX.


I am not sure of the compression algorithm, I will check.

gary adcock
Studio37

Post and Production Workflow Consultant
Production and Post Stereographer
Chicago, IL

http://blogs.creativecow.net/24640



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Zak Ray
Re: ARRIRAW Questions
on Feb 1, 2011 at 2:52:52 pm

Thanks, Gary, I'd love to know.


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Christy MacKarell
Re: ARRIRAW Questions
on Feb 1, 2011 at 3:59:44 pm

Does this answer the compression algorithm question?:

"An Uncompressed RAW signal is the direct electrical value feed from the photosites of the camera sensor without any processing or manipulation. Think of it as the “digital negative” from the camera"
-Abel Cine Tech blog.

Lots of folks can do an ARRIraw debayer: Baselight
Codex, Nucoda etc. But right now, very few have implemented ARRI's own SDK to do it; it's not released generally at time of writing.

Christy MacKarell
Deluxe NY


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Zak Ray
Re: ARRIRAW Questions
on Feb 2, 2011 at 2:53:46 am

So... it's uncompressed?


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Fredrik Harreschou
Re: ARRIRAW Questions
on Feb 6, 2011 at 12:02:01 pm

Actually, RED has patented in-camera raw compression (Redcode). So unless Arri wants to license Redcode to use in their products, they will have to do uncompressed raw.


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gary adcock
Re: ARRIRAW Questions
on Feb 7, 2011 at 2:29:50 pm

[Fredrik Harreschou] "Actually, RED has patented in-camera raw compression (Redcode). So unless Arri wants to license Redcode to use in their products, they will have to do uncompressed raw."


Arri has always regarded ArriRaw as an uncompressed capture- this is more because of it being a direct data capture as opposed to being a signal stream over T-link.


for the record.
The ArriRaw codec released to the public 3-years(?) before Red Digital was a camera company, at the time ArriRaw was released the only way to capture was as an uncompressed signal.

gary adcock
Studio37

Post and Production Workflow Consultant
Production and Post Stereographer
Chicago, IL

http://blogs.creativecow.net/24640



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David Battistella
Re: ARRIRAW Questions
on Feb 7, 2011 at 5:49:38 pm

I always thought ARRIRAW was based on wavelet compression scheme. That makes it 2.5:1 lossless compression if this is true.

For the record REDCODE raw is also a wavelet based scheme. But at 2.5:1 it would be considered lossless which is mathematically exactly the same as uncompressed.

David

Peace



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Fredrik Harreschou
Re: ARRIRAW Questions
on Feb 8, 2011 at 8:21:37 pm

Hi!

My comment was directed to Zak who asked if it was uncompressed. Which I assume it has to be, because of the RED patent.

First, just to make it clear, I am no troll or Red "fanboy". We actually received our first of two Alexas last week. But I think it is an interesting discussion.

David, I am not sure if ARRIRAW is wavelet compressed. And Gary seems to confirm that. According to Jim Jannard from RED, the reason they were able to get their "in-camera raw compression patent approved was because the competition was asleep", me paraphrasing. The thread was actually removed from reduser.net soon after he posted. I am *guessing* that it was for legal reasons.

If indeed RED has patented compressed RAW in camera, as they claim, that will be a big issue for the competition when they want to go 4k with bayer pattern sensors. Something I hope and believe Arri has on their roadmap. The I/O requirements for getting uncompressed 4K RAW off the camera will be challenging (read: expensive) for years to come, the same with storage needs. And debayered RGB will be even higher data rates, or heavily compressed, and demand a lot of the in-camera processing to do a full debayer in realtime.

Cheers,
Fred


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Fredrik Harreschou
Re: ARRIRAW Questions
on Feb 8, 2011 at 8:28:03 pm

The reason the RAW file is smaller (approx 1/3) is because the RAW signal is one channel, not three as in RGB. The RGB file is made during debayer/demosaic. Or put another way, RAW is inherently a 3:1 compressed RGB file.

EDIT: Sorry, I am not used to the different reply functions on this board (how do I quote?). This was a reply to Gary´s comment about file sizes in ARRIRAW vs DPX.


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Robert Monaghan
Re: ARRIRAW Questions
on Feb 9, 2011 at 5:11:38 pm

Hi Everyone,

(A bit of background.. I am the first "ARRIRAW Partner" that ARRI signed on. I have (and continue to be) a developer supporting the camera and their image formats. My Info is first hand.)

This information is already publicly available, but I will summarize it here:

- There is no compression. Period. No wavelet, DCT, etc. Just uncompressed, untouched, unmolested bayer pattern image data. *Truely* raw data. Not a compressed bayer image, as others would use.

- T-Link is a packing method to transmit the bayer data to a recording device. Think of HD-SDI as a "video specific" ethernet system. Not only does HD-SDI send video packets over its network, but it can be re-purposed to send data packets, too. In T-Link mode, the D-21 and Alexa send bayer data over the HD-SDI *AS DATA* -- not as video.

- The D-21 and Alexa produces a 12-bit Bayer Sensor image which is sent to the recording device.

- There is no Audio support with ARRIRAW files. It is just bayer sensor data. Other means of recording the audio will have to be adopted. Consult with your recorder manufacturer. They may have a solution already.

- The Colorspaces supported after the image is processed, will depend upon the tools you use.
In general, any company that uses the ARRI SDK should get what ever the SDK offers. For example, you should get Rec709 and LogC. DCI P3 is also available. I imagine other colorspaces would be supported in the SDK in the future. If you had something specific that you needed, I would contact ARRI and put in a request.

- ProRes that is recorded from an Alexa via the SxS card uses the very same ARRIRAW color processing engine. If an ARRIRAW image and a Rec709 ProRes movie are recorded at the same time, they should look pretty much identical, color wise. Naturally, the resolution and debayer quality will be different.

Hope this helps.

bob.
http://www.gluetools.com

Robert Monaghan, CEO
Glue Tools LLC
POBox 24124
Santa Barbara, CA, 93121
United States

tel: +1 805 456 7997
fax: +1 805 456 7998

http://www.gluetools.com


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Fredrik Harreschou
Re: ARRIRAW Questions
on Feb 9, 2011 at 8:40:40 pm

Hi Robert,

thank you for your reply.

So a possible solution if/when Arri releases a 4K Alexa would be to use T-Link to say a Cineform based hardware solution that can intelligently compress the raw data?

As I said in my earlier post, handling uncompressed 4K (even if it´s "only" RAW) takes a lot of bandwidth and would be very unpractical and too expensive for a lot of productions.

Cheers,
Fredrik Harreschou
Colorist / online editor
Krypton Lab, Oslo, Norway


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Robert Monaghan
Re: ARRIRAW Questions
on Feb 11, 2011 at 6:14:11 am

The current 2880x2160 files that a D-21 generates are about 12.4Megs, if they are unpacked. There is a packing method that would drop it well under 10Megs. Codex and S.Two both provide this packed file format.

I can't say what the best solution is for compressing the sensor data. But I will say this: There is a lot of R&D to be done in this area. Red's patent is pretty specific to their camera, and the way it works with its Log space. There are many other ways to do compression.

I think that we will see others work on this. Perhaps someone will even to provide an "open" system for compression. (This is key.. as we don't want to be forced to rely on a proprietary system, 30 years from now, of a company's proprietary and secret format that no longer doesn't exist.)

For now, ARRI has a great RAW solution that is very good for 99% of the shots a production uses and is very much in line with HD sized DPX files. (And 30 years from now, you can still open them and use them. No proprietary compression or encryption.)

bob..

Robert Monaghan, CEO
Glue Tools LLC
POBox 24124
Santa Barbara, CA, 93121
United States

tel: +1 805 456 7997
fax: +1 805 456 7998

http://www.gluetools.com


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Fredrik Harreschou
Re: ARRIRAW Questions
on Feb 11, 2011 at 12:46:04 pm

Great points on using open formats, Robert. I really agree. It will be interesting to see what the other players come up with.

I think the issues with storing RAW is just dawning on producers and DPs. Like you say, how do we make sure that it is possible to open up the proprietary files in the future.

The best would be if there was an industry standard set by a committee.

Cheers,
Fredrik


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gary adcock
Re: ARRIRAW Questions
on Feb 11, 2011 at 2:34:28 pm

[Fredrik Harreschou] "The best would be if there was an industry standard set by a committee. "

I cannot disagree enough with that statement.
Committees have given us the wonderful world of MPEG/ HDV/ MXF/AVCHD where any and a bazillion variations to work with, rather than defining ONE.

IMHO committees tend to placate the masses rather than define structure to last for eternity

The are any number of existing structures for archive and delivery.

Today
DPX can do a lot of things, however OpenEXR or the Academy IFF proposals offer future proofing with far more robust metadata controls and maintenance. I don't understand why Adobe does not do more with their DNG format.

gary adcock
Studio37

Post and Production Workflow Consultant
Production and Post Stereographer
Chicago, IL

http://blogs.creativecow.net/24640



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Fredrik Harreschou
Re: ARRIRAW Questions
on Feb 11, 2011 at 2:56:39 pm

Hi,

my point wasn´t the committee part, but a common, open format with a future, as opposed to a dozen proprietary formats.

OpenEXR is great and evolving into a superformat. Adobe has CinemaDNG but does anyone actually use it?

Cheers,
Fredrik


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Bastiaan Houtkooper NSC
Re: ARRIRAW Questions
on Feb 11, 2011 at 5:12:14 am

Bob, I was under the impression that the D21 was 12 bit and the Alexa 14 bit internally. That's why a 12 bit log RAW signal was created to keep all data in the signal for the Alexa.

Bastiaan

Resolve system:
MacPro 8 core 2010 - 16B memory
9TB harddisk (1 system disk, 8TB in software raid 0 for data)
Nvidea GTX285
Nvidea GT120
Blackmagic SDI Decklink
RedRocketcard.
Tangent Wave panel
Transvideo 15" Cinemontor Evolution

Also running it on a MacBook Pro 17" (5.2)


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Robert Monaghan
Re: ARRIRAW Questions
on Feb 11, 2011 at 5:59:22 am

Hi Bastiaan,

I can't comment on the internal specifics of the camera. If ARRI wants to output a different file, its certainly up to them to make those changes.

However, regardless of what the sensor's ability is, as of today you are still using a 12-bit file.

bob.

Robert Monaghan, CEO
Glue Tools LLC
POBox 24124
Santa Barbara, CA, 93121
United States

tel: +1 805 456 7997
fax: +1 805 456 7998

http://www.gluetools.com


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Robert Monaghan
Re: ARRIRAW Questions
on Feb 11, 2011 at 5:56:34 pm

Actually, I want to correct myself... :)
Yes, the Alexa sensor does do 14 bit. Yes, the 12-bit ARI file will reproduce 16-bit data if the appropriate process is used to convert from 12-bit to 16-bit.

bob.

Robert Monaghan, CEO
Glue Tools LLC
POBox 24124
Santa Barbara, CA, 93121
United States

tel: +1 805 456 7997
fax: +1 805 456 7998

http://www.gluetools.com


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Fredrik Harreschou
Re: ARRIRAW Questions
on Feb 11, 2011 at 6:29:19 pm

Interesting...

Doesn´t that imply that it in fact is not a direct "raw" data readout? True raw from a 14 bit sensor should be 14 bit, right? There has to be some "rounding off" to get the 14 bit raw into a 12 bit container, will it not?

Not sure how to interpret this statement: "Yes, the 12-bit ARI file will reproduce 16-bit data if the appropriate process is used to convert from 12-bit to 16-bit."

I understand that we can decode at higher depths, but what do you mean by "reproduce 16 bit data"? Do you mean "produce"? ;)

Best,
Fredrik


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Robert Monaghan
Re: ARRIRAW Questions
on Feb 11, 2011 at 6:50:25 pm

Typically many camera manufactures will use a curve to take the sensor data (14-bit, or even 12 bit, for instance) to selectively remove parts of the image data. The results are then stored, compressed, etc. (I suspect Red works this way, and I know that some Phantom Cameras work this way, for instance.)

To reconstitute the data, the reverse version of the curve is applied, to generate the new image. Afterwards a series of steps (the "Color Science") is performed. Actually, the curve that is used to reconstitute the data is often specialized color science, as well. Many cameras use this technique right now.

To answer your question: "Produce or Re-produce". The fact that the image is Bayer Pattern, means that regardless of your bit depth, you are still missing 2/3rds of your initial data. So 12 bit or 16 bit is just more missing data. The 12-bit isn't 12-bits of color. Its 4096 values. Those values could be 4096 "32-bit" pixels. Or 4096 "8-bit values".

Once "Produced/Reproduced", the color processing steps really change the way this original sensor image looks like, anyways. The process that is used to take a Bayer Pattern Image and convincingly creates an RGB image is simply amazing. The amount of applied science and creative mathematics is astounding.

Interestingly "FYI" , the human eye is about 12-bit, anything higher is visually imperceptible. Only VFX people find that the 14-16 bit data is really needed for their work.

Hope this helps.

Bob.

Robert Monaghan, CEO
Glue Tools LLC
POBox 24124
Santa Barbara, CA, 93121
United States

tel: +1 805 456 7997
fax: +1 805 456 7998

http://www.gluetools.com


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Fredrik Harreschou
Re: ARRIRAW Questions
on Feb 11, 2011 at 8:06:41 pm

The kind of techy answer I love! Hope you don´t take my critical questions personal or as an attack. But it´s important to technically go deeper than the sales brochure... ;)

I have great respect and little technical understanding of the color science involved in debayer. But I have seen what better algorithms can do to a raw file. The difference between a RED R3D developed with build 16 two years ago and todays color science is like a completely new sensor.

I believe that RED has changed the R3D file format from 12 to 16 bit because the new sensor (MX) is 14 bit (the original M sensor is 12 bit). Makes sense. Not sure if I´m convinced that the 12 bit raw output from the 14 bit Alev III is a perfect solution.

Cheers,
Fred


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Fred Jodry
Re: ARRIRAW Questions
on Feb 12, 2011 at 12:50:40 am

Bear in mind it`s always curious just how many f stops or how much log of greyscale brightness is described by the 12 or 14 or so- on bits as it is in the camera, as it is in the encoding and it`s (matching?) decoding and as it is in or on the display, on the display being of course, projection, compared to direct lighting. Wanted curves or unwanted distortions can come in from almost anywhere. Subtle is subtle, wide scale is not as subtle. And when tolerances of binary digital to analog or analog to digital converters gets poor enough to get noticeable, hold on to your hat. Minor noise or nice greyscales can turn into digital sandpaper. Fortunately these problems should be more likely to go on the Fritz on your everyday sound card (unless the camera men keep bringing back tests undermodulating the video every time with light you can hardly see your hand with). Do I have to remind the guys, for their good habits, that the definition of an ASA speed is the, full therefore maximum, amount of light needed to produce best results?


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Zak Ray
Re: ARRIRAW Questions
on Feb 20, 2011 at 2:05:08 am

Thanks all for your responses. I wanted to put ARRIRAW in my codec chart, I think I got it all in there: http://worldwide-studios.com/Worldwide_Studios/Resources_files/Digital%20Vi...

Let me know if it's inaccurate...


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John Heagy
Re: ARRIRAW Questions
on Feb 22, 2011 at 12:32:53 am

Nice list Zac! I ike your proper use of 29.97i for frame rate instead of 59.94i.

A few things I noticed:

I think your giving the Quicktime Animation codec to much credit. I've always found it limited to 8bits. It can be intra or inter.

You should ad the open standard VC-2 aka Dirac from the BBC
http://en.wikipedia.org/wiki/Dirac_(video_compression_format)

Also Avid's DNX is an open standard aka VC-3

Apple's "NONE" codec is still used. It's basically an uncompressed Animation.

John Heagy


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Zak Ray
Re: ARRIRAW Questions
on Mar 6, 2011 at 8:56:45 pm

Thanks for the tips, John! I've updated the list accordingly.


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paul schilens
Re: ARRIRAW Questions
on Feb 12, 2013 at 12:25:11 pm

[Zak Ray] "Thanks all for your responses. I wanted to put ARRIRAW in my codec chart, I think I got it all in there: http://worldwide-studios.com/Worldwide_Studios/Resources_files/Digital%20Vi.....

Let me know if it's inaccurate...
"


WOW, thanks Zak! Where can I find your most recent updated chart? Does it include ProRes 2K specs for Alexa?

Thanks!

...Always learning


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Zak Ray
Re: ARRIRAW Questions
on Feb 18, 2013 at 6:30:53 pm

Thanks Paul! The most recent version can be found here:
http://zak-ray.com/resources/

It's not so much device-based as codec-based, so ProRes isn't defined by it's specific use in the Alexa. I am thinking about making an iOS version however, which might have the ability to cycle through based on codec OR device... we'll see if my time allows it!


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Ichsan Rachmaditta
Re: ARRIRAW Questions
on Jan 22, 2014 at 4:18:59 am

Hallo everyone..i have some question about arri alexa xt plus.
I am shooting with this camera, and sending the audio to the input..but the result seems to be that the sound only recorded on the pro res file, but not on the raw file ( arriraw )
Why is this happening?, anyone can help?
Thank you very much


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gary adcock
Re: ARRIRAW Questions
on Jan 22, 2014 at 3:18:06 pm

[Ichsan Rachmaditta] "Why is this happening?, anyone can help?
"




the .ari fil sequence does not allow for the audio recording internally because there is no provision for the audio file to be included with a sequence of still frames. This is the correct recording procedure and the reason for using dual system sound.

gary adcock
Studio37

Post and Production Workflow Consultant
Production and Post Stereographer
Chicago, IL


Follow my blog at http://www.garyadcock.com

Or follow me on Twitter
@garyadcock




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