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What is the bit depth of RED QT proxy files?

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Miklos Philips
What is the bit depth of RED QT proxy files?
on Mar 7, 2009 at 5:49:13 pm

I couldn't find any info on this funny enough. I've been searching for 30 min now so I'm asking you guys. Thanks in avance.

...............................
Point Zero Pictures
<http://www.pointzeropictures.com>


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Russell Lasson
Re: What is the bit depth of RED QT proxy files?
on Mar 7, 2009 at 9:11:36 pm

This is according to the RED Final Cut Studio Whitepaper:

Specifications for RED QuickTime Media
Once ingested, RED QuickTime files have the following characteristics:
• Color space — RGB
• Chroma subsampling — 4:4:4
• Bit Depth — 12-bit
• Supported resolution — 2048 x 1024 (2:1 aspect ratio)
• Pixel aspect ratio — Square
• Field dominance — None
• Supported progressive frame rates— 23.98, 24
• Timecode — Non-drop

Which Applications Are Compatible with RED QuickTime Media?
RED QuickTime files are read-only compatible with Final Cut Pro, Color, and
Compressor. These applications can import RED QuickTime files for use in a project,
but can neither render nor export clips using the REDCode compressor.

RED QuickTime files have not been tested extensively with Motion, LiveType, or Shake.
If you want to send RED QuickTime files to any of these applications, you should
perform workflow tests first. If in doubt, you can always transcode the media you need
to work on using another codec such as ProRes 422 or Uncompressed.

-Russ

Russell Lasson
Universal Post
Ridgeline Digital Cinema Mastering
Salt Lake City, UT


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gary adcock
Re: What is the bit depth of RED QT proxy files?
on Mar 7, 2009 at 9:48:59 pm

[Russell Lasson] "Once ingested, RED QuickTime files have the following characteristics:
• Color space — RGB
• Bit Depth — 12-bit
• Supported resolution — 2048 x 1024 (2:1 aspect ratio) "


I surprised no one (but me) complains about this.

QT absolutely abhors RGB files and does an atrocious job at handling the conversions to YUV.

Very very expensive monitors cannot even show 12bit color since that is not possible as video resolution, and how in the hell can you grade 12bit color in a 10bit scope displayed on an 8bit monitor?

and Since when is 2048x1024 a SMPTE standard size for HD or 2K?



and the Proxy files are still only 8bit.


gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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Russell Lasson
Re: What is the bit depth of RED QT proxy files?
on Mar 7, 2009 at 10:09:32 pm

:)

-Russ

Russell Lasson
Universal Post
Ridgeline Digital Cinema Mastering
Salt Lake City, UT


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Graeme Nattress
Re: What is the bit depth of RED QT proxy files?
on Mar 9, 2009 at 5:23:10 pm

The underlying RAW data is 12bit. The codec translates that into the pixel type requested by the Quicktime app. For FCP that's 8bit YCbCr for preview, 8bit RGB for RT, and 32 float YCbCr for final rendering. 32float YCbCr 4:4:4 is more than enough quality access the underlying 12bit RGB data.

So no the proxys are not 8bit (unless you ask for an 8bit buffer from them, at which point they'll happily oblige).

Graeme

- http://www.nattress.com - Film Effects and Standards Conversion for FCP


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gary adcock
Re: What is the bit depth of RED QT proxy files?
on Mar 9, 2009 at 6:15:32 pm

[Graeme Nattress] "So no the proxys are not 8bit (unless you ask for an 8bit buffer from them, at which point they'll happily oblige). "

a clarification Graeme.

So if the user in this instance only cuts with H proxy versions then outputs direct from FCP without ever going beyond those ref files in his project, this user has most likely never accessed the root level of the Raw file and is therefore only utilizing the 8-bit data stream. Correct?

Does this hold true for the camera proxy as well or does one need to be using L&T to access the native codec during import?

Secondarily,
if this is the case, then why is it necessary to re-link to the R3D files in say Color, if the QT proxies have the ability to access the 32 bit 4:4:4 files directly?



gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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Graeme Nattress
Re: What is the bit depth of RED QT proxy files?
on Mar 9, 2009 at 6:34:02 pm

Say you render to a prores timeline, that codec will ask for an R4FL pixeltype from the RED codec, which is 32float YCbCr, so that's what will get rendered and output. Camera reference movies and wrapped native Quicktime movies use both the same codec, and access the underlying RAW data in the same way. Just that one is a pointer to the R3D, and the other contains the R3D within itself.

Color likes the native wrapped ones so that it can track the files better back and forth between FCP and Color. It's not for RAW data access reasons.

Graeme

- http://www.nattress.com - Film Effects and Standards Conversion for FCP


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gary adcock
Re: What is the bit depth of RED QT proxy files?
on Mar 7, 2009 at 9:41:26 pm

[Miklos Philips] "I couldn't find any info on this funny enough. I've been searching for 30 min now so I'm asking you guys."


QT proxy files are 8bit YUV.

the only exception I know of is if you use a special tool to wrap from highend frame based workflows using Targa, DPX or Cineon frames.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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Mohamed Kamel
Re: What is the bit depth of RED QT proxy files?
on Mar 7, 2009 at 10:19:56 pm

since no one replied in my thread, i might as well as in here (:

so can i master using the proxy files if i'm delivering SD? what will be my losses if there is any?

Thank you in advance



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gary adcock
Re: What is the bit depth of RED QT proxy files?
on Mar 8, 2009 at 4:25:43 pm


Yes I did Mohammed.

[gary adcock] "QT proxy files are 8bit YUV. "

for an SD output from the proxy files should be fine.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows

Inside look at the IoHD
http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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