Canon 5DMK3 clean HDMI output - first impressions (+ download uncompressed files)

Hi all,

Yesterday Canon released their so sought-after update for the Canon 5DMK3.
To be honest, for me, the cross type AF is not as interesting as the clean HDMI output.

So I've recorded initial test footage for some testing:

Youtube:


Download uncompressed:
http://www.solidfiles.com/d/579e4310bc/

Youtube:


Download uncompressed:
http://www.solidfiles.com/d/5a88f92606/

(The files are huge so the ones I've uploaded are very short)

Equipment:
Camera: Canon 5D Mark 3
Profile: Neutral - 0,-4,-2,0
Lens: 24-105L F4 @ F8
Shutter speed: 1/160
Recording device: BlackMagic Shuttle

Brief review:
Canon declares that the output is 8bpc@4:2:2, which is a little bit disappointing especially when the HDMI standard supports 10bpc and I almost sure that in Canon cameras the video processing pipe works at least in 12bpc.
I decided to go beyond Canon's declares and check if I can force it to push 10bpc, in the following way:
- BlackMagic Shuttle will always record at 10bpc; if the input is 8bpc, the Shuttle bit shifts the values (multiplies by 4: 0->0, 1->4 ... 255->1020).
- I've extracted a single YUV frame and warped it in 16bpc (w/o bit shift).
- In hex editor you get, for example, this (in this case it is the U channel):

And you can see that each value (little endian) divides by 4 without fraction.
A801 = 424 -> 424/4 = 106
9C01 = 412 -> 412/4 = 103
etc...

So yes, the conclusion is that the output of the HDMI in the 5D is 8bpc only.
Think how would it be if it was 10bps... In short, the following operation theoretically would give an image without the ugly banding:

The question that should be asked now is: Does it really give 4:2:2 chroma sub-sampling?

Well, I don't know in this moment. Canon may perform scale-up algorithm other than nearest-neighbor (x2 width) and you will never find cloned pixels (although you can see a lot of typical duplicates in the hex viewer, but it is not an indicator), especially in the so soft Canon's 3x3 sensor binning with flat picture style.

For for this moment, lets believe it is pure 4:2:2, and maybe in the future posts I'll do some more in-depth test that will approve or refute the claim :)

That's all for today,

Mark.