Question for Rafael

[Rafael Amador]

Hi Martin,
[Martin Jordan] “This is shot in AVC-Intra 50 and is transcoded in LT with the appropriate Preference setting of Apple ProRes 422 (HQ). But during this transcoding process it shows the readings I mentioned. So when you say this is plain DVCProHD: 1440 x 1080 I don’t know why you say this.”

You are right, I thought you could be shooting DVCProHD instead of AVC-1.
Anyway, the codec is very similar DVCProHD in “sizes” and “pixels aspect” ( but curiously worst in terms of chroma sampling: just 4.2.0)

AVC-Intra 50:
nominally 50 Mbit/s, size of each frame is fixed
CABAC entropy coding only.
1920×1080 formats are High 10 Intra Profile, Level 4
1280×720 formats are High 10 Intra Profile, Level 3.2
4:2:0 chrominance sampling
frames are horizontally scaled by 3/4 (1920×1080 is scaled to 1440×1080. 1280×720 is scaled to 960×720)

So the AVC-intra stuff is 1440×1080 HD Pixels and the Canon stuff is 1980×1080 Square pixels.

Transcoding means CHANGING JUST THE CODEC, so with L&T you will be getting Prores clips with the original size: two different sizes and pixels for each footage.

Nothing wrong. You just need to be aware of this.
If you want to edit “Full Raster HD” (1920×1080 or 1280×720: which are the real HD standards), conform your sequence to any of the Canon clip.
cheers,
rafael

http://www.nagavideo.com

[Martin Jordan]

Thank you. You had me wondering and questioning myself.

One more question…Would there be ANY benefit concerning this size issue by shooting AVC-100? Probably not but just wondering?

Remember…all this video will ultimately be web only streaming.

Quad-Core, 2.93GHz, OS 10.6.2, 32GB Ram, external 4TB RAID eSATA, 4TB Internal, ATI Radeon HD 4870 graphics card, FCP Studio 7, AE 9.0.2, Boris BCC, FEC, CoreMelt 2, FxFactory Pro 2, idustrial revolution Volumetrix, Yanobox Motype, Squeeze for the Web, MacBook Pro (MBP) 2.6 GHz, Panasonic HPX300 Video Camera, 2 – Canon 5DMKII’s w/Pclix controllers.
The entire Adobe Creative Suite 4, Design Premium.
Owner of Full Graphics Design Firm Houston, Tx 21 yrs.
Mac user since 1988.

[Rafael Amador]

[Martin Jordan] “One more question…Would there be ANY benefit concerning this size issue by shooting AVC-100? Probably not but just wondering?”
With AVC-100 you record always in real 16×9 with the same pixels you will be using for standard HDTV, web, BR, Mobile devices, etc. You just need to scale the clip.
With the 1440×1080, beside scaling, you will need to distort the picture too.
That’s is and advantage to consider if you want to scrap the most from your rushes.

I would never shot AVCI-50 if I could shot AVC-100.
I have no experience with AVCI-50, but up to the specs doesn’t looks much appealing (10b/420?)
rafael

http://www.nagavideo.com