4:2:2 v.s. 4:2:0 / HD vs HDV
 

Hi,

I'm sort of a new guy when it comes to the more complex issues of video. I've been working in the DV realm of things since about '98.

I have a client who is using a production team who is wanting to shoot in HD and downresing to uncompressed SD instead of using a HDV camera like the Z1U.

The entire shoot is green screen and we're creating a virtual studio to boot.

I'm just trying to figure out, besides the keying aspect of 4:2:2, what other benefits are there to shooting HD 4:2:2 and downresing to SD Uncompressed as opposed to shooting on a Z1U.

Our final output is an SD DVD and a couple of 30 second spots for broadcast.

Thanks for the info,

Jim

What software are you using and what is your comp set up?
Flame, combustion and other discrete products might be able to do a better green screen, AE and motion have presets to help you use uncompressed, but the big thing with HDV is that it's GOP based (not frame based) and if your using uncompressed then it will be heaps easier to render, and it will be alot easier to view it in real time.

over all even if the final viewing is DVD 4:2:2 will look better.. DVD mpeg2 is 4:2:2 .... green screen = less problems then 4:1:1 or 4:2:0 ... cleaner edges- less stair stepping ... you client wants a excellent product ... give them 4:2:2

i read recently on the jvc website that dvd is actually 4:1:0.

I think you'll find it's 4:2:0 for both PAL and NTSC. For PAL, DV25 is also 4:2:0 whilst for NTSC DV25 is 4:1:1. Hence, in the case of PAL no colour space information is lost when making a DVD from DV. In the case of NTSC, the combination leads to an effective 4:1:0 end product - the DVD is 4:2:0, but every other horizontal sample is missing due to the 4:1:1 sampling.

This is one raeson why 4:2:2 origination is seen as more important in the States than PAL countries, more that it's NOT 4:1:1, and ends up as true 4:2:0 when coded to a DVD.

right, that's what I was supposed to say.

If you downrez hdv-material you will pretty much end with 4:4:4 color space when it's in dv-rez.

Yeah, but no, but yeah, but no, but... well, 4:2:2 anyway...

Take HDV, place it carefully into a DVCPro50 (or DV50) timeline (ANAMORPHIC), reoutput as SD anamorphic video and use that.

There's other hoops you can jump through with Sony HDV. You could deinterlace it and downconvert to 1280x720p and save it as DVCPro-HD - this is a sweetspot for an HDV workflow, though that could be upset by JPEG-2K and whatever surfaces from NAB in a couple of hours.

:-)

not true of the hd100 though right? can't give 4.2.2 SD?