Native HDV editing

That's right: it will not affect the quality (..see my post just below this one..)

David, you usually write good explanations, but this time your surpassed yourself.

Thanks for a really good summary/explanation.

[..I've just measured my HDTV screen: 50" diagonally, and my HDV footage - straight from the camera or after editing it in iMovie HD 6 - looks absolutely pin sharp. The edited footage has the same hi-definition sharpness of the original material..]

David,
this is a bookmarker...!

excellent discription ...
AND in English... without pics ... purrrfect ... ;-))

Thanks for your HDV comments, David!

One thing that puzzles me is the HDV 1080i resolution:

Some sources report 1080i as 1920x1080 (and 720p as 1280x720) while iMovie HD uses 1440x1080 for 1080i.

So are there two options for 1080i resolution in the HDV spec?

BTW, do you touch type (your insightful comments are often, um, quite verbose ;-)?

1080 is the vertical resolution (..number of pixels..), as described by Wikipedia here.

1920x1080 is 16:9 (widescreen) mode ..which is the norm for HDV/hi-def. (Divide 1920 by 16 = 120. Multiply 120 by 9 = 1080.)

By simple maths, 1440x1080 is 4:3 mode.

From Wikipedia's HDTV page: "PAL TV sets with an aspect ratio of 4:3 use a fixed pixel grid of 768 × 576 or 720 × 540; with an aspect ratio of 16:9 they use 1440 x 768, 1024 × 576 or 960 × 540; NTSC ones use 640 × 480 and 852 × 480 or, seldom, 720 × 540" (..my emphasis.)

I've never looked to see what 1440x1080 might be, except that it'd seem to be 4:3 (normal shape TV screen) in hi-def ..maybe the format in which traditional-shape 4x3 still photos or graphics are imported into iMovie when in 1080i hi-def mode?

No: I don't touch type ..we-ell, not with all fingers on the keys like a proper typist! I do fast 2-finger typing: I used to write for a living, so got to be a fast 2-finger typist on a portable Olympia typewriter! (Mavis Beacon didn't manage to teach me a thing!) I try not to be too verbose [..no words just for the sake of having them there..] but to explain things clearly one does need to use, erm; well: just the right number of words to make it clear!

(..I tend to model my writing on a mixture of Len Deighton's terse, evocative, and just-sufficient descriptive style in " The Ipcress File", plus a hint of " Private Eye" (..the printed magazine has a far better style than that weak online version..) ..I used to earn my crust writing things like this ..I didn't write that item, but I used to churn out similar things, plus camera reviews, technique hints, etc..)

1920x1080 is 16:9

By simple maths, 1440x1080 is 4:3 mode.

That makes sense.

I recently fiddled with iMovie's HDV slideshows and did a quick comparison to the very same Wikipedia page you referred to. I don't remember if the iMovie HDV project was 4:3 or 16:9. Or is there a setting to choose 4:3 vs 16:9 HDV iMovie project (I'm at a Winbox right now so I can't check it)?

I imported some still images (and some standard DV) to the HDV project and took a peek to the imported media clips and their resolution. HDV as well as the intermediary codec use square pixels, right?

I'll try to do more homework about HDV.

Anyway, this is just of academic interest to me since I don't have a HD camcorder...

Thanks.

I really disagree with that. HDV >> AIC > HDV will kill the original quality. What camcorder do you have? What kind of video (sunny day, light room, dark room)?

BTW, as I remember it was discussed on Doom9.org about one year ago. We compared HDV >> Raw >> HDV with DV. The sharpness of HDV (not original) was little higher or little lower in some sample clips.

1440x1080 is not 4:3. HDV just uses non-square pixel. When you play 1440x1080 video, you see it like 1920x1080 on the TV.

BTW, widescreen DVDs also use non-square pixel.

Ah, thank you Alexey.

Oh yes, HDV uses rectangular pixels but (unlike in standard DV) the aspect ratio now seems to be the same (and more simple 4:3!) for PAL (128:117 for standard DV) and NTSC (4320:4739 for standard DV). And the HDV frame is always 16:9.

And it is just a "coincidence" that the HDV aspect ratio and (16/9)/(4/3) is ~1.33.

http://en.wikipedia.org/wiki/HDV#Resolutionand_aspectratio

"In HDV, the video frame is defined to have an aspect ratio of 16:9."

"HDV 1080i, like other new HD recording formats, uses a pixel aspect ratio of 1.33 ... HDV 1080i uses a pixel resolution of 1440×1080, but when displayed is scaled to an aspect ratio of 1920×1080 = (1440 × 1.33)×1080."

So 1440x1080 is the underlying resolution for 1080i and the corresponding square pixel resolution is 1920x1080.

I presume for 720p the underlying resolution is then 960x720 and the corresponding square pixel resolution is 1280x720, right? The Wikipedia article is a bit ambiguous about that.

Dear old 1.33 ..!

1.33:1 is, of course, the same as 4:3 ratio, and the same as the old original 'Academy' ratio (and traditional TV aspect ratio) of 35mm films.

It's just the ' golden section' all over again..

Well, 1.33:1 pixel is not the same as 4:3 TV screen. There are 1280x1080, 960x1080 HD formats, but it's still 16:9.

I should have been more clear and said that HDV 1080i's (1440x1080) pixel aspect ratio is 4:3 or ~1.33.

On the other hand, HDV 720p's (1280x720) pixel aspect ratio is 1:1 so it uses square pixels:

http://www.adamwilt.com/HDV/