SD Video into HD Project

[Tim Kolb]

It depends on whet your configuration is…but basically, yeah, that’s the essence of it.

I use an AJA Xena LH card and I can edit in HD…then I simply switch the card for HD output (HDSDI), master…then switch the card to SD downconvert (component analog or SDI) and without changing the media, I’ve done both…

Some editing systems may demand that you export a HD master clip and bring it back into an SD timeline… Whatever the specifics are, the point is that concentrating on an HD workflow will always give you good SD when you convert…upconverting SD is a distant second. So the question becomes whether to upconvert SOME of your footage (and edit HD) or upconvert ALL your footage (after editing SD and down converting the resolution you had in your HD footage in the first place…).

My answer wasn’t meant to be flip…it just seems rather straightforward to me…

TimK,
Director, Consultant
Kolb Productions,

CPO, Digieffects

[Erik Davis]

Tim,

As I’m learning more it does seem pretty straightforward. That is until last night when I found out that Matrox Axio LE will not output an “edge cropped” HD timeline to SD video in real time. Matrox claims simulataneous HD and SD output but what they don’t mention is that the HD downconvert choices of “letterbox” or “anamorphic” really add up to either a letterboxed SD video or a squished/stretched SD video. You can have either of those in real time without any rendering. If you want to have a center cut output though you better start applying zoom/scale/crop filters and see if you can get a clean image. Not likely.

Erik

[Tim Kolb]

[Erik Davis] “I found out that Matrox Axio LE will not output an “edge cropped” HD timeline to SD video in real time. Matrox claims simulataneous HD and SD output but what they don’t mention is that the HD downconvert choices of “letterbox” or “anamorphic” really add up to either a letterboxed SD video or a squished/stretched SD video.”

I’m not sure i understand… Letterbox and anamorphic are pretty common terms. Matrox is following industry paradigm in applying the terms this way.

I think that center-cropping is not used nearly as often as the two modes you refer to, so Matrox is not being so unreasonable…

Letterbox outputs a 4:3 image and maintains all the composition proportionately inside a 4:3 “canvas” which leaves black top and bottom. Anamorphic is exactly how SD does 16:9. DVcam for instance has the same number of pixels 4:3 or 16:9…it’s simply a matter of whether the pixel shape is .9x as wide as it is tall or 1.2x. Hence, SD widescreen is formed by “stretching” 4:3…which is why it’s called “anamorphic.”

TimK,
Director, Consultant
Kolb Productions,

CPO, Digieffects

[Erik Davis]

Tim,

I agree with all you said except I believe there is a strong need to have a “center cut” option for output. For those like myself who are archiving hundreds of hours of HD footage now in preparation for HD only production in the future, we need the option to simply downconvert our HD video for standard 4×3 SD without letterbox and without rendering.

For my program needs, letterboxing or stretching the video is not an option. Not just my needs I believe either as 99% of all SD programming is fullscreen 4×3.

Appreciate your thoughts and taking time to help out

Erik

[Brian Vanheuverswyn]

Hi Erik,

Does Premiere CS3 allow you to use “Print-To-Tape” to export back to XDCAM?

I’m curious if you’ve done that??

Brian