Avoiding downconversion artifacts
 

I wonder what must be done in order to downconvert a footage with no artifacts. Just as any Hollywood movie would when releasing a DVD (Episode II, III, etc.)

I downloaded one of Kaku's footage (thanks Kaku), the one with the cars passing and a person crossing the street, but when I downconvert it it loses quality and it adds motion artifacts, and some multicolored lines on edges.

I'm using FCP4.5. What should I do in order to get the most when downrezzing?

-EDWIN

I dont know about other people but I downrezzed the quicktime to an anamoprphic SD PAL project in atfer effects. This did not produce any artifacts at all. The picture was very sharp and clear.

Autodesk Combustion also has several choices of rescale algorythms you can choose - I have yet to try these. I would not use an NLE to rescale an image personally, but maybe others have had better luck.

Edwin,

There is a phenomenal improvement in the scaling algorithm between FCP4.5 and FCP5 !!!!

I had to always use plugins to scale with FCP4.5

With FCP5, the scaling is soooo much better !

I have news. I downrezzed it directly for DVD playback using Quicktime and burned it in DVDSP3, it rules.

If you have the choice of math for scaling down, choose SinC.
If you want to scale SD up to HD then use Cubic B Spline.

If you don't have those two choices then select Lanczos which is a good all around general scaling algorithm (up or down).

Stephen: What are those? Algorythms within Quicktime? or other software?

Not in Quick Time or After Effect. Broadcast editors like Liquid and XpressPro give you control over scaling algorithms for sequences or clips.