Avoiding downconversion artifacts at DVinfo.net

Edwin Hernandez · December 31st, 2005, 09:30 AM

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

Karl Holt · December 31st, 2005, 11:19 AM

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.

Antoine Fabi · December 31st, 2005, 12:05 PM

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 !

Edwin Hernandez · January 2nd, 2006, 11:07 AM

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

Stephen L. Noe · January 2nd, 2006, 01:24 PM

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).

Edwin Hernandez · January 2nd, 2006, 10:06 PM

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

Stephen L. Noe · January 2nd, 2006, 10:26 PM

Quote:

Originally Posted by Edwin Hernandez

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.

December 31st, 2005, 09:30 AM	#1
Edwin Hernandez Regular Crew Join Date: Sep 2004 Location: Panama City, Panama Posts: 162	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

December 31st, 2005, 11:19 AM	#2
Karl Holt New Boot Join Date: Dec 2005 Posts: 6	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.

December 31st, 2005, 12:05 PM	#3
Antoine Fabi Regular Crew Join Date: Mar 2004 Location: sherbrooke (Quebec) Canada Posts: 108	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 !

January 2nd, 2006, 11:07 AM	#4
Edwin Hernandez Regular Crew Join Date: Sep 2004 Location: Panama City, Panama Posts: 162	I have news. I downrezzed it directly for DVD playback using Quicktime and burned it in DVDSP3, it rules.

January 2nd, 2006, 01:24 PM	#5
Stephen L. Noe Trustee Join Date: Apr 2005 Location: Chicago Posts: 1,214	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).

January 2nd, 2006, 10:06 PM	#6
Edwin Hernandez Regular Crew Join Date: Sep 2004 Location: Panama City, Panama Posts: 162	Stephen: What are those? Algorythms within Quicktime? or other software?