deinterlace 25p to 50p how? at DVinfo.net

Yiannis Kall · May 1st, 2007, 03:30 AM

Hi
i deinterlaced my videos of sony HC1 to 25p but the footage is jerky. When i use yadif deinterlacer or DGBOB to output 50p the video is smoother but looses image quality-sharpness. How can i achieve 50p output without image quality degression?
thanks

Bob Grant · May 2nd, 2007, 06:17 AM

Each field contains half the resolution. The best way to keep the resolution and avoid artifacts is some form of smart de-interlacing.
The simplest form merges those parts of the two fields that have no motion and interpolates those that do. The theory here is that the motion blur will cover the loss of resolution in those parts of the frame with motion. A number of free plug-ins for VDub and Vegas work this way.
A better approach is to derive motion vectors in an attempt to re-align the two fields. The only thing that I'm aware of that does this are boxes from S&W which are pretty pricey however there may be plugins that do this available by now. Certainly it'd be a slow process as this involves a lot of computation. Note that motion compensation seems to require clean (i.e. low noise) video to work.
Hm, come to think of it I was told that even the Alchemist from S&W only does 'smart' de-interlacing at HD res.

Glenn Chan · May 2nd, 2007, 12:44 PM

I believe Compressor (in Final CUt Studio) uses the optical flow algorithms from Shake in standards conversion. However, it sometimes screws up from what I've heard.

Quote:

Hm, come to think of it I was told that even the Alchemist from S&W only does 'smart' de-interlacing at HD res.

I don't believe the Teranex does either.

May 1st, 2007, 03:30 AM	#1
Yiannis Kall Regular Crew Join Date: Nov 2004 Location: Greece-Athens Posts: 37	deinterlace 25p to 50p how? Hi i deinterlaced my videos of sony HC1 to 25p but the footage is jerky. When i use yadif deinterlacer or DGBOB to output 50p the video is smoother but looses image quality-sharpness. How can i achieve 50p output without image quality degression? thanks

May 2nd, 2007, 06:17 AM	#2
Bob Grant Trustee Join Date: Nov 2005 Location: Sydney Australia Posts: 1,570	Each field contains half the resolution. The best way to keep the resolution and avoid artifacts is some form of smart de-interlacing. The simplest form merges those parts of the two fields that have no motion and interpolates those that do. The theory here is that the motion blur will cover the loss of resolution in those parts of the frame with motion. A number of free plug-ins for VDub and Vegas work this way. A better approach is to derive motion vectors in an attempt to re-align the two fields. The only thing that I'm aware of that does this are boxes from S&W which are pretty pricey however there may be plugins that do this available by now. Certainly it'd be a slow process as this involves a lot of computation. Note that motion compensation seems to require clean (i.e. low noise) video to work. Hm, come to think of it I was told that even the Alchemist from S&W only does 'smart' de-interlacing at HD res.