resize and video quality

[nicco]

I have a PAL 720x576 video and I have to encode it.
I can leave it at 720x576, but when I play it at "full screen mode" on PC I have some margins on left and right becouse of the different proportion between the movie and the monitor.
So I'd want to resize it, maybe in 640x480 (reducing file size too), using lanczos resize (I red it's the better in term of quality).
My question are:
Do I lose image-quality with resizing? If yes, how much?
In order to reach the best final quality of my encoded video do I have to leave it in its original size?
Thanks

[Wilbert]

What is your source? Analogue cap?

[nicco]

Original Source: DV-PAL 720x576

[zilog jones]

Newer graphics cards often have a 720x576 resolution, or if it doesn't, try getting new drivers for it. My GeForce2 Ti has one anyway, and I assume other nividia cards do since they all use similar drivers. Some programs like Media Player Classic let you choose exactly what resolution to use when going into full-screen mode.

Only problem is that my monitor can only do that resolution at 60Hz, and PAL video is 50Hz, so it *does not* look good - frames have to be dropped and whatnot. 75 or 100Hz would be perfect, if possible (VGA monitors generally can't do 50Hz).

[bb]

Originally posted by nicco
I have a PAL 720x576 video and I have to encode it.
I can leave it at 720x576, but when I play it at "full screen mode" on PC I have some margins on left and right becouse of the different proportion between the movie and the monitor.
So I'd want to resize it, maybe in 640x480 (reducing file size too), using lanczos resize (I red it's the better in term of quality).
My question are:
Do I lose image-quality with resizing? If yes, how much?
In order to reach the best final quality of my encoded video do I have to leave it in its original size?
Thanks
If filesize doesn't matter you should keep the original resolution. Downsizing to 640x480 means to decrease quality (just a little), but you can compensate for a 1:1 pixel aspect ratio (PAR), which is an advantage if you want to play back on PC monitors (don't forget to crop correctly, and to deal correctly with interlaced material, see DV guide). You can keep the filesize down by downsizing, too.

If you see margins during playback, you should let your player correct that during playback. If your primary display device is TV, you may wish to encode with PAL PAR instead of 1:1. For PC playback, your player must correct that.

bb

[nicco]

from DV guide:
1. You can crop 32 pixels, 16 from each side and resize to 640x480.
AVS sample script:
AviSource("C:\DV\testAR_DV_type2.AVI")
crop(16,0,688,576)
BilinearResize(640,480)

2. You can resize to 640x464.
AVS sample script:
AviSource("C:\DV\testAR_DV_type2.AVI")
BilinearResize(640,464)


So for 1:1 par I have to resize?!

[bb]

Yes, either crop and resize, or resize.

bb