Wrongly deinterlaced video fix-up?

[andy_blah]

Is there any way to fix those artefacts that you can see in the image with AviSynth?

http://i61.photobucket.com/albums/h41/andy_blah/shot.png

These artefacts aren't so visible when the video is playing, but you can still see them there, and makes everything look sloppy, and I also suppose that it makes the video larger that it should

Video details:

Format : AVI
Format/Info : Audio Video Interleave
File size : 227 MiB
Duration : 23mn 39s
Overall bit rate : 1 343 Kbps
Writing application : VirtualDubMod 1.5.10.1 (build 2439/release)
Writing library : VirtualDub build 30009/release

Video
Format : MPEG-4 Visual
Format profile : Streaming Video@L1
Format settings, BVOP : Yes
Format settings, QPel : No
Format settings, GMC : No warppoints
Format settings, Matrix : Default
Muxing mode : Packed bitstream
Codec ID : XVID
Codec ID/Hint : XviD
Duration : 23mn 39s
Bit rate : 1 171 Kbps
Width : 640 pixels
Height : 480 pixels
Display aspect ratio : 4/3
Frame rate : 29.970 fps
Resolution : 24 bits
Colorimetry : 4:2:0
Scan type : Progressive
Bits/(Pixel*Frame) : 0.127
Stream size : 198 MiB (87%)
Writing library : XviD 1.1.2 (UTC 2006-11-01)

Audio
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Codec ID : 55
Codec ID/Hint : MP3
Duration : 23mn 39s
Bit rate mode : Constant
Bit rate : 160 Kbps
Minimum bit rate : 160 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Resolution : 16 bits
Stream size : 27.1 MiB (12%)
Alignment : Split accross interleaves
Interleave, duration : 33 ms (1.00 video frame)
Interleave, preload duration : 500 ms
Writing library : LAME3.98r
Encoding settings : CBR

[Guest]

Re-encode from your original DVD.

[andy_blah]

The problem is that I don't have the original DVD, and this wasn't encoded by me, otherwise, I wouldn't have asked this here ^_^