VCD suffers from 3 major problems:
- Progressive only, meaning it was likely a deinterlaced video source.
- 352x240 resolution, which means it can be rather soft video quality -- half as much detail as a typical VHS tape has.
- Low bitrate specs (1150kbps) that leads to excessive blocky MPEG-1 quality.
This is what you can do about it:
- The deinterlacing can be fixed, to a degree, with anti-alising filters in Avisynth.
- Not much of anything can be done about the loss of detail. At best, some mild sharpening filters in Avisynth, at minimal settings.
- Deblock filters, either in VirtualDub or in Avisynth (my preference).
Chroma noise can be handled in either Avisynth or
VirtualDub. The VirtualDub filters are very aggressive, and can easily lead to color ghosting in your video. As such, you'll want to use settings that are less than half of the defaults. Pull back as much as you can.
The CNR filter in Avisynth is nowhere near as aggressive, and is my current preferred choice of chroma NR.
When opening MPEG-2 in VirtualDub, you want to go to Video > Color Depth and change the input/decompression method to 4:2:2 YUY2. Otherwise it will likely lead to chroma ghosting, due to an MPEG-2 decode bug in VirtualDub.
AvsPMod is a great GUI for Avisynth.
Some ready-to-use downloads and samples scripts will be made available on the site this month. The packaging is finished, and some of the scripting guides are done. It's not "finished" as planned for long-term, but it'll made for a great short-term update/addition to the site. Keep watch for those. They'll be mentioned in this month's newsletter, when it's sent out.