use iuvcr to capture, best use with huffy codec(lossless quality)
capture at 352x240 if you want to create a NTSC VCD
dont go higher than 352x240 if you only gona make a vcd cause you wont see the different and it require a lot of spaces to capture at a higher resolution also longer encoding.
SVCD- capture at 480x480
DVD - capture at 704x480

just capture at the resonlution that you gona use to make your VCD, SVCD, DVD.