What do u mean by ur TV Tuner card supports mpeg 1, mpeg 2, mpeg 4, DV, VCD, SVCD, DVD, AVI?? TV Tuner card (AFAIK) basically converts (tunes) TV signals for viewing on computer, thats all it does, but sometimes they also contain on-board chips for hardware encoding, like mpeg1, mpeg2 or avi. If ur card is capable of hardware encoding, there is no question of a separate software codec as the default codec will be chosen by the hardware (if u have option to select between hardware codecs, then select the one with highest bitrate). Otherwise, its wise to save movies as uncompressed AVI and then recompress it with a high compression codec, like XViD. U can use capturing softwares (like vdub etc.) for on-the-fly compression but unless u have a very fast computer, there will be dropped frames and most of the times, audio will go out of sync.
Cable TV signals (which are digital mostly, nowadays) are of DVD quality, i.e., 702 X 540 (PAL) resolution, and VCD is 320X240, so if u save in VCD quality, ur movie will be nothing but crаp. Although some people are happy with craps, but I suggest otherwise.
