As per https://www.redhat.com/mailman/private/video4linux-list/2006-December/msg00401.html, the horizontal resolution for NTSC in the cx88 driver is too low and should be increased to improve the quality of video captures from cx88 devices. I don't know why the v4l developers haven't made this change, but it would be nice if the FC kernel could have it. The change is simple, but I'll attach a patch anyway.
Created attachment 148086 [details] patch to increase NTSC cx88 resolution
Actually, hold off on this change. I tried it and it causes both mencoder and tvtime to break. I'm going to ask the video4linux folks what the story is.