When i copy old pics/vids taken from various older dv cams to my new dv cam's SD card, i can't read/playback them on this new dv cam even if they're "physically" there when viewed from my pc....

is this because of the codecs of my DV? how do i know what codecs it can read? can i alter my old pics/vids' codecs/attribs/properties to become readable and playable on this new dv cam?

thanks!