 The combined audio and video bit rates should not exceed 2.7 Mbps.This data rate was chosen, in part, to ensure compatibility with slower and less expensive "2 × speed" CD drives.As with most compact disc-based video formats, SVCD audio is incompatible with the DVD-Video standard due to the difference in frequency; DVDs require 48 kHz, whereas SVCDs use 44.1 kHz.