by Steven Hacker 600 divided by the number of minutes. Then subtract 1.6 if you are using PCM audio or .2 if you are using AC3 audio. For example- if your video is 75 minutes: 600/75-1.6= 6.4 or 6400 kbits/sec (PCM audio) 600/75-.2= 7.8 or 7800 kbits/sec (AC3 audio)...