Question about the length of video that you can put on a dvd-r?

Question

I bought a spindle of dvd-rs today and it said (on the front of the spindle. 16x, 4.7 gig, 120 min dvd-r. is there any possiblility that i can put a video longer than 120 min on it as long as the file size is less than 4.7 gigs? i'm wondering this because i saw another spindle by memorax (or memorex i dunno how to spell it) and it claimed that it can do 240 min or 320 min depending on some specific quality thingamabob. so i'm wondering...even though it doesn't say that it can do 240 min or whatever seeing as how the disc seems to be identicle does it really matter that it doesn't specifically say 240 min.

Answer 1

You can put as long a video as you want, but quality will suffer

Formula is simple: (Overall bit rate [audio+video](Mbits/s) ) * time (s)/8 has to be less than 4700

Example: Video at 4 Mbits/s
Audio at 128 kbits/s

(4700*8)/(4.128) = 9100 sec = 150 min

At 2 Mbits/s, you can fit almost 5 hours of video, but the quality will be worst than VCR. At that point, you may be better off using H.264, WMV or Divx and a lower picture resolution.