The OFFICIAL X(S)VCD vid bitrate equation

[sean madison]

ShiZZZoN-

Hey everyone, once again, i am here to help out those you need it.
For someone people who have gotten my xvcd calc still have some problems so I have the BEST equation for you to find your bitrate for your video to put any length movie onto 1 cd; here is equation-

A(x)= Audio bitrate
T = Time in seconds of your clip
C = Your cd size(this is for an 80 min cd only, you will be using the KB size of- 819,200 KB).

Now for the equation-

A(x)T = C - x \ T

To understand this, here it is in explanation-
Your audio(A(x)) is multiplied by your vid clip length in sec(T). Once you get that, you take that answer and subtract it from your cd length(C which is 819,200 kb).
When you get that answer, you divide that answer by your time(T).

So Audio bitrate multiplied by vid clip time. That answer subtracted from CD size in KB. That answer divided by your vid clip time.

That should explain everything now

[sean madison]

oh and one more thing-
When you substitute your audio bitrate in for A(X), make sure all your units are the same.
The cd size for 80min cd is 819,200KB which is Kilobytes, not kilobits. So if you use 128kbit audio, you are really using 16 Kilobyte audio. now if you want to find out everything in kbits, multiply 819,200 by 8. if you want to find out everything in kilobytes, when you finally get your answer, multiply it by 8.

If anyone has any wrong or abnormal answer, i KNOW i can help, cuz you would just have a mathematical error

[TPW]

I managed to make a program on my TI-83 that will do the exact same thing...

but better and much more simpler

AudioBirate(Length) + VideoBitrate(Length)= (Space on CDR * 1374)

Ex
224(80) + 1150(80) = (80 min CDR * 1374)

Now to implement this to find the video bitrate,

VideoBitrate = ((CDR * 1374)- (AudioBitrate * Length)) / Length

I use 79.5 for 80 min CDR's ( and 73.5 for 74 min CDS) in the equations to make room for the necessary VCD files, I highly recommend using this equation because a lot of the X(S)VCD Calcs out there tend to be bloated with features or dont properly calculate the MAXIMUM amount a CDR can hold

<font size=-1>[ This Message was edited by: TPW on 2001-11-20 00:54:31 ]</font>