About Choosing the Bit Rates
When determining average and maximum bit rates for standard DVD playback, remember
to consider the bit rate of your audio track as well as the MPEG-2 bit rate.
You must keep the total of both average and maximum audio and video bit rates under
10.08 Mbps, the maximum guaranteed transfer rate from standard DVD players. Because
DVD-compatible audio formats are constant bit rate (CBR), there is no maximum audio
bit rate to worry about.
For example, if you are using AIFF audio at 1.5 Mbps, you should keep both the average
and maximum video bit rates under 8.5 Mbps. Typically, your average bit rate will be
lower than this (for example, 3.5 Mbps for 2 hours of footage on your DVD). However,
your maximum bit rate must also stay below this number. A maximum bit rate of 8.0 Mbps
is recommended to provide an extra margin for error (for example, to accommodate
subtitle streams). If you are using one of the DVD-compatible compressed audio formats
such as Dolby Digital or MPEG-1/Layer-2, your audio bit rate may be as low as 0.2 to
0.4 Mbps, in which case you can set your maximum bit rate about 1 Mbps higher.
Also, as a general rule, set your maximum bit rate at least 1 Mbps higher than your average
bit rate, to allow for bit-rate variability in achieving the goal of constant quality.