About the Bit-Rate Settings

When determining average and maximum bit rates for DVD playback, remember to consider the bit rate of your audio tracks as well as the H.264 bit rate.

Important: For maximum compatibility with HD DVD players, avoid setting the maximum bit rate above 18 Mbps.

You must keep the total of both average and maximum audio and video bit rates under 30 Mbps, the maximum guaranteed transfer rate from high definition 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 for high definition DVDs under 28.5 Mbps. Typically, your average bit rate will be lower than this (from 7 Mbps to 15 Mbps). However, your maximum bit rate must also stay under this number. The 28.0 Mbps maximum bit rate 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 Mbps to 0.4 Mbps, in which case you can set your maximum bit rate about 1 Mbps higher. 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.