DVD Shrink Original DVD and Backup DVD Bit Rate Question

[Michael Glay]

Hi all!
I backup DVD with DVD Shrink.(Full Disk, No Compression) Then use DVD Bit Rate Viewer to test the Bit Rate. The Backup DVD same as the original DVD.
but I backup main movie only.(No Compression, strip some Audio and subtiles) The Bit Rate of the backup DVD is smaller than the original DVD. Why not same as the original? Is the bir rate contain the audio data?

[maa]

The bit rate is the sum of the audio and video bit rates.

[Michael Glay]

...