CD Precision - MPEG Encode

[itabb]

I noticed on several MPEG-2 encoding tools that there is a setting for DC Precision. The Choices are 8, 9, 10, and 11, usually. I could not find this anywhere to describe how to use this setting. Could anyone point me in the right direction for how to set this?

I see this in HCenc and QUenc.

[redwudz]

This is probably not much help for setting it, but from 'MPEG-FAQ: multimedia compression' : http://www.faqs.org/faqs/mpeg-faq/part3/

intra_dc_precision: the MPEG-1 DC value is mandatory quantized to a
precision of 8 bits. MPEG-2 introduced 9, 10, and 11 bit precision set
on a picture basis to increase the accuracy of the DC component, which
by very nature, has the most significant contribution towards picture
quality. Particularly useful at high bit rates to reduce
posterization. Main and Simple Profiles are limited to 8, 9, or 10 bits
of precision. The 4:2:2 High Profile, which is geared towards higher
bitrate applications (up to 50 Mbits/sec), permits all values (up to 11
bits).