dolby digital plus (audio codec) (DD+)

Dolby Digital Plus(DD+), also known as Enhanced AC-3 (E-AC-3), provides efficient audio compression at low bit rates.

DD+ bit rates range from 32 kbit/s to 6.144 Mbit/s. The clock rates of DD+ can be 32 kHz, 44.1 kHz, or 48 kHz, and the conversion depth is 24 bits per channel. DD+ has 14 audio channels for 13.1 playback with 13 full-range speakers and a subwoofer. Unlike E-AC-3, conventional AudioCode Number 3 (AC-3) provides five full-range audio channels and one low- frequency channel for 5.1 playbacks.

The DD+ process can be used in high-definition television( HDTV), it has been made mandatory for HD DVD, and optional for Blu-Ray discs.