|Dolby AC-3: "Audio CODEC 3,"
is a discrete, non-matrixed, 6- channel audio coding technology
that is in the standard for ATSC DTV. Also used in DVD
video and some DVD-ROM titles, Dolby Digital’s popular
"5.1" designation results from the sixth, low
frequency effects channel occupying only one tenth of
the original bandwidth. Its low data rate results from
8:1 to 12:1 compression using hearing threshold limitations
and frequency domain masking.
Dolby E: Is a higher bit rate, cascadable post-production
and distribution process that claims to offer up to ten
reproduction cycles without audible degradation. The "5.1
+ 2" system allows up to eight channels of encoding/decoding
plus SMPTE time code on either a single pair of AES/EBU
channels or stereo digital tracks at 1.92 Mbits/sec.
Major Video Related Organizations, ATSC,
Audio Engineering Society, DVB, FCC, IEEE, International Telecom
Union, NAB, SMPTE, Video Services Forum