Dolby Laboratories DP569 - Manual (Page 71)

Model DP569 User’s Manual Metadata
A–13
whether the LFE Channel parameter can be set. You must have at least three channels
in order to be able to add an LFE channel.
LFE Channel Setting
Enable
Disable
Bitstream Mode
This parameter describes the audio service contained within the Dolby Digital
bitstream. A complete audio program may consist of a main audio service (a complete
mix of all the program audio), an associated audio service comprising a complete
mix, or one main service combined with an associated service. To form a complete
audio program, it may be (but rarely is) necessary to decode both a main service and
an associated service using a maximum total bit rate of 512 kbps. Refer to the Guide
to the Use of the ATSC Digital Television Standard, Document A/54 (www.atsc.org)
for further information. Although a detailed description of each option follows, in
practice most programming uses the default setting, Complete Main. An example of
an exception to this rule is a special karaoke DVD, or an emergency service within
digital television.
Table A-4 Bitstream Mode Definitions
Bitstream Mode
Setting
Definition
Complete Main
(CM)
CM flags the bitstream as the Main Audio Service for the program and all elements
are present to form a complete audio program. Currently, this is the most common
setting. The CM Service may contain from one (mono) to six (5.1) channels.
Main M&E
(ME)
The bitstream is the Main Audio Service for the program, minus a dialogue channel.
The dialogue channel, if any, is intended to be carried by an Associated Dialogue
Service. Different Dialogue Services can be associated with a single ME Service to
support multiple languages.
Assc. Visual Imp.
(VI)
This is typically a single-channel program intended to provide a narrative description
of the picture content to be decoded along with the Main Audio Service. The VI
Service may also be a complete mix of all program channels, comprising up to six
channels.
Assc. Hear Imp.
(HI)
This is typically a single-channel program intended to convey audio that has been
processed for increased intelligibility and decoded along with the Main Audio
Service. The HI Service may also be a complete mix of all program channels,
comprising up to six channels.
Assc. Dialogue
(D)
This is typically a single-channel program intended to provide a dialogue channel for
an ME Service. If the ME Service contains more than two channels, the D Service is
limited to only one channel. If the ME Service is two channels, the D Service can be a
stereo pair; the appropriate channels of each service are mixed together (requires
special decoders).