Dolby Laboratories DP569 User Manual

Page of 90
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).