Dolby Laboratories S01/13621 manual 6.3Metadata Connections

Dolby Installation Guidelines Serial Communications

Table 6-4Pin Connections for RS-485 Ports (Excluding Metadata Outputs)

Pin	Connection	Comment
1	Shield (chassis ground)
2	TX A	Asynchronous data out –
3	RX B	Asynchronous data in +
4	Ground
5	NC
6	Ground
7	TX B	Asynchronous data out +
8	RX A	Asynchronous data in –
9	Shield (chassis ground)

•DP570 Metadata output

•DP572 Metadata output

Table 6-5Pin Connections for Metadata Output Ports

Pin	Connection	Comment
1	Shield (chassis ground)
2	RX A	Asynchronous data in –
3	TX B	Asynchronous data out +
4	Ground
5	NC
6	Ground
7	RX B	Asynchronous data in +
8	TX A	Asynchronous data out –
9	Shield (chassis ground)

6.3Metadata Connections

Metadata is data that relates to audio data. It is carried in both Dolby E and Dolby Digital bitstreams.

The dialogue level is given here as an example of a metadata parameter. The dialogue level (dialnorm) value represents the average level of the audio. It is referenced to a level of digital full scale. It represents this average level even in a program that has no dialogue. As part of the Dolby Digital decoding process, the average level of the audio will be reduced to –31 dBFS. If the dialogue level was set as –27 dBFS, then a 4 dB reduction will be applied. This can be used to ensure that the decoded audio is kept at the same level, and that a listener does not have to “gain ride” every time they change channels.

6-3