Dolby Laboratories DP524 Uživatelský manuál stáhnout pdf (Strana 42)

DP571 Dolby

E Encoder User’s Manual Setup Menus

The VRef input rate must match the selected frame rate. For example, if the incoming

VRef signal is 29.97 Hz/NTSC/black burst, the frame rate must be 29.97 fps;

otherwise, the VRef LED turns from green to yellow and encoding is stopped.

The frame rates are for use as follows:

• 29.97 fps—For Dolby E output used with NTSC equipment (default value)

• 25 fps—For Dolby E output used with PAL equipment

• 23.98, 24, 30 fps—For Dolby E output when used with HD equipment and tri-

level sync

7.2.7 Bit Depth

The DP571 can encode both 16- and 20-bit Dolby E bitstreams.

Note: Sixteen-bit mode affects only the space the Dolby E bitstream occupies in the

main AES output, not the resolution of the underlying PCM audio.

A 16-bit/48 kHz AES channel has a data rate of 1.5 Mbps, which is 400 kbps less

than a 20-bit/48 kHz channel. To compensate for this lower data rate and to maintain

the highest audio quality over the maximum number of encode/decode generations,

only six audio channels can be encoded in 16-bit mode. As a DP572 automatically

switches from 16- to 20-bit decoding in response to the input stream, it seamlessly

enables decoding the two additional channels.

Sixteen-bit mode is only available when the current program configuration uses no

more than six channels. For example, while the 5.1 + 2 program configuration is

selected, 16-bit mode is not visible and cannot be selected.

When 16-bit mode is selected, program configurations with more than six channels

are not available and are therefore not displayed.

7-4

1 2 ... 37 38 39 40 41 42 43 44 45

Žádné komentáře

Dolby Laboratories DP524 Uživatelský manuál Strana 42