Linear Acoustic LA-5269, Руководство пользователя, Страница: 31 / 42

Linear Acoustic LA-5269 Transcoder User Guide Detailed Operation
27
WARNING: Use of “Last Valid” can be dangerous. If the last good metadata signal
indicated a stereo program and the audio changes to 5.1 channels, there will be loss
of dialogue. Best to use “Internal” and set the encoder for 3/0 or greater.
Encoder A
• Encoder Mode EnA: Sets the encoder type for Encoder A to DD for Dolby Digital
(AC-3) or DD Plus for Dolby Digital Plus (E-AC-3). Normal default is DD. Note that
if Transcoding is enabled, Encoder Mode EnA and EnB MUST be the same type!
• DD+ Rate EnA: Sets the output data rate for Encoder A when it is in Dolby Digital
Plus mode. Default is 448 kbps.
• DD Rate EnA: Sets the output data rate for Encoder A when it is in Dolby Digital
(AC-3) mode. Default is 448 kbps.
• Acmod EnA: Sets the acmod or Encoding Mode for Encoder A. Notation is front
channels/rear channels/LFE. So 3/2L is 5.1 while 2/0 is 2.0 stereo.
• Line Mode EnA: Choose the Encoder A Dolby Digital DRC profile for Line Mode
dynamic range compression (i.e the default mode for the stereo line-level outputs of
most set top boxes and TV sets). Choices include Film Std, Film Lgt, Music Std, Music
Lgt, Speech, and “None”. Default is Film Std.
• RF Mode EnA: Choose the Encoder A Dolby Digital DRC profile for RF Mode dy-
namic range compression (i.e the default mode for the RF re-modulated outputs of
most set top boxes). Choices include Film Std, Film Lgt, Music Std, Music Lgt, Speech,
and “None”. Default is Film Std.
WARNING: It is Strongly recommended not to choose “None” mode for either Line
Mode or RF Mode. This is a test mode intended for controlled laboratory use and not
for over the air applications. Choosing “None” mode may result in unnecessary pro-
tection limiting occurring during downmix, so “None” is not really None! Choose Film
Lgt. for minimal DRC action.
• Dialnorm EnA: Using an ITU loudness meter (Linear Acoustic LAMBDA, LQ-1000
or equivalent), set the transmitted dialnorm value here. Note that the factory default
preset of TV 5B Gen is pre-adjusted to produce -24 on average with typical program
audio inputs so the default setting is -24. This should be measured as part of initial sys-
tem setup. The actual value does not matter as long as it matches the measurement.