Dolby CP750 Digital Cinema Processor Manual - Projectionniste.net

Configuring the CP750 Software
Global Audio Delay
The Global Audio Delay field specifies an audio delay in addition to the CP750 decoding
delay of approximately 7 ms for 4xAES PCM. Use this function to synchronize the audio
with the video from digital cinema projectors, which add a video processing delay. Use the
up and down arrows to set the Global Audio Delay between 0 and 250 ms. This delay
value is set independently for each digital input.
Note:
Systems that use an external video scaler may add another decoding delay.
Mute Main Bsl/Bsr Output Pins
Choose Enable to mute these pins if your auditorium does not use them.
Fader Preset
To use the Fader Preset feature, choose Enable and indicate a value on the slider. This
ensures that inputs play at correct values each time they are selected.
PCM Channel Assignment
The analog audio output channels (L, R, C, LFE, Ls, Rs) are always fixed and hardwired to
a cinema processor. However, when a PCM bitstream’s input‐channel mapping is not a
default SMPTE configuration (L/R, C/LFE, Ls/Rs), you must reassign the input channels to
match the hardwired audio outputs. For channel reassignment, the surround delay and the
LFE filter are always tied at the output, and therefore cause no problem.
To reassign the input channels, use the drop‐down Assigned To menu for each of the AES
Input channels or click one of the three preset buttons (L/R C/Sw Ls/Rs; L/C R/Ls Rs/Sw;
or L/Ls C/Rs R/Sw). To activate your changes, click the Apply changes button. To cancel
your changes, click the Discard changes button.
PCM Decode Mode
You can select one of four surround channel processing options:
• None
• Pro Logic
• Pro Logic II
• Surround EX
PCM Processing Mode
You have three choices of mode:
• Minimum Latency—When selected, this default mode provides the quickest audio
processing (approximately 7 ms) for PCM audio.
• Silent Switch—When selected, the CP750 constantly checks for transitions between
PCM and coded audio, and switches between the two silently. This mode adds a 40
ms latency to the audio processing (for a total latency of approximately 47 ms).
26 Dolby ® CP750 Digital Cinema Processor Manual