Grass Valley Imagestore 750 v.3.0.1 User Manual
Page 184
168
Imagestore 750 Configurator
Modes
Audio Delay Calculation
The following audio blocks incur audio delays of varying duration:
•
Dolby decode and encode modules
•
Metadata delays
•
Up-mix modules
•
Audio delay blocks
The audio delay calculation feature lets you determine the cumulative audio delay at any pin on
any audio block in the ‘Audio Graph’. The delay is shown in frames (including fractions of frames
to two decimal places) and samples (at 48
kHz). This helps to ensure that there is consistent and
unchanging audio delay throughout the system.
To calculate audio delays, perform the following steps:
•
Create your audio configuration using the Imagestore 750 Configurator’s ‘Audio Graph’
page.
•
Select ‘Tools > Calculate delays’ from the menu, or press ‘F2’.
•
Select ‘Yes’ in the warning dialog, “Calculating the delays in a configuration can take a very
long time. Do you wish to continue?”
•
Position your mouse over audio or metadata pins on any block within the ‘Audio Graph’ to
see the delay in both frames and samples.
Note: Calculation of audio delays in complex audio configurations with many route permuta-
tions can take a long time. It might be possible to remove non-essential parts of the ‘Audio
Graph’ before starting the audio calculation.
Audio Modules
The audio modules present depend on the hardware and licences present in the Imagestore
750:
Metadata
The metadata blocks generate and manipulate metadata. See
general metadata information and
on page 126 for more information on the
‘Metadata’ tab of the Imagestore 750 Configurator.
Block Type
Description
Dolby decoder module
This module (1) decodes Dolby E and Dolby Digital
(AC-3) and (2) outputs surround PCM with a stereo
down-mix alternative. It also decodes Dolby metadata
and provides backup audio capability. See
on page 113 for a details
Dolby Digital (AC-3) encoder module
Encodes up to 8 channels of PCM as Dolby Digital (AC-
3). See
Dolby E encoder module
Encodes up to 8 channels of PCM as Dolby E. See
Up-mix module
Provides up-mix capability from stereo to 5.1
surround audio. See
Table 8-4: Audio Graph - Audio Modules