Operating the Equipment Locally — Setup Menu: Audio Menu - Linear PCM [Direct]/via SRC] Menu
Reference Guide: Voyager E5784 and E5788 HD DSNG Encoder
Page 4-83
ST.RE.E10137.3
mode.
Linear PCM (Via SRC)
When selected, the audio passes through the sample rate converter before encoding. As a
consequence, any user data bits in the incoming digital audio stream are lost. Audio passes
through the SRC for all input sources i.e. Embedded, Digital, Analogue (though not really
relevant for analogue).
Audio Alignment
When checked, Auto Lip Sync is forced On, the delay can be ‘nudged’
using the Lip Sync Adjustment option.
When set, each PES contains an integral number of audio access units
(AU’s) and the PTS shall be the same as the nearest video frame.
This is to support the SMPTE 302M-2002 specification for carriage of AES3
data in an MPEG transport stream. It provides one audio PES packet per
video frame, such that the PES packet is aligned to that video frame and
stamped with the same PTS.
NOTE…
Choose the Audio Alignment option to enable the SMPTE 302M 2002 standard. This disables the
SMPTE 302M Standard option.
Lip Sync Adjustment
NOTE…
This option is only available when the Audio Alignment option is enabled.
Using the Lip Sync Adjustment option, audio can be advanced by 1 or 2
frames to compensate for the audio encoder delay and 1 frame as the
decoder expects the audio a frame before the video. Table 4.63 shows the
option.
Table 4.88: Lip Sync Adjustment Options
Selected Option
Description
-1 frame
0
+1 frame
+2 frames
When Audio Alignment is enabled, the audio
delay can be nudged as indicated. The
default is 0.
Input Level L Option
This indicates the input level of the left audio channel. It is for status only
and cannot be changed.
Input Level R Option
This indicates the input level of the right audio channel. It is for status only
and cannot be changed.
