Cobalt Digital COMPASS 9085 Loudness Processor - Manual (Page 52)

3
9085 Function Submenu List and Descriptions
3-14 9085 PRODUCT MANUAL 9085-OM (V4.3)
Audio/Video Resync (Framesync tab)
Provides Audio/Video Re-sync function.
Note: Although labeled as “Framesync”, the 9085 framesync function is mainly intended to provide audio/video resyncing
(loudness processing induces an 8 msec delay which can be nulled by advancing the audio 8 msec using the Audio
Offset from Video control described below). When loudness processing is enabled, the glitch-free audio resyncing
provided by the framesync audio SRC is not available. To ensure glitch-free audio resyncing, it is recommended that the
incoming video be locked to reference upstream of this card, and to have the framesync on this card set to the
corresponding external reference (Reference 1 or Reference 2).
In this manner, the audio SRC is never called upon by the 9085 card processing, while also allowing the 9085 to benefit
in providing full Freeze to Last Frame or Freeze to Color protection upon loss of input. If this protection is required
without the incoming video being upstream frame synced and with framesync enable set to an external reference on
this card, hard audio resets (and the resulting audio “hits”) must be expected.
• Framesync Enable Disables the Frame Sync function, or selects from choices below.
• Off: Disables Frame Sync function; output video timing matches the
input video timing.
• Reference 1: Allows Frame Sync function to use external
Reference 1 as the reference standard.
• Reference 2: Allows Frame Sync function to use external
Reference 2 as the reference standard.
Note: If Reference 1 or Reference 2 is selected and an
appropriate external reference is not received, the
indication appears in the Card Info
status portion of DashBoard™, indicating invalid frame sync
reference error. (Additionally, the card edge ERR indicator
illuminates indicating the same.) External reference signals
Reference 1 and Reference 2 are distributed to the card
and other cards via a frame bus.
• Input Video: Uses the input video signal as the
reference standard.
Note: If Input Video is used for framesync, any timing instability
on the input video will result in corresponding instability on
the output video.
• Vertical Delay Control When Framesync is enabled, sets vertical delay (in number of lines of
output video timing) between the output video and the frame sync
reference.
(Range is -1124 thru 1124 lines.)
Note: Lines refer to lines in the output video format, and not to the
reference format.
• Horizontal Delay Control When Framesync is enabled, sets (in µsec of output video timing)
horizontal delay between the output video and the frame sync reference.
(Range is -64.000 thru 64.000 µsec)
Note: When an external framesync reference is used, the card will not
produce a framesync reset until the variance between framesync
reference and output video exceeds ± 2 clock periods. Therefore, a
framesync reset will not result if offsets within this window are
applied.
To apply an offset/framesync reset within this window, first apply a
relatively large offset, then apply the target smaller offset.
Example: To apply a 1-period offset, first apply a 10-period positive
offset and then apply a 9-period negative offset. This results in the
target 1-period offset being applied to the output video.
Table 3-2 9085 Function Submenu List — continued