Grass Valley AMX-3981 2014 - Manual (Page 28)

GUIDE TO INSTALLATION AND OPERATION
22 | AMX-3981
If the source has no time code, a fixed time code of 00:00:00:00 will be generated in the appropriate format – DVITC
(SD), ATC-VITC or ATC-LTC (HD) – to carry the GPI and ensure that it is embedded.
Note that to accommodate on-card processing requirements, the GPI should be asserted no later that 1 ms before the
switch line in order to ensure that it is embedded in the next field.
GPI De-embedding Config
SD Extract Line (SD signals only): Select the line from which the GPI data will be de-embedded [10-20 for 525, 7-22
for 625] provided DVITC timecode is present.
GPI Source Type (3G/HD signals only): select the ATC format from which GPI data will be de-embedded [ATC-VITC,
ATC-LTC] provided the selected ATC format is present.
GPI Latch Mode: When no valid time code with embedded GPI data has been detected, the user has the option of
releasing the GPI outputs (Latch mode OFF), or holding the last valid de-embedded values (Latch Mode ON).
5.3.3 AFD tab
The Active Format Descriptor (AFD) flag is used to identify the aspect ratio and protected areas of a video signal. The
AMX-3981 manages the transfer of the AFD flag between its input and output, but does not use the AFD flag to
perform any picture manipulation. The AFD flag is implemented differently in HD and SD:
• In HD, the AFD flag (SMPTE 2016) is sent as an ancillary packet, normally found on line 11 in the vertical ancillary
space.
• In SD, the AFD flag is sent as a Video Line Index (VLI) signal (RP 186), as a Wide Screen Signaling (WSS) signal
(ITU-R BT.1119-2) for 625 only, and as an AFD packet (SMPTE 2016).
Note: The term AFD is used to represent all three types of
flags – SMPTE 2016 ancillary packet, VLI, and WSS.
The two graphics at the top of the panel show the input and
output AFDs and indicate the status (e.g. detected,
inserted). See ANNEX 6 – AFD Flags on page 109 for
information about AFD flags and terminology.
5.3.3.1 Config section
Presence: The status indicator turns Green when AFD is
detected on the input signal. On an SD input, the status
indicator will indicate the presence of AFD flags carried as
selected by the Source pulldown below, i.e. AFD, VLI or
WSS (for 625 sources only)
Mode: use the pulldown list to specify how AFD information
will be handled. Available choices are:
• Pass – pass the incoming AFD flag through without
change
• Insert – insert the ‘Forced’ AFD flag into the output,
overwriting any incoming flags
• Auto – if incoming flags are detected, pass them
through, otherwise, insert the “Default” flag
• Blank – ensure that no AFD flags are embedded in the
output stream.
Figure 5.10 Metadata - AFD tab