DWC-HD
Rev.
2
The picture will first freeze for a user specified time (Hold time in Video in), and then possibly
(See section “If video input disappears” above) go to a fallback generator. The output is now
referenced to the local clock source. However, this clock source will be kept within 1 ppm of
the last sync source.
3.6.2 Frame delay mode
In this mode a sync signal is not present. The delay set is then directly related to the
incoming video. 1 frame and 1 line delay means that the output will be 1 frame and 1 line
delayed version of the input.
If video signal disappears
The picture will first freeze for a user specified time (Hold time in Video in), and then possibly
(See section “If video input disappear” under Frame sync mode above) go to a fallback
generator. The output is now referenced to the local clock source. However, this clock source
will be kept within 1 ppm of the last video source.
If video signal reappears
The video output will reappear after a user specified time of locked video. This
Lock time
(in
Video in) defaults to 3 seconds. The delay will now be the same as before loosing input.
NOTE: This may cause a frame roll.
If a sync input appears
Given that a stable SDI input exists: If a sync signal appears the delay mode will change to
Frame Sync mode, see Chapter 3.6.1. Hence the internal clock will be locked to the sync
signal and the delay will once again change.
NOTE: This will result in a frame roll as the delay changes.
3.7 Video
generator
The video generator can produce different simple signals: Color bar, Check field and flat
field.
The flat field option allows the user to specify any combination of luma and chroma values, or
to select a predefined color from the following list:
-
Black
-
White
-
Yellow
-
Cyan
-
Green
-
Magenta
-
Red
-
Blue
In normal operation (as a fallback generator), the video generator will take its video standard
setting from the last lockable video input seen by the board. To enable the board to act as a
standalone and user configurable video generator, the video generator must be either set as
the first priority input when Mode is auto, or selected manually by setting Mode to Video
generator. Both settings are done in Processed video out. This will override any video input
but the generator signal will still be locked to the sync or SDI inputs, if present. For true
standalone generator operation, the inputs should be removed. Available video standards
are 486/25i and 576/25i.
network-electronics.com
|
14
