Nevion PGM-HD-2x1-PB - Manual (Page 17)

PGM-HD-2x1-PB Rev. B
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For a scenario where the card receives different HD video standards, (e.g.
1080i25 and 720p50) the user may want to conserve a specific delay in
microseconds for all HD video standards. This is accomplished by
specifying the delay in number of samples instead of frames and lines. (For
HD video standards the sample frequency is equal over standards, but the
line and frame frequencies are different for the different standards).
If video input disappears
Given that stable SDI input and sync input exists: If the SDI input disappears, the
picture will freeze for <hold time> and then go to video generator if the card is in default
configuration. When the SDI input disappears, the Frame Delay pulses at the back
plane will also disappear.
If video input reappears
Given stable sync input, the video will reappear after <lock time> of locked video input
if card is in default settings.
If sync input disappears
Given that stable SDI input and sync input exists: If the sync signal disappears, the
card will act as in frame delay mode, see Chapter 5.4.2.
NOTE: This will result in a frame roll as the delay changes.
If sync input reappears
Given that a stable SDI input exists: If the sync signal reappears the delay mode will
change back to Frame Sync mode. Hence the internal clock will be locked to the sync
signal and the delay will again change.
NOTE: This will result in a frame roll as the delay changes.
If both signals disappears
The picture will first freeze for <hold time> and then go to video 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.
5.4.2 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 <hold time> and then go to video 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
If the input video signal reappears, the video will reappear on the output <lock time>
after stable input video. The delay will be set to the same delay 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 5.4.1. Hence the internal clock will be
locked to the sync signal and the delay will again change.
NOTE: This will result in a frame roll as the delay changes.