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FS4 Frame Synchronizer/Converter v1.1
Quad Link
Quad Link referred to here is 4K/UltraHD on four 1.5 Gb HD-SDI connections, or
4K/UltraHD high frame rate video on four 3 Gb connections. Selecting Quad Link as the
Video Input will allocate all four SDI Inputs for Quad Link use. The SFP inputs operate the
same way.
See
“System Video/Audio Cable Connections” on page 33
for more information about FS4
signal routing.
2 Loss of Input
This parameter selects the automatic action that occurs if the video input is lost. The
Black
selection (default) cuts the video to black. The
Freeze
selection freezes video on the
last available good frame.
3 Reverse Telecine
This parameters can be used to control film cadence detection.
About Reverse Telecine
and Film Cadence
Film cadence is a way to convert film frame rates to interlaced field rate video suitable for
broadcast, commonly employed by telecine equipment when converting film to video
(for example, converting from 24 frames to 60 interlaced fields, or 23.98 frames to 59.94
fields). This requires a 4/5 conversion ratio. For 3:2 pulldown cadence, the most common,
two fields are duplicated for every four input frames, with a resulting 2:3:2:3 field output
pattern. 3:2 pulldown outputs four fields of the original two input frames, then one
duplicate field, then four more fields of the next two input frames, and then another
duplicate field. This provides the smoothest motion, but results in two of the five video
output frames being “dirty”, having fields from different original frames. Another
commonly used film cadence is 2:3:3:2, which has only one “dirty” frame but results in
motion that is slightly less smooth. Many other more exotic film cadences exist, but they
are rarely used.
Film cadence removal reverses pulldown (Reverse Telecine), and can turn interlaced
video originally sourced from film with pulldown back to progressive frame rate video,
removing the duplicated fields. This can be useful for post-production facilities that have
a need to accurately re-edit this type of material.
FS4 Reverse Telecine
Conditions
The FS4 converter can perform film cadence removal under the following conditions:
• Input signal must be 525i59.94, 1080i59.94 and output format selected must be p23.98
or PsF23.98, OR the input signal must be 1080i60 and output format p24 or PsF24.
• Input signal must have consistent 3:2 pulldown.
• The Reverse Telecine parameter must be set to Auto.
Under the conditions above, the FS4 will automatically identify and remove the duplicate
fields, and perform motion detection and de-interlacing processing to create high
quality output with clean frames.
NOTE:
Approximately 10 incoming frames are required before film cadence can be detected and
correctly processed. If the cadence pattern changes (for example, the source pulldown video
Black (default)
Freeze
Switches to black if input video is lost.
Freezes on the last available good video frame if input is lost.
Off (default)
Film cadence detection is disabled. This setting should remain Off
unless you are processing interlaced pulldown input.
Auto
3:2 pull down field removal is enabled for interlaced video
sources.
