2011

Table Of Contents
You can then select the pulldown cadence by choosing one of the following
five patterns of whole (W) and split (S) frames from the Cadence menu.
Whole and Split frames are a consequence of using every second input frame
to create three output fields and every other input frame to create two output
fields, as in the following list of output field pairs.
PAL Cadences
For PAL pulldown, 12 frames of progressive input become 25 fields of interlaced
output. This means that out of every 12 input frames, 11 contribute to exactly
2 output fields, and 1 contributes to 3 output fields.
One example might be the following list of output field pairs where the 6th
input frame is used 3 times:
There are actually 25 cadence possibilities for 25i, as compared to only 5 in
the NTSC 30i case. It is too awkward to refer to these cadences in the same
way as for NTSC, for example: WSSSSSSSSSSSSWWWWWWWWWWWW.
Therefore, the 25 cadences have been labeled 1 to 25 in the Cadence
drop-down menu where the number indicates the index of the split frame
that follows a whole frame.
Autodetecting the Cadence
Similar to the Deinterlace tool, you can push the Guess Cadence button to
analyze the sequence of interlaced frames to automatically set the proper
cadence and dominance. Note that this assumes that the cadence and
dominance do not change over the length of the input sequence. This button
PAL Cadences | 803