3:2 Pushup Node

The 3:2 Pushup node enables you to convert imagery from the frame rate of video (30 fps) to the frame rate of film (24 fps). It performs an inverse of a 3:2 pulldown by creating two film frames from five video fields by disposing of one of the fields.

There are five different phase shifts to choose from, each of which corresponds to a pulldown phase shift. For more information, refer to the 3:2 Pulldown Node description.

Note:
When using the 3:2 Pushup node to convert video frames that were originally created from film frames using the 3:2 Pulldown node, it is essential to use the same Phase Shift and Field Order parameter settings that were used in the 3:2 Pulldown node.

Executing a 3:2 Pushup Sequence

By the nature of the conversion operation, the output will contain fewer frames than the input sequence. Therefore, to render a sequence that has passed through a 3:2 Pushup node, you must specify Start and End values in the Exec node panel that correspond to the number of frames resulting from the pushup operation--not the frame range of the original input.

For example, a six-second, 180-frame video sequence that is processed through the 3:2 Pushup node becomes 144 frames long. To execute the entire six-second sequence, you would key a value of 1 into the Start parameter field of the Exec node and a value of 144 into the End field.

Check the Frame Range display in the Info tab of the 3:2 Pushup node to find out the length of the sequence as output from the node. (To actually calculate the number of frames in the output, you would multiply the number of input frames by 4, and divide the result by 5.)

Pushup Parameter Tab

Phase Shift

The Phase Shift parameter enables you to choose a pattern by which the 3:2 Pushup node will perform the conversion.

Field Order

This parameter specifies whether video field 1 should be used to create the odd fields (lines 1, 3, 5, etc.) in the film frame, and field 2 the interlacing even fields (lines 2, 4, 6, etc.), or vice-versa.

Even, Odd

Field 1 is used to create the even field lines of the film frame, and field 2 is used to create the odd field lines.

Odd, Even

Field 1 is used to create the odd field lines of the film frame, and field 2 is used to create the even field lines.




Table of Contents | Index



Copyright 1996-1999 by Silicon Grail Corporation