User Manual

Field Ordering in Graphic Imports and Exports
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24p and 25p Import and Export
The spatial field selection options do not apply for 24p and 25p projects because the frames in
these projects are already in progressive or still-image form.
Field Dominance
Editing in Avid applications is frame based. All timecode is expressed in frame numbers, and all
cuts are at frame boundaries. A raw video stream has no concept of frames (ignoring color
framing) until the frame unit is defined. Defining the dominant field for the system defines the
“frameness” of the video stream, as shown in the following illustration.
Left: the dotted lines represent the limits of a field-1 dominant frame. Right: the dotted lines represent the limits of a
field-2 dominant frame.
Avid editing applications all use field 1 as the dominant field. This means that the first field
temporally in the edit frame is always field 1 and the second frame is always field 2. Cuts will
always precede field 1.
Fields in Video
In the video signal, fields have a temporal position that is unambiguously and uniquely tied to the
details of the video signal, regardless of whether the signal is analog or digital (SDI). This means
that you should work around a field spatial mismatch by correcting the spatial relation between
the two fields rather than the temporal position. In some cases, you can modify the field
dominance of the input image files, but this is results in the loss of two fields, and is more
difficult to carry out than either the workaround provided in Avid editing applications or
rerendering properly to the other spatial relationship.
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