Page 349 - Manual_Movie Edit Pro 2021_EN_Neat

MPEG glossary 349
preceding and/or following frame are also found in MPEG video (P frame = "predicted
frame", B frame = "bidirectional frame", see Prediction (view page 350)).

Interlace

For historical reasons, pictures in a movie are always recorded and transmitted in the
form of two fields, first the lines with even numbers and then those with odd numbers.
These fields are alternatively displayed with a double-frame rate. The (lazy) eye of the
viewer or the processing of the TV tube puts the two frames together to form one.

The output image First field Second field
You normally don’t have to worry about field processing. The video material goes
through the entire processing chain as fields and is exported again as fields or burned
onto DVD or shown on TV when played back on a DVD as a full picture. Only in
certain rare conditions is it necessary to delve deeper into this process. Two problems
can occur:

Interlace artifacts
To be displayed on a computer monitor the two fields must be combined to form a
full screen.

These two fields are not the same, since two fields are created during the recording
(between which a 1/50 of a second gap is evident). Moving objects can therefore
produce artifacts at the vertical edges.

Typical interlacing errors
You can use so-called "de-interlacing" to avoid these artifacts. A picture in between
the two fields is created (interpolated). So if you want to create stationary pictures
from movies, then you should definitely use a de-interlace filter.