Using Pocket Divx Encoder, I have the options of B-frames and de-interlacing when re-encoding a video file. Does anyone know what these two options are and what they do?

Thanks,
ek778

Interlacing is the use of two half-frames (fields) instead of one whole frame. The two fields are shown at a slight time difference and in a way so line 1,3,5... is from the first field and line 2,4,6... is from the second. Most TV’s will show the picture this way, first field 1 then field 2. Computer monitors on the other hand will show both fields at once, so some form of deinterlacing must be used on interlaced material. What follows is a picture of an interlaced frame and another of the same picture deinterlaced by blending:

http://images.google.com/imgres?imgu...3Doff%26sa%3DN

B-frames (from divx.com)

DivX Pro 5.0 introduces the ability to also use "B-frames". B-frames allow the DivX codec to predict frames from the future, choosing the best prediction match among 2 prediction frames. B-frames are not only coded by using forward predicted frames but also from backward predicted frames which can be an I or P frame. Using B-frames reduces the amount of data needed to code a frame and improves quality more specifically in areas where moving objects reveal hidden areas.

Thanks very much for answering my questions in such an informative manner!