MPEG Video

MPEG compression is essentially a attempts to over come some shortcomings of H.261 and JPEG:

• Recall H.261 dependencies:

  

• The Problem here is that many macroblocks need information is not in the reference frame.

• For example:

  

• The MPEG solution is to add a third frame type which is a bidirectional frame, or B-frame

• B-frames search for macroblock in past and future frames.

• Typical pattern is IBBPBBPBB IBBPBBPBB IBBPBBPBB

  Actual pattern is up to encoder, and need not be regular.