CHAPTER 7 End-to-end data
32. The mpeg stat program can be used to display statistics for video
streams. Use it to determine, for several streams:
(a) Number and sequence of I, B, and P frames.
(b) Average compression rate for the entire video.
(c) Average compression rate for each type of frame.
33. Suppose we have a video of two white points moving toward each
other at a uniformrate against a black background.We encode it
via MPEG. In one I frame the two points are 100 pixels apart; in the
next I frame they have merged. The final point of merger happens
to lie at the center of a 16×16 macroblock.
(a) Describe how you might optimally encode the Y component of
the intervening B (or P) frames.
(b) Now suppose the points are in color and that the color
changes slowly as the points move. Describe what the
encoding of the U and V values might look like.