Image Processing Reference
Static macroblock (no change)
Figure 13-4 Macroblock composition of a frame.
of efficiency in the coding. The increased complexity is evident in the way that frames are
derived in Figure 13-5. Even so, this diagram is a simplified example and the dependen-
cies between frames are very complex.
As a sequence of frames is processed, the number of intra-coded macroblocks
reduces as they change to static macroblocks. This is good because intra macroblocks are
the ones that consume the most bit rate. Figure 13-6 shows a sequence of 4 frames dis-
played on a Tektronix analyzer. You can see that the number of intra blocks is significantly
reduced in Frames 3 and 4.
Figure 13-5 H.264 macroblock references to frames in different GOPs.