B. P. Lathi, Zhi Ding - Modern Digital and Analog Communication Systems-Oxford University Press (2009)

308 SAMPLING AND ANALOG-TO-DIGITAL CONVERSION
TABLE 6.5
Denormalized DCT Coefficients
1260 0 -12 0 0 0 0 0
23 -18 0 0 0 0 0 0
-11 10 0 0 0 0 0 0
k 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0
jn
TABLE 6.6
Inverse DCT Coefficients Reconstructed Residual
158 158 158 163 161 161 162 162
157 157 157 162 163 161 162 162
157 157 157 160 161 161 161 161
m 155 155 155 162 162 161 160 159
159 159 159 160 160 162 161
156 156 156 158 163 160 155 150
156 156 156 159 156 153 151 144
155 155 155 155 153 149 144 139
n
159
Figure 6.37
Zigzag DCT
coefficient
scanning pattern.
P-frame, and the bidirectionally predictive frame or B-frame. The P-frames are predicted from
the I-frames. The B-frames are bidirectionally predicted from either past or future frames. An
I-frame and one or more P-frames and B-frames make up the basic MPEG processing pattern,
called a group of pictures (GOP). Most of the frames in an MPEG compressed image are
B-frames. The I-frame provides the initial reference for the frame differences to start the
MPEG encoding process. Note that the bidirectional aspect of the procedure introduces a
delay in the transmission of the frames. This is because the GOP is transmitted as a unit and,
hence, transmission cannot start until the GOP is complete (Fig. 6.38). The details of the
procedure are beyond the scope of this text. There are many easily accessible books that cover
this subject in detail. In addition, one may find numerous references to MPEG compression
and HDTV on the internet.