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ISO/IEC 10918-1 : 1993(E)
D.1.5.4
Estimation following renormalization after LPS
The procedure for estimating the probability on the LPS renormalization path is shown in Figure D.6. The procedure is
similar to that of Figure D.5 except that when Switch_MPS(I) is 1, the sense of MPS(S) must be inverted.
TISO1070-93/d044
Figure D.6 Probability estimation on LPS renormalization path
Estimate_Qe(S)_
after_LPS
I = Index(S)
No
Yes
Switch_MPS(I) = 1
?
I = Next_Index_LPS(I)
Index(S) = I
Qe(S) = Qe_Value(I)
MPS(S) = 1 MPS(S)
Done
Figure D.6 [D44], = 14 cm = 547.%
D.1.6
Renormalization in the encoder
The Renorm_e procedure for the encoder renormalization is shown in Figure D.7. Both the probability interval register A
and the code register C are shifted, one bit at a time. The number of shifts is counted in the counter CT; when CT is zero,
a byte of compressed data is removed from C by the procedure Byte_out and CT is reset to 8. Renormalization continues
until A is no longer less than X'8000'.
62
CCITT Rec. T.81 (1992 E)
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