| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform a parameter compensation process so as to suppress deterioration of subjective quality in predictive quantization. <P>SOLUTION: Amplifiers (305-1 through 305-M) multiply input quantized predictive residual vectors x<SB POS="POST">n-1</SB>through x<SB POS="POST">n-M</SB>by weighing factors β<SB POS="POST">1</SB>through β<SB POS="POST">M</SB>. An amplifier (306) multiplies a decoded LSF vector y<SB POS="POST">n-1</SB>of a previous frame by a weighting factor β<SB POS="POST">-1</SB>. An amplifier (307) multiplies a code vector x<SB POS="POST">n+1</SB>output from a code book (301) by a weighting factor β<SB POS="POST">0</SB>. An adder (308) calculates a sum total of vectors output from the amplifiers (305-1 through 305-M), the amplifier (306) and the amplifier (307). If a lost-frame code B<SB POS="POST">n</SB>of the current frame indicates that "the n-th frame is a lost frame" and if a lost-frame code B<SB POS="POST">n+1</SB>of the next frame indicates that "the n+1-th frame is a normal frame", a changeover switch (309) selects a vector output from the adder (308). <P>COPYRIGHT: (C)2013,JPO&INPIT |
