Analysis filterbank, synthesis filterbank, encoder, decoder, mixer and conferencing system

摘要

#$%^&*AU2011201330B220110825.pdf#####Abstract: There is disclosed a synthesis filterbank for filtering a plurality of input frames, each input frame comprising M ordered input values Yk(O),...,yk(M-l), wherein M is a 5 positive integer, and wherein k is an integer indicating a frame index, comprising: an inverse type-IV discrete cosine transform frequency/time converter configured to providing a plurality of output frames, an output frame comprising 2M ordered output samples xk(O),...,Xk(2M-l) based 10 on the input values yk(O),...,yk(M-1); a windower configured to generating a plurality of windowed frames, a windowed frame comprising a plurality of windowed samples Zk(O), . zk(2M-1) based on the equation zk(n) = w(n) - xk(n) for n = 0,..., 2M-1 , wherein n is an integer indicating a 15 sample index, and wherein w(n) is a real-valued window function coefficient corresponding to the sample index n; an overlap/adder configured to providing an intermediate frame comprising a plurality of intermediate samples mk(O) ,...,mk(M-1) based on the equation mk(n) = zk(n) + Zk. 20 1 (n+M) for n = 0,...,M-1 ; and a lifter configured to providing an added frame comprising a plurality of added samples outk(O),...,outk(M-1) based on the equation outk(n) = mk(n) + l(n-M/2) - mk.l(M-1-n) for n = M/2,...,M-1 ; and outk(n) = mk(n) + l(M-1-n) outk.l(M-1-n) for 25 n=O,...,M/2-l , wherein l(O),...,l(M-l) are real-valued lifting coefficients. 2609100.1 (GHMatters) P80447.AU.11/25 100 1100 110 120 FIG 1 SUBSTITUTE SHEET (RULE 26)