static void fft(AC3MDCTContext *mdct, IComplex *z, int ln) { int j, l, np, np2; int nblocks, nloops; register IComplex *p,*q; int tmp_re, tmp_im; np = 1 << ln; /* reverse */ for (j = 0; j < np; j++) { int k = av_reverse[j] >> (8 - ln); if (k < j) FFSWAP(IComplex, z[k], z[j]); } /* pass 0 */ p = &z[0]; j = np >> 1; do { BF(p[0].re, p[0].im, p[1].re, p[1].im, p[0].re, p[0].im, p[1].re, p[1].im); p += 2; } while (--j); /* pass 1 */ p = &z[0]; j = np >> 2; do { BF(p[0].re, p[0].im, p[2].re, p[2].im, p[0].re, p[0].im, p[2].re, p[2].im); BF(p[1].re, p[1].im, p[3].re, p[3].im, p[1].re, p[1].im, p[3].im, -p[3].re); p+=4; } while (--j); /* pass 2 .. ln-1 */ nblocks = np >> 3; nloops = 1 << 2; np2 = np >> 1; do { p = z; q = z + nloops; for (j = 0; j < nblocks; j++) { BF(p->re, p->im, q->re, q->im, p->re, p->im, q->re, q->im); p++; q++; for(l = nblocks; l < np2; l += nblocks) { CMUL(tmp_re, tmp_im, mdct->costab[l], -mdct->sintab[l], q->re, q->im, 15); BF(p->re, p->im, q->re, q->im, p->re, p->im, tmp_re, tmp_im); p++; q++; } p += nloops; q += nloops; } nblocks = nblocks >> 1; nloops = nloops << 1; } while (nblocks); }