void RENAME(ff_init_mpadsp_tabs)(void) { int i, j; /* compute mdct windows */ for (i = 0; i < 36; i++) { for (j = 0; j < 4; j++) { double d; if (j == 2 && i % 3 != 1) continue; d = sin(M_PI * (i + 0.5) / 36.0); if (j == 1) { if (i >= 30) d = 0; else if (i >= 24) d = sin(M_PI * (i - 18 + 0.5) / 12.0); else if (i >= 18) d = 1; } else if (j == 3) { if (i < 6) d = 0; else if (i < 12) d = sin(M_PI * (i - 6 + 0.5) / 12.0); else if (i < 18) d = 1; } //merge last stage of imdct into the window coefficients d *= 0.5 / cos(M_PI * (2 * i + 19) / 72); if (j == 2) RENAME(ff_mdct_win)[j][i/3] = FIXHR((d / (1<<5))); else { int idx = i < 18 ? i : i + (MDCT_BUF_SIZE/2 - 18); RENAME(ff_mdct_win)[j][idx] = FIXHR((d / (1<<5))); } } } /* NOTE: we do frequency inversion adter the MDCT by changing the sign of the right window coefs */ for (j = 0; j < 4; j++) { for (i = 0; i < MDCT_BUF_SIZE; i += 2) { RENAME(ff_mdct_win)[j + 4][i ] = RENAME(ff_mdct_win)[j][i ]; RENAME(ff_mdct_win)[j + 4][i + 1] = -RENAME(ff_mdct_win)[j][i + 1]; } } }