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Diffstat (limited to 'ac3dec/imdct_c.c')
| -rw-r--r-- | ac3dec/imdct_c.c | 218 |
1 files changed, 0 insertions, 218 deletions
diff --git a/ac3dec/imdct_c.c b/ac3dec/imdct_c.c deleted file mode 100644 index 1f2bfe8..0000000 --- a/ac3dec/imdct_c.c +++ /dev/null @@ -1,218 +0,0 @@ -/* - * imdct.c - * - * Copyright (C) Aaron Holtzman - May 1999 - * - * This file is part of ac3dec, a free Dolby AC-3 stream decoder. - * - * ac3dec is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2, or (at your option) - * any later version. - * - * ac3dec is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with GNU Make; see the file COPYING. If not, write to - * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. - * - * - */ - -#include <stdlib.h> -#include <stdio.h> -#include <math.h> -#include "ac3.h" -#include "ac3_internal.h" - -#include "downmix.h" -#include "imdct_c.h" -#include "srfft.h" - - -#define N 512 - -extern void (*imdct_do_512) (float data[],float delay[]); -extern void (*imdct_do_512_nol) (float data[], float delay[]); -extern void (*fft_64p) (complex_t *); - -extern const int pm128[]; -extern float window[]; -extern complex_t buf[128]; - -extern void fft_64p_c (complex_t *); -extern void fft_128p_c (complex_t *); - -static void imdct_do_512_c (float data[],float delay[]); -static void imdct_do_512_nol_c (float data[], float delay[]); - -/* Twiddle factors for IMDCT */ -static float xcos1[128] __attribute__((aligned(16))); -static float xsin1[128] __attribute__((aligned(16))); - - -int imdct_init_c (void) -{ - int i; - float scale = 255.99609372; - - imdct_do_512 = imdct_do_512_c; - imdct_do_512_nol = imdct_do_512_nol_c; - fft_64p = fft_64p_c; - - /* Twiddle factors to turn IFFT into IMDCT */ - - for (i=0; i < 128; i++) { - xcos1[i] = cos(2.0f * M_PI * (8*i+1)/(8*N)) * scale; - xsin1[i] = sin(2.0f * M_PI * (8*i+1)/(8*N)) * scale; - } - - return 0; -} - - -static void imdct_do_512_c (float data[], float delay[]) -{ - int i, j; - float tmp_a_r, tmp_a_i; - float *data_ptr; - float *delay_ptr; - float *window_ptr; - -// 512 IMDCT with source and dest data in 'data' -// Pre IFFT complex multiply plus IFFT complex conjugate - - for( i=0; i < 128; i++) { - j = pm128[i]; - //a = (data[256-2*j-1] - data[2*j]) * (xcos1[j] + xsin1[j]); - //c = data[2*j] * xcos1[j]; - //b = data[256-2*j-1] * xsin1[j]; - //buf1[i].re = a - b + c; - //buf1[i].im = b + c; - buf[i].re = (data[256-2*j-1] * xcos1[j]) - (data[2*j] * xsin1[j]); - buf[i].im = -1.0 * (data[2*j] * xcos1[j] + data[256-2*j-1] * xsin1[j]); - } - - fft_128p_c (&buf[0]); - -// Post IFFT complex multiply plus IFFT complex conjugate - for (i=0; i < 128; i++) { - tmp_a_r = buf[i].re; - tmp_a_i = buf[i].im; - //a = (tmp_a_r - tmp_a_i) * (xcos1[j] + xsin1[j]); - //b = tmp_a_r * xsin1[j]; - //c = tmp_a_i * xcos1[j]; - //buf[j].re = a - b + c; - //buf[j].im = b + c; - buf[i].re =(tmp_a_r * xcos1[i]) + (tmp_a_i * xsin1[i]); - buf[i].im =(tmp_a_r * xsin1[i]) - (tmp_a_i * xcos1[i]); - } - - data_ptr = data; - delay_ptr = delay; - window_ptr = window; - -// Window and convert to real valued signal - for (i=0; i< 64; i++) { - *data_ptr++ = -buf[64+i].im * *window_ptr++ + *delay_ptr++; - *data_ptr++ = buf[64-i-1].re * *window_ptr++ + *delay_ptr++; - } - - for(i=0; i< 64; i++) { - *data_ptr++ = -buf[i].re * *window_ptr++ + *delay_ptr++; - *data_ptr++ = buf[128-i-1].im * *window_ptr++ + *delay_ptr++; - } - -// The trailing edge of the window goes into the delay line - delay_ptr = delay; - - for(i=0; i< 64; i++) { - *delay_ptr++ = -buf[64+i].re * *--window_ptr; - *delay_ptr++ = buf[64-i-1].im * *--window_ptr; - } - - for(i=0; i<64; i++) { - *delay_ptr++ = buf[i].im * *--window_ptr; - *delay_ptr++ = -buf[128-i-1].re * *--window_ptr; - } -} - - -static void imdct_do_512_nol_c (float data[], float delay[]) -{ - int i, j; - - float tmp_a_i; - float tmp_a_r; - - float *data_ptr; - float *delay_ptr; - float *window_ptr; - - // - // 512 IMDCT with source and dest data in 'data' - // - - // Pre IFFT complex multiply plus IFFT cmplx conjugate - - for( i=0; i < 128; i++) { - /* z[i] = (X[256-2*i-1] + j * X[2*i]) * (xcos1[i] + j * xsin1[i]) */ - j = pm128[i]; - //a = (data[256-2*j-1] - data[2*j]) * (xcos1[j] + xsin1[j]); - //c = data[2*j] * xcos1[j]; - //b = data[256-2*j-1] * xsin1[j]; - //buf1[i].re = a - b + c; - - //buf1[i].im = b + c; - buf[i].re = (data[256-2*j-1] * xcos1[j]) - (data[2*j] * xsin1[j]); - buf[i].im = -1.0 * (data[2*j] * xcos1[j] + data[256-2*j-1] * xsin1[j]); - } - - fft_128p_c (&buf[0]); - - /* Post IFFT complex multiply plus IFFT complex conjugate*/ - for (i=0; i < 128; i++) { - /* y[n] = z[n] * (xcos1[n] + j * xsin1[n]) ; */ - /* int j1 = i; */ - tmp_a_r = buf[i].re; - tmp_a_i = buf[i].im; - //a = (tmp_a_r - tmp_a_i) * (xcos1[j] + xsin1[j]); - //b = tmp_a_r * xsin1[j]; - //c = tmp_a_i * xcos1[j]; - //buf[j].re = a - b + c; - //buf[j].im = b + c; - buf[i].re =(tmp_a_r * xcos1[i]) + (tmp_a_i * xsin1[i]); - buf[i].im =(tmp_a_r * xsin1[i]) - (tmp_a_i * xcos1[i]); - } - - data_ptr = data; - delay_ptr = delay; - window_ptr = window; - - /* Window and convert to real valued signal, no overlap here*/ - for (i=0; i< 64; i++) { - *data_ptr++ = -buf[64+i].im * *window_ptr++; - *data_ptr++ = buf[64-i-1].re * *window_ptr++; - } - - for(i=0; i< 64; i++) { - *data_ptr++ = -buf[i].re * *window_ptr++; - *data_ptr++ = buf[128-i-1].im * *window_ptr++; - } - - /* The trailing edge of the window goes into the delay line */ - delay_ptr = delay; - - for(i=0; i< 64; i++) { - *delay_ptr++ = -buf[64+i].re * *--window_ptr; - *delay_ptr++ = buf[64-i-1].im * *--window_ptr; - } - - for(i=0; i<64; i++) { - *delay_ptr++ = buf[i].im * *--window_ptr; - *delay_ptr++ = -buf[128-i-1].re * *--window_ptr; - } -} |