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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@95 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Mark Spencer
383
codecs/mp3/src/icdct.c
Executable file
383
codecs/mp3/src/icdct.c
Executable file
@@ -0,0 +1,383 @@
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/*____________________________________________________________________________
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FreeAmp - The Free MP3 Player
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MP3 Decoder originally Copyright (C) 1995-1997 Xing Technology
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Corp. http://www.xingtech.com
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Portions Copyright (C) 1998 EMusic.com
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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$Id$
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____________________________________________________________________________*/
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/**** icdct.c ***************************************************
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MPEG audio decoder, dct
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portable C integer dct
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mod 1/8/97 warnings
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******************************************************************/
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#include <stdlib.h>
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#include <stdio.h>
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#include <float.h>
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#include <math.h>
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#include "itype.h"
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/*-------------------------------------------------------------------*/
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static DCTCOEF coef32[32]; /* 32 pt dct coefs */
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#define forward_bf idx_forward_bf
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/*--- #define forward_bf ptr_forward_bf ---*/
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/*------------------------------------------------------------*/
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DCTCOEF *i_dct_coef_addr()
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{
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return coef32;
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}
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/*------------------------------------------------------------*/
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static void idx_forward_bf(int m, int n, INT32 x[], INT32 f[], DCTCOEF coef[])
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{
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int i, j, n2;
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int p, q, p0, k;
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p0 = 0;
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n2 = n >> 1;
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for (i = 0; i < m; i++, p0 += n)
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{
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k = 0;
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p = p0;
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q = p + n - 1;
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for (j = 0; j < n2; j++, p++, q--, k++)
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{
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f[p] = x[p] + x[q];
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f[n2 + p] = ((x[p] - x[q]) * coef[k]) >> DCTBITS;
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}
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}
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}
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/*------------------------------------------------------------*/
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/*--
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static void ptr_forward_bf(int m, int n, INT32 x[], INT32 f[], DCTCOEF coef[])
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{
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int i, j, n2;
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DCTCOEF *c;
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INT32 *y;
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n2 = n >> 1;
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for(i=0; i<m; i++) {
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c = coef;
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y = x+n;
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for(j=0; j<n2; j++) {
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*f = *x + *--y;
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*((f++)+n2) = ( (*x++ - *y) * (*c++) ) >> DCTBITS;
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}
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f+=n2;
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x+=n2;
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}
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}
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---*/
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/*------------------------------------------------------------*/
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static void forward_bfm(int m, INT32 x[], INT32 f[])
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{
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int i;
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int p;
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/*--- special case last fwd stage ----*/
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for (p = 0, i = 0; i < m; i++, p += 2)
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{
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f[p] = x[p] + x[p + 1];
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f[p + 1] = ((x[p] - x[p + 1]) * coef32[30]) >> DCTBITS;
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}
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}
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/*------------------------------------------------------------*/
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static void back_bf(int m, int n, INT32 x[], INT32 f[])
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{
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int i, j, n2, n21;
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int p, q, p0;
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p0 = 0;
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n2 = n >> 1;
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n21 = n2 - 1;
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for (i = 0; i < m; i++, p0 += n)
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{
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p = p0;
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q = p0;
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for (j = 0; j < n2; j++, p += 2, q++)
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f[p] = x[q];
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p = p0 + 1;
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for (j = 0; j < n21; j++, p += 2, q++)
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f[p] = x[q] + x[q + 1];
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f[p] = x[q];
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}
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}
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/*------------------------------------------------------------*/
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static void back_bf0(int n, INT32 x[], WININT f[])
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{
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int p, q;
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n--;
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#if DCTSATURATE
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for (p = 0, q = 0; p < n; p += 2, q++)
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{
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tmp = x[q];
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if (tmp > 32767)
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tmp = 32767;
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else if (tmp < -32768)
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tmp = -32768;
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f[p] = tmp;
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}
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for (p = 1; q < n; p += 2, q++)
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{
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tmp = x[q] + x[q + 1];
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if (tmp > 32767)
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tmp = 32767;
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else if (tmp < -32768)
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tmp = -32768;
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f[p] = tmp;
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}
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tmp = x[q];
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if (tmp > 32767)
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tmp = 32767;
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else if (tmp < -32768)
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tmp = -32768;
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f[p] = tmp;
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#else
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for (p = 0, q = 0; p < n; p += 2, q++)
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f[p] = x[q];
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for (p = 1; q < n; p += 2, q++)
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f[p] = x[q] + x[q + 1];
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f[p] = x[q];
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#endif
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}
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/*------------------------------------------------------------*/
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void i_dct32(SAMPLEINT x[], WININT c[])
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{
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INT32 a[32]; /* ping pong buffers */
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INT32 b[32];
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int p, q;
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/* special first stage */
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for (p = 0, q = 31; p < 16; p++, q--)
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{
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a[p] = (INT32) x[p] + x[q];
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a[16 + p] = (coef32[p] * ((INT32) x[p] - x[q])) >> DCTBITS;
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}
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forward_bf(2, 16, a, b, coef32 + 16);
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forward_bf(4, 8, b, a, coef32 + 16 + 8);
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forward_bf(8, 4, a, b, coef32 + 16 + 8 + 4);
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forward_bfm(16, b, a);
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back_bf(8, 4, a, b);
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back_bf(4, 8, b, a);
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back_bf(2, 16, a, b);
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back_bf0(32, b, c);
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}
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/*------------------------------------------------------------*/
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void i_dct32_dual(SAMPLEINT x[], WININT c[])
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{
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INT32 a[32]; /* ping pong buffers */
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INT32 b[32];
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int p, pp, qq;
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/* special first stage for dual chan (interleaved x) */
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pp = 0;
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qq = 2 * 31;
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for (p = 0; p < 16; p++, pp += 2, qq -= 2)
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{
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a[p] = (INT32) x[pp] + x[qq];
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a[16 + p] = (coef32[p] * ((INT32) x[pp] - x[qq])) >> DCTBITS;
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}
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forward_bf(2, 16, a, b, coef32 + 16);
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forward_bf(4, 8, b, a, coef32 + 16 + 8);
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forward_bf(8, 4, a, b, coef32 + 16 + 8 + 4);
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forward_bfm(16, b, a);
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back_bf(8, 4, a, b);
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back_bf(4, 8, b, a);
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back_bf(2, 16, a, b);
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back_bf0(32, b, c);
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}
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/*---------------convert dual to mono------------------------------*/
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void i_dct32_dual_mono(SAMPLEINT x[], WININT c[])
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{
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INT32 a[32]; /* ping pong buffers */
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INT32 b[32];
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INT32 t1, t2;
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int p, pp, qq;
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/* special first stage */
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pp = 0;
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qq = 2 * 31;
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for (p = 0; p < 16; p++, pp += 2, qq -= 2)
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{
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t1 = ((INT32) x[pp] + x[pp + 1]);
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t2 = ((INT32) x[qq] + x[qq + 1]);
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a[p] = (t1 + t2) >> 1;
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a[16 + p] = coef32[p] * (t1 - t2) >> (DCTBITS + 1);
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}
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forward_bf(2, 16, a, b, coef32 + 16);
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forward_bf(4, 8, b, a, coef32 + 16 + 8);
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forward_bf(8, 4, a, b, coef32 + 16 + 8 + 4);
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forward_bfm(16, b, a);
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back_bf(8, 4, a, b);
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back_bf(4, 8, b, a);
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back_bf(2, 16, a, b);
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back_bf0(32, b, c);
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}
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/*------------------------------------------------------------*/
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/*---------------- 16 pt dct -------------------------------*/
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void i_dct16(SAMPLEINT x[], WININT c[])
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{
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INT32 a[16]; /* ping pong buffers */
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INT32 b[16];
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int p, q;
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/* special first stage (drop highest sb) */
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a[0] = x[0];
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a[8] = (a[0] * coef32[16]) >> DCTBITS;
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for (p = 1, q = 14; p < 8; p++, q--)
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{
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a[p] = (INT32) x[p] + x[q];
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a[8 + p] = (((INT32) x[p] - x[q]) * coef32[16 + p]) >> DCTBITS;
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}
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forward_bf(2, 8, a, b, coef32 + 16 + 8);
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forward_bf(4, 4, b, a, coef32 + 16 + 8 + 4);
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forward_bfm(8, a, b);
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back_bf(4, 4, b, a);
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back_bf(2, 8, a, b);
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back_bf0(16, b, c);
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}
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/*------------------------------------------------------------*/
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/*---------------- 16 pt dct dual chan---------------------*/
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void i_dct16_dual(SAMPLEINT x[], WININT c[])
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{
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int p, pp, qq;
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INT32 a[16]; /* ping pong buffers */
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INT32 b[16];
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/* special first stage for interleaved input */
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a[0] = x[0];
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a[8] = (coef32[16] * a[0]) >> DCTBITS;
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pp = 2;
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qq = 2 * 14;
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for (p = 1; p < 8; p++, pp += 2, qq -= 2)
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{
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a[p] = (INT32) x[pp] + x[qq];
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a[8 + p] = (coef32[16 + p] * ((INT32) x[pp] - x[qq])) >> DCTBITS;
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}
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forward_bf(2, 8, a, b, coef32 + 16 + 8);
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forward_bf(4, 4, b, a, coef32 + 16 + 8 + 4);
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forward_bfm(8, a, b);
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back_bf(4, 4, b, a);
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back_bf(2, 8, a, b);
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back_bf0(16, b, c);
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}
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/*------------------------------------------------------------*/
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/*---------------- 16 pt dct dual to mono-------------------*/
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void i_dct16_dual_mono(SAMPLEINT x[], WININT c[])
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{
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INT32 a[16]; /* ping pong buffers */
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INT32 b[16];
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INT32 t1, t2;
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int p, pp, qq;
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/* special first stage */
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a[0] = ((INT32) x[0] + x[1]) >> 1;
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a[8] = (coef32[16] * a[0]) >> DCTBITS;
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pp = 2;
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qq = 2 * 14;
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for (p = 1; p < 8; p++, pp += 2, qq -= 2)
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{
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t1 = (INT32) x[pp] + x[pp + 1];
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t2 = (INT32) x[qq] + x[qq + 1];
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a[p] = (t1 + t2) >> 1;
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a[8 + p] = (coef32[16 + p] * (t1 - t2)) >> (DCTBITS + 1);
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}
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forward_bf(2, 8, a, b, coef32 + 16 + 8);
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forward_bf(4, 4, b, a, coef32 + 16 + 8 + 4);
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forward_bfm(8, a, b);
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back_bf(4, 4, b, a);
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back_bf(2, 8, a, b);
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back_bf0(16, b, c);
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}
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/*------------------------------------------------------------*/
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/*---------------- 8 pt dct -------------------------------*/
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void i_dct8(SAMPLEINT x[], WININT c[])
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{
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int p, q;
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INT32 a[8]; /* ping pong buffers */
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INT32 b[8];
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/* special first stage */
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for (p = 0, q = 7; p < 4; p++, q--)
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{
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b[p] = (INT32) x[p] + x[q];
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b[4 + p] = (coef32[16 + 8 + p] * ((INT32) x[p] - x[q])) >> DCTBITS;
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}
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forward_bf(2, 4, b, a, coef32 + 16 + 8 + 4);
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forward_bfm(4, a, b);
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back_bf(2, 4, b, a);
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back_bf0(8, a, c);
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}
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/*------------------------------------------------------------*/
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/*---------------- 8 pt dct dual chan---------------------*/
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void i_dct8_dual(SAMPLEINT x[], WININT c[])
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{
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int p, pp, qq;
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INT32 a[8]; /* ping pong buffers */
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INT32 b[8];
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/* special first stage for interleaved input */
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for (p = 0, pp = 0, qq = 14; p < 4; p++, pp += 2, qq -= 2)
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{
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b[p] = (INT32) x[pp] + x[qq];
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b[4 + p] = (coef32[16 + 8 + p] * ((INT32) x[pp] - x[qq])) >> DCTBITS;
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}
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forward_bf(2, 4, b, a, coef32 + 16 + 8 + 4);
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forward_bfm(4, a, b);
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back_bf(2, 4, b, a);
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back_bf0(8, a, c);
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}
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/*------------------------------------------------------------*/
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/*---------------- 8 pt dct dual to mono---------------------*/
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void i_dct8_dual_mono(SAMPLEINT x[], WININT c[])
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{
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int p, pp, qq;
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INT32 a[8]; /* ping pong buffers */
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INT32 b[8];
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INT32 t1, t2;
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/* special first stage */
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for (p = 0, pp = 0, qq = 14; p < 4; p++, pp += 2, qq -= 2)
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{
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t1 = (INT32) x[pp] + x[pp + 1];
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t2 = (INT32) x[qq] + x[qq + 1];
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b[p] = (t1 + t2) >> 1;
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b[4 + p] = (coef32[16 + 8 + p] * (t1 - t2)) >> (DCTBITS + 1);
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}
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forward_bf(2, 4, b, a, coef32 + 16 + 8 + 4);
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forward_bfm(4, a, b);
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back_bf(2, 4, b, a);
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back_bf0(8, a, c);
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}
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/*------------------------------------------------------------*/
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