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-rw-r--r--faad2/src/libfaad/mdct.c301
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diff --git a/faad2/src/libfaad/mdct.c b/faad2/src/libfaad/mdct.c
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--- a/faad2/src/libfaad/mdct.c
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-/*
-** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
-** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
-**
-** This program 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 of the License, or
-** (at your option) any later version.
-**
-** This program 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 this program; if not, write to the Free Software
-** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-**
-** Any non-GPL usage of this software or parts of this software is strictly
-** forbidden.
-**
-** The "appropriate copyright message" mentioned in section 2c of the GPLv2
-** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
-**
-** Commercial non-GPL licensing of this software is possible.
-** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
-**
-** $Id: mdct.c,v 1.47 2007/11/01 12:33:31 menno Exp $
-**/
-
-/*
- * Fast (I)MDCT Implementation using (I)FFT ((Inverse) Fast Fourier Transform)
- * and consists of three steps: pre-(I)FFT complex multiplication, complex
- * (I)FFT, post-(I)FFT complex multiplication,
- *
- * As described in:
- * P. Duhamel, Y. Mahieux, and J.P. Petit, "A Fast Algorithm for the
- * Implementation of Filter Banks Based on 'Time Domain Aliasing
- * Cancellation’," IEEE Proc. on ICASSP‘91, 1991, pp. 2209-2212.
- *
- *
- * As of April 6th 2002 completely rewritten.
- * This (I)MDCT can now be used for any data size n, where n is divisible by 8.
- *
- */
-
-#include "common.h"
-#include "structs.h"
-
-#include <stdlib.h>
-#ifdef _WIN32_WCE
-#define assert(x)
-#else
-#include <assert.h>
-#endif
-
-#include "cfft.h"
-#include "mdct.h"
-#include "mdct_tab.h"
-
-
-mdct_info *faad_mdct_init(uint16_t N)
-{
- mdct_info *mdct = (mdct_info*)faad_malloc(sizeof(mdct_info));
-
- assert(N % 8 == 0);
-
- mdct->N = N;
-
- /* NOTE: For "small framelengths" in FIXED_POINT the coefficients need to be
- * scaled by sqrt("(nearest power of 2) > N" / N) */
-
- /* RE(mdct->sincos[k]) = scale*(real_t)(cos(2.0*M_PI*(k+1./8.) / (real_t)N));
- * IM(mdct->sincos[k]) = scale*(real_t)(sin(2.0*M_PI*(k+1./8.) / (real_t)N)); */
- /* scale is 1 for fixed point, sqrt(N) for floating point */
- switch (N)
- {
- case 2048: mdct->sincos = (complex_t*)mdct_tab_2048; break;
- case 256: mdct->sincos = (complex_t*)mdct_tab_256; break;
-#ifdef LD_DEC
- case 1024: mdct->sincos = (complex_t*)mdct_tab_1024; break;
-#endif
-#ifdef ALLOW_SMALL_FRAMELENGTH
- case 1920: mdct->sincos = (complex_t*)mdct_tab_1920; break;
- case 240: mdct->sincos = (complex_t*)mdct_tab_240; break;
-#ifdef LD_DEC
- case 960: mdct->sincos = (complex_t*)mdct_tab_960; break;
-#endif
-#endif
-#ifdef SSR_DEC
- case 512: mdct->sincos = (complex_t*)mdct_tab_512; break;
- case 64: mdct->sincos = (complex_t*)mdct_tab_64; break;
-#endif
- }
-
- /* initialise fft */
- mdct->cfft = cffti(N/4);
-
-#ifdef PROFILE
- mdct->cycles = 0;
- mdct->fft_cycles = 0;
-#endif
-
- return mdct;
-}
-
-void faad_mdct_end(mdct_info *mdct)
-{
- if (mdct != NULL)
- {
-#ifdef PROFILE
- printf("MDCT[%.4d]: %I64d cycles\n", mdct->N, mdct->cycles);
- printf("CFFT[%.4d]: %I64d cycles\n", mdct->N/4, mdct->fft_cycles);
-#endif
-
- cfftu(mdct->cfft);
-
- faad_free(mdct);
- }
-}
-
-void faad_imdct(mdct_info *mdct, real_t *X_in, real_t *X_out)
-{
- uint16_t k;
-
- complex_t x;
-#ifdef ALLOW_SMALL_FRAMELENGTH
-#ifdef FIXED_POINT
- real_t scale, b_scale = 0;
-#endif
-#endif
- ALIGN complex_t Z1[512];
- complex_t *sincos = mdct->sincos;
-
- uint16_t N = mdct->N;
- uint16_t N2 = N >> 1;
- uint16_t N4 = N >> 2;
- uint16_t N8 = N >> 3;
-
-#ifdef PROFILE
- int64_t count1, count2 = faad_get_ts();
-#endif
-
-#ifdef ALLOW_SMALL_FRAMELENGTH
-#ifdef FIXED_POINT
- /* detect non-power of 2 */
- if (N & (N-1))
- {
- /* adjust scale for non-power of 2 MDCT */
- /* 2048/1920 */
- b_scale = 1;
- scale = COEF_CONST(1.0666666666666667);
- }
-#endif
-#endif
-
- /* pre-IFFT complex multiplication */
- for (k = 0; k < N4; k++)
- {
- ComplexMult(&IM(Z1[k]), &RE(Z1[k]),
- X_in[2*k], X_in[N2 - 1 - 2*k], RE(sincos[k]), IM(sincos[k]));
- }
-
-#ifdef PROFILE
- count1 = faad_get_ts();
-#endif
-
- /* complex IFFT, any non-scaling FFT can be used here */
- cfftb(mdct->cfft, Z1);
-
-#ifdef PROFILE
- count1 = faad_get_ts() - count1;
-#endif
-
- /* post-IFFT complex multiplication */
- for (k = 0; k < N4; k++)
- {
- RE(x) = RE(Z1[k]);
- IM(x) = IM(Z1[k]);
- ComplexMult(&IM(Z1[k]), &RE(Z1[k]),
- IM(x), RE(x), RE(sincos[k]), IM(sincos[k]));
-
-#ifdef ALLOW_SMALL_FRAMELENGTH
-#ifdef FIXED_POINT
- /* non-power of 2 MDCT scaling */
- if (b_scale)
- {
- RE(Z1[k]) = MUL_C(RE(Z1[k]), scale);
- IM(Z1[k]) = MUL_C(IM(Z1[k]), scale);
- }
-#endif
-#endif
- }
-
- /* reordering */
- for (k = 0; k < N8; k+=2)
- {
- X_out[ 2*k] = IM(Z1[N8 + k]);
- X_out[ 2 + 2*k] = IM(Z1[N8 + 1 + k]);
-
- X_out[ 1 + 2*k] = -RE(Z1[N8 - 1 - k]);
- X_out[ 3 + 2*k] = -RE(Z1[N8 - 2 - k]);
-
- X_out[N4 + 2*k] = RE(Z1[ k]);
- X_out[N4 + + 2 + 2*k] = RE(Z1[ 1 + k]);
-
- X_out[N4 + 1 + 2*k] = -IM(Z1[N4 - 1 - k]);
- X_out[N4 + 3 + 2*k] = -IM(Z1[N4 - 2 - k]);
-
- X_out[N2 + 2*k] = RE(Z1[N8 + k]);
- X_out[N2 + + 2 + 2*k] = RE(Z1[N8 + 1 + k]);
-
- X_out[N2 + 1 + 2*k] = -IM(Z1[N8 - 1 - k]);
- X_out[N2 + 3 + 2*k] = -IM(Z1[N8 - 2 - k]);
-
- X_out[N2 + N4 + 2*k] = -IM(Z1[ k]);
- X_out[N2 + N4 + 2 + 2*k] = -IM(Z1[ 1 + k]);
-
- X_out[N2 + N4 + 1 + 2*k] = RE(Z1[N4 - 1 - k]);
- X_out[N2 + N4 + 3 + 2*k] = RE(Z1[N4 - 2 - k]);
- }
-
-#ifdef PROFILE
- count2 = faad_get_ts() - count2;
- mdct->fft_cycles += count1;
- mdct->cycles += (count2 - count1);
-#endif
-}
-
-#ifdef LTP_DEC
-void faad_mdct(mdct_info *mdct, real_t *X_in, real_t *X_out)
-{
- uint16_t k;
-
- complex_t x;
- ALIGN complex_t Z1[512];
- complex_t *sincos = mdct->sincos;
-
- uint16_t N = mdct->N;
- uint16_t N2 = N >> 1;
- uint16_t N4 = N >> 2;
- uint16_t N8 = N >> 3;
-
-#ifndef FIXED_POINT
- real_t scale = REAL_CONST(N);
-#else
- real_t scale = REAL_CONST(4.0/N);
-#endif
-
-#ifdef ALLOW_SMALL_FRAMELENGTH
-#ifdef FIXED_POINT
- /* detect non-power of 2 */
- if (N & (N-1))
- {
- /* adjust scale for non-power of 2 MDCT */
- /* *= sqrt(2048/1920) */
- scale = MUL_C(scale, COEF_CONST(1.0327955589886444));
- }
-#endif
-#endif
-
- /* pre-FFT complex multiplication */
- for (k = 0; k < N8; k++)
- {
- uint16_t n = k << 1;
- RE(x) = X_in[N - N4 - 1 - n] + X_in[N - N4 + n];
- IM(x) = X_in[ N4 + n] - X_in[ N4 - 1 - n];
-
- ComplexMult(&RE(Z1[k]), &IM(Z1[k]),
- RE(x), IM(x), RE(sincos[k]), IM(sincos[k]));
-
- RE(Z1[k]) = MUL_R(RE(Z1[k]), scale);
- IM(Z1[k]) = MUL_R(IM(Z1[k]), scale);
-
- RE(x) = X_in[N2 - 1 - n] - X_in[ n];
- IM(x) = X_in[N2 + n] + X_in[N - 1 - n];
-
- ComplexMult(&RE(Z1[k + N8]), &IM(Z1[k + N8]),
- RE(x), IM(x), RE(sincos[k + N8]), IM(sincos[k + N8]));
-
- RE(Z1[k + N8]) = MUL_R(RE(Z1[k + N8]), scale);
- IM(Z1[k + N8]) = MUL_R(IM(Z1[k + N8]), scale);
- }
-
- /* complex FFT, any non-scaling FFT can be used here */
- cfftf(mdct->cfft, Z1);
-
- /* post-FFT complex multiplication */
- for (k = 0; k < N4; k++)
- {
- uint16_t n = k << 1;
- ComplexMult(&RE(x), &IM(x),
- RE(Z1[k]), IM(Z1[k]), RE(sincos[k]), IM(sincos[k]));
-
- X_out[ n] = -RE(x);
- X_out[N2 - 1 - n] = IM(x);
- X_out[N2 + n] = -IM(x);
- X_out[N - 1 - n] = RE(x);
- }
-}
-#endif
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