From cf43e5083b9e0f87de262ea31fd8067225ebfcda Mon Sep 17 00:00:00 2001 From: Mohamed Tarek Date: Fri, 30 Apr 2010 11:11:56 +0000 Subject: Add libwmapro to apps/codecs. These files comprise a set of unmodified files needed from ffmpeg's libavcodec and libavutil to compile and use the wma pro decoder standalone. The files were taken from ffmpeg's svn r22886 dated 15 April 2010. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25763 a1c6a512-1295-4272-9138-f99709370657 --- apps/codecs/libwmapro/mdct.c | 232 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 232 insertions(+) create mode 100644 apps/codecs/libwmapro/mdct.c (limited to 'apps/codecs/libwmapro/mdct.c') diff --git a/apps/codecs/libwmapro/mdct.c b/apps/codecs/libwmapro/mdct.c new file mode 100644 index 0000000000..9d0a59dc84 --- /dev/null +++ b/apps/codecs/libwmapro/mdct.c @@ -0,0 +1,232 @@ +/* + * MDCT/IMDCT transforms + * Copyright (c) 2002 Fabrice Bellard + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include +#include +#include "libavutil/common.h" +#include "libavutil/mathematics.h" +#include "fft.h" + +/** + * @file libavcodec/mdct.c + * MDCT/IMDCT transforms. + */ + +// Generate a Kaiser-Bessel Derived Window. +#define BESSEL_I0_ITER 50 // default: 50 iterations of Bessel I0 approximation +av_cold void ff_kbd_window_init(float *window, float alpha, int n) +{ + int i, j; + double sum = 0.0, bessel, tmp; + double local_window[n]; + double alpha2 = (alpha * M_PI / n) * (alpha * M_PI / n); + + for (i = 0; i < n; i++) { + tmp = i * (n - i) * alpha2; + bessel = 1.0; + for (j = BESSEL_I0_ITER; j > 0; j--) + bessel = bessel * tmp / (j * j) + 1; + sum += bessel; + local_window[i] = sum; + } + + sum++; + for (i = 0; i < n; i++) + window[i] = sqrt(local_window[i] / sum); +} + +#include "mdct_tablegen.h" + +/** + * init MDCT or IMDCT computation. + */ +av_cold int ff_mdct_init(FFTContext *s, int nbits, int inverse, double scale) +{ + int n, n4, i; + double alpha, theta; + int tstep; + + memset(s, 0, sizeof(*s)); + n = 1 << nbits; + s->mdct_bits = nbits; + s->mdct_size = n; + n4 = n >> 2; + s->permutation = FF_MDCT_PERM_NONE; + + if (ff_fft_init(s, s->mdct_bits - 2, inverse) < 0) + goto fail; + + s->tcos = av_malloc(n/2 * sizeof(FFTSample)); + if (!s->tcos) + goto fail; + + switch (s->permutation) { + case FF_MDCT_PERM_NONE: + s->tsin = s->tcos + n4; + tstep = 1; + break; + case FF_MDCT_PERM_INTERLEAVE: + s->tsin = s->tcos + 1; + tstep = 2; + break; + default: + goto fail; + } + + theta = 1.0 / 8.0 + (scale < 0 ? n4 : 0); + scale = sqrt(fabs(scale)); + for(i=0;itcos[i*tstep] = -cos(alpha) * scale; + s->tsin[i*tstep] = -sin(alpha) * scale; + } + return 0; + fail: + ff_mdct_end(s); + return -1; +} + +/* complex multiplication: p = a * b */ +#define CMUL(pre, pim, are, aim, bre, bim) \ +{\ + FFTSample _are = (are);\ + FFTSample _aim = (aim);\ + FFTSample _bre = (bre);\ + FFTSample _bim = (bim);\ + (pre) = _are * _bre - _aim * _bim;\ + (pim) = _are * _bim + _aim * _bre;\ +} + +/** + * Compute the middle half of the inverse MDCT of size N = 2^nbits, + * thus excluding the parts that can be derived by symmetry + * @param output N/2 samples + * @param input N/2 samples + */ +void ff_imdct_half_c(FFTContext *s, FFTSample *output, const FFTSample *input) +{ + int k, n8, n4, n2, n, j; + const uint16_t *revtab = s->revtab; + const FFTSample *tcos = s->tcos; + const FFTSample *tsin = s->tsin; + const FFTSample *in1, *in2; + FFTComplex *z = (FFTComplex *)output; + + n = 1 << s->mdct_bits; + n2 = n >> 1; + n4 = n >> 2; + n8 = n >> 3; + + /* pre rotation */ + in1 = input; + in2 = input + n2 - 1; + for(k = 0; k < n4; k++) { + j=revtab[k]; + CMUL(z[j].re, z[j].im, *in2, *in1, tcos[k], tsin[k]); + in1 += 2; + in2 -= 2; + } + ff_fft_calc(s, z); + + /* post rotation + reordering */ + for(k = 0; k < n8; k++) { + FFTSample r0, i0, r1, i1; + CMUL(r0, i1, z[n8-k-1].im, z[n8-k-1].re, tsin[n8-k-1], tcos[n8-k-1]); + CMUL(r1, i0, z[n8+k ].im, z[n8+k ].re, tsin[n8+k ], tcos[n8+k ]); + z[n8-k-1].re = r0; + z[n8-k-1].im = i0; + z[n8+k ].re = r1; + z[n8+k ].im = i1; + } +} + +/** + * Compute inverse MDCT of size N = 2^nbits + * @param output N samples + * @param input N/2 samples + */ +void ff_imdct_calc_c(FFTContext *s, FFTSample *output, const FFTSample *input) +{ + int k; + int n = 1 << s->mdct_bits; + int n2 = n >> 1; + int n4 = n >> 2; + + ff_imdct_half_c(s, output+n4, input); + + for(k = 0; k < n4; k++) { + output[k] = -output[n2-k-1]; + output[n-k-1] = output[n2+k]; + } +} + +/** + * Compute MDCT of size N = 2^nbits + * @param input N samples + * @param out N/2 samples + */ +void ff_mdct_calc_c(FFTContext *s, FFTSample *out, const FFTSample *input) +{ + int i, j, n, n8, n4, n2, n3; + FFTSample re, im; + const uint16_t *revtab = s->revtab; + const FFTSample *tcos = s->tcos; + const FFTSample *tsin = s->tsin; + FFTComplex *x = (FFTComplex *)out; + + n = 1 << s->mdct_bits; + n2 = n >> 1; + n4 = n >> 2; + n8 = n >> 3; + n3 = 3 * n4; + + /* pre rotation */ + for(i=0;itcos); + ff_fft_end(s); +} -- cgit v1.2.3