diff options
Diffstat (limited to 'ffmpeg1/libavcodec/mdct.c')
| -rw-r--r-- | ffmpeg1/libavcodec/mdct.c | 203 |
1 files changed, 0 insertions, 203 deletions
diff --git a/ffmpeg1/libavcodec/mdct.c b/ffmpeg1/libavcodec/mdct.c deleted file mode 100644 index 2232024..0000000 --- a/ffmpeg1/libavcodec/mdct.c +++ /dev/null @@ -1,203 +0,0 @@ -/* - * 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 <stdlib.h> -#include <string.h> -#include "libavutil/common.h" -#include "libavutil/mathematics.h" -#include "fft.h" -#include "fft-internal.h" - -/** - * @file - * MDCT/IMDCT transforms. - */ - -#if CONFIG_FFT_FLOAT -# define RSCALE(x) (x) -#else -# define RSCALE(x) ((x) >> 1) -#endif - -/** - * 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->mdct_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->mdct_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;i<n4;i++) { - alpha = 2 * M_PI * (i + theta) / n; - s->tcos[i*tstep] = FIX15(-cos(alpha) * scale); - s->tsin[i*tstep] = FIX15(-sin(alpha) * scale); - } - return 0; - fail: - ff_mdct_end(s); - return -1; -} - -/** - * 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; - } - s->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; - FFTDouble 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;i<n8;i++) { - re = RSCALE(-input[2*i+n3] - input[n3-1-2*i]); - im = RSCALE(-input[n4+2*i] + input[n4-1-2*i]); - j = revtab[i]; - CMUL(x[j].re, x[j].im, re, im, -tcos[i], tsin[i]); - - re = RSCALE( input[2*i] - input[n2-1-2*i]); - im = RSCALE(-input[n2+2*i] - input[ n-1-2*i]); - j = revtab[n8 + i]; - CMUL(x[j].re, x[j].im, re, im, -tcos[n8 + i], tsin[n8 + i]); - } - - s->fft_calc(s, x); - - /* post rotation */ - for(i=0;i<n8;i++) { - FFTSample r0, i0, r1, i1; - CMUL(i1, r0, x[n8-i-1].re, x[n8-i-1].im, -tsin[n8-i-1], -tcos[n8-i-1]); - CMUL(i0, r1, x[n8+i ].re, x[n8+i ].im, -tsin[n8+i ], -tcos[n8+i ]); - x[n8-i-1].re = r0; - x[n8-i-1].im = i0; - x[n8+i ].re = r1; - x[n8+i ].im = i1; - } -} - -av_cold void ff_mdct_end(FFTContext *s) -{ - av_freep(&s->tcos); - ff_fft_end(s); -} |