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Diffstat (limited to 'contrib/ffmpeg/libavcodec/mdct.c')
| -rw-r--r-- | contrib/ffmpeg/libavcodec/mdct.c | 177 |
1 files changed, 0 insertions, 177 deletions
diff --git a/contrib/ffmpeg/libavcodec/mdct.c b/contrib/ffmpeg/libavcodec/mdct.c deleted file mode 100644 index de3275289..000000000 --- a/contrib/ffmpeg/libavcodec/mdct.c +++ /dev/null @@ -1,177 +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 "dsputil.h" - -/** - * @file mdct.c - * MDCT/IMDCT transforms. - */ - -/** - * init MDCT or IMDCT computation. - */ -int ff_mdct_init(MDCTContext *s, int nbits, int inverse) -{ - int n, n4, i; - float alpha; - - memset(s, 0, sizeof(*s)); - n = 1 << nbits; - s->nbits = nbits; - s->n = n; - n4 = n >> 2; - s->tcos = av_malloc(n4 * sizeof(FFTSample)); - if (!s->tcos) - goto fail; - s->tsin = av_malloc(n4 * sizeof(FFTSample)); - if (!s->tsin) - goto fail; - - for(i=0;i<n4;i++) { - alpha = 2 * M_PI * (i + 1.0 / 8.0) / n; - s->tcos[i] = -cos(alpha); - s->tsin[i] = -sin(alpha); - } - if (ff_fft_init(&s->fft, s->nbits - 2, inverse) < 0) - goto fail; - return 0; - fail: - av_freep(&s->tcos); - av_freep(&s->tsin); - return -1; -} - -/* complex multiplication: p = a * b */ -#define CMUL(pre, pim, are, aim, bre, bim) \ -{\ - float _are = (are);\ - float _aim = (aim);\ - float _bre = (bre);\ - float _bim = (bim);\ - (pre) = _are * _bre - _aim * _bim;\ - (pim) = _are * _bim + _aim * _bre;\ -} - -/** - * Compute inverse MDCT of size N = 2^nbits - * @param output N samples - * @param input N/2 samples - * @param tmp N/2 samples - */ -void ff_imdct_calc(MDCTContext *s, FFTSample *output, - const FFTSample *input, FFTSample *tmp) -{ - int k, n8, n4, n2, n, j; - const uint16_t *revtab = s->fft.revtab; - const FFTSample *tcos = s->tcos; - const FFTSample *tsin = s->tsin; - const FFTSample *in1, *in2; - FFTComplex *z = (FFTComplex *)tmp; - - n = 1 << s->nbits; - 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->fft, z); - - /* post rotation + reordering */ - /* XXX: optimize */ - for(k = 0; k < n4; k++) { - CMUL(z[k].re, z[k].im, z[k].re, z[k].im, tcos[k], tsin[k]); - } - for(k = 0; k < n8; k++) { - output[2*k] = -z[n8 + k].im; - output[n2-1-2*k] = z[n8 + k].im; - - output[2*k+1] = z[n8-1-k].re; - output[n2-1-2*k-1] = -z[n8-1-k].re; - - output[n2 + 2*k]=-z[k+n8].re; - output[n-1- 2*k]=-z[k+n8].re; - - output[n2 + 2*k+1]=z[n8-k-1].im; - output[n-2 - 2 * k] = z[n8-k-1].im; - } -} - -/** - * Compute MDCT of size N = 2^nbits - * @param input N samples - * @param out N/2 samples - * @param tmp temporary storage of N/2 samples - */ -void ff_mdct_calc(MDCTContext *s, FFTSample *out, - const FFTSample *input, FFTSample *tmp) -{ - int i, j, n, n8, n4, n2, n3; - FFTSample re, im, re1, im1; - const uint16_t *revtab = s->fft.revtab; - const FFTSample *tcos = s->tcos; - const FFTSample *tsin = s->tsin; - FFTComplex *x = (FFTComplex *)tmp; - - n = 1 << s->nbits; - n2 = n >> 1; - n4 = n >> 2; - n8 = n >> 3; - n3 = 3 * n4; - - /* pre rotation */ - for(i=0;i<n8;i++) { - re = -input[2*i+3*n4] - input[n3-1-2*i]; - im = -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 = input[2*i] - input[n2-1-2*i]; - im = -(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]); - } - - ff_fft_calc(&s->fft, x); - - /* post rotation */ - for(i=0;i<n4;i++) { - re = x[i].re; - im = x[i].im; - CMUL(re1, im1, re, im, -tsin[i], -tcos[i]); - out[2*i] = im1; - out[n2-1-2*i] = re1; - } -} - -void ff_mdct_end(MDCTContext *s) -{ - av_freep(&s->tcos); - av_freep(&s->tsin); - ff_fft_end(&s->fft); -} |