1/* 2 * copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at> 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21#include "fft.h" 22#include "synth_filter.h" 23 24static void synth_filter_float(FFTContext *imdct, 25 float *synth_buf_ptr, int *synth_buf_offset, 26 float synth_buf2[32], const float window[512], 27 float out[32], const float in[32], float scale) 28{ 29 float *synth_buf= synth_buf_ptr + *synth_buf_offset; 30 int i, j; 31 32 imdct->imdct_half(imdct, synth_buf, in); 33 34 for (i = 0; i < 16; i++){ 35 float a= synth_buf2[i ]; 36 float b= synth_buf2[i + 16]; 37 float c= 0; 38 float d= 0; 39 for (j = 0; j < 512 - *synth_buf_offset; j += 64){ 40 a += window[i + j ]*(-synth_buf[15 - i + j ]); 41 b += window[i + j + 16]*( synth_buf[ i + j ]); 42 c += window[i + j + 32]*( synth_buf[16 + i + j ]); 43 d += window[i + j + 48]*( synth_buf[31 - i + j ]); 44 } 45 for ( ; j < 512; j += 64){ 46 a += window[i + j ]*(-synth_buf[15 - i + j - 512]); 47 b += window[i + j + 16]*( synth_buf[ i + j - 512]); 48 c += window[i + j + 32]*( synth_buf[16 + i + j - 512]); 49 d += window[i + j + 48]*( synth_buf[31 - i + j - 512]); 50 } 51 out[i ] = a*scale; 52 out[i + 16] = b*scale; 53 synth_buf2[i ] = c; 54 synth_buf2[i + 16] = d; 55 } 56 *synth_buf_offset= (*synth_buf_offset - 32)&511; 57} 58 59av_cold void ff_synth_filter_init(SynthFilterContext *c) 60{ 61 c->synth_filter_float = synth_filter_float; 62 63 if (ARCH_ARM) ff_synth_filter_init_arm(c); 64 if (ARCH_X86) ff_synth_filter_init_x86(c); 65} 66