| /* |
| * copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at> |
| * |
| * 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 "fft.h" |
| #include "synth_filter.h" |
| |
| static void synth_filter_float(FFTContext *imdct, |
| float *synth_buf_ptr, int *synth_buf_offset, |
| float synth_buf2[32], const float window[512], |
| float out[32], const float in[32], float scale) |
| { |
| float *synth_buf= synth_buf_ptr + *synth_buf_offset; |
| int i, j; |
| |
| imdct->imdct_half(imdct, synth_buf, in); |
| |
| for (i = 0; i < 16; i++){ |
| float a= synth_buf2[i ]; |
| float b= synth_buf2[i + 16]; |
| float c= 0; |
| float d= 0; |
| for (j = 0; j < 512 - *synth_buf_offset; j += 64){ |
| a += window[i + j ]*(-synth_buf[15 - i + j ]); |
| b += window[i + j + 16]*( synth_buf[ i + j ]); |
| c += window[i + j + 32]*( synth_buf[16 + i + j ]); |
| d += window[i + j + 48]*( synth_buf[31 - i + j ]); |
| } |
| for ( ; j < 512; j += 64){ |
| a += window[i + j ]*(-synth_buf[15 - i + j - 512]); |
| b += window[i + j + 16]*( synth_buf[ i + j - 512]); |
| c += window[i + j + 32]*( synth_buf[16 + i + j - 512]); |
| d += window[i + j + 48]*( synth_buf[31 - i + j - 512]); |
| } |
| out[i ] = a*scale; |
| out[i + 16] = b*scale; |
| synth_buf2[i ] = c; |
| synth_buf2[i + 16] = d; |
| } |
| *synth_buf_offset= (*synth_buf_offset - 32)&511; |
| } |
| |
| av_cold void ff_synth_filter_init(SynthFilterContext *c) |
| { |
| c->synth_filter_float = synth_filter_float; |
| |
| if (ARCH_ARM) ff_synth_filter_init_arm(c); |
| } |