| 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 | |
| 24 | static 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 | |
| 59 | av_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 | } |