yading@10: /* yading@10: * Atrac common functions yading@10: * Copyright (c) 2006-2008 Maxim Poliakovski yading@10: * Copyright (c) 2006-2008 Benjamin Larsson yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: /** yading@10: * @file yading@10: */ yading@10: yading@10: #include yading@10: #include yading@10: #include yading@10: #include yading@10: yading@10: #include "avcodec.h" yading@10: #include "atrac.h" yading@10: yading@10: float ff_atrac_sf_table[64]; yading@10: static float qmf_window[48]; yading@10: yading@10: static const float qmf_48tap_half[24] = { yading@10: -0.00001461907, -0.00009205479,-0.000056157569,0.00030117269, yading@10: 0.0002422519, -0.00085293897,-0.0005205574, 0.0020340169, yading@10: 0.00078333891, -0.0042153862, -0.00075614988, 0.0078402944, yading@10: -0.000061169922,-0.01344162, 0.0024626821, 0.021736089, yading@10: -0.007801671, -0.034090221, 0.01880949, 0.054326009, yading@10: -0.043596379, -0.099384367, 0.13207909, 0.46424159 yading@10: }; yading@10: yading@10: /** yading@10: * Generate common tables yading@10: */ yading@10: yading@10: void ff_atrac_generate_tables(void) yading@10: { yading@10: int i; yading@10: float s; yading@10: yading@10: /* Generate scale factors */ yading@10: if (!ff_atrac_sf_table[63]) yading@10: for (i=0 ; i<64 ; i++) yading@10: ff_atrac_sf_table[i] = pow(2.0, (i - 15) / 3.0); yading@10: yading@10: /* Generate the QMF window. */ yading@10: if (!qmf_window[47]) yading@10: for (i=0 ; i<24; i++) { yading@10: s = qmf_48tap_half[i] * 2.0; yading@10: qmf_window[i] = qmf_window[47 - i] = s; yading@10: } yading@10: } yading@10: yading@10: yading@10: /** yading@10: * Quadrature mirror synthesis filter. yading@10: * yading@10: * @param inlo lower part of spectrum yading@10: * @param inhi higher part of spectrum yading@10: * @param nIn size of spectrum buffer yading@10: * @param pOut out buffer yading@10: * @param delayBuf delayBuf buffer yading@10: * @param temp temp buffer yading@10: */ yading@10: yading@10: yading@10: void ff_atrac_iqmf (float *inlo, float *inhi, unsigned int nIn, float *pOut, float *delayBuf, float *temp) yading@10: { yading@10: int i, j; yading@10: float *p1, *p3; yading@10: yading@10: memcpy(temp, delayBuf, 46*sizeof(float)); yading@10: yading@10: p3 = temp + 46; yading@10: yading@10: /* loop1 */ yading@10: for(i=0; i