/* * AAC decoder * Copyright (c) 2005-2006 Oded Shimon ( ods15 ods15 dyndns org ) * Copyright (c) 2006-2007 Maxim Gavrilov ( maxim.gavrilov gmail com ) * Copyright (c) 2008-2013 Alex Converse <alex.converse@gmail.com> * * AAC LATM decoder * Copyright (c) 2008-2010 Paul Kendall <paul@kcbbs.gen.nz> * Copyright (c) 2010      Janne Grunau <janne-libav@jannau.net> * * AAC decoder fixed-point implementation * Copyright (c) 2013 *      MIPS Technologies, Inc., California. * * 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 */ #ifndef AVCODEC_AAC_AACDEC_FIXED_DEQUANT_H#define AVCODEC_AAC_AACDEC_FIXED_DEQUANT_H #include "aacdec_tab.h" static void inline vector_pow43(int *coefs, int len){    int i, coef;     for (i=0; i<len; i++) {        coef = coefs[i];        if (coef < 0)            coef = -(int)ff_cbrt_tab_fixed[(-coef) & 8191];        else            coef =  (int)ff_cbrt_tab_fixed[  coef  & 8191];        coefs[i] = coef;    }} /* 2^0, 2^0.25, 2^0.5, 2^0.75 */static const int exp2tab[4] = {    Q31(1.0000000000/2), Q31(1.1892071150/2),    Q31(1.4142135624/2), Q31(1.6817928305/2)}; static void inline subband_scale(int *dst, int *src, int scale,                                 int offset, int len, void *log_context){    int ssign = scale < 0 ? -1 : 1;    int s = FFABS(scale);    unsigned int round;    int i, out, c = exp2tab[s & 3];     s = offset - (s >> 2);     if (s > 31) {        for (i=0; i<len; i++) {            dst[i] = 0;        }    } else if (s > 0) {        round = 1 << (s-1);        for (i=0; i<len; i++) {            out = (int)(((int64_t)src[i] * c) >> 32);            dst[i] = ((int)(out+round) >> s) * ssign;        }    } else if (s > -32) {        s = s + 32;        round = 1U << (s-1);        for (i=0; i<len; i++) {            out = (int)((int64_t)((int64_t)src[i] * c + round) >> s);            dst[i] = out * (unsigned)ssign;        }    } else {        av_log(log_context, AV_LOG_ERROR, "Overflow in subband_scale()\n");    }} static void noise_scale(int *coefs, int scale, int band_energy, int len){    int s = -scale;    unsigned int round;    int i, out, c = exp2tab[s & 3];    int nlz = 0;     av_assert0(s >= 0);    while (band_energy > 0x7fff) {        band_energy >>= 1;        nlz++;    }    c /= band_energy;    s = 21 + nlz - (s >> 2);     if (s > 31) {        for (i=0; i<len; i++) {            coefs[i] = 0;        }    } else if (s >= 0) {        round = s ? 1 << (s-1) : 0;        for (i=0; i<len; i++) {            out = (int)(((int64_t)coefs[i] * c) >> 32);            coefs[i] = -((int)(out+round) >> s);        }    }    else {        s = s + 32;        if (s > 0) {            round = 1 << (s-1);            for (i=0; i<len; i++) {                out = (int)((int64_t)((int64_t)coefs[i] * c + round) >> s);                coefs[i] = -out;            }        } else {            for (i=0; i<len; i++)                coefs[i] = -(int64_t)coefs[i] * c * (1 << -s);        }    }} static inline int *DEC_SPAIR(int *dst, unsigned idx){    dst[0] = (idx & 15) - 4;    dst[1] = (idx >> 4 & 15) - 4;     return dst + 2;} static inline int *DEC_SQUAD(int *dst, unsigned idx){    dst[0] = (idx & 3) - 1;    dst[1] = (idx >> 2 & 3) - 1;    dst[2] = (idx >> 4 & 3) - 1;    dst[3] = (idx >> 6 & 3) - 1;     return dst + 4;} static inline int *DEC_UPAIR(int *dst, unsigned idx, unsigned sign){    dst[0] = (idx & 15) * (1 - (sign & 0xFFFFFFFE));    dst[1] = (idx >> 4 & 15) * (1 - ((sign & 1) * 2));     return dst + 2;} static inline int *DEC_UQUAD(int *dst, unsigned idx, unsigned sign){    unsigned nz = idx >> 12;     dst[0] = (idx & 3) * (1 + (((int)sign >> 31) * 2));    sign <<= nz & 1;    nz >>= 1;    dst[1] = (idx >> 2 & 3) * (1 + (((int)sign >> 31) * 2));    sign <<= nz & 1;    nz >>= 1;    dst[2] = (idx >> 4 & 3) * (1 + (((int)sign >> 31) * 2));    sign <<= nz & 1;    nz >>= 1;    dst[3] = (idx >> 6 & 3) * (1 + (((int)sign >> 31) * 2));     return dst + 4;} #endif /* AVCODEC_AAC_AACDEC_FIXED_DEQUANT_H */