| /* |
| * 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 */ |