mirror of https://github.com/FFmpeg/FFmpeg.git
Lynne
10 months ago
parent
b1718ce0f9
commit
49e7be1e37
9 changed files with 306 additions and 230 deletions
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/*
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* AAC decoder |
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* Copyright (c) 2005-2006 Oded Shimon ( ods15 ods15 dyndns org ) |
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* Copyright (c) 2006-2007 Maxim Gavrilov ( maxim.gavrilov gmail com ) |
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* Copyright (c) 2008-2013 Alex Converse <alex.converse@gmail.com> |
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* |
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* AAC LATM decoder |
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* Copyright (c) 2008-2010 Paul Kendall <paul@kcbbs.gen.nz> |
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* Copyright (c) 2010 Janne Grunau <janne-libav@jannau.net> |
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* |
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* AAC decoder fixed-point implementation |
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* Copyright (c) 2013 |
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* MIPS Technologies, Inc., California. |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#ifndef AVCODEC_AAC_AACDEC_FIXED_PREDICTION_H |
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#define AVCODEC_AAC_AACDEC_FIXED_PREDICTION_H |
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static av_always_inline SoftFloat flt16_round(SoftFloat pf) |
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{ |
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SoftFloat tmp; |
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int s; |
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tmp.exp = pf.exp; |
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s = pf.mant >> 31; |
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tmp.mant = (pf.mant ^ s) - s; |
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tmp.mant = (tmp.mant + 0x00200000U) & 0xFFC00000U; |
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tmp.mant = (tmp.mant ^ s) - s; |
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return tmp; |
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} |
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static av_always_inline SoftFloat flt16_even(SoftFloat pf) |
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{ |
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SoftFloat tmp; |
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int s; |
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tmp.exp = pf.exp; |
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s = pf.mant >> 31; |
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tmp.mant = (pf.mant ^ s) - s; |
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tmp.mant = (tmp.mant + 0x001FFFFFU + (tmp.mant & 0x00400000U >> 16)) & 0xFFC00000U; |
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tmp.mant = (tmp.mant ^ s) - s; |
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return tmp; |
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} |
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static av_always_inline SoftFloat flt16_trunc(SoftFloat pf) |
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{ |
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SoftFloat pun; |
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int s; |
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pun.exp = pf.exp; |
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s = pf.mant >> 31; |
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pun.mant = (pf.mant ^ s) - s; |
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pun.mant = pun.mant & 0xFFC00000U; |
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pun.mant = (pun.mant ^ s) - s; |
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return pun; |
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} |
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static av_always_inline void predict(PredictorState *ps, int *coef, |
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int output_enable) |
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{ |
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const SoftFloat a = { 1023410176, 0 }; // 61.0 / 64
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const SoftFloat alpha = { 973078528, 0 }; // 29.0 / 32
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SoftFloat e0, e1; |
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SoftFloat pv; |
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SoftFloat k1, k2; |
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SoftFloat r0 = ps->r0, r1 = ps->r1; |
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SoftFloat cor0 = ps->cor0, cor1 = ps->cor1; |
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SoftFloat var0 = ps->var0, var1 = ps->var1; |
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SoftFloat tmp; |
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if (var0.exp > 1 || (var0.exp == 1 && var0.mant > 0x20000000)) { |
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k1 = av_mul_sf(cor0, flt16_even(av_div_sf(a, var0))); |
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} |
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else { |
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k1.mant = 0; |
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k1.exp = 0; |
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} |
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if (var1.exp > 1 || (var1.exp == 1 && var1.mant > 0x20000000)) { |
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k2 = av_mul_sf(cor1, flt16_even(av_div_sf(a, var1))); |
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} |
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else { |
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k2.mant = 0; |
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k2.exp = 0; |
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} |
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tmp = av_mul_sf(k1, r0); |
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pv = flt16_round(av_add_sf(tmp, av_mul_sf(k2, r1))); |
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if (output_enable) { |
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int shift = 28 - pv.exp; |
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if (shift < 31) { |
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if (shift > 0) { |
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*coef += (unsigned)((pv.mant + (1 << (shift - 1))) >> shift); |
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} else |
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*coef += (unsigned)pv.mant << -shift; |
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} |
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} |
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e0 = av_int2sf(*coef, 2); |
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e1 = av_sub_sf(e0, tmp); |
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ps->cor1 = flt16_trunc(av_add_sf(av_mul_sf(alpha, cor1), av_mul_sf(r1, e1))); |
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tmp = av_add_sf(av_mul_sf(r1, r1), av_mul_sf(e1, e1)); |
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tmp.exp--; |
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ps->var1 = flt16_trunc(av_add_sf(av_mul_sf(alpha, var1), tmp)); |
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ps->cor0 = flt16_trunc(av_add_sf(av_mul_sf(alpha, cor0), av_mul_sf(r0, e0))); |
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tmp = av_add_sf(av_mul_sf(r0, r0), av_mul_sf(e0, e0)); |
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tmp.exp--; |
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ps->var0 = flt16_trunc(av_add_sf(av_mul_sf(alpha, var0), tmp)); |
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ps->r1 = flt16_trunc(av_mul_sf(a, av_sub_sf(r0, av_mul_sf(k1, e0)))); |
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ps->r0 = flt16_trunc(av_mul_sf(a, e0)); |
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} |
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static av_always_inline void reset_predict_state(PredictorState *ps) |
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{ |
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ps->r0.mant = 0; |
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ps->r0.exp = 0; |
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ps->r1.mant = 0; |
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ps->r1.exp = 0; |
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ps->cor0.mant = 0; |
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ps->cor0.exp = 0; |
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ps->cor1.mant = 0; |
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ps->cor1.exp = 0; |
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ps->var0.mant = 0x20000000; |
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ps->var0.exp = 1; |
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ps->var1.mant = 0x20000000; |
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ps->var1.exp = 1; |
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} |
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#endif /* AVCODEC_AAC_AACDEC_FIXED_PREDICTION_H */ |
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@ -0,0 +1,100 @@ |
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/*
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* AAC decoder |
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* Copyright (c) 2005-2006 Oded Shimon ( ods15 ods15 dyndns org ) |
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* Copyright (c) 2006-2007 Maxim Gavrilov ( maxim.gavrilov gmail com ) |
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* Copyright (c) 2008-2013 Alex Converse <alex.converse@gmail.com> |
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* |
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* AAC LATM decoder |
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* Copyright (c) 2008-2010 Paul Kendall <paul@kcbbs.gen.nz> |
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* Copyright (c) 2010 Janne Grunau <janne-libav@jannau.net> |
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* |
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* AAC decoder fixed-point implementation |
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* Copyright (c) 2013 |
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* MIPS Technologies, Inc., California. |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#ifndef AVCODEC_AAC_AACDEC_FLOAT_PREDICTION_H |
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#define AVCODEC_AAC_AACDEC_FLOAT_PREDICTION_H |
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static av_always_inline float flt16_round(float pf) |
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{ |
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union av_intfloat32 tmp; |
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tmp.f = pf; |
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tmp.i = (tmp.i + 0x00008000U) & 0xFFFF0000U; |
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return tmp.f; |
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} |
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static av_always_inline float flt16_even(float pf) |
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{ |
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union av_intfloat32 tmp; |
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tmp.f = pf; |
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tmp.i = (tmp.i + 0x00007FFFU + (tmp.i & 0x00010000U >> 16)) & 0xFFFF0000U; |
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return tmp.f; |
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} |
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static av_always_inline float flt16_trunc(float pf) |
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{ |
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union av_intfloat32 pun; |
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pun.f = pf; |
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pun.i &= 0xFFFF0000U; |
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return pun.f; |
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} |
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static av_always_inline void predict(PredictorState *ps, float *coef, |
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int output_enable) |
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{ |
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const float a = 0.953125; // 61.0 / 64
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const float alpha = 0.90625; // 29.0 / 32
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float e0, e1; |
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float pv; |
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float k1, k2; |
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float r0 = ps->r0, r1 = ps->r1; |
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float cor0 = ps->cor0, cor1 = ps->cor1; |
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float var0 = ps->var0, var1 = ps->var1; |
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k1 = var0 > 1 ? cor0 * flt16_even(a / var0) : 0; |
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k2 = var1 > 1 ? cor1 * flt16_even(a / var1) : 0; |
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pv = flt16_round(k1 * r0 + k2 * r1); |
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if (output_enable) |
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*coef += pv; |
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e0 = *coef; |
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e1 = e0 - k1 * r0; |
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ps->cor1 = flt16_trunc(alpha * cor1 + r1 * e1); |
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ps->var1 = flt16_trunc(alpha * var1 + 0.5f * (r1 * r1 + e1 * e1)); |
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ps->cor0 = flt16_trunc(alpha * cor0 + r0 * e0); |
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ps->var0 = flt16_trunc(alpha * var0 + 0.5f * (r0 * r0 + e0 * e0)); |
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ps->r1 = flt16_trunc(a * (r0 - k1 * e0)); |
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ps->r0 = flt16_trunc(a * e0); |
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} |
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static av_always_inline void reset_predict_state(PredictorState *ps) |
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{ |
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ps->r0 = 0.0f; |
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ps->r1 = 0.0f; |
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ps->cor0 = 0.0f; |
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ps->cor1 = 0.0f; |
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ps->var0 = 1.0f; |
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ps->var1 = 1.0f; |
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} |
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#endif /* AVCODEC_AAC_AACDEC_FLOAT_PREDICTION_H */ |
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