mirror of https://github.com/FFmpeg/FFmpeg.git
Originally committed as revision 1089 to svn://svn.ffmpeg.org/ffmpeg/trunkpull/126/head
Fabrice Bellard
23 years ago
parent
bb6f569072
commit
6107fa87b4
4 changed files with 206 additions and 121 deletions
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/*
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* Common code between AC3 encoder and decoder |
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* Copyright (c) 2000, 2001, 2002 Fabrice Bellard. |
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* |
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* This library 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 of the License, or (at your option) any later version. |
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* |
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* This library 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 this library; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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#define AC3_MAX_CODED_FRAME_SIZE 3840 /* in bytes */ |
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#define AC3_MAX_CHANNELS 6 /* including LFE channel */ |
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#define NB_BLOCKS 6 /* number of PCM blocks inside an AC3 frame */ |
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#define AC3_FRAME_SIZE (NB_BLOCKS * 256) |
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/* exponent encoding strategy */ |
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#define EXP_REUSE 0 |
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#define EXP_NEW 1 |
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#define EXP_D15 1 |
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#define EXP_D25 2 |
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#define EXP_D45 3 |
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typedef struct AC3BitAllocParameters { |
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int fscod; /* frequency */ |
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int halfratecod; |
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int sgain, sdecay, fdecay, dbknee, floor; |
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int cplfleak, cplsleak; |
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} AC3BitAllocParameters; |
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extern const UINT16 ac3_freqs[3]; |
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extern const UINT16 ac3_bitratetab[19]; |
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extern const INT16 ac3_window[256]; |
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extern const UINT8 sdecaytab[4]; |
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extern const UINT8 fdecaytab[4]; |
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extern const UINT16 sgaintab[4]; |
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extern const UINT16 dbkneetab[4]; |
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extern const UINT16 floortab[8]; |
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extern const UINT16 fgaintab[8]; |
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void ac3_common_init(void); |
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void ac3_parametric_bit_allocation(AC3BitAllocParameters *s, UINT8 *bap, |
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INT8 *exp, int start, int end, |
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int snroffset, int fgain, int is_lfe, |
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int deltbae,int deltnseg,
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UINT8 *deltoffst, UINT8 *deltlen, UINT8 *deltba); |
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@ -1,34 +0,0 @@ |
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#define AC3_FRAME_SIZE (6*256) |
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#define AC3_MAX_CODED_FRAME_SIZE 3840 /* in bytes */ |
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#define AC3_MAX_CHANNELS 6 |
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typedef struct AC3EncodeContext { |
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PutBitContext pb; |
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int nb_channels; |
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int nb_all_channels; |
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int lfe_channel; |
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int bit_rate; |
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int sample_rate; |
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int bsid; |
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int frame_size_min; /* minimum frame size in case rounding is necessary */ |
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int frame_size; /* current frame size in words */ |
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int halfratecod; |
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int frmsizecod; |
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int fscod; /* frequency */ |
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int acmod; |
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int lfe; |
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int bsmod; |
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short last_samples[AC3_MAX_CHANNELS][256]; |
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int chbwcod[AC3_MAX_CHANNELS]; |
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int nb_coefs[AC3_MAX_CHANNELS]; |
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/* bitrate allocation control */ |
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int sgaincod, sdecaycod, fdecaycod, dbkneecod, floorcod;
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int sgain, sdecay, fdecay, dbknee, floor; |
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int csnroffst; |
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int fgaincod[AC3_MAX_CHANNELS]; |
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int fsnroffst[AC3_MAX_CHANNELS]; |
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/* mantissa encoding */ |
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int mant1_cnt, mant2_cnt, mant4_cnt; |
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} AC3EncodeContext; |
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