ffmpeg/libavcodec/aac/aacdec_ac.h

55 lines
1.7 KiB
C

/*
* AAC definitions and structures
* Copyright (c) 2024 Lynne
*
* 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_AC_H
#define AVCODEC_AAC_AACDEC_AC_H
#include "libavcodec/get_bits.h"
typedef struct AACArithState {
uint8_t last[512 /* 2048 / 4 */ + 1];
int last_len;
uint8_t cur[4];
uint16_t state_pre;
} AACArithState;
typedef struct AACArith {
uint16_t low;
uint16_t high;
uint16_t val;
} AACArith;
#define FF_AAC_AC_ESCAPE 16
uint32_t ff_aac_ac_map_process(AACArithState *state, int reset, int len);
uint32_t ff_aac_ac_get_context(AACArithState *state, uint32_t old_c, int idx, int len);
uint32_t ff_aac_ac_get_pk(uint32_t c);
void ff_aac_ac_update_context(AACArithState *state, int idx, uint16_t a, uint16_t b);
void ff_aac_ac_init(AACArith *ac, GetBitContext *gb);
uint16_t ff_aac_ac_decode(AACArith *ac, GetBitContext *gb,
const uint16_t *cdf, uint16_t cdf_len);
void ff_aac_ac_finish(AACArithState *state, int offset, int nb);
#endif /* AVCODEC_AACDEC_AC_H */