/*****************************************************************************
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* aac.h: ISO/IEC 14496-3 Advanced Audio Coding
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*****************************************************************************
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* Copyright (C) 2010, 2013, 2017 VideoLAN
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*
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* Authors: Christophe Massiot <massiot@via.ecp.fr>
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject
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* to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*****************************************************************************/
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/*
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* Normative references:
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* - ISO/IEC 14496-3 Subpart 4:1998(E)
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* (Advanced Audio Coding, Time/Frequency Coding)
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* - ISO/IEC 13818-1:2013(E) (MPEG-2 Systems)
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*/
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#ifndef __BITSTREAM_MPEG_AAC_H__
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#define __BITSTREAM_MPEG_AAC_H__
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#include <stdint.h> /* uint8_t, uint16_t, etc... */
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#include <stdbool.h> /* bool */
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#ifdef __cplusplus
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extern "C"
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{
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#endif
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/*****************************************************************************
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* ADTS header
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*****************************************************************************/
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#define ADTS_HEADER_SIZE 7
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#define ADTS_CRC_SIZE 2
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#define ADTS_SAMPLES_PER_BLOCK 1024
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#define ADTS_PROFILE_MAIN 0
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#define ADTS_PROFILE_LC 1
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#define ADTS_PROFILE_SSR 2
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/* fixed header */
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static inline void adts_set_sync(uint8_t *p_adts)
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{
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p_adts[0] = 0xff;
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p_adts[1] = 0xf9; /* protection absent */
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p_adts[2] = 0x0;
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p_adts[3] = 0x0;
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p_adts[4] = 0x0;
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p_adts[5] = 0x0;
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p_adts[6] = 0x0;
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}
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static inline bool adts_get_protection_absent(const uint8_t *p_adts)
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{
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return !!(p_adts[1] & 0x01);
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}
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static inline void adts_clear_protection_absent(uint8_t *p_adts)
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{
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p_adts[1] &= ~0x01;
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}
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static inline uint8_t adts_get_profile(const uint8_t *p_adts)
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{
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return p_adts[2] >> 6;
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}
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static inline void adts_set_profile(uint8_t *p_adts, uint8_t i_profile)
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{
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p_adts[2] &= ~0xc0;
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p_adts[2] |= i_profile << 6;
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}
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static inline uint8_t adts_get_sampling_freq(const uint8_t *p_adts)
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{
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return (p_adts[2] & 0x3c) >> 2;
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}
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static inline void adts_set_sampling_freq(uint8_t *p_adts, uint8_t i_freq)
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{
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p_adts[2] &= ~0x3c;
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p_adts[2] |= (i_freq & 0xf) << 2;
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}
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static inline uint8_t adts_get_channels(const uint8_t *p_adts)
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{
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return ((p_adts[2] & 0x01) << 2) | (p_adts[3] >> 6);
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}
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static inline void adts_set_channels(uint8_t *p_adts, uint8_t i_channels)
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{
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p_adts[2] &= ~0x03; /* also clear out the private bit */
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p_adts[2] |= (i_channels & 0x7) >> 2;
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p_adts[3] &= ~0xc0;
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p_adts[3] |= (i_channels & 0x7) << 6;
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}
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static inline bool adts_get_copy(const uint8_t *p_adts)
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{
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return !!(p_adts[3] & 0x20);
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}
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static inline void adts_set_copy(uint8_t *p_adts)
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{
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p_adts[3] |= 0x20;
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}
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static inline bool adts_get_home(const uint8_t *p_adts)
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{
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return !!(p_adts[3] & 0x10);
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}
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static inline void adts_set_home(uint8_t *p_adts)
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{
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p_adts[3] |= 0x10;
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}
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/* variable header */
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static inline void adts_get_cp_id(const uint8_t *p_adts, bool *pb_bit, bool *pb_start)
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{
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*pb_bit = !!(p_adts[3] & 0x08);
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*pb_start = !!(p_adts[3] & 0x04);
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}
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static inline void adts_set_cp_id(uint8_t *p_adts, bool b_bit, bool b_start)
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{
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p_adts[3] &= ~0x0c;
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if (b_bit)
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p_adts[3] |= 0x08;
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if (b_start)
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p_adts[3] |= 0x04;
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}
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static inline uint16_t adts_get_length(const uint8_t *p_adts)
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{
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return ((p_adts[3] & 0x03) << 11) | (p_adts[4] << 3) | (p_adts[5] >> 5);
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}
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static inline void adts_set_length(uint8_t *p_adts, uint16_t i_length)
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{
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p_adts[3] &= ~0x03;
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p_adts[3] |= (i_length >> 11) & 0x03;
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p_adts[4] = i_length >> 3;
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p_adts[5] &= ~0xe0;
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p_adts[5] |= (i_length << 5) & 0xe0;
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}
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static inline uint16_t adts_get_fullness(const uint8_t *p_adts)
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{
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return ((p_adts[5] & 0x1f) << 6) | (p_adts[6] >> 2);
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}
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static inline void adts_set_fullness(uint8_t *p_adts, uint16_t i_fullness)
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{
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p_adts[5] &= ~0x1f;
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p_adts[5] |= (i_fullness >> 6) & 0x1f;
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p_adts[6] &= ~0xfc;
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p_adts[6] |= (i_fullness << 2) & 0xfc;
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}
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/* blocks == number of blocks - 1 */
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static inline uint8_t adts_get_num_blocks(const uint8_t *p_adts)
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{
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return (p_adts[6] & 0x03);
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}
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static inline void adts_set_num_blocks(uint8_t *p_adts, uint8_t i_blocks_min1)
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{
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p_adts[6] &= ~0x03;
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p_adts[6] |= i_blocks_min1 & 0x03;
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}
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static inline bool adts_sync_compare(const uint8_t *p_adts1, const uint8_t *p_adts2)
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{
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return p_adts1[0] == p_adts2[0] &&
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p_adts1[1] == p_adts2[1] &&
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p_adts1[2] == p_adts2[2] &&
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(p_adts1[3] & 0xfc) == (p_adts2[3] & 0xfc);
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}
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/* same but only takes into account meaningful fields */
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static inline bool adts_sync_compare_formats(const uint8_t *p_adts1, const uint8_t *p_adts2)
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{
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return p_adts1[0] == p_adts2[0] &&
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(p_adts1[1] & 0xfe) == (p_adts2[1] & 0xfe) &&
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p_adts1[2] == p_adts2[2] &&
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(p_adts1[3] & 0xc0) == (p_adts2[3] & 0xc0);
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}
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/*****************************************************************************
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* LOAS header
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*****************************************************************************/
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#define LOAS_HEADER_SIZE 3
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static inline void loas_set_sync(uint8_t *p)
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{
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p[0] = 0x56;
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p[1] = 0xe0;
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p[2] = 0x0;
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}
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static inline uint16_t loas_get_length(const uint8_t *p)
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{
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return ((p[1] & 0x01f) << 8) | p[2];
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}
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static inline void loas_set_length(uint8_t *p, uint16_t val)
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{
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p[1] = 0xe0 | (val >> 8);
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p[2] = val & 0xff;
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}
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/*****************************************************************************
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* AudioSpecificConfig
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*****************************************************************************/
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#define ASC_TYPE_MAIN 1
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#define ASC_TYPE_LC 2
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#define ASC_TYPE_SSR 3
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#define ASC_TYPE_LTP 4
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#define ASC_TYPE_SBR 5
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#define ASC_TYPE_SCALABLE 6
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#define ASC_TYPE_TWINVQ 7
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#define ASC_TYPE_CELP 8
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#define ASC_TYPE_HVXC 9
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#define ASC_TYPE_ER_LC 17
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#define ASC_TYPE_ER_LTP 19
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#define ASC_TYPE_ER_SCALABLE 20
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#define ASC_TYPE_ER_TWINVQ 21
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#define ASC_TYPE_ER_BSAC 22
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#define ASC_TYPE_ER_LD 23
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#define ASC_TYPE_PS 29
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#define ASC_FLT_VARIABLE 0
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#define ASC_FLT_FIXED 1
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#define ASC_FLT_CELP_2 3
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#define ASC_FLT_CELP_FIXED 4
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#define ASC_FLT_CELP_4 5
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#define ASC_FLT_HVXC_FIXED 6
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#define ASC_FLT_HVXC_4 7
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/* Returns the profile_and_level structure for MPEG-4 audio descriptor */
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static inline uint8_t asc_get_profilelevel(uint8_t asc_aot, uint8_t channels, uint32_t rate)
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{
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uint8_t profilelevel;
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switch (asc_aot) {
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case ASC_TYPE_LC:
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profilelevel = 0x50;
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break;
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case ASC_TYPE_SBR:
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profilelevel = 0x58;
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break;
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case ASC_TYPE_ER_LD:
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return 0x38;
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case ASC_TYPE_PS:
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profilelevel = 0x60;
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break;
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default:
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return 0xf;
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}
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if (rate > 48000)
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return profilelevel + 3;
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if (channels > 2)
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return profilelevel + 2;
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if (rate > 24000)
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return profilelevel + 1;
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return profilelevel;
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}
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/*****************************************************************************
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* AAC syntactic elements
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*****************************************************************************/
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#define AAC_SYN_SCE 0
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#define AAC_SYN_CPE 1
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#define AAC_SYN_CCE 2
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#define AAC_SYN_LFE 3
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#define AAC_SYN_DSE 4
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#define AAC_SYN_PCE 5
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#define AAC_SYN_FIL 6
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#define AAC_SYN_END 7
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#ifdef __cplusplus
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}
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#endif
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#endif
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