/* * AAC definitions and structures * Copyright (c) 2005-2006 Oded Shimon ( ods15 ods15 dyndns org ) * Copyright (c) 2006-2007 Maxim Gavrilov ( maxim.gavrilov gmail com ) * * 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 */ /** * @file * AAC definitions and structures * @author Oded Shimon  ( ods15 ods15 dyndns org ) * @author Maxim Gavrilov ( maxim.gavrilov gmail com ) */ #ifndef AVCODEC_AAC_H#define AVCODEC_AAC_H #define MAX_CHANNELS 64#define MAX_ELEM_ID 64 #define TNS_MAX_ORDER 20#define MAX_LTP_LONG_SFB 40 enum RawDataBlockType {    TYPE_SCE,    TYPE_CPE,    TYPE_CCE,    TYPE_LFE,    TYPE_DSE,    TYPE_PCE,    TYPE_FIL,    TYPE_END,}; enum ExtensionPayloadID {    EXT_FILL,    EXT_FILL_DATA,    EXT_DATA_ELEMENT,    EXT_DYNAMIC_RANGE = 0xb,    EXT_SBR_DATA      = 0xd,    EXT_SBR_DATA_CRC  = 0xe,}; enum WindowSequence {    ONLY_LONG_SEQUENCE,    LONG_START_SEQUENCE,    EIGHT_SHORT_SEQUENCE,    LONG_STOP_SEQUENCE,}; enum BandType {    ZERO_BT        = 0,     ///< Scalefactors and spectral data are all zero.    FIRST_PAIR_BT  = 5,     ///< This and later band types encode two values (rather than four) with one code word.    ESC_BT         = 11,    ///< Spectral data are coded with an escape sequence.    RESERVED_BT    = 12,    ///< Band types following are encoded differently from others.    NOISE_BT       = 13,    ///< Spectral data are scaled white noise not coded in the bitstream.    INTENSITY_BT2  = 14,    ///< Scalefactor data are intensity stereo positions (out of phase).    INTENSITY_BT   = 15,    ///< Scalefactor data are intensity stereo positions (in phase).}; enum ChannelPosition {    AAC_CHANNEL_OFF   = 0,    AAC_CHANNEL_FRONT = 1,    AAC_CHANNEL_SIDE  = 2,    AAC_CHANNEL_BACK  = 3,    AAC_CHANNEL_LFE   = 4,    AAC_CHANNEL_CC    = 5,}; #define MAX_PREDICTORS 672 #define SCALE_DIV_512    36    ///< scalefactor difference that corresponds to scale difference in 512 times#define SCALE_ONE_POS   140    ///< scalefactor index that corresponds to scale=1.0#define SCALE_MAX_POS   255    ///< scalefactor index maximum value#define SCALE_MAX_DIFF   60    ///< maximum scalefactor difference allowed by standard#define SCALE_DIFF_ZERO  60    ///< codebook index corresponding to zero scalefactor indices difference #define POW_SF2_ZERO    200    ///< ff_aac_pow2sf_tab index corresponding to pow(2, 0); #define NOISE_PRE       256    ///< preamble for NOISE_BT, put in bitstream with the first noise band#define NOISE_PRE_BITS    9    ///< length of preamble#define NOISE_OFFSET     90    ///< subtracted from global gain, used as offset for the preamble typedef struct Pulse {    int num_pulse;    int start;    int pos[4];    int amp[4];} Pulse; static inline int ff_aac_sample_rate_idx(int rate){         if (92017 <= rate) return 0;    else if (75132 <= rate) return 1;    else if (55426 <= rate) return 2;    else if (46009 <= rate) return 3;    else if (37566 <= rate) return 4;    else if (27713 <= rate) return 5;    else if (23004 <= rate) return 6;    else if (18783 <= rate) return 7;    else if (13856 <= rate) return 8;    else if (11502 <= rate) return 9;    else if (9391  <= rate) return 10;    else                    return 11;} #endif /* AVCODEC_AAC_H */