libavcodec/aac.h - nest-android-app/ffmpeg - Git at Google

 /*
  * 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


 #include "aac_defines.h"
 #include "libavutil/float_dsp.h"
 #include "libavutil/fixed_dsp.h"
 #include "avcodec.h"
 #if !USE_FIXED
 #include "imdct15.h"
 #endif
 #include "fft.h"
 #include "mpeg4audio.h"
 #include "sbr.h"

 #include <stdint.h>

 #define MAX_CHANNELS 64
 #define MAX_ELEM_ID 16

 #define TNS_MAX_ORDER 20
 #define MAX_LTP_LONG_SFB 40

 #define CLIP_AVOIDANCE_FACTOR 0.95f

 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).
 };

 #define IS_CODEBOOK_UNSIGNED(x) (((x) - 1) & 10)

 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,
 };

 /**
  * The point during decoding at which channel coupling is applied.
  */
 enum CouplingPoint {
     BEFORE_TNS,
     BETWEEN_TNS_AND_IMDCT,
     AFTER_IMDCT = 3,
 };

 /**
  * Output configuration status
  */
 enum OCStatus {
     OC_NONE,        ///< Output unconfigured
     OC_TRIAL_PCE,   ///< Output configuration under trial specified by an inband PCE
     OC_TRIAL_FRAME, ///< Output configuration under trial specified by a frame header
     OC_GLOBAL_HDR,  ///< Output configuration set in a global header but not yet locked
     OC_LOCKED,      ///< Output configuration locked in place
 };

 typedef struct OutputConfiguration {
     MPEG4AudioConfig m4ac;
     uint8_t layout_map[MAX_ELEM_ID*4][3];
     int layout_map_tags;
     int channels;
     uint64_t channel_layout;
     enum OCStatus status;
 } OutputConfiguration;

 /**
  * Predictor State
  */
 typedef struct PredictorState {
     AAC_FLOAT cor0;
     AAC_FLOAT cor1;
     AAC_FLOAT var0;
     AAC_FLOAT var1;
     AAC_FLOAT r0;
     AAC_FLOAT r1;
     AAC_FLOAT k1;
     AAC_FLOAT x_est;
 } PredictorState;

 #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

 /**
  * Long Term Prediction
  */
 typedef struct LongTermPrediction {
     int8_t present;
     int16_t lag;
     int coef_idx;
     INTFLOAT coef;
     int8_t used[MAX_LTP_LONG_SFB];
 } LongTermPrediction;

 /**
  * Individual Channel Stream
  */
 typedef struct IndividualChannelStream {
     uint8_t max_sfb;            ///< number of scalefactor bands per group
     enum WindowSequence window_sequence[2];
     uint8_t use_kb_window[2];   ///< If set, use Kaiser-Bessel window, otherwise use a sine window.
     int num_window_groups;
     uint8_t group_len[8];
     LongTermPrediction ltp;
     const uint16_t *swb_offset; ///< table of offsets to the lowest spectral coefficient of a scalefactor band, sfb, for a particular window
     const uint8_t *swb_sizes;   ///< table of scalefactor band sizes for a particular window
     int num_swb;                ///< number of scalefactor window bands
     int num_windows;
     int tns_max_bands;
     int predictor_present;
     int predictor_initialized;
     int predictor_reset_group;
     int predictor_reset_count[31];  ///< used by encoder to count prediction resets
     uint8_t prediction_used[41];
     uint8_t window_clipping[8]; ///< set if a certain window is near clipping
     float clip_avoidance_factor; ///< set if any window is near clipping to the necessary atennuation factor to avoid it
 } IndividualChannelStream;

 /**
  * Temporal Noise Shaping
  */
 typedef struct TemporalNoiseShaping {
     int present;
     int n_filt[8];
     int length[8][4];
     int direction[8][4];
     int order[8][4];
     int coef_idx[8][4][TNS_MAX_ORDER];
     INTFLOAT coef[8][4][TNS_MAX_ORDER];
 } TemporalNoiseShaping;

 /**
  * Dynamic Range Control - decoded from the bitstream but not processed further.
  */
 typedef struct DynamicRangeControl {
     int pce_instance_tag;                           ///< Indicates with which program the DRC info is associated.
     int dyn_rng_sgn[17];                            ///< DRC sign information; 0 - positive, 1 - negative
     int dyn_rng_ctl[17];                            ///< DRC magnitude information
     int exclude_mask[MAX_CHANNELS];                 ///< Channels to be excluded from DRC processing.
     int band_incr;                                  ///< Number of DRC bands greater than 1 having DRC info.
     int interpolation_scheme;                       ///< Indicates the interpolation scheme used in the SBR QMF domain.
     int band_top[17];                               ///< Indicates the top of the i-th DRC band in units of 4 spectral lines.
     int prog_ref_level;                             /**< A reference level for the long-term program audio level for all
                                                      *   channels combined.
                                                      */
 } DynamicRangeControl;

 typedef struct Pulse {
     int num_pulse;
     int start;
     int pos[4];
     int amp[4];
 } Pulse;

 /**
  * coupling parameters
  */
 typedef struct ChannelCoupling {
     enum CouplingPoint coupling_point;  ///< The point during decoding at which coupling is applied.
     int num_coupled;       ///< number of target elements
     enum RawDataBlockType type[8];   ///< Type of channel element to be coupled - SCE or CPE.
     int id_select[8];      ///< element id
     int ch_select[8];      /**< [0] shared list of gains; [1] list of gains for right channel;
                             *   [2] list of gains for left channel; [3] lists of gains for both channels
                             */
     INTFLOAT gain[16][120];
 } ChannelCoupling;

 /**
  * Single Channel Element - used for both SCE and LFE elements.
  */
 typedef struct SingleChannelElement {
     IndividualChannelStream ics;
     TemporalNoiseShaping tns;
     Pulse pulse;
     enum BandType band_type[128];                   ///< band types
     enum BandType band_alt[128];                    ///< alternative band type (used by encoder)
     int band_type_run_end[120];                     ///< band type run end points
     INTFLOAT sf[120];                               ///< scalefactors
     int sf_idx[128];                                ///< scalefactor indices (used by encoder)
     uint8_t zeroes[128];                            ///< band is not coded (used by encoder)
     uint8_t can_pns[128];                           ///< band is allowed to PNS (informative)
     float  is_ener[128];                            ///< Intensity stereo pos (used by encoder)
     float pns_ener[128];                            ///< Noise energy values (used by encoder)
     DECLARE_ALIGNED(32, INTFLOAT, pcoeffs)[1024];   ///< coefficients for IMDCT, pristine
     DECLARE_ALIGNED(32, INTFLOAT, coeffs)[1024];    ///< coefficients for IMDCT, maybe processed
     DECLARE_ALIGNED(32, INTFLOAT, saved)[1536];     ///< overlap
     DECLARE_ALIGNED(32, INTFLOAT, ret_buf)[2048];   ///< PCM output buffer
     DECLARE_ALIGNED(16, INTFLOAT, ltp_state)[3072]; ///< time signal for LTP
     DECLARE_ALIGNED(32, AAC_FLOAT, lcoeffs)[1024];  ///< MDCT of LTP coefficients (used by encoder)
     DECLARE_ALIGNED(32, AAC_FLOAT, prcoeffs)[1024]; ///< Main prediction coefs (used by encoder)
     PredictorState predictor_state[MAX_PREDICTORS];
     INTFLOAT *ret;                                  ///< PCM output
 } SingleChannelElement;

 /**
  * channel element - generic struct for SCE/CPE/CCE/LFE
  */
 typedef struct ChannelElement {
     int present;
     // CPE specific
     int common_window;        ///< Set if channels share a common 'IndividualChannelStream' in bitstream.
     int     ms_mode;          ///< Signals mid/side stereo flags coding mode (used by encoder)
     uint8_t is_mode;          ///< Set if any bands have been encoded using intensity stereo (used by encoder)
     uint8_t ms_mask[128];     ///< Set if mid/side stereo is used for each scalefactor window band
     uint8_t is_mask[128];     ///< Set if intensity stereo is used (used by encoder)
     // shared
     SingleChannelElement ch[2];
     // CCE specific
     ChannelCoupling coup;
     SpectralBandReplication sbr;
 } ChannelElement;

 /**
  * main AAC context
  */
 struct AACContext {
     AVClass        *class;
     AVCodecContext *avctx;
     AVFrame *frame;

     int is_saved;                 ///< Set if elements have stored overlap from previous frame.
     DynamicRangeControl che_drc;

     /**
      * @name Channel element related data
      * @{
      */
     ChannelElement          *che[4][MAX_ELEM_ID];
     ChannelElement  *tag_che_map[4][MAX_ELEM_ID];
     int tags_mapped;
     int warned_remapping_once;
     /** @} */

     /**
      * @name temporary aligned temporary buffers
      * (We do not want to have these on the stack.)
      * @{
      */
     DECLARE_ALIGNED(32, INTFLOAT, buf_mdct)[1024];
     /** @} */

     /**
      * @name Computed / set up during initialization
      * @{
      */
     FFTContext mdct;
     FFTContext mdct_small;
     FFTContext mdct_ld;
     FFTContext mdct_ltp;
 #if USE_FIXED
     AVFixedDSPContext *fdsp;
 #else
     IMDCT15Context *mdct480;
     AVFloatDSPContext *fdsp;
 #endif /* USE_FIXED */
     int random_state;
     /** @} */

     /**
      * @name Members used for output
      * @{
      */
     SingleChannelElement *output_element[MAX_CHANNELS]; ///< Points to each SingleChannelElement
     /** @} */


     /**
      * @name Japanese DTV specific extension
      * @{
      */
     int force_dmono_mode;///< 0->not dmono, 1->use first channel, 2->use second channel
     int dmono_mode;      ///< 0->not dmono, 1->use first channel, 2->use second channel
     /** @} */

     DECLARE_ALIGNED(32, INTFLOAT, temp)[128];

     OutputConfiguration oc[2];
     int warned_num_aac_frames;

     /* aacdec functions pointers */
     void (*imdct_and_windowing)(AACContext *ac, SingleChannelElement *sce);
     void (*apply_ltp)(AACContext *ac, SingleChannelElement *sce);
     void (*apply_tns)(INTFLOAT coef[1024], TemporalNoiseShaping *tns,
                       IndividualChannelStream *ics, int decode);
     void (*windowing_and_mdct_ltp)(AACContext *ac, INTFLOAT *out,
                                    INTFLOAT *in, IndividualChannelStream *ics);
     void (*update_ltp)(AACContext *ac, SingleChannelElement *sce);
     void (*vector_pow43)(int *coefs, int len);
     void (*subband_scale)(int *dst, int *src, int scale, int offset, int len);

 };

 void ff_aacdec_init_mips(AACContext *c);

 #endif /* AVCODEC_AAC_H */
	/*
	* 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


	#include "aac_defines.h"
	#include "libavutil/float_dsp.h"
	#include "libavutil/fixed_dsp.h"
	#include "avcodec.h"
	#if !USE_FIXED
	#include "imdct15.h"
	#endif
	#include "fft.h"
	#include "mpeg4audio.h"
	#include "sbr.h"

	#include <stdint.h>

	#define MAX_CHANNELS 64
	#define MAX_ELEM_ID 16

	#define TNS_MAX_ORDER 20
	#define MAX_LTP_LONG_SFB 40

	#define CLIP_AVOIDANCE_FACTOR 0.95f

	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).
	};

	#define IS_CODEBOOK_UNSIGNED(x) (((x) - 1) & 10)

	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,
	};

	/**
	* The point during decoding at which channel coupling is applied.
	*/
	enum CouplingPoint {
	BEFORE_TNS,
	BETWEEN_TNS_AND_IMDCT,
	AFTER_IMDCT = 3,
	};

	/**
	* Output configuration status
	*/
	enum OCStatus {
	OC_NONE, ///< Output unconfigured
	OC_TRIAL_PCE, ///< Output configuration under trial specified by an inband PCE
	OC_TRIAL_FRAME, ///< Output configuration under trial specified by a frame header
	OC_GLOBAL_HDR, ///< Output configuration set in a global header but not yet locked
	OC_LOCKED, ///< Output configuration locked in place
	};

	typedef struct OutputConfiguration {
	MPEG4AudioConfig m4ac;
	uint8_t layout_map[MAX_ELEM_ID*4][3];
	int layout_map_tags;
	int channels;
	uint64_t channel_layout;
	enum OCStatus status;
	} OutputConfiguration;

	/**
	* Predictor State
	*/
	typedef struct PredictorState {
	AAC_FLOAT cor0;
	AAC_FLOAT cor1;
	AAC_FLOAT var0;
	AAC_FLOAT var1;
	AAC_FLOAT r0;
	AAC_FLOAT r1;
	AAC_FLOAT k1;
	AAC_FLOAT x_est;
	} PredictorState;

	#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

	/**
	* Long Term Prediction
	*/
	typedef struct LongTermPrediction {
	int8_t present;
	int16_t lag;
	int coef_idx;
	INTFLOAT coef;
	int8_t used[MAX_LTP_LONG_SFB];
	} LongTermPrediction;

	/**
	* Individual Channel Stream
	*/
	typedef struct IndividualChannelStream {
	uint8_t max_sfb; ///< number of scalefactor bands per group
	enum WindowSequence window_sequence[2];
	uint8_t use_kb_window[2]; ///< If set, use Kaiser-Bessel window, otherwise use a sine window.
	int num_window_groups;
	uint8_t group_len[8];
	LongTermPrediction ltp;
	const uint16_t *swb_offset; ///< table of offsets to the lowest spectral coefficient of a scalefactor band, sfb, for a particular window
	const uint8_t *swb_sizes; ///< table of scalefactor band sizes for a particular window
	int num_swb; ///< number of scalefactor window bands
	int num_windows;
	int tns_max_bands;
	int predictor_present;
	int predictor_initialized;
	int predictor_reset_group;
	int predictor_reset_count[31]; ///< used by encoder to count prediction resets
	uint8_t prediction_used[41];
	uint8_t window_clipping[8]; ///< set if a certain window is near clipping
	float clip_avoidance_factor; ///< set if any window is near clipping to the necessary atennuation factor to avoid it
	} IndividualChannelStream;

	/**
	* Temporal Noise Shaping
	*/
	typedef struct TemporalNoiseShaping {
	int present;
	int n_filt[8];
	int length[8][4];
	int direction[8][4];
	int order[8][4];
	int coef_idx[8][4][TNS_MAX_ORDER];
	INTFLOAT coef[8][4][TNS_MAX_ORDER];
	} TemporalNoiseShaping;

	/**
	* Dynamic Range Control - decoded from the bitstream but not processed further.
	*/
	typedef struct DynamicRangeControl {
	int pce_instance_tag; ///< Indicates with which program the DRC info is associated.
	int dyn_rng_sgn[17]; ///< DRC sign information; 0 - positive, 1 - negative
	int dyn_rng_ctl[17]; ///< DRC magnitude information
	int exclude_mask[MAX_CHANNELS]; ///< Channels to be excluded from DRC processing.
	int band_incr; ///< Number of DRC bands greater than 1 having DRC info.
	int interpolation_scheme; ///< Indicates the interpolation scheme used in the SBR QMF domain.
	int band_top[17]; ///< Indicates the top of the i-th DRC band in units of 4 spectral lines.
	int prog_ref_level; /**< A reference level for the long-term program audio level for all
	* channels combined.
	*/
	} DynamicRangeControl;

	typedef struct Pulse {
	int num_pulse;
	int start;
	int pos[4];
	int amp[4];
	} Pulse;

	/**
	* coupling parameters
	*/
	typedef struct ChannelCoupling {
	enum CouplingPoint coupling_point; ///< The point during decoding at which coupling is applied.
	int num_coupled; ///< number of target elements
	enum RawDataBlockType type[8]; ///< Type of channel element to be coupled - SCE or CPE.
	int id_select[8]; ///< element id
	int ch_select[8]; /**< [0] shared list of gains; [1] list of gains for right channel;
	* [2] list of gains for left channel; [3] lists of gains for both channels
	*/
	INTFLOAT gain[16][120];
	} ChannelCoupling;

	/**
	* Single Channel Element - used for both SCE and LFE elements.
	*/
	typedef struct SingleChannelElement {
	IndividualChannelStream ics;
	TemporalNoiseShaping tns;
	Pulse pulse;
	enum BandType band_type[128]; ///< band types
	enum BandType band_alt[128]; ///< alternative band type (used by encoder)
	int band_type_run_end[120]; ///< band type run end points
	INTFLOAT sf[120]; ///< scalefactors
	int sf_idx[128]; ///< scalefactor indices (used by encoder)
	uint8_t zeroes[128]; ///< band is not coded (used by encoder)
	uint8_t can_pns[128]; ///< band is allowed to PNS (informative)
	float is_ener[128]; ///< Intensity stereo pos (used by encoder)
	float pns_ener[128]; ///< Noise energy values (used by encoder)
	DECLARE_ALIGNED(32, INTFLOAT, pcoeffs)[1024]; ///< coefficients for IMDCT, pristine
	DECLARE_ALIGNED(32, INTFLOAT, coeffs)[1024]; ///< coefficients for IMDCT, maybe processed
	DECLARE_ALIGNED(32, INTFLOAT, saved)[1536]; ///< overlap
	DECLARE_ALIGNED(32, INTFLOAT, ret_buf)[2048]; ///< PCM output buffer
	DECLARE_ALIGNED(16, INTFLOAT, ltp_state)[3072]; ///< time signal for LTP
	DECLARE_ALIGNED(32, AAC_FLOAT, lcoeffs)[1024]; ///< MDCT of LTP coefficients (used by encoder)
	DECLARE_ALIGNED(32, AAC_FLOAT, prcoeffs)[1024]; ///< Main prediction coefs (used by encoder)
	PredictorState predictor_state[MAX_PREDICTORS];
	INTFLOAT *ret; ///< PCM output
	} SingleChannelElement;

	/**
	* channel element - generic struct for SCE/CPE/CCE/LFE
	*/
	typedef struct ChannelElement {
	int present;
	// CPE specific
	int common_window; ///< Set if channels share a common 'IndividualChannelStream' in bitstream.
	int ms_mode; ///< Signals mid/side stereo flags coding mode (used by encoder)
	uint8_t is_mode; ///< Set if any bands have been encoded using intensity stereo (used by encoder)
	uint8_t ms_mask[128]; ///< Set if mid/side stereo is used for each scalefactor window band
	uint8_t is_mask[128]; ///< Set if intensity stereo is used (used by encoder)
	// shared
	SingleChannelElement ch[2];
	// CCE specific
	ChannelCoupling coup;
	SpectralBandReplication sbr;
	} ChannelElement;

	/**
	* main AAC context
	*/
	struct AACContext {
	AVClass *class;
	AVCodecContext *avctx;
	AVFrame *frame;

	int is_saved; ///< Set if elements have stored overlap from previous frame.
	DynamicRangeControl che_drc;

	/**
	* @name Channel element related data
	* @{
	*/
	ChannelElement *che[4][MAX_ELEM_ID];
	ChannelElement *tag_che_map[4][MAX_ELEM_ID];
	int tags_mapped;
	int warned_remapping_once;
	/** @} */

	/**
	* @name temporary aligned temporary buffers
	* (We do not want to have these on the stack.)
	* @{
	*/
	DECLARE_ALIGNED(32, INTFLOAT, buf_mdct)[1024];
	/** @} */

	/**
	* @name Computed / set up during initialization
	* @{
	*/
	FFTContext mdct;
	FFTContext mdct_small;
	FFTContext mdct_ld;
	FFTContext mdct_ltp;
	#if USE_FIXED
	AVFixedDSPContext *fdsp;
	#else
	IMDCT15Context *mdct480;
	AVFloatDSPContext *fdsp;
	#endif /* USE_FIXED */
	int random_state;
	/** @} */

	/**
	* @name Members used for output
	* @{
	*/
	SingleChannelElement *output_element[MAX_CHANNELS]; ///< Points to each SingleChannelElement
	/** @} */


	/**
	* @name Japanese DTV specific extension
	* @{
	*/
	int force_dmono_mode;///< 0->not dmono, 1->use first channel, 2->use second channel
	int dmono_mode; ///< 0->not dmono, 1->use first channel, 2->use second channel
	/** @} */

	DECLARE_ALIGNED(32, INTFLOAT, temp)[128];

	OutputConfiguration oc[2];
	int warned_num_aac_frames;

	/* aacdec functions pointers */
	void (imdct_and_windowing)(AACContext ac, SingleChannelElement *sce);
	void (apply_ltp)(AACContext ac, SingleChannelElement *sce);
	void (apply_tns)(INTFLOAT coef[1024], TemporalNoiseShaping tns,
	IndividualChannelStream *ics, int decode);
	void (windowing_and_mdct_ltp)(AACContext ac, INTFLOAT *out,
	INTFLOAT in, IndividualChannelStream ics);
	void (update_ltp)(AACContext ac, SingleChannelElement *sce);
	void (vector_pow43)(int coefs, int len);
	void (subband_scale)(int dst, int *src, int scale, int offset, int len);

	};

	void ff_aacdec_init_mips(AACContext *c);

	#endif /* AVCODEC_AAC_H */