shithub: aacenc

ref: d09e11ba1abdd440a610d4661ca1e5b5a1ca2cad
dir: /libfaac/coder.h/

/*
 * FAAC - Freeware Advanced Audio Coder
 * Copyright (C) 2001 Menno Bakker
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * $Id: coder.h,v 1.6 2001/05/02 05:39:14 menno Exp $
 */

#ifndef CODER_H
#define CODER_H

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */


#define MAX_CHANNELS 64
#define FRAME_LEN 1024

#define NSFB_LONG  51
#define NSFB_SHORT 15
#define MAX_SHORT_WINDOWS 8
#define BLOCK_LEN_LONG 1024
#define BLOCK_LEN_SHORT 128
#define MAX_SCFAC_BANDS ((NSFB_SHORT+1)*MAX_SHORT_WINDOWS)

enum WINDOW_TYPE {
	ONLY_LONG_WINDOW, 
	LONG_SHORT_WINDOW, 
	ONLY_SHORT_WINDOW,
	SHORT_LONG_WINDOW
};

#define TNS_MAX_ORDER 20
#define DEF_TNS_GAIN_THRESH 1.4
#define DEF_TNS_COEFF_THRESH 0.1
#define DEF_TNS_COEFF_RES 4
#define DEF_TNS_RES_OFFSET 3
#define LEN_TNS_NFILTL 2
#define LEN_TNS_NFILTS 1

#define DELAY 2048
#define	LEN_LTP_DATA_PRESENT 1
#define	LEN_LTP_LAG 11
#define	LEN_LTP_COEF 3
#define	LEN_LTP_SHORT_USED 1
#define	LEN_LTP_SHORT_LAG_PRESENT 1
#define	LEN_LTP_SHORT_LAG 5
#define	LTP_LAG_OFFSET 16
#define	LEN_LTP_LONG_USED 1
#define	MAX_LT_PRED_LONG_SFB 40
#define	MAX_LT_PRED_SHORT_SFB 13
#define SHORT_SQ_OFFSET (BLOCK_LEN_LONG-(BLOCK_LEN_SHORT*4+BLOCK_LEN_SHORT/2))
#define CODESIZE 8
#define NOK_LT_BLEN (3 * BLOCK_LEN_LONG)


typedef struct {
	int order;                           /* Filter order */
	int direction;		                 /* Filtering direction */
	int coefCompress;		             /* Are coeffs compressed? */
	int length;                          /* Length, in bands */                     
	double aCoeffs[TNS_MAX_ORDER+1];     /* AR Coefficients */
	double kCoeffs[TNS_MAX_ORDER+1];     /* Reflection Coefficients */
	int index[TNS_MAX_ORDER+1];	         /* Coefficient indices */
} TnsFilterData;

typedef struct {
	int numFilters;				                /* Number of filters */
	int coefResolution;				            /* Coefficient resolution */
	TnsFilterData tnsFilter[1<<LEN_TNS_NFILTL];	/* TNS filters */
} TnsWindowData;

typedef struct {
	int tnsDataPresent;
	int tnsMinBandNumberLong;
	int tnsMinBandNumberShort;
	int tnsMaxBandsLong;
	int tnsMaxBandsShort;
	int tnsMaxOrderLong;
	int tnsMaxOrderShort;
	TnsWindowData windowData[MAX_SHORT_WINDOWS]; /* TNS data per window */
} TnsInfo;

typedef struct
{
	int weight_idx;
	double weight;
	int sbk_prediction_used[MAX_SHORT_WINDOWS];
	int sfb_prediction_used[MAX_SCFAC_BANDS];
	int delay[MAX_SHORT_WINDOWS];
	int global_pred_flag;
	int side_info;
	double *buffer;
	double *mdct_predicted;

	double *time_buffer;
	double *ltp_overlap_buffer;
} LtpInfo;

typedef struct {
	int window_shape;
	int prev_window_shape;
	int block_type;
	int desired_block_type;

	int global_gain;
	int old_value;
	int CurrentStep;
	int scale_factor[MAX_SCFAC_BANDS];

	int num_window_groups;
	int window_group_length[8];
	int max_sfb;
	int nr_of_sfb;
	int sfb_offset[250];

	int spectral_count;

	/* Huffman codebook selected for each sf band */
	int book_vector[MAX_SCFAC_BANDS];

	/* Data of spectral bitstream elements, for each spectral pair,
	   5 elements are required: 1*(esc)+2*(sign)+2*(esc value)=5 */
	int *data;

	/* Lengths of spectral bitstream elements */
	int *len;

	/* Holds the requantized spectrum */
	double *requantFreq;

	TnsInfo tnsInfo;
	LtpInfo ltpInfo;

	int max_pred_sfb;
	int pred_global_flag;
	int pred_sfb_flag[MAX_SCFAC_BANDS];
	int reset_group_number;

} CoderInfo;

typedef struct { 
  unsigned long sampling_rate;  /* the following entries are for this sampling rate */
  int num_cb_long;
  int num_cb_short;
  int cb_width_long[NSFB_LONG];
  int cb_width_short[NSFB_SHORT];
} SR_INFO;

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* CODER_H */