ref: 708eea7d2978b554421e6f485ce237430cfeed80
dir: /ltp_enc.h/
/*
* Function prototypes for LTP
*
* Copyright (c) 1999 M. 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, 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; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/**************************************************************************
Version Control Information Method: CVS
Identifiers:
$Revision: 1.1 $
$Date: 2000/10/06 14:47:27 $ (check in)
$Author: menno $
*************************************************************************/
#ifndef _LTP_ENC_H
#define _LTP_ENC_H
#include "interface.h"
#include "bitstream.h"
/*
Macro: LT_BLEN
Purpose: Length of the history buffer.
Explanation: Has to hold two long windows of time domain data. */
#ifndef LT_BLEN
#define LT_BLEN (4 * BLOCK_LEN_LONG)
#endif
/* Purpose: Number of LTP coefficients. */
#define LPC 1
/* Purpose: Maximum LTP lag. */
#define DELAY 2048
/* Purpose: Length of the bitstream element ltp_data_present. */
#define LEN_LTP_DATA_PRESENT 1
/* Purpose: Length of the bitstream element ltp_lag. */
#define LEN_LTP_LAG 11
/* Purpose: Length of the bitstream element ltp_coef. */
#define LEN_LTP_COEF 3
/* Purpose: Length of the bitstream element ltp_short_used. */
#define LEN_LTP_SHORT_USED 1
/* Purpose: Length of the bitstream element ltp_short_lag_present. */
#define LEN_LTP_SHORT_LAG_PRESENT 1
/* Purpose: Length of the bitstream element ltp_short_lag. */
#define LEN_LTP_SHORT_LAG 5
/* Purpose: Offset of the lags written in the bitstream. */
#define LTP_LAG_OFFSET 16
/* Purpose: Length of the bitstream element ltp_long_used. */
#define LEN_LTP_LONG_USED 1
/* Purpose: Upper limit for the number of scalefactor bands
which can use lt prediction with long windows.
Explanation: Bands 0..MAX_LT_PRED_SFB-1 can use lt prediction. */
#define MAX_LT_PRED_LONG_SFB 40
/* Purpose: Upper limit for the number of scalefactor bands
which can use lt prediction with short windows.
Explanation: Bands 0..MAX_LT_PRED_SFB-1 can use lt prediction. */
#define MAX_LT_PRED_SHORT_SFB 13
/* Purpose: Buffer offset to maintain block alignment.
Explanation: This is only used for a short window sequence. */
#define SHORT_SQ_OFFSET (BLOCK_LEN_LONG-(BLOCK_LEN_SHORT*4+BLOCK_LEN_SHORT/2))
/* Purpose: Number of codes for LTP weight. */
#define CODESIZE 8
/* Purpose: Float type for external data
Explanation: - */
typedef double float_ext;
/* Type: LT_PRED_STATUS
Purpose: Type of the struct holding the LTP encoding parameters.
Explanation: - */
typedef struct
{
short buffer[LT_BLEN];
double pred_mdct[2 * BLOCK_LEN_LONG];
int weight_idx;
double weight;
int sbk_prediction_used[MAX_SHORT_WINDOWS];
int sfb_prediction_used[MAX_SCFAC_BANDS];
int *delay;
int global_pred_flag;
int side_info;
} LT_PRED_STATUS;
double snr_pred (double *mdct_in, double *mdct_pred, int *sfb_flag,
int *sfb_offset, enum WINDOW_TYPE block_type, int side_info,
int num_of_sfb);
void prediction (short *buffer, double *predicted_samples, double *weight,
int delay, int flen);
int estimate_delay (double *sb_samples, short *x_buffer);
void pitch (double *sb_samples, double *sb_samples_pred, short *x_buffer,
int *ltp_coef, int delay, int flen);
void init_lt_pred(LT_PRED_STATUS * lt_status);
int ltp_enc(double *p_spectrum, double *p_time_signal,
enum WINDOW_TYPE win_type, Window_shape win_shape,
int *sfb_offset, int num_of_sfb,
LT_PRED_STATUS *lt_status);
void ltp_reconstruct(double *p_spectrum, enum WINDOW_TYPE win_type,
Window_shape win_shape,
int *sfb_offset, int num_of_sfb,
LT_PRED_STATUS *lt_status);
int ltp_encode (BsBitStream *bs, enum WINDOW_TYPE win_type, int num_of_sfb,
LT_PRED_STATUS *lt_status, int write_flag);
#endif /* not defined _LTP_ENC_H */