vad2.h

arm音频编解码库

/*
********************************************************************************
*                                                                        
*      GSM AMR-NB speech codec   R98   Version 7.6.0   December 12, 2001
*                                R99   Version 3.3.0                
*                                REL-4 Version 4.1.0                
*
********************************************************************************
*
*      File             : vad2.h
*      Purpose          : Voice Activity Detection (VAD) for AMR (option 2)
*
********************************************************************************
*/

#ifndef vad2_h
#define vad2_h "$Id $"

#include "typedef.h"

/***** Defines ****/

#define		YES		1
#define		NO		0
#define		ON		1
#define		OFF		0
#define		TRUE		1
#define		FALSE		0

#define         FRM_LEN                 80
#define         DELAY                   24
#define         FFT_LEN                 128

#define         NUM_CHAN                16
#define         LO_CHAN                 0
#define         HI_CHAN                 15

#define         UPDATE_THLD             35
#define         HYSTER_CNT_THLD         6
#define         UPDATE_CNT_THLD         50

#define		SHIFT_STATE_0		0		/* channel energy scaled as 22,9 */
#define		SHIFT_STATE_1		1		/* channel energy scaled as 27,4 */

#define		NOISE_FLOOR_CHAN_0	512		/* 1.0    scaled as 22,9 */
#define		MIN_CHAN_ENRG_0		32		/* 0.0625 scaled as 22,9 */
#define		MIN_NOISE_ENRG_0	32		/* 0.0625 scaled as 22,9 */
#define		INE_NOISE_0		8192		/* 16.0   scaled as 22,9 */
#define		FRACTIONAL_BITS_0	9		/* used as input to fn10Log10() */

#define		NOISE_FLOOR_CHAN_1	16		/* 1.0    scaled as 27,4 */
#define		MIN_CHAN_ENRG_1		1		/* 0.0625 scaled as 27,4 */
#define		MIN_NOISE_ENRG_1	1		/* 0.0625 scaled as 27,4 */
#define		INE_NOISE_1		256		/* 16.0   scaled as 27,4 */
#define		FRACTIONAL_BITS_1	4		/* used as input to fn10Log10() */

#define		STATE_1_TO_0_SHIFT_R	(FRACTIONAL_BITS_1-FRACTIONAL_BITS_0)	/* state correction factor */
#define		STATE_0_TO_1_SHIFT_R	(FRACTIONAL_BITS_0-FRACTIONAL_BITS_1)	/* state correction factor */

#define         HIGH_ALPHA              29491		/* 0.9 scaled as 0,15 */
#define         LOW_ALPHA               22938		/* 0.7 scaled as 0,15 */
#define         ALPHA_RANGE             (HIGH_ALPHA - LOW_ALPHA)
#define         DEV_THLD                7168		/* 28.0 scaled as 7,8 */

#define         PRE_EMP_FAC             (-26214)	/* -0.8 scaled as 0,15 */

#define         CEE_SM_FAC              18022		/* 0.55 scaled as 0,15 */
#define         ONE_MINUS_CEE_SM_FAC    14746		/* 0.45 scaled as 0,15 */

#define         CNE_SM_FAC              3277		/* 0.1 scaled as 0,15 */
#define         ONE_MINUS_CNE_SM_FAC    29491		/* 0.9 scaled as 0,15 */

#define         FFT_HEADROOM            2


typedef struct
{
	Word16 pre_emp_mem;
	Word16 update_cnt;
	Word16 hyster_cnt;
	Word16 last_update_cnt;
	Word16 ch_enrg_long_db[NUM_CHAN];	/* scaled as 7,8  */

	Word32 Lframe_cnt;
	Word32 Lch_enrg[NUM_CHAN];	/* scaled as 22,9 or 27,4 */
	Word32 Lch_noise[NUM_CHAN];	/* scaled as 22,9 */

	Word16 last_normb_shift;	/* last block norm shift count */

	Word16 tsnr;			/* total signal-to-noise ratio in dB (scaled as 7,8) */
	Word16 hangover;
	Word16 burstcount;
	Word16 fupdate_flag;		/* forced update flag from previous frame */
	Word16 negSNRvar;		/* Negative SNR variance (scaled as 7,8) */
	Word16 negSNRbias;		/* sensitivity bias from negative SNR variance (scaled as 15,0) */

	Word16 shift_state;		/* use 22,9 or 27,4 scaling for ch_enrg[] */

	Word32 L_R0;
	Word32 L_Rmax;
	Flag   LTP_flag;		/* Use to indicate the the LTP gain is > LTP_THRESH */

} vadState2;

/**** Prototypes ****/

Word16	vad2 (Word16 *farray_ptr, vadState2 *st);
int	vad2_init (vadState2 **st);
int	vad2_reset (vadState2 *st);
void	vad2_exit (vadState2 **state);

void	r_fft (Word16 *farray_ptr);
void	LTP_flag_update (vadState2 *st, Word16 mode);

#endif