最近把opus编码器里的VAD算法提取了出来，之前在网上没找到合适的开源VAD模块，就把代码放在这里吧，希望能帮助到人。
下面是.h文件和.cpp文件，使用的时候，需要调用silk_VAD_Get()这个函数，每次输入一个帧（我默认了帧长是20ms，采样率16khz，可以自己在silk_VAD_Get里修改），返回0或者1，代表该帧是否为静音帧。
.h文件代码：
#include <stdlib.h>
#include <malloc.h>
#include <intrin.h>
#include <string.h>
int silk_VAD_Get(
//int state, /* Encoder state */
const short pIn[] /* I PCM input */
);
#define TYPE_NO_VOICE_ACTIVITY 0
#define TYPE_UNVOICED 1
#define TYPE_VOICED 2
#define SPEECH_ACTIVITY_DTX_THRES 0.05f
#define SILK_FIX_CONST( C, Q ) ((int)((C) * ((long)1 << (Q)) + 0.5))
#define silk_int16_MAX 0x7FFF /* 2^15 - 1 = 32767 */
#define silk_int16_MIN ((short)0x8000) /* -2^15 = -32768 */
#define silk_int32_MAX 0x7FFFFFFF /* 2^31 - 1 = 2147483647 */
#define silk_int32_MIN ((int)0x80000000) /* -2^31 = -2147483648 */
#define silk_memset(dest, src, size) memset((dest), (src), (size))
#define VAD_NOISE_LEVEL_SMOOTH_COEF_Q16 1024 /* Must be < 4096 */
#define VAD_NOISE_LEVELS_BIAS 50
/* Sigmoid settings */
#define VAD_NEGATIVE_OFFSET_Q5 128 /* sigmoid is 0 at -128 */
#define VAD_SNR_FACTOR_Q16 45000
/* smoothing for SNR measurement */
#define VAD_SNR_SMOOTH_COEF_Q18 4096
#define VAD_N_BANDS 4
#define VAD_INTERNAL_SUBFRAMES_LOG2 2
#define VAD_INTERNAL_SUBFRAMES ( 1 << VAD_INTERNAL_SUBFRAMES_LOG2 )
#define silk_uint8_MAX 0xFF /* 2^8 - 1 = 255 */
#define VARDECL(type, var) type *var
#define silk_RSHIFT32(a, shift) ((a)>>(shift))
#define silk_RSHIFT(a, shift) ((a)>>(shift))
#define silk_LSHIFT32(a, shift) ((a)<<(shift))
#define silk_LSHIFT(a, shift) ((a)<<(shift))
#define ALLOC(var, size, type) var = ((type*)alloca(sizeof(type)*(size)))
#define silk_ADD16(a, b) ((a) + (b))
#define silk_ADD32(a, b) ((a) + (b))
#define silk_ADD64(a, b) ((a) + (b))
#define silk_SUB16(a, b) ((a) - (b))
#define silk_SUB32(a, b) ((a) - (b))
#define silk_SUB64(a, b) ((a) - (b))
#define silk_SMULWB(a32, b32) ((((a32) >> 16) * (int)((short)(b32))) + ((((a32) & 0x0000FFFF) * (int)((short)(b32))) >> 16))
#define silk_SMLAWB(a32, b32, c32) ((a32) + ((((b32) >> 16) * (int)((short)(c32))) + ((((b32) & 0x0000FFFF) * (int)((short)(c32))) >> 16)))
#define silk_SAT16(a) ((a) > silk_int16_MAX ? silk_int16_MAX : \
((a) < silk_int16_MIN ? silk_int16_MIN : (a)))
#define silk_MLA(a32, b32, c32) silk_ADD32((a32),((b32) * (c32)))
#define silk_SMLABB(a32, b32, c32) ((a32) + ((int)((short)(b32))) * (int)((short)(c32)))
#define silk_ADD_POS_SAT32(a, b) ((((unsigned int)(a)+(unsigned int)(b)) & 0x80000000) ? silk_int32_MAX : ((a)+(b)))
#define silk_ADD_POS_SAT32(a, b) ((((unsigned int)(a)+(unsigned int)(b)) & 0x80000000) ? silk_int32_MAX : ((a)+(b)))
#define silk_DIV32_16(a32, b16) ((int)((a32) / (b16)))
#define silk_DIV32(a32, b32) ((int)((a32) / (b32)))
#define silk_RSHIFT_ROUND(a, shift) ((shift) == 1 ? ((a) >> 1) + ((a) & 1) : (((a) >> ((shift) - 1)) + 1) >> 1)
#define silk_SMULWW(a32, b32) silk_MLA(silk_SMULWB((a32), (b32)), (a32), silk_RSHIFT_ROUND((b32), 16))
#define silk_min(a, b) (((a) < (b)) ? (a) : (b))
#define silk_max(a, b) (((a) > (b)) ? (a) : (b))
#define silk_ADD_LSHIFT32(a, b, shift) silk_ADD32((a), silk_LSHIFT32((b), (shift))) /* shift >= 0 */
#define silk_MUL(a32, b32) ((a32) * (b32))
#define silk_SMULBB(a32, b32) ((int)((short)(a32)) * (int)((short)(b32)))
#define silk_LIMIT( a, limit1, limit2) ((limit1) > (limit2) ? ((a) > (limit1) ? (limit1) : ((a) < (limit2) ? (limit2) : (a))) \
: ((a) > (limit2) ? (limit2) : ((a) < (limit1) ? (limit1) : (a))))
#define silk_LSHIFT_SAT32(a, shift) (silk_LSHIFT32( silk_LIMIT( (a), silk_RSHIFT32( silk_int32_MIN, (shift) ), \
silk_RSHIFT32( silk_int32_MAX, (shift) ) ), (shift) ))
static const int tiltWeights[VAD_N_BANDS] = { 30000, 6000, -12000, -12000 };
static const int sigm_LUT_neg_Q15[6] = {
16384, 8812, 3906, 1554, 589, 219
};
static const int sigm_LUT_slope_Q10[6] = {
237, 153, 73, 30, 12, 7
};
static const int sigm_LUT_pos_Q15[6] = {
16384, 23955, 28861, 31213, 32178, 32548
};
static __inline int ec_bsr(unsigned long _x) {
unsigned long ret;
_BitScanReverse(&ret, _x);
return (int)ret;
}
# define EC_CLZ0 (1)
# define EC_CLZ(_x) (-ec_bsr(_x))
# define EC_ILOG(_x) (EC_CLZ0-EC_CLZ(_x))
static int silk_min_int(int a, int b)
{
return (((a) < (b)) ? (a) : (b));
}
static int silk_max_int(int a, int b)
{
return (((a) > (b)) ? (a) : (b));
}
static int silk_max_32(int a, int b)
{
return (((a) > (b)) ? (a) : (b));
}
static int silk_CLZ32(int in32)
{
return in32 ? 32 - EC_ILOG(in32) : 32;
}
static int silk_ROR32(int a32, int rot)
{
unsigned int x = (unsigned int)a32;
unsigned int r = (unsigned int)rot;
unsigned int m = (unsigned int)-rot;
if (rot == 0) {
return a32;
}
else if (rot < 0) {
return (int)((x << m) | (x >> (32 - m)));
}
else {
return (int)((x << (32 - r)) | (x >> r));
}
}
static void silk_CLZ_FRAC(
int in, /* I input */
int *lz, /* O number of leading zeros */
int *frac_Q7 /* O the 7 bits right after the leading one */
)
{
int lzeros = silk_CLZ32(in);
*lz = lzeros;
*frac_Q7 = silk_ROR32(in, 24 - lzeros) & 0x7f;
}
/* Approximation of square root */
/* Accuracy: < +/- 10% for output values > 15 */
/* < +/- 2.5% for output values > 120 */
static int silk_SQRT_APPROX(int x)
{
int y, lz, frac_Q7;
if (x <= 0) {
return 0;
}
silk_CLZ_FRAC(x, &lz, &frac_Q7);
if (lz & 1) {
y = 32768;
}
else {
y = 46214; /* 46214 = sqrt(2) * 32768 */
}
/* get scaling right */
y >>= silk_RSHIFT(lz, 1);
/* increment using fractional part of input */
y = silk_SMLAWB(y, y, silk_SMULBB(213, frac_Q7));
return y;
}
.cpp文件代码：
#include "opusvad.h"
#include <stdlib.h>
static short A_fb1_20 = 5394 << 1;
static short A_fb1_21 = -24290; /* (int16)(20623 << 1) */
typedef struct {
int AnaState[2]; /* Analysis filterbank state: 0-8 kHz */
int AnaState1[2]; /* Analysis filterbank state: 0-4 kHz */
int AnaState2[2]; /* Analysis filterbank state: 0-2 kHz */
int XnrgSubfr[4]; /* Subframe energies */
int NrgRatioSmth_Q8[VAD_N_BANDS]; /* Smoothed energy level in each band */
short HPstate; /* State of differentiator in the lowest band */
int NL[VAD_N_BANDS]; /* Noise energy level in each band */
int inv_NL[VAD_N_BANDS]; /* Inverse noise energy level in each band */
int NoiseLevelBias[VAD_N_BANDS]; /* Noise level estimator bias/offset */
int counter; /* Frame counter used in the initial phase */
} VAD_state;
/* Split signal into two decimated bands using first-order allpass filters */
void silk_ana_filt_bank_1(
const short *in, /* I Input signal [N] */
int *S, /* I/O State vector [2] */
short *outL, /* O Low band [N/2] */
short *outH, /* O High band [N/2] */
const int N /* I Number of input samples */
)
{
int k, N2 = silk_RSHIFT(N, 1);
int in32, X, Y, out_1, out_2;
/* Internal variables and state are in Q10 format */
for (k = 0; k < N2; k++) {
/* Convert to Q10 */
in32 = silk_LSHIFT((int)in[2 * k], 10);
/* All-pass section for even input sample */
Y = silk_SUB32(in32, S[0]);
X = silk_SMLAWB(Y, Y, A_fb1_21);
out_1 = silk_ADD32(S[0], X);
S[0] = silk_ADD32(in32, X);
/* Convert to Q10 */
in32 = silk_LSHIFT((int)in[2 * k + 1], 10);
/* All-pass section for odd input sample, and add to output of previous section */
Y = silk_SUB32(in32, S[1]);
X = silk_SMULWB(Y, A_fb1_20);
out_2 = silk_ADD32(S[1], X);
S[1] = silk_ADD32(in32, X);
/* Add/subtract, convert back to int16 and store to output */
outL[k] = (short)silk_SAT16(silk_RSHIFT_ROUND(silk_ADD32(out_2, out_1), 11));
outH[k] = (short)silk_SAT16(silk_RSHIFT_ROUND(silk_SUB32(out_2, out_1), 11));
}
}
void silk_VAD_GetNoiseLevels(
const int pX[VAD_N_BANDS], /* I subband energies */
VAD_state *psSilk_VAD /* I/O Pointer to Silk VAD state */
)
{
int k;
int nl, nrg, inv_nrg;
int coef, min_coef;
/* Initially faster smoothing */
if (psSilk_VAD->counter < 1000) { /* 1000 = 20 sec */
min_coef = silk_DIV32_16(silk_int16_MAX, silk_RSHIFT(psSilk_VAD->counter, 4) + 1);
}
else {
min_coef = 0;
}
for (k = 0; k < VAD_N_BANDS; k++) {
/* Get old noise level estimate for current band */
nl = psSilk_VAD->NL[k];
//silk_assert(nl >= 0);
/* Add bias */
nrg = silk_ADD_POS_SAT32(pX[k], psSilk_VAD->NoiseLevelBias[k]);
//silk_assert(nrg > 0);
/* Invert energies */
inv_nrg = silk_DIV32(silk_int32_MAX, nrg);
//silk_assert(inv_nrg >= 0);
/* Less update when subband energy is high */
if (nrg > silk_LSHIFT(nl, 3)) {
coef = VAD_NOISE_LEVEL_SMOOTH_COEF_Q16 >> 3;
}
else if (nrg < nl) {
coef = VAD_NOISE_LEVEL_SMOOTH_COEF_Q16;
}
else {
coef = silk_SMULWB(silk_SMULWW(inv_nrg, nl), VAD_NOISE_LEVEL_SMOOTH_COEF_Q16 << 1);
}
/* Initially faster smoothing */
coef = silk_max_int(coef, min_coef);
/* Smooth inverse energies */
psSilk_VAD->inv_NL[k] = silk_SMLAWB(psSilk_VAD->inv_NL[k], inv_nrg - psSilk_VAD->inv_NL[k], coef);
//silk_assert(psSilk_VAD->inv_NL[k] >= 0);
/* Compute noise level by inverting again */
nl = silk_DIV32(silk_int32_MAX, psSilk_VAD->inv_NL[k]);
//silk_assert(nl >= 0);
/* Limit noise levels (guarantee 7 bits of head room) */
nl = silk_min(nl, 0x00FFFFFF);
/* Store as part of state */
psSilk_VAD->NL[k] = nl;
}
/* Increment frame counter */
psSilk_VAD->counter++;
}
int silk_lin2log(
const int inLin /* I input in linear scale */
)
{
int lz, frac_Q7;
silk_CLZ_FRAC(inLin, &lz, &frac_Q7);
/* Piece-wise parabolic approximation */
return silk_ADD_LSHIFT32(silk_SMLAWB(frac_Q7, silk_MUL(frac_Q7, 128 - frac_Q7), 179), 31 - lz, 7);
}
int silk_sigm_Q15(
int in_Q5 /* I */
)
{
int ind;
if (in_Q5 < 0) {
/* Negative input */
in_Q5 = -in_Q5;
if (in_Q5 >= 6 * 32) {
return 0; /* Clip */
}
else {
/* Linear interpolation of look up table */
ind = silk_RSHIFT(in_Q5, 5);
return(sigm_LUT_neg_Q15[ind] - silk_SMULBB(sigm_LUT_slope_Q10[ind], in_Q5 & 0x1F));
}
}
else {
/* Positive input */
if (in_Q5 >= 6 * 32) {
return 32767; /* clip */
}
else {
/* Linear interpolation of look up table */
ind = silk_RSHIFT(in_Q5, 5);
return(sigm_LUT_pos_Q15[ind] + silk_SMULBB(sigm_LUT_slope_Q10[ind], in_Q5 & 0x1F));
}
}
}
int silk_VAD_Init( /* O Return value, 0 if success */
VAD_state *psSilk_VAD /* I/O Pointer to Silk VAD state */
)
{
int b, ret = 0;
/* reset state memory */
silk_memset(psSilk_VAD, 0, sizeof(VAD_state));
/* init noise levels */
/* Initialize array with approx pink noise levels (psd proportional to inverse of frequency) */
for (b = 0; b < VAD_N_BANDS; b++) {
psSilk_VAD->NoiseLevelBias[b] = silk_max_32(silk_DIV32_16(VAD_NOISE_LEVELS_BIAS, b + 1), 1);
}
/* Initialize state */
for (b = 0; b < VAD_N_BANDS; b++) {
psSilk_VAD->NL[b] = silk_MUL(100, psSilk_VAD->NoiseLevelBias[b]);
psSilk_VAD->inv_NL[b] = silk_DIV32(silk_int32_MAX, psSilk_VAD->NL[b]);
}
psSilk_VAD->counter = 15;
/* init smoothed energy-to-noise ratio*/
for (b = 0; b < VAD_N_BANDS; b++) {
psSilk_VAD->NrgRatioSmth_Q8[b] = 100 * 256; /* 100 * 256 --> 20 dB SNR */
}
return(ret);
}
static int noSpeechCounter;
int silk_VAD_Get(
//int state, /* Encoder state */
const short pIn[] /* I PCM input */
)
{
int SA_Q15, pSNR_dB_Q7, input_tilt;
int decimated_framelength1, decimated_framelength2;
int decimated_framelength;
int dec_subframe_length, dec_subframe_offset, SNR_Q7, i, b, s;
int sumSquared, smooth_coef_Q16;
short HPstateTmp;
VARDECL(short, X);
int Xnrg[4];
int NrgToNoiseRatio_Q8[4];
int speech_nrg, x_tmp;
int X_offset[4];
int ret = 0;
int frame_length = 20;//
int fs_kHz = 16;
int input_quality_bands_Q15[VAD_N_BANDS];
int signalType;
int VAD_flag;
/* Safety checks
silk_assert(4 == 4);
silk_assert(MAX_FRAME_LENGTH >= frame_length);
silk_assert(frame_length <= 512);
silk_assert(frame_length == 8 * silk_RSHIFT(frame_length, 3));
*/
/***********************/
/* Filter and Decimate */
/***********************/
decimated_framelength1 = silk_RSHIFT(frame_length, 1);
decimated_framelength2 = silk_RSHIFT(frame_length, 2);
decimated_framelength = silk_RSHIFT(frame_length, 3);
/* Decimate into 4 bands:
0 L 3L L 3L 5L
- -- - -- --
8 8 2 4 4
[0-1 kHz| temp. |1-2 kHz| 2-4 kHz | 4-8 kHz |
They're arranged to allow the minimal ( frame_length / 4 ) extra
scratch space during the downsampling process */
X_offset[0] = 0;
X_offset[1] = decimated_framelength + decimated_framelength2;
X_offset[2] = X_offset[1] + decimated_framelength;
X_offset[3] = X_offset[2] + decimated_framelength2;
ALLOC(X, X_offset[3] + decimated_framelength1, short);
VAD_state *psSilk_VAD;
psSilk_VAD = (VAD_state*)malloc(sizeof(VAD_state));
int ret1 = silk_VAD_Init(psSilk_VAD);
/* 0-8 kHz to 0-4 kHz and 4-8 kHz */
silk_ana_filt_bank_1(pIn, &psSilk_VAD->AnaState[0],
X, &X[X_offset[3]], frame_length);
/* 0-4 kHz to 0-2 kHz and 2-4 kHz */
silk_ana_filt_bank_1(X, &psSilk_VAD->AnaState1[0],
X, &X[X_offset[2]], decimated_framelength1);
/* 0-2 kHz to 0-1 kHz and 1-2 kHz */
silk_ana_filt_bank_1(X, &psSilk_VAD->AnaState2[0],
X, &X[X_offset[1]], decimated_framelength2);
/*********************************************/
/* HP filter on lowest band (differentiator) */
/*********************************************/
X[decimated_framelength - 1] = silk_RSHIFT(X[decimated_framelength - 1], 1);
HPstateTmp = X[decimated_framelength - 1];
for (i = decimated_framelength - 1; i > 0; i--) {
X[i - 1] = silk_RSHIFT(X[i - 1], 1);
X[i] -= X[i - 1];
}
X[0] -= psSilk_VAD->HPstate;
psSilk_VAD->HPstate = HPstateTmp;
/*************************************/
/* Calculate the energy in each band */
/*************************************/
for (b = 0; b < 4; b++) {
/* Find the decimated framelength in the non-uniformly divided bands */
decimated_framelength = silk_RSHIFT(frame_length, silk_min_int(4 - b, 4 - 1));
/* Split length into subframe lengths */
dec_subframe_length = silk_RSHIFT(decimated_framelength, VAD_INTERNAL_SUBFRAMES_LOG2);
dec_subframe_offset = 0;
/* Compute energy per sub-frame */
/* initialize with summed energy of last subframe */
Xnrg[b] = psSilk_VAD->XnrgSubfr[b];
for (s = 0; s < VAD_INTERNAL_SUBFRAMES; s++) {
sumSquared = 0;
for (i = 0; i < dec_subframe_length; i++) {
/* The energy will be less than dec_subframe_length * ( silk_short_MIN / 8 ) ^ 2. */
/* Therefore we can accumulate with no risk of overflow (unless dec_subframe_length > 128) */
x_tmp = silk_RSHIFT(
X[X_offset[b] + i + dec_subframe_offset], 3);
sumSquared = silk_SMLABB(sumSquared, x_tmp, x_tmp);
/* Safety check */
//silk_assert(sumSquared >= 0);
}
/* Add/saturate summed energy of current subframe */
if (s < VAD_INTERNAL_SUBFRAMES - 1) {
Xnrg[b] = silk_ADD_POS_SAT32(Xnrg[b], sumSquared);
}
else {
/* Look-ahead subframe */
Xnrg[b] = silk_ADD_POS_SAT32(Xnrg[b], silk_RSHIFT(sumSquared, 1));
}
dec_subframe_offset += dec_subframe_length;
}
psSilk_VAD->XnrgSubfr[b] = sumSquared;
}
/********************/
/* Noise estimation */
/********************/
silk_VAD_GetNoiseLevels(&Xnrg[0], psSilk_VAD);
/***********************************************/
/* Signal-plus-noise to noise ratio estimation */
/***********************************************/
sumSquared = 0;
input_tilt = 0;
for (b = 0; b < 4; b++) {
speech_nrg = Xnrg[b] - psSilk_VAD->NL[b];
if (speech_nrg > 0) {
/* Divide, with sufficient resolution */
if ((Xnrg[b] & 0xFF800000) == 0) {
NrgToNoiseRatio_Q8[b] = silk_DIV32(silk_LSHIFT(Xnrg[b], 8), psSilk_VAD->NL[b] + 1);
}
else {
NrgToNoiseRatio_Q8[b] = silk_DIV32(Xnrg[b], silk_RSHIFT(psSilk_VAD->NL[b], 8) + 1);
}
/* Convert to log domain */
SNR_Q7 = silk_lin2log(NrgToNoiseRatio_Q8[b]) - 8 * 128;
/* Sum-of-squares */
sumSquared = silk_SMLABB(sumSquared, SNR_Q7, SNR_Q7); /* Q14 */
/* Tilt measure */
if (speech_nrg < ((int)1 << 20)) {
/* Scale down SNR value for small subband speech energies */
SNR_Q7 = silk_SMULWB(silk_LSHIFT(silk_SQRT_APPROX(speech_nrg), 6), SNR_Q7);
}
input_tilt = silk_SMLAWB(input_tilt, tiltWeights[b], SNR_Q7);
}
else {
NrgToNoiseRatio_Q8[b] = 256;
}
}
/* Mean-of-squares */
sumSquared = silk_DIV32_16(sumSquared, 4); /* Q14 */
/* Root-mean-square approximation, scale to dBs, and write to output pointer */
pSNR_dB_Q7 = (short)(3 * silk_SQRT_APPROX(sumSquared)); /* Q7 */
/*********************************/
/* Speech Probability Estimation */
/*********************************/
SA_Q15 = silk_sigm_Q15(silk_SMULWB(VAD_SNR_FACTOR_Q16, pSNR_dB_Q7) - VAD_NEGATIVE_OFFSET_Q5);
/**************************/
/* Frequency Tilt Measure */
/**************************/
int input_tilt_Q15 = silk_LSHIFT(silk_sigm_Q15(input_tilt) - 16384, 1);
/**************************************************/
/* Scale the sigmoid output based on power levels */
/**************************************************/
speech_nrg = 0;
for (b = 0; b < 4; b++) {
/* Accumulate signal-without-noise energies, higher frequency bands have more weight */
speech_nrg += (b + 1) * silk_RSHIFT(Xnrg[b] - psSilk_VAD->NL[b], 4);
}
/* Power scaling */
if (speech_nrg <= 0) {
SA_Q15 = silk_RSHIFT(SA_Q15, 1);
}
else if (speech_nrg < 32768) {
if (frame_length == 10 * fs_kHz) {
speech_nrg = silk_LSHIFT_SAT32(speech_nrg, 16);
}
else {
speech_nrg = silk_LSHIFT_SAT32(speech_nrg, 15);
}
/* square-root */
speech_nrg = silk_SQRT_APPROX(speech_nrg);
SA_Q15 = silk_SMULWB(32768 + speech_nrg, SA_Q15);
}
/* Copy the resulting speech activity in Q8 */
int speech_activity_Q8 = silk_min_int(silk_RSHIFT(SA_Q15, 7), silk_uint8_MAX);
/***********************************/
/* Energy Level and SNR estimation */
/***********************************/
/* Smoothing coefficient */
smooth_coef_Q16 = silk_SMULWB(VAD_SNR_SMOOTH_COEF_Q18, silk_SMULWB((int)SA_Q15, SA_Q15));
if (frame_length == 10 * fs_kHz) {
smooth_coef_Q16 >>= 1;
}
for (b = 0; b < 4; b++) {
/* compute smoothed energy-to-noise ratio per band */
psSilk_VAD->NrgRatioSmth_Q8[b] = silk_SMLAWB(psSilk_VAD->NrgRatioSmth_Q8[b],
NrgToNoiseRatio_Q8[b] - psSilk_VAD->NrgRatioSmth_Q8[b], smooth_coef_Q16);
/* signal to noise ratio in dB per band */
SNR_Q7 = 3 * (silk_lin2log(psSilk_VAD->NrgRatioSmth_Q8[b]) - 8 * 128);
/* quality = sigmoid( 0.25 * ( SNR_dB - 16 ) ); */
input_quality_bands_Q15[b] = silk_sigm_Q15(silk_RSHIFT(SNR_Q7 - 16 * 128, 4));
}
//gap************************************************************//
if (speech_activity_Q8 < SILK_FIX_CONST(SPEECH_ACTIVITY_DTX_THRES, 8)) {
signalType = TYPE_NO_VOICE_ACTIVITY;
//noSpeechCounter++;
VAD_flag = 0;
}
else {
signalType = TYPE_UNVOICED;
VAD_flag = 1;
}
free(psSilk_VAD);
return(VAD_flag);
}