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Diffstat (limited to 'media/libstagefright/codecs/amrwbenc/src/wb_vad.c')
-rw-r--r--media/libstagefright/codecs/amrwbenc/src/wb_vad.c1616
1 files changed, 808 insertions, 808 deletions
diff --git a/media/libstagefright/codecs/amrwbenc/src/wb_vad.c b/media/libstagefright/codecs/amrwbenc/src/wb_vad.c
index 0126853..7e1d673 100644
--- a/media/libstagefright/codecs/amrwbenc/src/wb_vad.c
+++ b/media/libstagefright/codecs/amrwbenc/src/wb_vad.c
@@ -1,808 +1,808 @@
-/*
- ** Copyright 2003-2010, VisualOn, Inc.
- **
- ** Licensed under the Apache License, Version 2.0 (the "License");
- ** you may not use this file except in compliance with the License.
- ** You may obtain a copy of the License at
- **
- ** http://www.apache.org/licenses/LICENSE-2.0
- **
- ** Unless required by applicable law or agreed to in writing, software
- ** distributed under the License is distributed on an "AS IS" BASIS,
- ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- ** See the License for the specific language governing permissions and
- ** limitations under the License.
- */
-
-/***********************************************************************
-* File: wb_vad.c *
-* *
-* Description: Voice Activity Detection *
-* *
-************************************************************************/
-
-#include <stdlib.h>
-#include <stdio.h>
-#include "cnst.h"
-#include "wb_vad.h"
-#include "typedef.h"
-#include "basic_op.h"
-#include "math_op.h"
-#include "wb_vad_c.h"
-#include "mem_align.h"
-
-/******************************************************************************
-* Calculate Log2 and scale the signal:
-*
-* ilog2(Word32 in) = -1024*log10(in * 2^-31)/log10(2), where in = [1, 2^31-1]
-*
-* input output
-* 32768 16384
-* 1 31744
-*
-* When input is in the range of [1,2^16], max error is 0.0380%.
-*********************************************************************************/
-
-static Word16 ilog2( /* return: output value of the log2 */
- Word16 mant /* i: value to be converted */
- )
-{
- Word16 ex, ex2, res;
- Word32 i, l_temp;
-
- if (mant <= 0)
- {
- mant = 1;
- }
- ex = norm_s(mant);
- mant = mant << ex;
-
- for (i = 0; i < 3; i++)
- mant = vo_mult(mant, mant);
- l_temp = vo_L_mult(mant, mant);
-
- ex2 = norm_l(l_temp);
- mant = extract_h(l_temp << ex2);
-
- res = (ex + 16) << 10;
- res = add1(res, (ex2 << 6));
- res = vo_sub(add1(res, 127), (mant >> 8));
- return (res);
-}
-
-/******************************************************************************
-*
-* Function : filter5
-* Purpose : Fifth-order half-band lowpass/highpass filter pair with
-* decimation.
-*
-*******************************************************************************/
-
-static void filter5(
- Word16 * in0, /* i/o : input values; output low-pass part */
- Word16 * in1, /* i/o : input values; output high-pass part */
- Word16 data[] /* i/o : filter memory */
- )
-{
- Word16 temp0, temp1, temp2;
-
- temp0 = vo_sub(*in0, vo_mult(COEFF5_1, data[0]));
- temp1 = add1(data[0], vo_mult(COEFF5_1, temp0));
- data[0] = temp0;
-
- temp0 = vo_sub(*in1, vo_mult(COEFF5_2, data[1]));
- temp2 = add1(data[1], vo_mult(COEFF5_2, temp0));
- data[1] = temp0;
-
- *in0 = extract_h((vo_L_add(temp1, temp2) << 15));
- *in1 = extract_h((vo_L_sub(temp1, temp2) << 15));
-}
-
-/******************************************************************************
-*
-* Function : filter3
-* Purpose : Third-order half-band lowpass/highpass filter pair with
-* decimation.
-*
-*******************************************************************************/
-
-static void filter3(
- Word16 * in0, /* i/o : input values; output low-pass part */
- Word16 * in1, /* i/o : input values; output high-pass part */
- Word16 * data /* i/o : filter memory */
- )
-{
- Word16 temp1, temp2;
-
- temp1 = vo_sub(*in1, vo_mult(COEFF3, *data));
- temp2 = add1(*data, vo_mult(COEFF3, temp1));
- *data = temp1;
-
- *in1 = extract_h((vo_L_sub(*in0, temp2) << 15));
- *in0 = extract_h((vo_L_add(*in0, temp2) << 15));
-}
-
-/******************************************************************************
-*
-* Function : level_calculation
-* Purpose : Calculate signal level in a sub-band. Level is calculated
-* by summing absolute values of the input data.
-*
-* Signal level calculated from of the end of the frame
-* (data[count1 - count2]) is stored to (*sub_level)
-* and added to the level of the next frame.
-*
-******************************************************************************/
-
-static Word16 level_calculation( /* return: signal level */
- Word16 data[], /* i : signal buffer */
- Word16 * sub_level, /* i : level calculated at the end of the previous frame*/
- /* o : level of signal calculated from the last */
- /* (count2 - count1) samples */
- Word16 count1, /* i : number of samples to be counted */
- Word16 count2, /* i : number of samples to be counted */
- Word16 ind_m, /* i : step size for the index of the data buffer */
- Word16 ind_a, /* i : starting index of the data buffer */
- Word16 scale /* i : scaling for the level calculation */
- )
-{
- Word32 i, l_temp1, l_temp2;
- Word16 level;
-
- l_temp1 = 0L;
- for (i = count1; i < count2; i++)
- {
- l_temp1 += (abs_s(data[ind_m * i + ind_a])<<1);
- }
-
- l_temp2 = vo_L_add(l_temp1, L_shl(*sub_level, 16 - scale));
- *sub_level = extract_h(L_shl(l_temp1, scale));
-
- for (i = 0; i < count1; i++)
- {
- l_temp2 += (abs_s(data[ind_m * i + ind_a])<<1);
- }
- level = extract_h(L_shl2(l_temp2, scale));
-
- return level;
-}
-
-/******************************************************************************
-*
-* Function : filter_bank
-* Purpose : Divide input signal into bands and calculate level of
-* the signal in each band
-*
-*******************************************************************************/
-
-static void filter_bank(
- VadVars * st, /* i/o : State struct */
- Word16 in[], /* i : input frame */
- Word16 level[] /* o : signal levels at each band */
- )
-{
- Word32 i;
- Word16 tmp_buf[FRAME_LEN];
-
- /* shift input 1 bit down for safe scaling */
- for (i = 0; i < FRAME_LEN; i++)
- {
- tmp_buf[i] = in[i] >> 1;
- }
-
- /* run the filter bank */
- for (i = 0; i < 128; i++)
- {
- filter5(&tmp_buf[2 * i], &tmp_buf[2 * i + 1], st->a_data5[0]);
- }
- for (i = 0; i < 64; i++)
- {
- filter5(&tmp_buf[4 * i], &tmp_buf[4 * i + 2], st->a_data5[1]);
- filter5(&tmp_buf[4 * i + 1], &tmp_buf[4 * i + 3], st->a_data5[2]);
- }
- for (i = 0; i < 32; i++)
- {
- filter5(&tmp_buf[8 * i], &tmp_buf[8 * i + 4], st->a_data5[3]);
- filter5(&tmp_buf[8 * i + 2], &tmp_buf[8 * i + 6], st->a_data5[4]);
- filter3(&tmp_buf[8 * i + 3], &tmp_buf[8 * i + 7], &st->a_data3[0]);
- }
- for (i = 0; i < 16; i++)
- {
- filter3(&tmp_buf[16 * i + 0], &tmp_buf[16 * i + 8], &st->a_data3[1]);
- filter3(&tmp_buf[16 * i + 4], &tmp_buf[16 * i + 12], &st->a_data3[2]);
- filter3(&tmp_buf[16 * i + 6], &tmp_buf[16 * i + 14], &st->a_data3[3]);
- }
-
- for (i = 0; i < 8; i++)
- {
- filter3(&tmp_buf[32 * i + 0], &tmp_buf[32 * i + 16], &st->a_data3[4]);
- filter3(&tmp_buf[32 * i + 8], &tmp_buf[32 * i + 24], &st->a_data3[5]);
- }
-
- /* calculate levels in each frequency band */
-
- /* 4800 - 6400 Hz */
- level[11] = level_calculation(tmp_buf, &st->sub_level[11], 16, 64, 4, 1, 14);
- /* 4000 - 4800 Hz */
- level[10] = level_calculation(tmp_buf, &st->sub_level[10], 8, 32, 8, 7, 15);
- /* 3200 - 4000 Hz */
- level[9] = level_calculation(tmp_buf, &st->sub_level[9],8, 32, 8, 3, 15);
- /* 2400 - 3200 Hz */
- level[8] = level_calculation(tmp_buf, &st->sub_level[8],8, 32, 8, 2, 15);
- /* 2000 - 2400 Hz */
- level[7] = level_calculation(tmp_buf, &st->sub_level[7],4, 16, 16, 14, 16);
- /* 1600 - 2000 Hz */
- level[6] = level_calculation(tmp_buf, &st->sub_level[6],4, 16, 16, 6, 16);
- /* 1200 - 1600 Hz */
- level[5] = level_calculation(tmp_buf, &st->sub_level[5],4, 16, 16, 4, 16);
- /* 800 - 1200 Hz */
- level[4] = level_calculation(tmp_buf, &st->sub_level[4],4, 16, 16, 12, 16);
- /* 600 - 800 Hz */
- level[3] = level_calculation(tmp_buf, &st->sub_level[3],2, 8, 32, 8, 17);
- /* 400 - 600 Hz */
- level[2] = level_calculation(tmp_buf, &st->sub_level[2],2, 8, 32, 24, 17);
- /* 200 - 400 Hz */
- level[1] = level_calculation(tmp_buf, &st->sub_level[1],2, 8, 32, 16, 17);
- /* 0 - 200 Hz */
- level[0] = level_calculation(tmp_buf, &st->sub_level[0],2, 8, 32, 0, 17);
-}
-
-/******************************************************************************
-*
-* Function : update_cntrl
-* Purpose : Control update of the background noise estimate.
-*
-*******************************************************************************/
-
-static void update_cntrl(
- VadVars * st, /* i/o : State structure */
- Word16 level[] /* i : sub-band levels of the input frame */
- )
-{
- Word32 i;
- Word16 num, temp, stat_rat, exp, denom;
- Word16 alpha;
-
- /* if a tone has been detected for a while, initialize stat_count */
- if (sub((Word16) (st->tone_flag & 0x7c00), 0x7c00) == 0)
- {
- st->stat_count = STAT_COUNT;
- } else
- {
- /* if 8 last vad-decisions have been "0", reinitialize stat_count */
- if ((st->vadreg & 0x7f80) == 0)
- {
- st->stat_count = STAT_COUNT;
- } else
- {
- stat_rat = 0;
- for (i = 0; i < COMPLEN; i++)
- {
- if(level[i] > st->ave_level[i])
- {
- num = level[i];
- denom = st->ave_level[i];
- } else
- {
- num = st->ave_level[i];
- denom = level[i];
- }
- /* Limit nimimum value of num and denom to STAT_THR_LEVEL */
- if(num < STAT_THR_LEVEL)
- {
- num = STAT_THR_LEVEL;
- }
- if(denom < STAT_THR_LEVEL)
- {
- denom = STAT_THR_LEVEL;
- }
- exp = norm_s(denom);
- denom = denom << exp;
-
- /* stat_rat = num/denom * 64 */
- temp = div_s(num >> 1, denom);
- stat_rat = add1(stat_rat, shr(temp, (8 - exp)));
- }
-
- /* compare stat_rat with a threshold and update stat_count */
- if(stat_rat > STAT_THR)
- {
- st->stat_count = STAT_COUNT;
- } else
- {
- if ((st->vadreg & 0x4000) != 0)
- {
-
- if (st->stat_count != 0)
- {
- st->stat_count = st->stat_count - 1;
- }
- }
- }
- }
- }
-
- /* Update average amplitude estimate for stationarity estimation */
- alpha = ALPHA4;
- if(st->stat_count == STAT_COUNT)
- {
- alpha = 32767;
- } else if ((st->vadreg & 0x4000) == 0)
- {
- alpha = ALPHA5;
- }
- for (i = 0; i < COMPLEN; i++)
- {
- st->ave_level[i] = add1(st->ave_level[i], vo_mult_r(alpha, vo_sub(level[i], st->ave_level[i])));
- }
-}
-
-/******************************************************************************
-*
-* Function : hangover_addition
-* Purpose : Add hangover after speech bursts
-*
-*******************************************************************************/
-
-static Word16 hangover_addition( /* return: VAD_flag indicating final VAD decision */
- VadVars * st, /* i/o : State structure */
- Word16 low_power, /* i : flag power of the input frame */
- Word16 hang_len, /* i : hangover length */
- Word16 burst_len /* i : minimum burst length for hangover addition */
- )
-{
- /* if the input power (pow_sum) is lower than a threshold, clear counters and set VAD_flag to "0" */
- if (low_power != 0)
- {
- st->burst_count = 0;
- st->hang_count = 0;
- return 0;
- }
- /* update the counters (hang_count, burst_count) */
- if ((st->vadreg & 0x4000) != 0)
- {
- st->burst_count = st->burst_count + 1;
- if(st->burst_count >= burst_len)
- {
- st->hang_count = hang_len;
- }
- return 1;
- } else
- {
- st->burst_count = 0;
- if (st->hang_count > 0)
- {
- st->hang_count = st->hang_count - 1;
- return 1;
- }
- }
- return 0;
-}
-
-/******************************************************************************
-*
-* Function : noise_estimate_update
-* Purpose : Update of background noise estimate
-*
-*******************************************************************************/
-
-static void noise_estimate_update(
- VadVars * st, /* i/o : State structure */
- Word16 level[] /* i : sub-band levels of the input frame */
- )
-{
- Word32 i;
- Word16 alpha_up, alpha_down, bckr_add = 2;
-
- /* Control update of bckr_est[] */
- update_cntrl(st, level);
-
- /* Choose update speed */
- if ((0x7800 & st->vadreg) == 0)
- {
- alpha_up = ALPHA_UP1;
- alpha_down = ALPHA_DOWN1;
- } else
- {
- if ((st->stat_count == 0))
- {
- alpha_up = ALPHA_UP2;
- alpha_down = ALPHA_DOWN2;
- } else
- {
- alpha_up = 0;
- alpha_down = ALPHA3;
- bckr_add = 0;
- }
- }
-
- /* Update noise estimate (bckr_est) */
- for (i = 0; i < COMPLEN; i++)
- {
- Word16 temp;
- temp = (st->old_level[i] - st->bckr_est[i]);
-
- if (temp < 0)
- { /* update downwards */
- st->bckr_est[i] = add1(-2, add(st->bckr_est[i],vo_mult_r(alpha_down, temp)));
- /* limit minimum value of the noise estimate to NOISE_MIN */
- if(st->bckr_est[i] < NOISE_MIN)
- {
- st->bckr_est[i] = NOISE_MIN;
- }
- } else
- { /* update upwards */
- st->bckr_est[i] = add1(bckr_add, add1(st->bckr_est[i],vo_mult_r(alpha_up, temp)));
-
- /* limit maximum value of the noise estimate to NOISE_MAX */
- if(st->bckr_est[i] > NOISE_MAX)
- {
- st->bckr_est[i] = NOISE_MAX;
- }
- }
- }
-
- /* Update signal levels of the previous frame (old_level) */
- for (i = 0; i < COMPLEN; i++)
- {
- st->old_level[i] = level[i];
- }
-}
-
-/******************************************************************************
-*
-* Function : vad_decision
-* Purpose : Calculates VAD_flag
-*
-*******************************************************************************/
-
-static Word16 vad_decision( /* return value : VAD_flag */
- VadVars * st, /* i/o : State structure */
- Word16 level[COMPLEN], /* i : sub-band levels of the input frame */
- Word32 pow_sum /* i : power of the input frame */
- )
-{
- Word32 i;
- Word32 L_snr_sum;
- Word32 L_temp;
- Word16 vad_thr, temp, noise_level;
- Word16 low_power_flag;
- Word16 hang_len, burst_len;
- Word16 ilog2_speech_level, ilog2_noise_level;
- Word16 temp2;
-
- /* Calculate squared sum of the input levels (level) divided by the background noise components
- * (bckr_est). */
- L_snr_sum = 0;
- for (i = 0; i < COMPLEN; i++)
- {
- Word16 exp;
-
- exp = norm_s(st->bckr_est[i]);
- temp = (st->bckr_est[i] << exp);
- temp = div_s((level[i] >> 1), temp);
- temp = shl(temp, (exp - (UNIRSHFT - 1)));
- L_snr_sum = L_mac(L_snr_sum, temp, temp);
- }
-
- /* Calculate average level of estimated background noise */
- L_temp = 0;
- for (i = 1; i < COMPLEN; i++) /* ignore lowest band */
- {
- L_temp = vo_L_add(L_temp, st->bckr_est[i]);
- }
-
- noise_level = extract_h((L_temp << 12));
- /* if SNR is lower than a threshold (MIN_SPEECH_SNR), and increase speech_level */
- temp = vo_mult(noise_level, MIN_SPEECH_SNR) << 3;
-
- if(st->speech_level < temp)
- {
- st->speech_level = temp;
- }
- ilog2_noise_level = ilog2(noise_level);
-
- /* If SNR is very poor, speech_level is probably corrupted by noise level. This is correctred by
- * subtracting MIN_SPEECH_SNR*noise_level from speech level */
- ilog2_speech_level = ilog2(st->speech_level - temp);
-
- temp = add1(vo_mult(NO_SLOPE, (ilog2_noise_level - NO_P1)), THR_HIGH);
-
- temp2 = add1(SP_CH_MIN, vo_mult(SP_SLOPE, (ilog2_speech_level - SP_P1)));
- if (temp2 < SP_CH_MIN)
- {
- temp2 = SP_CH_MIN;
- }
- if (temp2 > SP_CH_MAX)
- {
- temp2 = SP_CH_MAX;
- }
- vad_thr = temp + temp2;
-
- if(vad_thr < THR_MIN)
- {
- vad_thr = THR_MIN;
- }
- /* Shift VAD decision register */
- st->vadreg = (st->vadreg >> 1);
-
- /* Make intermediate VAD decision */
- if(L_snr_sum > vo_L_mult(vad_thr, (512 * COMPLEN)))
- {
- st->vadreg = (Word16) (st->vadreg | 0x4000);
- }
- /* check if the input power (pow_sum) is lower than a threshold" */
- if(pow_sum < VAD_POW_LOW)
- {
- low_power_flag = 1;
- } else
- {
- low_power_flag = 0;
- }
- /* Update background noise estimates */
- noise_estimate_update(st, level);
-
- /* Calculate values for hang_len and burst_len based on vad_thr */
- hang_len = add1(vo_mult(HANG_SLOPE, (vad_thr - HANG_P1)), HANG_HIGH);
- if(hang_len < HANG_LOW)
- {
- hang_len = HANG_LOW;
- }
- burst_len = add1(vo_mult(BURST_SLOPE, (vad_thr - BURST_P1)), BURST_HIGH);
-
- return (hangover_addition(st, low_power_flag, hang_len, burst_len));
-}
-
-/******************************************************************************
-*
-* Function : Estimate_Speech()
-* Purpose : Estimate speech level
-*
-* Maximum signal level is searched and stored to the variable sp_max.
-* The speech frames must locate within SP_EST_COUNT number of frames.
-* Thus, noisy frames having occasional VAD = "1" decisions will not
-* affect to the estimated speech_level.
-*
-*******************************************************************************/
-
-static void Estimate_Speech(
- VadVars * st, /* i/o : State structure */
- Word16 in_level /* level of the input frame */
- )
-{
- Word16 alpha;
-
- /* if the required activity count cannot be achieved, reset counters */
- if((st->sp_est_cnt - st->sp_max_cnt) > (SP_EST_COUNT - SP_ACTIVITY_COUNT))
- {
- st->sp_est_cnt = 0;
- st->sp_max = 0;
- st->sp_max_cnt = 0;
- }
- st->sp_est_cnt += 1;
-
- if (((st->vadreg & 0x4000)||(in_level > st->speech_level)) && (in_level > MIN_SPEECH_LEVEL1))
- {
- /* update sp_max */
- if(in_level > st->sp_max)
- {
- st->sp_max = in_level;
- }
- st->sp_max_cnt += 1;
-
- if(st->sp_max_cnt >= SP_ACTIVITY_COUNT)
- {
- Word16 tmp;
- /* update speech estimate */
- tmp = (st->sp_max >> 1); /* scale to get "average" speech level */
-
- /* select update speed */
- if(tmp > st->speech_level)
- {
- alpha = ALPHA_SP_UP;
- } else
- {
- alpha = ALPHA_SP_DOWN;
- }
- if(tmp > MIN_SPEECH_LEVEL2)
- {
- st->speech_level = add1(st->speech_level, vo_mult_r(alpha, vo_sub(tmp, st->speech_level)));
- }
- /* clear all counters used for speech estimation */
- st->sp_max = 0;
- st->sp_max_cnt = 0;
- st->sp_est_cnt = 0;
- }
- }
-}
-
-/******************************************************************************
-*
-* Function: wb_vad_init
-* Purpose: Allocates state memory and initializes state memory
-*
-*******************************************************************************/
-
-Word16 wb_vad_init( /* return: non-zero with error, zero for ok. */
- VadVars ** state, /* i/o : State structure */
- VO_MEM_OPERATOR *pMemOP
- )
-{
- VadVars *s;
-
- if (state == (VadVars **) NULL)
- {
- fprintf(stderr, "vad_init: invalid parameter\n");
- return -1;
- }
- *state = NULL;
-
- /* allocate memory */
- if ((s = (VadVars *) mem_malloc(pMemOP, sizeof(VadVars), 32, VO_INDEX_ENC_AMRWB)) == NULL)
- {
- fprintf(stderr, "vad_init: can not malloc state structure\n");
- return -1;
- }
- wb_vad_reset(s);
-
- *state = s;
-
- return 0;
-}
-
-/******************************************************************************
-*
-* Function: wb_vad_reset
-* Purpose: Initializes state memory
-*
-*******************************************************************************/
-
-Word16 wb_vad_reset( /* return: non-zero with error, zero for ok. */
- VadVars * state /* i/o : State structure */
- )
-{
- Word32 i, j;
-
- if (state == (VadVars *) NULL)
- {
- fprintf(stderr, "vad_reset: invalid parameter\n");
- return -1;
- }
- state->tone_flag = 0;
- state->vadreg = 0;
- state->hang_count = 0;
- state->burst_count = 0;
- state->hang_count = 0;
-
- /* initialize memory used by the filter bank */
- for (i = 0; i < F_5TH_CNT; i++)
- {
- for (j = 0; j < 2; j++)
- {
- state->a_data5[i][j] = 0;
- }
- }
-
- for (i = 0; i < F_3TH_CNT; i++)
- {
- state->a_data3[i] = 0;
- }
-
- /* initialize the rest of the memory */
- for (i = 0; i < COMPLEN; i++)
- {
- state->bckr_est[i] = NOISE_INIT;
- state->old_level[i] = NOISE_INIT;
- state->ave_level[i] = NOISE_INIT;
- state->sub_level[i] = 0;
- }
-
- state->sp_est_cnt = 0;
- state->sp_max = 0;
- state->sp_max_cnt = 0;
- state->speech_level = SPEECH_LEVEL_INIT;
- state->prev_pow_sum = 0;
- return 0;
-}
-
-/******************************************************************************
-*
-* Function: wb_vad_exit
-* Purpose: The memory used for state memory is freed
-*
-*******************************************************************************/
-
-void wb_vad_exit(
- VadVars ** state, /* i/o : State structure */
- VO_MEM_OPERATOR *pMemOP
- )
-{
- if (state == NULL || *state == NULL)
- return;
- /* deallocate memory */
- mem_free(pMemOP, *state, VO_INDEX_ENC_AMRWB);
- *state = NULL;
- return;
-}
-
-/******************************************************************************
-*
-* Function : wb_vad_tone_detection
-* Purpose : Search maximum pitch gain from a frame. Set tone flag if
-* pitch gain is high. This is used to detect
-* signaling tones and other signals with high pitch gain.
-*
-*******************************************************************************/
-
-void wb_vad_tone_detection(
- VadVars * st, /* i/o : State struct */
- Word16 p_gain /* pitch gain */
- )
-{
- /* update tone flag */
- st->tone_flag = (st->tone_flag >> 1);
-
- /* if (pitch_gain > TONE_THR) set tone flag */
- if (p_gain > TONE_THR)
- {
- st->tone_flag = (Word16) (st->tone_flag | 0x4000);
- }
-}
-
-/******************************************************************************
-*
-* Function : wb_vad
-* Purpose : Main program for Voice Activity Detection (VAD) for AMR
-*
-*******************************************************************************/
-
-Word16 wb_vad( /* Return value : VAD Decision, 1 = speech, 0 = noise */
- VadVars * st, /* i/o : State structure */
- Word16 in_buf[] /* i : samples of the input frame */
- )
-{
- Word16 level[COMPLEN];
- Word32 i;
- Word16 VAD_flag, temp;
- Word32 L_temp, pow_sum;
-
- /* Calculate power of the input frame. */
- L_temp = 0L;
- for (i = 0; i < FRAME_LEN; i++)
- {
- L_temp = L_mac(L_temp, in_buf[i], in_buf[i]);
- }
-
- /* pow_sum = power of current frame and previous frame */
- pow_sum = L_add(L_temp, st->prev_pow_sum);
-
- /* save power of current frame for next call */
- st->prev_pow_sum = L_temp;
-
- /* If input power is very low, clear tone flag */
- if (pow_sum < POW_TONE_THR)
- {
- st->tone_flag = (Word16) (st->tone_flag & 0x1fff);
- }
- /* Run the filter bank and calculate signal levels at each band */
- filter_bank(st, in_buf, level);
-
- /* compute VAD decision */
- VAD_flag = vad_decision(st, level, pow_sum);
-
- /* Calculate input level */
- L_temp = 0;
- for (i = 1; i < COMPLEN; i++) /* ignore lowest band */
- {
- L_temp = vo_L_add(L_temp, level[i]);
- }
-
- temp = extract_h(L_temp << 12);
-
- Estimate_Speech(st, temp); /* Estimate speech level */
- return (VAD_flag);
-}
-
-
-
-
+/*
+ ** Copyright 2003-2010, VisualOn, Inc.
+ **
+ ** Licensed under the Apache License, Version 2.0 (the "License");
+ ** you may not use this file except in compliance with the License.
+ ** You may obtain a copy of the License at
+ **
+ ** http://www.apache.org/licenses/LICENSE-2.0
+ **
+ ** Unless required by applicable law or agreed to in writing, software
+ ** distributed under the License is distributed on an "AS IS" BASIS,
+ ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ ** See the License for the specific language governing permissions and
+ ** limitations under the License.
+ */
+
+/***********************************************************************
+* File: wb_vad.c *
+* *
+* Description: Voice Activity Detection *
+* *
+************************************************************************/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include "cnst.h"
+#include "wb_vad.h"
+#include "typedef.h"
+#include "basic_op.h"
+#include "math_op.h"
+#include "wb_vad_c.h"
+#include "mem_align.h"
+
+/******************************************************************************
+* Calculate Log2 and scale the signal:
+*
+* ilog2(Word32 in) = -1024*log10(in * 2^-31)/log10(2), where in = [1, 2^31-1]
+*
+* input output
+* 32768 16384
+* 1 31744
+*
+* When input is in the range of [1,2^16], max error is 0.0380%.
+*********************************************************************************/
+
+static Word16 ilog2( /* return: output value of the log2 */
+ Word16 mant /* i: value to be converted */
+ )
+{
+ Word16 ex, ex2, res;
+ Word32 i, l_temp;
+
+ if (mant <= 0)
+ {
+ mant = 1;
+ }
+ ex = norm_s(mant);
+ mant = mant << ex;
+
+ for (i = 0; i < 3; i++)
+ mant = vo_mult(mant, mant);
+ l_temp = vo_L_mult(mant, mant);
+
+ ex2 = norm_l(l_temp);
+ mant = extract_h(l_temp << ex2);
+
+ res = (ex + 16) << 10;
+ res = add1(res, (ex2 << 6));
+ res = vo_sub(add1(res, 127), (mant >> 8));
+ return (res);
+}
+
+/******************************************************************************
+*
+* Function : filter5
+* Purpose : Fifth-order half-band lowpass/highpass filter pair with
+* decimation.
+*
+*******************************************************************************/
+
+static void filter5(
+ Word16 * in0, /* i/o : input values; output low-pass part */
+ Word16 * in1, /* i/o : input values; output high-pass part */
+ Word16 data[] /* i/o : filter memory */
+ )
+{
+ Word16 temp0, temp1, temp2;
+
+ temp0 = vo_sub(*in0, vo_mult(COEFF5_1, data[0]));
+ temp1 = add1(data[0], vo_mult(COEFF5_1, temp0));
+ data[0] = temp0;
+
+ temp0 = vo_sub(*in1, vo_mult(COEFF5_2, data[1]));
+ temp2 = add1(data[1], vo_mult(COEFF5_2, temp0));
+ data[1] = temp0;
+
+ *in0 = extract_h((vo_L_add(temp1, temp2) << 15));
+ *in1 = extract_h((vo_L_sub(temp1, temp2) << 15));
+}
+
+/******************************************************************************
+*
+* Function : filter3
+* Purpose : Third-order half-band lowpass/highpass filter pair with
+* decimation.
+*
+*******************************************************************************/
+
+static void filter3(
+ Word16 * in0, /* i/o : input values; output low-pass part */
+ Word16 * in1, /* i/o : input values; output high-pass part */
+ Word16 * data /* i/o : filter memory */
+ )
+{
+ Word16 temp1, temp2;
+
+ temp1 = vo_sub(*in1, vo_mult(COEFF3, *data));
+ temp2 = add1(*data, vo_mult(COEFF3, temp1));
+ *data = temp1;
+
+ *in1 = extract_h((vo_L_sub(*in0, temp2) << 15));
+ *in0 = extract_h((vo_L_add(*in0, temp2) << 15));
+}
+
+/******************************************************************************
+*
+* Function : level_calculation
+* Purpose : Calculate signal level in a sub-band. Level is calculated
+* by summing absolute values of the input data.
+*
+* Signal level calculated from of the end of the frame
+* (data[count1 - count2]) is stored to (*sub_level)
+* and added to the level of the next frame.
+*
+******************************************************************************/
+
+static Word16 level_calculation( /* return: signal level */
+ Word16 data[], /* i : signal buffer */
+ Word16 * sub_level, /* i : level calculated at the end of the previous frame*/
+ /* o : level of signal calculated from the last */
+ /* (count2 - count1) samples */
+ Word16 count1, /* i : number of samples to be counted */
+ Word16 count2, /* i : number of samples to be counted */
+ Word16 ind_m, /* i : step size for the index of the data buffer */
+ Word16 ind_a, /* i : starting index of the data buffer */
+ Word16 scale /* i : scaling for the level calculation */
+ )
+{
+ Word32 i, l_temp1, l_temp2;
+ Word16 level;
+
+ l_temp1 = 0L;
+ for (i = count1; i < count2; i++)
+ {
+ l_temp1 += (abs_s(data[ind_m * i + ind_a])<<1);
+ }
+
+ l_temp2 = vo_L_add(l_temp1, L_shl(*sub_level, 16 - scale));
+ *sub_level = extract_h(L_shl(l_temp1, scale));
+
+ for (i = 0; i < count1; i++)
+ {
+ l_temp2 += (abs_s(data[ind_m * i + ind_a])<<1);
+ }
+ level = extract_h(L_shl2(l_temp2, scale));
+
+ return level;
+}
+
+/******************************************************************************
+*
+* Function : filter_bank
+* Purpose : Divide input signal into bands and calculate level of
+* the signal in each band
+*
+*******************************************************************************/
+
+static void filter_bank(
+ VadVars * st, /* i/o : State struct */
+ Word16 in[], /* i : input frame */
+ Word16 level[] /* o : signal levels at each band */
+ )
+{
+ Word32 i;
+ Word16 tmp_buf[FRAME_LEN];
+
+ /* shift input 1 bit down for safe scaling */
+ for (i = 0; i < FRAME_LEN; i++)
+ {
+ tmp_buf[i] = in[i] >> 1;
+ }
+
+ /* run the filter bank */
+ for (i = 0; i < 128; i++)
+ {
+ filter5(&tmp_buf[2 * i], &tmp_buf[2 * i + 1], st->a_data5[0]);
+ }
+ for (i = 0; i < 64; i++)
+ {
+ filter5(&tmp_buf[4 * i], &tmp_buf[4 * i + 2], st->a_data5[1]);
+ filter5(&tmp_buf[4 * i + 1], &tmp_buf[4 * i + 3], st->a_data5[2]);
+ }
+ for (i = 0; i < 32; i++)
+ {
+ filter5(&tmp_buf[8 * i], &tmp_buf[8 * i + 4], st->a_data5[3]);
+ filter5(&tmp_buf[8 * i + 2], &tmp_buf[8 * i + 6], st->a_data5[4]);
+ filter3(&tmp_buf[8 * i + 3], &tmp_buf[8 * i + 7], &st->a_data3[0]);
+ }
+ for (i = 0; i < 16; i++)
+ {
+ filter3(&tmp_buf[16 * i + 0], &tmp_buf[16 * i + 8], &st->a_data3[1]);
+ filter3(&tmp_buf[16 * i + 4], &tmp_buf[16 * i + 12], &st->a_data3[2]);
+ filter3(&tmp_buf[16 * i + 6], &tmp_buf[16 * i + 14], &st->a_data3[3]);
+ }
+
+ for (i = 0; i < 8; i++)
+ {
+ filter3(&tmp_buf[32 * i + 0], &tmp_buf[32 * i + 16], &st->a_data3[4]);
+ filter3(&tmp_buf[32 * i + 8], &tmp_buf[32 * i + 24], &st->a_data3[5]);
+ }
+
+ /* calculate levels in each frequency band */
+
+ /* 4800 - 6400 Hz */
+ level[11] = level_calculation(tmp_buf, &st->sub_level[11], 16, 64, 4, 1, 14);
+ /* 4000 - 4800 Hz */
+ level[10] = level_calculation(tmp_buf, &st->sub_level[10], 8, 32, 8, 7, 15);
+ /* 3200 - 4000 Hz */
+ level[9] = level_calculation(tmp_buf, &st->sub_level[9],8, 32, 8, 3, 15);
+ /* 2400 - 3200 Hz */
+ level[8] = level_calculation(tmp_buf, &st->sub_level[8],8, 32, 8, 2, 15);
+ /* 2000 - 2400 Hz */
+ level[7] = level_calculation(tmp_buf, &st->sub_level[7],4, 16, 16, 14, 16);
+ /* 1600 - 2000 Hz */
+ level[6] = level_calculation(tmp_buf, &st->sub_level[6],4, 16, 16, 6, 16);
+ /* 1200 - 1600 Hz */
+ level[5] = level_calculation(tmp_buf, &st->sub_level[5],4, 16, 16, 4, 16);
+ /* 800 - 1200 Hz */
+ level[4] = level_calculation(tmp_buf, &st->sub_level[4],4, 16, 16, 12, 16);
+ /* 600 - 800 Hz */
+ level[3] = level_calculation(tmp_buf, &st->sub_level[3],2, 8, 32, 8, 17);
+ /* 400 - 600 Hz */
+ level[2] = level_calculation(tmp_buf, &st->sub_level[2],2, 8, 32, 24, 17);
+ /* 200 - 400 Hz */
+ level[1] = level_calculation(tmp_buf, &st->sub_level[1],2, 8, 32, 16, 17);
+ /* 0 - 200 Hz */
+ level[0] = level_calculation(tmp_buf, &st->sub_level[0],2, 8, 32, 0, 17);
+}
+
+/******************************************************************************
+*
+* Function : update_cntrl
+* Purpose : Control update of the background noise estimate.
+*
+*******************************************************************************/
+
+static void update_cntrl(
+ VadVars * st, /* i/o : State structure */
+ Word16 level[] /* i : sub-band levels of the input frame */
+ )
+{
+ Word32 i;
+ Word16 num, temp, stat_rat, exp, denom;
+ Word16 alpha;
+
+ /* if a tone has been detected for a while, initialize stat_count */
+ if (sub((Word16) (st->tone_flag & 0x7c00), 0x7c00) == 0)
+ {
+ st->stat_count = STAT_COUNT;
+ } else
+ {
+ /* if 8 last vad-decisions have been "0", reinitialize stat_count */
+ if ((st->vadreg & 0x7f80) == 0)
+ {
+ st->stat_count = STAT_COUNT;
+ } else
+ {
+ stat_rat = 0;
+ for (i = 0; i < COMPLEN; i++)
+ {
+ if(level[i] > st->ave_level[i])
+ {
+ num = level[i];
+ denom = st->ave_level[i];
+ } else
+ {
+ num = st->ave_level[i];
+ denom = level[i];
+ }
+ /* Limit nimimum value of num and denom to STAT_THR_LEVEL */
+ if(num < STAT_THR_LEVEL)
+ {
+ num = STAT_THR_LEVEL;
+ }
+ if(denom < STAT_THR_LEVEL)
+ {
+ denom = STAT_THR_LEVEL;
+ }
+ exp = norm_s(denom);
+ denom = denom << exp;
+
+ /* stat_rat = num/denom * 64 */
+ temp = div_s(num >> 1, denom);
+ stat_rat = add1(stat_rat, shr(temp, (8 - exp)));
+ }
+
+ /* compare stat_rat with a threshold and update stat_count */
+ if(stat_rat > STAT_THR)
+ {
+ st->stat_count = STAT_COUNT;
+ } else
+ {
+ if ((st->vadreg & 0x4000) != 0)
+ {
+
+ if (st->stat_count != 0)
+ {
+ st->stat_count = st->stat_count - 1;
+ }
+ }
+ }
+ }
+ }
+
+ /* Update average amplitude estimate for stationarity estimation */
+ alpha = ALPHA4;
+ if(st->stat_count == STAT_COUNT)
+ {
+ alpha = 32767;
+ } else if ((st->vadreg & 0x4000) == 0)
+ {
+ alpha = ALPHA5;
+ }
+ for (i = 0; i < COMPLEN; i++)
+ {
+ st->ave_level[i] = add1(st->ave_level[i], vo_mult_r(alpha, vo_sub(level[i], st->ave_level[i])));
+ }
+}
+
+/******************************************************************************
+*
+* Function : hangover_addition
+* Purpose : Add hangover after speech bursts
+*
+*******************************************************************************/
+
+static Word16 hangover_addition( /* return: VAD_flag indicating final VAD decision */
+ VadVars * st, /* i/o : State structure */
+ Word16 low_power, /* i : flag power of the input frame */
+ Word16 hang_len, /* i : hangover length */
+ Word16 burst_len /* i : minimum burst length for hangover addition */
+ )
+{
+ /* if the input power (pow_sum) is lower than a threshold, clear counters and set VAD_flag to "0" */
+ if (low_power != 0)
+ {
+ st->burst_count = 0;
+ st->hang_count = 0;
+ return 0;
+ }
+ /* update the counters (hang_count, burst_count) */
+ if ((st->vadreg & 0x4000) != 0)
+ {
+ st->burst_count = st->burst_count + 1;
+ if(st->burst_count >= burst_len)
+ {
+ st->hang_count = hang_len;
+ }
+ return 1;
+ } else
+ {
+ st->burst_count = 0;
+ if (st->hang_count > 0)
+ {
+ st->hang_count = st->hang_count - 1;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+/******************************************************************************
+*
+* Function : noise_estimate_update
+* Purpose : Update of background noise estimate
+*
+*******************************************************************************/
+
+static void noise_estimate_update(
+ VadVars * st, /* i/o : State structure */
+ Word16 level[] /* i : sub-band levels of the input frame */
+ )
+{
+ Word32 i;
+ Word16 alpha_up, alpha_down, bckr_add = 2;
+
+ /* Control update of bckr_est[] */
+ update_cntrl(st, level);
+
+ /* Choose update speed */
+ if ((0x7800 & st->vadreg) == 0)
+ {
+ alpha_up = ALPHA_UP1;
+ alpha_down = ALPHA_DOWN1;
+ } else
+ {
+ if ((st->stat_count == 0))
+ {
+ alpha_up = ALPHA_UP2;
+ alpha_down = ALPHA_DOWN2;
+ } else
+ {
+ alpha_up = 0;
+ alpha_down = ALPHA3;
+ bckr_add = 0;
+ }
+ }
+
+ /* Update noise estimate (bckr_est) */
+ for (i = 0; i < COMPLEN; i++)
+ {
+ Word16 temp;
+ temp = (st->old_level[i] - st->bckr_est[i]);
+
+ if (temp < 0)
+ { /* update downwards */
+ st->bckr_est[i] = add1(-2, add(st->bckr_est[i],vo_mult_r(alpha_down, temp)));
+ /* limit minimum value of the noise estimate to NOISE_MIN */
+ if(st->bckr_est[i] < NOISE_MIN)
+ {
+ st->bckr_est[i] = NOISE_MIN;
+ }
+ } else
+ { /* update upwards */
+ st->bckr_est[i] = add1(bckr_add, add1(st->bckr_est[i],vo_mult_r(alpha_up, temp)));
+
+ /* limit maximum value of the noise estimate to NOISE_MAX */
+ if(st->bckr_est[i] > NOISE_MAX)
+ {
+ st->bckr_est[i] = NOISE_MAX;
+ }
+ }
+ }
+
+ /* Update signal levels of the previous frame (old_level) */
+ for (i = 0; i < COMPLEN; i++)
+ {
+ st->old_level[i] = level[i];
+ }
+}
+
+/******************************************************************************
+*
+* Function : vad_decision
+* Purpose : Calculates VAD_flag
+*
+*******************************************************************************/
+
+static Word16 vad_decision( /* return value : VAD_flag */
+ VadVars * st, /* i/o : State structure */
+ Word16 level[COMPLEN], /* i : sub-band levels of the input frame */
+ Word32 pow_sum /* i : power of the input frame */
+ )
+{
+ Word32 i;
+ Word32 L_snr_sum;
+ Word32 L_temp;
+ Word16 vad_thr, temp, noise_level;
+ Word16 low_power_flag;
+ Word16 hang_len, burst_len;
+ Word16 ilog2_speech_level, ilog2_noise_level;
+ Word16 temp2;
+
+ /* Calculate squared sum of the input levels (level) divided by the background noise components
+ * (bckr_est). */
+ L_snr_sum = 0;
+ for (i = 0; i < COMPLEN; i++)
+ {
+ Word16 exp;
+
+ exp = norm_s(st->bckr_est[i]);
+ temp = (st->bckr_est[i] << exp);
+ temp = div_s((level[i] >> 1), temp);
+ temp = shl(temp, (exp - (UNIRSHFT - 1)));
+ L_snr_sum = L_mac(L_snr_sum, temp, temp);
+ }
+
+ /* Calculate average level of estimated background noise */
+ L_temp = 0;
+ for (i = 1; i < COMPLEN; i++) /* ignore lowest band */
+ {
+ L_temp = vo_L_add(L_temp, st->bckr_est[i]);
+ }
+
+ noise_level = extract_h((L_temp << 12));
+ /* if SNR is lower than a threshold (MIN_SPEECH_SNR), and increase speech_level */
+ temp = vo_mult(noise_level, MIN_SPEECH_SNR) << 3;
+
+ if(st->speech_level < temp)
+ {
+ st->speech_level = temp;
+ }
+ ilog2_noise_level = ilog2(noise_level);
+
+ /* If SNR is very poor, speech_level is probably corrupted by noise level. This is correctred by
+ * subtracting MIN_SPEECH_SNR*noise_level from speech level */
+ ilog2_speech_level = ilog2(st->speech_level - temp);
+
+ temp = add1(vo_mult(NO_SLOPE, (ilog2_noise_level - NO_P1)), THR_HIGH);
+
+ temp2 = add1(SP_CH_MIN, vo_mult(SP_SLOPE, (ilog2_speech_level - SP_P1)));
+ if (temp2 < SP_CH_MIN)
+ {
+ temp2 = SP_CH_MIN;
+ }
+ if (temp2 > SP_CH_MAX)
+ {
+ temp2 = SP_CH_MAX;
+ }
+ vad_thr = temp + temp2;
+
+ if(vad_thr < THR_MIN)
+ {
+ vad_thr = THR_MIN;
+ }
+ /* Shift VAD decision register */
+ st->vadreg = (st->vadreg >> 1);
+
+ /* Make intermediate VAD decision */
+ if(L_snr_sum > vo_L_mult(vad_thr, (512 * COMPLEN)))
+ {
+ st->vadreg = (Word16) (st->vadreg | 0x4000);
+ }
+ /* check if the input power (pow_sum) is lower than a threshold" */
+ if(pow_sum < VAD_POW_LOW)
+ {
+ low_power_flag = 1;
+ } else
+ {
+ low_power_flag = 0;
+ }
+ /* Update background noise estimates */
+ noise_estimate_update(st, level);
+
+ /* Calculate values for hang_len and burst_len based on vad_thr */
+ hang_len = add1(vo_mult(HANG_SLOPE, (vad_thr - HANG_P1)), HANG_HIGH);
+ if(hang_len < HANG_LOW)
+ {
+ hang_len = HANG_LOW;
+ }
+ burst_len = add1(vo_mult(BURST_SLOPE, (vad_thr - BURST_P1)), BURST_HIGH);
+
+ return (hangover_addition(st, low_power_flag, hang_len, burst_len));
+}
+
+/******************************************************************************
+*
+* Function : Estimate_Speech()
+* Purpose : Estimate speech level
+*
+* Maximum signal level is searched and stored to the variable sp_max.
+* The speech frames must locate within SP_EST_COUNT number of frames.
+* Thus, noisy frames having occasional VAD = "1" decisions will not
+* affect to the estimated speech_level.
+*
+*******************************************************************************/
+
+static void Estimate_Speech(
+ VadVars * st, /* i/o : State structure */
+ Word16 in_level /* level of the input frame */
+ )
+{
+ Word16 alpha;
+
+ /* if the required activity count cannot be achieved, reset counters */
+ if((st->sp_est_cnt - st->sp_max_cnt) > (SP_EST_COUNT - SP_ACTIVITY_COUNT))
+ {
+ st->sp_est_cnt = 0;
+ st->sp_max = 0;
+ st->sp_max_cnt = 0;
+ }
+ st->sp_est_cnt += 1;
+
+ if (((st->vadreg & 0x4000)||(in_level > st->speech_level)) && (in_level > MIN_SPEECH_LEVEL1))
+ {
+ /* update sp_max */
+ if(in_level > st->sp_max)
+ {
+ st->sp_max = in_level;
+ }
+ st->sp_max_cnt += 1;
+
+ if(st->sp_max_cnt >= SP_ACTIVITY_COUNT)
+ {
+ Word16 tmp;
+ /* update speech estimate */
+ tmp = (st->sp_max >> 1); /* scale to get "average" speech level */
+
+ /* select update speed */
+ if(tmp > st->speech_level)
+ {
+ alpha = ALPHA_SP_UP;
+ } else
+ {
+ alpha = ALPHA_SP_DOWN;
+ }
+ if(tmp > MIN_SPEECH_LEVEL2)
+ {
+ st->speech_level = add1(st->speech_level, vo_mult_r(alpha, vo_sub(tmp, st->speech_level)));
+ }
+ /* clear all counters used for speech estimation */
+ st->sp_max = 0;
+ st->sp_max_cnt = 0;
+ st->sp_est_cnt = 0;
+ }
+ }
+}
+
+/******************************************************************************
+*
+* Function: wb_vad_init
+* Purpose: Allocates state memory and initializes state memory
+*
+*******************************************************************************/
+
+Word16 wb_vad_init( /* return: non-zero with error, zero for ok. */
+ VadVars ** state, /* i/o : State structure */
+ VO_MEM_OPERATOR *pMemOP
+ )
+{
+ VadVars *s;
+
+ if (state == (VadVars **) NULL)
+ {
+ fprintf(stderr, "vad_init: invalid parameter\n");
+ return -1;
+ }
+ *state = NULL;
+
+ /* allocate memory */
+ if ((s = (VadVars *) mem_malloc(pMemOP, sizeof(VadVars), 32, VO_INDEX_ENC_AMRWB)) == NULL)
+ {
+ fprintf(stderr, "vad_init: can not malloc state structure\n");
+ return -1;
+ }
+ wb_vad_reset(s);
+
+ *state = s;
+
+ return 0;
+}
+
+/******************************************************************************
+*
+* Function: wb_vad_reset
+* Purpose: Initializes state memory
+*
+*******************************************************************************/
+
+Word16 wb_vad_reset( /* return: non-zero with error, zero for ok. */
+ VadVars * state /* i/o : State structure */
+ )
+{
+ Word32 i, j;
+
+ if (state == (VadVars *) NULL)
+ {
+ fprintf(stderr, "vad_reset: invalid parameter\n");
+ return -1;
+ }
+ state->tone_flag = 0;
+ state->vadreg = 0;
+ state->hang_count = 0;
+ state->burst_count = 0;
+ state->hang_count = 0;
+
+ /* initialize memory used by the filter bank */
+ for (i = 0; i < F_5TH_CNT; i++)
+ {
+ for (j = 0; j < 2; j++)
+ {
+ state->a_data5[i][j] = 0;
+ }
+ }
+
+ for (i = 0; i < F_3TH_CNT; i++)
+ {
+ state->a_data3[i] = 0;
+ }
+
+ /* initialize the rest of the memory */
+ for (i = 0; i < COMPLEN; i++)
+ {
+ state->bckr_est[i] = NOISE_INIT;
+ state->old_level[i] = NOISE_INIT;
+ state->ave_level[i] = NOISE_INIT;
+ state->sub_level[i] = 0;
+ }
+
+ state->sp_est_cnt = 0;
+ state->sp_max = 0;
+ state->sp_max_cnt = 0;
+ state->speech_level = SPEECH_LEVEL_INIT;
+ state->prev_pow_sum = 0;
+ return 0;
+}
+
+/******************************************************************************
+*
+* Function: wb_vad_exit
+* Purpose: The memory used for state memory is freed
+*
+*******************************************************************************/
+
+void wb_vad_exit(
+ VadVars ** state, /* i/o : State structure */
+ VO_MEM_OPERATOR *pMemOP
+ )
+{
+ if (state == NULL || *state == NULL)
+ return;
+ /* deallocate memory */
+ mem_free(pMemOP, *state, VO_INDEX_ENC_AMRWB);
+ *state = NULL;
+ return;
+}
+
+/******************************************************************************
+*
+* Function : wb_vad_tone_detection
+* Purpose : Search maximum pitch gain from a frame. Set tone flag if
+* pitch gain is high. This is used to detect
+* signaling tones and other signals with high pitch gain.
+*
+*******************************************************************************/
+
+void wb_vad_tone_detection(
+ VadVars * st, /* i/o : State struct */
+ Word16 p_gain /* pitch gain */
+ )
+{
+ /* update tone flag */
+ st->tone_flag = (st->tone_flag >> 1);
+
+ /* if (pitch_gain > TONE_THR) set tone flag */
+ if (p_gain > TONE_THR)
+ {
+ st->tone_flag = (Word16) (st->tone_flag | 0x4000);
+ }
+}
+
+/******************************************************************************
+*
+* Function : wb_vad
+* Purpose : Main program for Voice Activity Detection (VAD) for AMR
+*
+*******************************************************************************/
+
+Word16 wb_vad( /* Return value : VAD Decision, 1 = speech, 0 = noise */
+ VadVars * st, /* i/o : State structure */
+ Word16 in_buf[] /* i : samples of the input frame */
+ )
+{
+ Word16 level[COMPLEN];
+ Word32 i;
+ Word16 VAD_flag, temp;
+ Word32 L_temp, pow_sum;
+
+ /* Calculate power of the input frame. */
+ L_temp = 0L;
+ for (i = 0; i < FRAME_LEN; i++)
+ {
+ L_temp = L_mac(L_temp, in_buf[i], in_buf[i]);
+ }
+
+ /* pow_sum = power of current frame and previous frame */
+ pow_sum = L_add(L_temp, st->prev_pow_sum);
+
+ /* save power of current frame for next call */
+ st->prev_pow_sum = L_temp;
+
+ /* If input power is very low, clear tone flag */
+ if (pow_sum < POW_TONE_THR)
+ {
+ st->tone_flag = (Word16) (st->tone_flag & 0x1fff);
+ }
+ /* Run the filter bank and calculate signal levels at each band */
+ filter_bank(st, in_buf, level);
+
+ /* compute VAD decision */
+ VAD_flag = vad_decision(st, level, pow_sum);
+
+ /* Calculate input level */
+ L_temp = 0;
+ for (i = 1; i < COMPLEN; i++) /* ignore lowest band */
+ {
+ L_temp = vo_L_add(L_temp, level[i]);
+ }
+
+ temp = extract_h(L_temp << 12);
+
+ Estimate_Speech(st, temp); /* Estimate speech level */
+ return (VAD_flag);
+}
+
+
+
+
generated by cgit v1.1 at 2024-05-17 02:39:33 +0000