diff options
Diffstat (limited to 'media/libstagefright/codecs/amrwbenc/src/wb_vad.c')
-rw-r--r-- | media/libstagefright/codecs/amrwbenc/src/wb_vad.c | 1616 |
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); +} + + + + |