diff options
Diffstat (limited to 'src/nlp.c')
| -rw-r--r-- | src/nlp.c | 609 |
1 files changed, 279 insertions, 330 deletions
@@ -25,115 +25,79 @@ along with this program; if not, see <http://www.gnu.org/licenses/>. */ -#include "defines.h" #include "nlp.h" -#include "dump.h" + #include "codec2_fft.h" +#include "defines.h" +#include "dump.h" #undef PROFILE -#include "machdep.h" -#include "os.h" - #include <assert.h> #include <math.h> #include <stdlib.h> +#include "machdep.h" +#include "os.h" + /*---------------------------------------------------------------------------*\ - DEFINES + DEFINES \*---------------------------------------------------------------------------*/ -#define PMAX_M 320 /* maximum NLP analysis window size */ -#define COEFF 0.95 /* notch filter parameter */ -#define PE_FFT_SIZE 512 /* DFT size for pitch estimation */ -#define DEC 5 /* decimation factor */ +#define PMAX_M 320 /* maximum NLP analysis window size */ +#define COEFF 0.95 /* notch filter parameter */ +#define PE_FFT_SIZE 512 /* DFT size for pitch estimation */ +#define DEC 5 /* decimation factor */ #define SAMPLE_RATE 8000 -#define PI 3.141592654 /* mathematical constant */ -#define T 0.1 /* threshold for local minima candidate */ -#define F0_MAX 500 -#define CNLP 0.3 /* post processor constant */ -#define NLP_NTAP 48 /* Decimation LPF order */ +#define PI 3.141592654 /* mathematical constant */ +#define T 0.1 /* threshold for local minima candidate */ +#define F0_MAX 500 +#define CNLP 0.3 /* post processor constant */ +#define NLP_NTAP 48 /* Decimation LPF order */ /* 8 to 16 kHz sample rate conversion */ -#define FDMDV_OS 2 /* oversampling rate */ -#define FDMDV_OS_TAPS_16K 48 /* number of OS filter taps at 16kHz */ -#define FDMDV_OS_TAPS_8K (FDMDV_OS_TAPS_16K/FDMDV_OS) /* number of OS filter taps at 8kHz */ +#define FDMDV_OS 2 /* oversampling rate */ +#define FDMDV_OS_TAPS_16K 48 /* number of OS filter taps at 16kHz */ +#define FDMDV_OS_TAPS_8K \ + (FDMDV_OS_TAPS_16K / FDMDV_OS) /* number of OS filter taps at 8kHz */ /*---------------------------------------------------------------------------*\ - GLOBALS + GLOBALS \*---------------------------------------------------------------------------*/ /* 48 tap 600Hz low pass FIR filter coefficients */ const float nlp_fir[] = { - -1.0818124e-03, - -1.1008344e-03, - -9.2768838e-04, - -4.2289438e-04, - 5.5034190e-04, - 2.0029849e-03, - 3.7058509e-03, - 5.1449415e-03, - 5.5924666e-03, - 4.3036754e-03, - 8.0284511e-04, - -4.8204610e-03, - -1.1705810e-02, - -1.8199275e-02, - -2.2065282e-02, - -2.0920610e-02, - -1.2808831e-02, - 3.2204775e-03, - 2.6683811e-02, - 5.5520624e-02, - 8.6305944e-02, - 1.1480192e-01, - 1.3674206e-01, - 1.4867556e-01, - 1.4867556e-01, - 1.3674206e-01, - 1.1480192e-01, - 8.6305944e-02, - 5.5520624e-02, - 2.6683811e-02, - 3.2204775e-03, - -1.2808831e-02, - -2.0920610e-02, - -2.2065282e-02, - -1.8199275e-02, - -1.1705810e-02, - -4.8204610e-03, - 8.0284511e-04, - 4.3036754e-03, - 5.5924666e-03, - 5.1449415e-03, - 3.7058509e-03, - 2.0029849e-03, - 5.5034190e-04, - -4.2289438e-04, - -9.2768838e-04, - -1.1008344e-03, - -1.0818124e-03 -}; + -1.0818124e-03, -1.1008344e-03, -9.2768838e-04, -4.2289438e-04, + 5.5034190e-04, 2.0029849e-03, 3.7058509e-03, 5.1449415e-03, + 5.5924666e-03, 4.3036754e-03, 8.0284511e-04, -4.8204610e-03, + -1.1705810e-02, -1.8199275e-02, -2.2065282e-02, -2.0920610e-02, + -1.2808831e-02, 3.2204775e-03, 2.6683811e-02, 5.5520624e-02, + 8.6305944e-02, 1.1480192e-01, 1.3674206e-01, 1.4867556e-01, + 1.4867556e-01, 1.3674206e-01, 1.1480192e-01, 8.6305944e-02, + 5.5520624e-02, 2.6683811e-02, 3.2204775e-03, -1.2808831e-02, + -2.0920610e-02, -2.2065282e-02, -1.8199275e-02, -1.1705810e-02, + -4.8204610e-03, 8.0284511e-04, 4.3036754e-03, 5.5924666e-03, + 5.1449415e-03, 3.7058509e-03, 2.0029849e-03, 5.5034190e-04, + -4.2289438e-04, -9.2768838e-04, -1.1008344e-03, -1.0818124e-03}; typedef struct { - int Fs; /* sample rate in Hz */ - int m; - float w[PMAX_M/DEC]; /* DFT window */ - float sq[PMAX_M]; /* squared speech samples */ - float mem_x,mem_y; /* memory for notch filter */ - float mem_fir[NLP_NTAP]; /* decimation FIR filter memory */ - codec2_fft_cfg fft_cfg; /* kiss FFT config */ - float *Sn16k; /* Fs=16kHz input speech vector */ - FILE *f; + int Fs; /* sample rate in Hz */ + int m; + float w[PMAX_M / DEC]; /* DFT window */ + float sq[PMAX_M]; /* squared speech samples */ + float mem_x, mem_y; /* memory for notch filter */ + float mem_fir[NLP_NTAP]; /* decimation FIR filter memory */ + codec2_fft_cfg fft_cfg; /* kiss FFT config */ + float *Sn16k; /* Fs=16kHz input speech vector */ + FILE *f; } NLP; -float post_process_sub_multiples(COMP Fw[], - int pmin, int pmax, float gmax, int gmax_bin, - float *prev_f0); +float post_process_sub_multiples(COMP Fw[], int pmin, int pmax, float gmax, + int gmax_bin, float *prev_f0); static void fdmdv_16_to_8(float out8k[], float in16k[], int n); /*---------------------------------------------------------------------------*\ @@ -144,56 +108,53 @@ static void fdmdv_16_to_8(float out8k[], float in16k[], int n); \*---------------------------------------------------------------------------*/ -void *nlp_create(C2CONST *c2const) -{ - NLP *nlp; - int i; - int m = c2const->m_pitch; - int Fs = c2const->Fs; +void *nlp_create(C2CONST *c2const) { + NLP *nlp; + int i; + int m = c2const->m_pitch; + int Fs = c2const->Fs; + + nlp = (NLP *)malloc(sizeof(NLP)); + if (nlp == NULL) return NULL; - nlp = (NLP*)malloc(sizeof(NLP)); - if (nlp == NULL) - return NULL; + assert((Fs == 8000) || (Fs == 16000)); + nlp->Fs = Fs; - assert((Fs == 8000) || (Fs == 16000)); - nlp->Fs = Fs; + nlp->m = m; - nlp->m = m; + /* if running at 16kHz allocate storage for decimating filter memory */ - /* if running at 16kHz allocate storage for decimating filter memory */ + if (Fs == 16000) { + nlp->Sn16k = + (float *)malloc(sizeof(float) * (FDMDV_OS_TAPS_16K + c2const->n_samp)); + for (i = 0; i < FDMDV_OS_TAPS_16K; i++) { + nlp->Sn16k[i] = 0.0; + } + if (nlp->Sn16k == NULL) { + free(nlp); + return NULL; + } - if (Fs == 16000) { - nlp->Sn16k = (float*)malloc(sizeof(float)*(FDMDV_OS_TAPS_16K + c2const->n_samp)); - for(i=0; i<FDMDV_OS_TAPS_16K; i++) { - nlp->Sn16k[i] = 0.0; - } - if (nlp->Sn16k == NULL) { - free(nlp); - return NULL; - } + /* most processing occurs at 8 kHz sample rate so halve m */ - /* most processing occurs at 8 kHz sample rate so halve m */ + m /= 2; + } - m /= 2; - } + assert(m <= PMAX_M); - assert(m <= PMAX_M); - - for(i=0; i<m/DEC; i++) { - nlp->w[i] = 0.5 - 0.5*cosf(2*PI*i/(m/DEC-1)); - } + for (i = 0; i < m / DEC; i++) { + nlp->w[i] = 0.5 - 0.5 * cosf(2 * PI * i / (m / DEC - 1)); + } - for(i=0; i<PMAX_M; i++) - nlp->sq[i] = 0.0; - nlp->mem_x = 0.0; - nlp->mem_y = 0.0; - for(i=0; i<NLP_NTAP; i++) - nlp->mem_fir[i] = 0.0; + for (i = 0; i < PMAX_M; i++) nlp->sq[i] = 0.0; + nlp->mem_x = 0.0; + nlp->mem_y = 0.0; + for (i = 0; i < NLP_NTAP; i++) nlp->mem_fir[i] = 0.0; - nlp->fft_cfg = codec2_fft_alloc (PE_FFT_SIZE, 0, NULL, NULL); - assert(nlp->fft_cfg != NULL); + nlp->fft_cfg = codec2_fft_alloc(PE_FFT_SIZE, 0, NULL, NULL); + assert(nlp->fft_cfg != NULL); - return (void*)nlp; + return (void *)nlp; } /*---------------------------------------------------------------------------*\ @@ -204,17 +165,16 @@ void *nlp_create(C2CONST *c2const) \*---------------------------------------------------------------------------*/ -void nlp_destroy(void *nlp_state) -{ - NLP *nlp; - assert(nlp_state != NULL); - nlp = (NLP*)nlp_state; +void nlp_destroy(void *nlp_state) { + NLP *nlp; + assert(nlp_state != NULL); + nlp = (NLP *)nlp_state; - codec2_fft_free(nlp->fft_cfg); - if (nlp->Fs == 16000) { - free(nlp->Sn16k); - } - free(nlp_state); + codec2_fft_free(nlp->fft_cfg); + if (nlp->Fs == 16000) { + free(nlp->Sn16k); + } + free(nlp_state); } /*---------------------------------------------------------------------------*\ @@ -248,162 +208,157 @@ void nlp_destroy(void *nlp_state) \*---------------------------------------------------------------------------*/ float nlp( - void *nlp_state, - float Sn[], /* input speech vector */ - int n, /* frames shift (no. new samples in Sn[]) */ - float *pitch, /* estimated pitch period in samples at current Fs */ - COMP Sw[], /* Freq domain version of Sn[] */ - float W[], /* Freq domain window */ - float *prev_f0 /* previous pitch f0 in Hz, memory for pitch tracking */ -) -{ - NLP *nlp; - float notch; /* current notch filter output */ - COMP Fw[PE_FFT_SIZE]; /* DFT of squared signal (input/output) */ - float gmax; - int gmax_bin; - int m, i, j; - float best_f0; - PROFILE_VAR(start, tnotch, filter, peakpick, window, fft, magsq, shiftmem); - - assert(nlp_state != NULL); - nlp = (NLP*)nlp_state; - m = nlp->m; - - /* Square, notch filter at DC, and LP filter vector */ - - /* If running at 16 kHz decimate to 8 kHz, as NLP ws designed for - Fs = 8kHz. The decimating filter introduces about 3ms of delay, - that shouldn't be a problem as pitch changes slowly. */ - - if (nlp->Fs == 8000) { - /* Square latest input samples */ - - for(i=m-n; i<m; i++) { - nlp->sq[i] = Sn[i]*Sn[i]; - } + void *nlp_state, float Sn[], /* input speech vector */ + int n, /* frames shift (no. new samples in Sn[]) */ + float *pitch, /* estimated pitch period in samples at current Fs */ + COMP Sw[], /* Freq domain version of Sn[] */ + float W[], /* Freq domain window */ + float *prev_f0 /* previous pitch f0 in Hz, memory for pitch tracking */ +) { + NLP *nlp; + float notch; /* current notch filter output */ + COMP Fw[PE_FFT_SIZE]; /* DFT of squared signal (input/output) */ + float gmax; + int gmax_bin; + int m, i, j; + float best_f0; + PROFILE_VAR(start, tnotch, filter, peakpick, window, fft, magsq, shiftmem); + + assert(nlp_state != NULL); + nlp = (NLP *)nlp_state; + m = nlp->m; + + /* Square, notch filter at DC, and LP filter vector */ + + /* If running at 16 kHz decimate to 8 kHz, as NLP ws designed for + Fs = 8kHz. The decimating filter introduces about 3ms of delay, + that shouldn't be a problem as pitch changes slowly. */ + + if (nlp->Fs == 8000) { + /* Square latest input samples */ + + for (i = m - n; i < m; i++) { + nlp->sq[i] = Sn[i] * Sn[i]; } - else { - assert(nlp->Fs == 16000); - - /* re-sample at 8 KHz */ - - for(i=0; i<n; i++) { - nlp->Sn16k[FDMDV_OS_TAPS_16K+i] = Sn[m-n+i]; - } - - m /= 2; n /= 2; + } else { + assert(nlp->Fs == 16000); - float Sn8k[n]; - fdmdv_16_to_8(Sn8k, &nlp->Sn16k[FDMDV_OS_TAPS_16K], n); + /* re-sample at 8 KHz */ - /* Square latest input samples */ - - for(i=m-n, j=0; i<m; i++, j++) { - nlp->sq[i] = Sn8k[j]*Sn8k[j]; - } - assert(j <= n); - } - //fprintf(stderr, "n: %d m: %d\n", n, m); - - PROFILE_SAMPLE(start); - - for(i=m-n; i<m; i++) { /* notch filter at DC */ - notch = nlp->sq[i] - nlp->mem_x; - notch += COEFF*nlp->mem_y; - nlp->mem_x = nlp->sq[i]; - nlp->mem_y = notch; - nlp->sq[i] = notch + 1.0; /* With 0 input vectors to codec, - kiss_fft() would take a long - time to execute when running in - real time. Problem was traced - to kiss_fft function call in - this function. Adding this small - constant fixed problem. Not - exactly sure why. */ + for (i = 0; i < n; i++) { + nlp->Sn16k[FDMDV_OS_TAPS_16K + i] = Sn[m - n + i]; } - PROFILE_SAMPLE_AND_LOG(tnotch, start, " square and notch"); + m /= 2; + n /= 2; - for(i=m-n; i<m; i++) { /* FIR filter vector */ + float Sn8k[n]; + fdmdv_16_to_8(Sn8k, &nlp->Sn16k[FDMDV_OS_TAPS_16K], n); - for(j=0; j<NLP_NTAP-1; j++) - nlp->mem_fir[j] = nlp->mem_fir[j+1]; - nlp->mem_fir[NLP_NTAP-1] = nlp->sq[i]; + /* Square latest input samples */ - nlp->sq[i] = 0.0; - for(j=0; j<NLP_NTAP; j++) - nlp->sq[i] += nlp->mem_fir[j]*nlp_fir[j]; + for (i = m - n, j = 0; i < m; i++, j++) { + nlp->sq[i] = Sn8k[j] * Sn8k[j]; } - - PROFILE_SAMPLE_AND_LOG(filter, tnotch, " filter"); - - /* Decimate and DFT */ - - for(i=0; i<PE_FFT_SIZE; i++) { - Fw[i].real = 0.0; - Fw[i].imag = 0.0; - } - for(i=0; i<m/DEC; i++) { - Fw[i].real = nlp->sq[i*DEC]*nlp->w[i]; - } - PROFILE_SAMPLE_AND_LOG(window, filter, " window"); - #ifdef DUMP - dump_dec(Fw); - #endif - - // FIXME: check if this can be converted to a real fft - // since all imag inputs are 0 - codec2_fft_inplace(nlp->fft_cfg, Fw); - PROFILE_SAMPLE_AND_LOG(fft, window, " fft"); - - for(i=0; i<PE_FFT_SIZE; i++) - Fw[i].real = Fw[i].real*Fw[i].real + Fw[i].imag*Fw[i].imag; - - PROFILE_SAMPLE_AND_LOG(magsq, fft, " mag sq"); - #ifdef DUMP - dump_sq(m, nlp->sq); - dump_Fw(Fw); - #endif - - /* todo: express everything in f0, as pitch in samples is dep on Fs */ - - int pmin = floor(SAMPLE_RATE*P_MIN_S); - int pmax = floor(SAMPLE_RATE*P_MAX_S); - - /* find global peak */ - - gmax = 0.0; - gmax_bin = PE_FFT_SIZE*DEC/pmax; - for(i=PE_FFT_SIZE*DEC/pmax; i<=PE_FFT_SIZE*DEC/pmin; i++) { - if (Fw[i].real > gmax) { - gmax = Fw[i].real; - gmax_bin = i; - } + assert(j <= n); + } + // fprintf(stderr, "n: %d m: %d\n", n, m); + + PROFILE_SAMPLE(start); + + for (i = m - n; i < m; i++) { /* notch filter at DC */ + notch = nlp->sq[i] - nlp->mem_x; + notch += COEFF * nlp->mem_y; + nlp->mem_x = nlp->sq[i]; + nlp->mem_y = notch; + nlp->sq[i] = notch + 1.0; /* With 0 input vectors to codec, + kiss_fft() would take a long + time to execute when running in + real time. Problem was traced + to kiss_fft function call in + this function. Adding this small + constant fixed problem. Not + exactly sure why. */ + } + + PROFILE_SAMPLE_AND_LOG(tnotch, start, " square and notch"); + + for (i = m - n; i < m; i++) { /* FIR filter vector */ + + for (j = 0; j < NLP_NTAP - 1; j++) nlp->mem_fir[j] = nlp->mem_fir[j + 1]; + nlp->mem_fir[NLP_NTAP - 1] = nlp->sq[i]; + + nlp->sq[i] = 0.0; + for (j = 0; j < NLP_NTAP; j++) nlp->sq[i] += nlp->mem_fir[j] * nlp_fir[j]; + } + + PROFILE_SAMPLE_AND_LOG(filter, tnotch, " filter"); + + /* Decimate and DFT */ + + for (i = 0; i < PE_FFT_SIZE; i++) { + Fw[i].real = 0.0; + Fw[i].imag = 0.0; + } + for (i = 0; i < m / DEC; i++) { + Fw[i].real = nlp->sq[i * DEC] * nlp->w[i]; + } + PROFILE_SAMPLE_AND_LOG(window, filter, " window"); +#ifdef DUMP + dump_dec(Fw); +#endif + + // FIXME: check if this can be converted to a real fft + // since all imag inputs are 0 + codec2_fft_inplace(nlp->fft_cfg, Fw); + PROFILE_SAMPLE_AND_LOG(fft, window, " fft"); + + for (i = 0; i < PE_FFT_SIZE; i++) + Fw[i].real = Fw[i].real * Fw[i].real + Fw[i].imag * Fw[i].imag; + + PROFILE_SAMPLE_AND_LOG(magsq, fft, " mag sq"); +#ifdef DUMP + dump_sq(m, nlp->sq); + dump_Fw(Fw); +#endif + + /* todo: express everything in f0, as pitch in samples is dep on Fs */ + + int pmin = floor(SAMPLE_RATE * P_MIN_S); + int pmax = floor(SAMPLE_RATE * P_MAX_S); + + /* find global peak */ + + gmax = 0.0; + gmax_bin = PE_FFT_SIZE * DEC / pmax; + for (i = PE_FFT_SIZE * DEC / pmax; i <= PE_FFT_SIZE * DEC / pmin; i++) { + if (Fw[i].real > gmax) { + gmax = Fw[i].real; + gmax_bin = i; } + } - PROFILE_SAMPLE_AND_LOG(peakpick, magsq, " peak pick"); + PROFILE_SAMPLE_AND_LOG(peakpick, magsq, " peak pick"); - best_f0 = post_process_sub_multiples(Fw, pmin, pmax, gmax, gmax_bin, prev_f0); + best_f0 = post_process_sub_multiples(Fw, pmin, pmax, gmax, gmax_bin, prev_f0); - PROFILE_SAMPLE_AND_LOG(shiftmem, peakpick, " post process"); + PROFILE_SAMPLE_AND_LOG(shiftmem, peakpick, " post process"); - /* Shift samples in buffer to make room for new samples */ + /* Shift samples in buffer to make room for new samples */ - for(i=0; i<m-n; i++) - nlp->sq[i] = nlp->sq[i+n]; + for (i = 0; i < m - n; i++) nlp->sq[i] = nlp->sq[i + n]; - /* return pitch period in samples and F0 estimate */ + /* return pitch period in samples and F0 estimate */ - *pitch = (float)nlp->Fs/best_f0; + *pitch = (float)nlp->Fs / best_f0; - PROFILE_SAMPLE_AND_LOG2(shiftmem, " shift mem"); + PROFILE_SAMPLE_AND_LOG2(shiftmem, " shift mem"); - PROFILE_SAMPLE_AND_LOG2(start, " nlp int"); + PROFILE_SAMPLE_AND_LOG2(start, " nlp int"); - *prev_f0 = best_f0; + *prev_f0 = best_f0; - return(best_f0); + return (best_f0); } /*---------------------------------------------------------------------------*\ @@ -427,59 +382,55 @@ float nlp( \*---------------------------------------------------------------------------*/ -float post_process_sub_multiples(COMP Fw[], - int pmin, int pmax, float gmax, int gmax_bin, - float *prev_f0) -{ - int min_bin, cmax_bin; - int mult; - float thresh, best_f0; - int b, bmin, bmax, lmax_bin; - float lmax; - int prev_f0_bin; - - /* post process estimate by searching submultiples */ - - mult = 2; - min_bin = PE_FFT_SIZE*DEC/pmax; - cmax_bin = gmax_bin; - prev_f0_bin = *prev_f0*(PE_FFT_SIZE*DEC)/SAMPLE_RATE; - - while(gmax_bin/mult >= min_bin) { - - b = gmax_bin/mult; /* determine search interval */ - bmin = 0.8*b; - bmax = 1.2*b; - if (bmin < min_bin) - bmin = min_bin; - - /* lower threshold to favour previous frames pitch estimate, - this is a form of pitch tracking */ - - if ((prev_f0_bin > bmin) && (prev_f0_bin < bmax)) - thresh = CNLP*0.5*gmax; - else - thresh = CNLP*gmax; - - lmax = 0; - lmax_bin = bmin; - for (b=bmin; b<=bmax; b++) /* look for maximum in interval */ - if (Fw[b].real > lmax) { - lmax = Fw[b].real; - lmax_bin = b; - } - - if (lmax > thresh) - if ((lmax > Fw[lmax_bin-1].real) && (lmax > Fw[lmax_bin+1].real)) { - cmax_bin = lmax_bin; - } - - mult++; - } - - best_f0 = (float)cmax_bin*SAMPLE_RATE/(PE_FFT_SIZE*DEC); - - return best_f0; +float post_process_sub_multiples(COMP Fw[], int pmin, int pmax, float gmax, + int gmax_bin, float *prev_f0) { + int min_bin, cmax_bin; + int mult; + float thresh, best_f0; + int b, bmin, bmax, lmax_bin; + float lmax; + int prev_f0_bin; + + /* post process estimate by searching submultiples */ + + mult = 2; + min_bin = PE_FFT_SIZE * DEC / pmax; + cmax_bin = gmax_bin; + prev_f0_bin = *prev_f0 * (PE_FFT_SIZE * DEC) / SAMPLE_RATE; + + while (gmax_bin / mult >= min_bin) { + b = gmax_bin / mult; /* determine search interval */ + bmin = 0.8 * b; + bmax = 1.2 * b; + if (bmin < min_bin) bmin = min_bin; + + /* lower threshold to favour previous frames pitch estimate, + this is a form of pitch tracking */ + + if ((prev_f0_bin > bmin) && (prev_f0_bin < bmax)) + thresh = CNLP * 0.5 * gmax; + else + thresh = CNLP * gmax; + + lmax = 0; + lmax_bin = bmin; + for (b = bmin; b <= bmax; b++) /* look for maximum in interval */ + if (Fw[b].real > lmax) { + lmax = Fw[b].real; + lmax_bin = b; + } + + if (lmax > thresh) + if ((lmax > Fw[lmax_bin - 1].real) && (lmax > Fw[lmax_bin + 1].real)) { + cmax_bin = lmax_bin; + } + + mult++; + } + + best_f0 = (float)cmax_bin * SAMPLE_RATE / (PE_FFT_SIZE * DEC); + + return best_f0; } /*---------------------------------------------------------------------------*\ @@ -502,20 +453,18 @@ float post_process_sub_multiples(COMP Fw[], \*---------------------------------------------------------------------------*/ -static void fdmdv_16_to_8(float out8k[], float in16k[], int n) -{ - float acc; - int i,j,k; +static void fdmdv_16_to_8(float out8k[], float in16k[], int n) { + float acc; + int i, j, k; - for(i=0, k=0; k<n; i+=FDMDV_OS, k++) { - acc = 0.0; - for(j=0; j<FDMDV_OS_TAPS_16K; j++) - acc += fdmdv_os_filter[j]*in16k[i-j]; - out8k[k] = acc; - } + for (i = 0, k = 0; k < n; i += FDMDV_OS, k++) { + acc = 0.0; + for (j = 0; j < FDMDV_OS_TAPS_16K; j++) + acc += fdmdv_os_filter[j] * in16k[i - j]; + out8k[k] = acc; + } - /* update filter memory */ + /* update filter memory */ - for(i=-FDMDV_OS_TAPS_16K; i<0; i++) - in16k[i] = in16k[i + n*FDMDV_OS]; + for (i = -FDMDV_OS_TAPS_16K; i < 0; i++) in16k[i] = in16k[i + n * FDMDV_OS]; } |