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/* libSoX internal DSP functions. * All public functions & data are prefixed with lsx_ . * * Copyright (c) 2008,2012 robs@users.sourceforge.net * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or (at * your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser * General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA */ #ifdef NDEBUG /* Enable assert always. */#undef NDEBUG /* Must undef above assert.h or other that might include it. */#endif #include "sox_i.h"#include <assert.h>#include <string.h> /* Concurrent Control with "Readers" and "Writers", P.J. Courtois et al, 1971:*/ #if defined HAVE_OPENMP typedef struct {  int readcount, writecount; /* initial value = 0 */  omp_lock_t mutex_1, mutex_2, mutex_3, w, r; /* initial value = 1 */} ccrw2_t; /* Problem #2: `writers-preference' */ #define ccrw2_become_reader(p) do {\  omp_set_lock(&p.mutex_3);\    omp_set_lock(&p.r);\      omp_set_lock(&p.mutex_1);\        if (++p.readcount == 1) omp_set_lock(&p.w);\      omp_unset_lock(&p.mutex_1);\    omp_unset_lock(&p.r);\  omp_unset_lock(&p.mutex_3);\} while (0)#define ccrw2_cease_reading(p) do {\  omp_set_lock(&p.mutex_1);\    if (!--p.readcount) omp_unset_lock(&p.w);\  omp_unset_lock(&p.mutex_1);\} while (0)#define ccrw2_become_writer(p) do {\  omp_set_lock(&p.mutex_2);\    if (++p.writecount == 1) omp_set_lock(&p.r);\  omp_unset_lock(&p.mutex_2);\  omp_set_lock(&p.w);\} while (0)#define ccrw2_cease_writing(p) do {\  omp_unset_lock(&p.w);\  omp_set_lock(&p.mutex_2);\    if (!--p.writecount) omp_unset_lock(&p.r);\  omp_unset_lock(&p.mutex_2);\} while (0)#define ccrw2_init(p) do {\  omp_init_lock(&p.mutex_1);\  omp_init_lock(&p.mutex_2);\  omp_init_lock(&p.mutex_3);\  omp_init_lock(&p.w);\  omp_init_lock(&p.r);\} while (0)#define ccrw2_clear(p) do {\  omp_destroy_lock(&p.r);\  omp_destroy_lock(&p.w);\  omp_destroy_lock(&p.mutex_3);\  omp_destroy_lock(&p.mutex_2);\  omp_destroy_lock(&p.mutex_1);\} while (0) #else #define ccrw2_become_reader(x) (void)0#define ccrw2_cease_reading(x) (void)0#define ccrw2_become_writer(x) (void)0#define ccrw2_cease_writing(x) (void)0#define ccrw2_init(x) (void)0#define ccrw2_clear(x) (void)0 #endif /* HAVE_OPENMP */ /* Numerical Recipes cubic spline: */ void lsx_prepare_spline3(double const * x, double const * y, int n,    double start_1d, double end_1d, double * y_2d){  double p, qn, sig, un, * u = lsx_malloc((n - 1) * sizeof(*u));  int i;   if (start_1d == HUGE_VAL)    y_2d[0] = u[0] = 0;      /* Start with natural spline or */  else {                     /* set the start first derivative */    y_2d[0] = -.5;    u[0] = (3 / (x[1] - x[0])) * ((y[1] - y[0]) / (x[1] - x[0]) - start_1d);  }   for (i = 1; i < n - 1; ++i) {    sig = (x[i] - x[i - 1]) / (x[i + 1] - x[i - 1]);    p = sig * y_2d[i - 1] + 2;    y_2d[i] = (sig - 1) / p;    u[i] = (y[i + 1] - y[i]) / (x[i + 1] - x[i]) -           (y[i] - y[i - 1]) / (x[i] - x[i - 1]);    u[i] = (6 * u[i] / (x[i + 1] - x[i - 1]) - sig * u[i - 1]) / p;  }  if (end_1d == HUGE_VAL)    qn = un = 0;             /* End with natural spline or */  else {                     /* set the end first derivative */    qn = .5;    un = 3 / (x[n - 1] - x[n - 2]) * (end_1d - (y[n - 1] - y[n - 2]) / (x[n - 1] - x[n - 2]));  }  y_2d[n - 1] = (un - qn * u[n - 2]) / (qn * y_2d[n - 2] + 1);  for (i = n - 2; i >= 0; --i)    y_2d[i] = y_2d[i] * y_2d[i + 1] + u[i];  free(u);} double lsx_spline3(double const * x, double const * y, double const * y_2d,    int n, double x1){  int     t, i[2] = {0, 0};  double  d, a, b;   for (i[1] = n - 1; i[1] - i[0] > 1; t = (i[1] + i[0]) >> 1, i[x[t] > x1] = t);  d = x[i[1]] - x[i[0]];  assert(d != 0);  a = (x[i[1]] - x1) / d;  b = (x1 - x[i[0]]) / d;  return a * y[i[0]] + b * y[i[1]] +    ((a * a * a - a) * y_2d[i[0]] + (b * b * b - b) * y_2d[i[1]]) * d * d / 6;} double lsx_bessel_I_0(double x){  double term = 1, sum = 1, last_sum, x2 = x / 2;  int i = 1;  do {    double y = x2 / i++;    last_sum = sum, sum += term *= y * y;  } while (sum != last_sum);  return sum;} int lsx_set_dft_length(int num_taps) /* Set to 4 x nearest power of 2 */{      /* or half of that if danger of causing too many cache misses. */  int min = sox_globals.log2_dft_min_size;  double d = log((double)num_taps) / log(2.);  return 1 << range_limit((int)(d + 2.77), min, max((int)(d + 1.77), 17));} #include "fft4g.h"static int * lsx_fft_br;static double * lsx_fft_sc;static int fft_len = -1;#if defined HAVE_OPENMPstatic ccrw2_t fft_cache_ccrw;#endif void init_fft_cache(void){  assert(lsx_fft_br == NULL);  assert(lsx_fft_sc == NULL);  assert(fft_len == -1);  ccrw2_init(fft_cache_ccrw);  fft_len = 0;} void clear_fft_cache(void){  assert(fft_len >= 0);  ccrw2_clear(fft_cache_ccrw);  free(lsx_fft_br);  free(lsx_fft_sc);  lsx_fft_sc = NULL;  lsx_fft_br = NULL;  fft_len = -1;} static sox_bool update_fft_cache(int len){  assert(lsx_is_power_of_2(len));  assert(fft_len >= 0);  ccrw2_become_reader(fft_cache_ccrw);  if (len > fft_len) {    ccrw2_cease_reading(fft_cache_ccrw);    ccrw2_become_writer(fft_cache_ccrw);    if (len > fft_len) {      int old_n = fft_len;      fft_len = len;      lsx_fft_br = lsx_realloc(lsx_fft_br, dft_br_len(fft_len) * sizeof(*lsx_fft_br));      lsx_fft_sc = lsx_realloc(lsx_fft_sc, dft_sc_len(fft_len) * sizeof(*lsx_fft_sc));      if (!old_n)        lsx_fft_br[0] = 0;      return sox_true;    }    ccrw2_cease_writing(fft_cache_ccrw);    ccrw2_become_reader(fft_cache_ccrw);  }  return sox_false;} static void done_with_fft_cache(sox_bool is_writer){  if (is_writer)    ccrw2_cease_writing(fft_cache_ccrw);  else ccrw2_cease_reading(fft_cache_ccrw);} void lsx_safe_rdft(int len, int type, double * d){  sox_bool is_writer = update_fft_cache(len);  lsx_rdft(len, type, d, lsx_fft_br, lsx_fft_sc);  done_with_fft_cache(is_writer);} void lsx_safe_cdft(int len, int type, double * d){  sox_bool is_writer = update_fft_cache(len);  lsx_cdft(len, type, d, lsx_fft_br, lsx_fft_sc);  done_with_fft_cache(is_writer);} void lsx_power_spectrum(int n, double const * in, double * out){  int i;  double * work = lsx_memdup(in, n * sizeof(*work));  lsx_safe_rdft(n, 1, work);  out[0] = sqr(work[0]);  for (i = 2; i < n; i += 2)    out[i >> 1] = sqr(work[i]) + sqr(work[i + 1]);  out[i >> 1] = sqr(work[1]);  free(work);} void lsx_power_spectrum_f(int n, float const * in, float * out){  int i;  double * work = lsx_malloc(n * sizeof(*work));  for (i = 0; i< n; ++i) work[i] = in[i];  lsx_safe_rdft(n, 1, work);  out[0] = sqr(work[0]);  for (i = 2; i < n; i += 2)    out[i >> 1] = sqr(work[i]) + sqr(work[i + 1]);  out[i >> 1] = sqr(work[1]);  free(work);} void lsx_apply_hann_f(float h[], const int num_points){  int i, m = num_points - 1;  for (i = 0; i < num_points; ++i) {    double x = 2 * M_PI * i / m;    h[i] *= .5 - .5 * cos(x);  }} void lsx_apply_hann(double h[], const int num_points){  int i, m = num_points - 1;  for (i = 0; i < num_points; ++i) {    double x = 2 * M_PI * i / m;    h[i] *= .5 - .5 * cos(x);  }} void lsx_apply_hamming(double h[], const int num_points){  int i, m = num_points - 1;  for (i = 0; i < num_points; ++i) {    double x = 2 * M_PI * i / m;    h[i] *= .53836 - .46164 * cos(x);  }} void lsx_apply_bartlett(double h[], const int num_points){  int i, m = num_points - 1;  for (i = 0; i < num_points; ++i) {    h[i] *= 2. / m * (m / 2. - fabs(i - m / 2.));  }} void lsx_apply_blackman(double h[], const int num_points, double alpha /*.16*/){  int i, m = num_points - 1;  for (i = 0; i < num_points; ++i) {    double x = 2 * M_PI * i / m;    h[i] *= (1 - alpha) *.5 - .5 * cos(x) + alpha * .5 * cos(2 * x);  }} void lsx_apply_blackman_nutall(double h[], const int num_points){  int i, m = num_points - 1;  for (i = 0; i < num_points; ++i) {    double x = 2 * M_PI * i / m;    h[i] *= .3635819 - .4891775 * cos(x) + .1365995 * cos(2 * x) - .0106411 * cos(3 * x);  }} double lsx_kaiser_beta(double att, double tr_bw){  if (att >= 60) {    static const double coefs[][4] = {      {-6.784957e-10,1.02856e-05,0.1087556,-0.8988365+.001},      {-6.897885e-10,1.027433e-05,0.10876,-0.8994658+.002},      {-1.000683e-09,1.030092e-05,0.1087677,-0.9007898+.003},      {-3.654474e-10,1.040631e-05,0.1087085,-0.8977766+.006},      {8.106988e-09,6.983091e-06,0.1091387,-0.9172048+.015},      {9.519571e-09,7.272678e-06,0.1090068,-0.9140768+.025},      {-5.626821e-09,1.342186e-05,0.1083999,-0.9065452+.05},      {-9.965946e-08,5.073548e-05,0.1040967,-0.7672778+.085},      {1.604808e-07,-5.856462e-05,0.1185998,-1.34824+.1},      {-1.511964e-07,6.363034e-05,0.1064627,-0.9876665+.18},    };    double realm = log(tr_bw/.0005)/log(2.);    double const * c0 = coefs[range_limit(  (int)realm, 0, (int)array_length(coefs)-1)];    double const * c1 = coefs[range_limit(1+(int)realm, 0, (int)array_length(coefs)-1)];    double b0 = ((c0[0]*att + c0[1])*att + c0[2])*att + c0[3];    double b1 = ((c1[0]*att + c1[1])*att + c1[2])*att + c1[3];    return b0 + (b1 - b0) * (realm - (int)realm);  }  if (att > 50   ) return .1102 * (att - 8.7);  if (att > 20.96) return .58417 * pow(att -20.96, .4) + .07886 * (att - 20.96);  return 0;} void lsx_apply_kaiser(double h[], const int num_points, double beta){  int i, m = num_points - 1;  for (i = 0; i <= m; ++i) {    double x = 2. * i / m - 1;    h[i] *= lsx_bessel_I_0(beta * sqrt(1 - x * x)) / lsx_bessel_I_0(beta);  }} void lsx_apply_dolph(double h[], const int N, double att){  double b = cosh(acosh(pow(10., att/20)) / (N-1)), sum, t, c, norm = 0;  int i, j;  for (c = 1 - 1 / (b*b), i = (N-1) / 2; i >= 0; --i) {    for (sum = !i, b = t = j = 1; j <= i && sum != t; b *= (i-j) * (1./j), ++j)      t = sum, sum += (b *= c * (N - i - j) * (1./j));    sum /= (N - 1 - i), sum /= (norm = norm? norm : sum);    h[i] *= sum, h[N - 1 - i] *= sum;  }} double * lsx_make_lpf(int num_taps, double Fc, double beta, double rho,    double scale, sox_bool dc_norm){  int i, m = num_taps - 1;  double * h = calloc(num_taps, sizeof(*h)), sum = 0;  double mult = scale / lsx_bessel_I_0(beta), mult1 = 1 / (.5 * m + rho);  assert(Fc >= 0 && Fc <= 1);  lsx_debug("make_lpf(n=%i Fc=%.7g β=%g ρ=%g dc-norm=%i scale=%g)", num_taps, Fc, beta, rho, dc_norm, scale);   if (!h)    return NULL;   for (i = 0; i <= m / 2; ++i) {    double z = i - .5 * m, x = z * M_PI, y = z * mult1;    h[i] = x? sin(Fc * x) / x : Fc;    sum += h[i] *= lsx_bessel_I_0(beta * sqrt(1 - y * y)) * mult;    if (m - i != i)      sum += h[m - i] = h[i];  }  for (i = 0; dc_norm && i < num_taps; ++i) h[i] *= scale / sum;  return h;} void lsx_kaiser_params(double att, double Fc, double tr_bw, double * beta, int * num_taps){  *beta = *beta < 0? lsx_kaiser_beta(att, tr_bw * .5 / Fc): *beta;  att = att < 60? (att - 7.95) / (2.285 * M_PI * 2) :    ((.0007528358-1.577737e-05**beta)**beta+.6248022)**beta+.06186902;  *num_taps = !*num_taps? ceil(att/tr_bw + 1) : *num_taps;} double * lsx_design_lpf(    double Fp,      /* End of pass-band */    double Fs,      /* Start of stop-band */    double Fn,      /* Nyquist freq; e.g. 0.5, 1, PI */    double att,     /* Stop-band attenuation in dB */    int * num_taps, /* 0: value will be estimated */    int k,          /* >0: number of phases; <0: num_taps ≡ 1 (mod -k) */    double beta)    /* <0: value will be estimated */{  int n = *num_taps, phases = max(k, 1), modulo = max(-k, 1);  double tr_bw, Fc, rho = phases == 1? .5 : att < 120? .63 : .75;   Fp /= fabs(Fn), Fs /= fabs(Fn);        /* Normalise to Fn = 1 */  tr_bw = .5 * (Fs - Fp); /* Transition band-width: 6dB to stop points */  tr_bw /= phases, Fs /= phases;  tr_bw = min(tr_bw, .5 * Fs);  Fc = Fs - tr_bw;  assert(Fc - tr_bw >= 0);  lsx_kaiser_params(att, Fc, tr_bw, &beta, num_taps);  if (!n)    *num_taps = phases > 1? *num_taps / phases * phases + phases - 1 : (*num_taps + modulo - 2) / modulo * modulo + 1;  return Fn < 0? 0 : lsx_make_lpf(      *num_taps, Fc, beta, rho, (double)phases, sox_false);} static double safe_log(double x){  assert(x >= 0);  if (x)    return log(x);  lsx_debug("log(0)");  return -26;} void lsx_fir_to_phase(double * * h, int * len, int * post_len, double phase){  double * pi_wraps, * work, phase1 = (phase > 50 ? 100 - phase : phase) / 50;  int i, work_len, begin, end, imp_peak = 0, peak = 0;  double imp_sum = 0, peak_imp_sum = 0;  double prev_angle2 = 0, cum_2pi = 0, prev_angle1 = 0, cum_1pi = 0;   for (i = *len, work_len = 2 * 2 * 8; i > 1; work_len <<= 1, i >>= 1);   work = lsx_calloc((size_t)work_len + 2, sizeof(*work)); /* +2: (UN)PACK */  pi_wraps = lsx_malloc((((size_t)work_len + 2) / 2) * sizeof(*pi_wraps));   memcpy(work, *h, *len * sizeof(*work));  lsx_safe_rdft(work_len, 1, work); /* Cepstral: */  LSX_UNPACK(work, work_len);   for (i = 0; i <= work_len; i += 2) {    double angle = atan2(work[i + 1], work[i]);    double detect = 2 * M_PI;    double delta = angle - prev_angle2;    double adjust = detect * ((delta < -detect * .7) - (delta > detect * .7));    prev_angle2 = angle;    cum_2pi += adjust;    angle += cum_2pi;    detect = M_PI;    delta = angle - prev_angle1;    adjust = detect * ((delta < -detect * .7) - (delta > detect * .7));    prev_angle1 = angle;    cum_1pi += fabs(adjust); /* fabs for when 2pi and 1pi have combined */    pi_wraps[i >> 1] = cum_1pi;     work[i] = safe_log(sqrt(sqr(work[i]) + sqr(work[i + 1])));    work[i + 1] = 0;  }  LSX_PACK(work, work_len);  lsx_safe_rdft(work_len, -1, work);  for (i = 0; i < work_len; ++i) work[i] *= 2. / work_len;   for (i = 1; i < work_len / 2; ++i) { /* Window to reject acausal components */    work[i] *= 2;    work[i + work_len / 2] = 0;  }  lsx_safe_rdft(work_len, 1, work);   for (i = 2; i < work_len; i += 2) /* Interpolate between linear & min phase */    work[i + 1] = phase1 * i / work_len * pi_wraps[work_len >> 1] +        (1 - phase1) * (work[i + 1] + pi_wraps[i >> 1]) - pi_wraps[i >> 1];   work[0] = exp(work[0]), work[1] = exp(work[1]);  for (i = 2; i < work_len; i += 2) {    double x = exp(work[i]);    work[i    ] = x * cos(work[i + 1]);    work[i + 1] = x * sin(work[i + 1]);  }   lsx_safe_rdft(work_len, -1, work);  for (i = 0; i < work_len; ++i) work[i] *= 2. / work_len;   /* Find peak pos. */  for (i = 0; i <= (int)(pi_wraps[work_len >> 1] / M_PI + .5); ++i) {    imp_sum += work[i];    if (fabs(imp_sum) > fabs(peak_imp_sum)) {      peak_imp_sum = imp_sum;      peak = i;    }    if (work[i] > work[imp_peak]) /* For debug check only */      imp_peak = i;  }  while (peak && fabs(work[peak-1]) > fabs(work[peak]) && work[peak-1] * work[peak] > 0)    --peak;   if (!phase1)    begin = 0;  else if (phase1 == 1)    begin = peak - *len / 2;  else {    begin = (.997 - (2 - phase1) * .22) * *len + .5;    end   = (.997 + (0 - phase1) * .22) * *len + .5;    begin = peak - (begin & ~3);    end   = peak + 1 + ((end + 3) & ~3);

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