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Rack/dep/speexdsp-SpeexDSP-1.2rc3/libspeexdsp/mdf.c

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  1. /* Copyright (C) 2003-2008 Jean-Marc Valin

  2. 

  3.    File: mdf.c

  4.    Echo canceller based on the MDF algorithm (see below)

  5. 

  6.    Redistribution and use in source and binary forms, with or without

  7.    modification, are permitted provided that the following conditions are

  8.    met:

  9. 

  10.    1. Redistributions of source code must retain the above copyright notice,

  11.    this list of conditions and the following disclaimer.

  12. 

  13.    2. Redistributions in binary form must reproduce the above copyright

  14.    notice, this list of conditions and the following disclaimer in the

  15.    documentation and/or other materials provided with the distribution.

  16. 

  17.    3. The name of the author may not be used to endorse or promote products

  18.    derived from this software without specific prior written permission.

  19. 

  20.    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

  21.    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

  22.    OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

  23.    DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,

  24.    INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

  25.    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

  26.    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

  27.    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

  28.    STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

  29.    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

  30.    POSSIBILITY OF SUCH DAMAGE.

  31. */

  32. 

  33. /*

  34.    The echo canceller is based on the MDF algorithm described in:

  35. 

  36.    J. S. Soo, K. K. Pang Multidelay block frequency adaptive filter, 

  37.    IEEE Trans. Acoust. Speech Signal Process., Vol. ASSP-38, No. 2, 

  38.    February 1990.

  39.    

  40.    We use the Alternatively Updated MDF (AUMDF) variant. Robustness to 

  41.    double-talk is achieved using a variable learning rate as described in:

  42.    

  43.    Valin, J.-M., On Adjusting the Learning Rate in Frequency Domain Echo 

  44.    Cancellation With Double-Talk. IEEE Transactions on Audio,

  45.    Speech and Language Processing, Vol. 15, No. 3, pp. 1030-1034, 2007.

  46.    http://people.xiph.org/~jm/papers/valin_taslp2006.pdf

  47.    

  48.    There is no explicit double-talk detection, but a continuous variation

  49.    in the learning rate based on residual echo, double-talk and background

  50.    noise.

  51.    

  52.    About the fixed-point version:

  53.    All the signals are represented with 16-bit words. The filter weights 

  54.    are represented with 32-bit words, but only the top 16 bits are used

  55.    in most cases. The lower 16 bits are completely unreliable (due to the

  56.    fact that the update is done only on the top bits), but help in the

  57.    adaptation -- probably by removing a "threshold effect" due to

  58.    quantization (rounding going to zero) when the gradient is small.

  59.    

  60.    Another kludge that seems to work good: when performing the weight

  61.    update, we only move half the way toward the "goal" this seems to

  62.    reduce the effect of quantization noise in the update phase. This

  63.    can be seen as applying a gradient descent on a "soft constraint"

  64.    instead of having a hard constraint.

  65.    

  66. */

  67. 

  68. #ifdef HAVE_CONFIG_H

  69. #include "config.h"

  70. #endif

  71. 

  72. #include "arch.h"

  73. #include "speex/speex_echo.h"

  74. #include "fftwrap.h"

  75. #include "pseudofloat.h"

  76. #include "math_approx.h"

  77. #include "os_support.h"

  78. 

  79. #ifndef M_PI

  80. #define M_PI 3.14159265358979323846

  81. #endif

  82. 

  83. #ifdef FIXED_POINT

  84. #define WEIGHT_SHIFT 11

  85. #define NORMALIZE_SCALEDOWN 5

  86. #define NORMALIZE_SCALEUP 3

  87. #else

  88. #define WEIGHT_SHIFT 0

  89. #endif

  90. 

  91. #ifdef FIXED_POINT

  92. #define WORD2INT(x) ((x) < -32767 ? -32768 : ((x) > 32766 ? 32767 : (x)))  

  93. #else

  94. #define WORD2INT(x) ((x) < -32767.5f ? -32768 : ((x) > 32766.5f ? 32767 : floor(.5+(x))))  

  95. #endif

  96. 

  97. /* If enabled, the AEC will use a foreground filter and a background filter to be more robust to double-talk

  98.    and difficult signals in general. The cost is an extra FFT and a matrix-vector multiply */

  99. #define TWO_PATH

  100. 

  101. #ifdef FIXED_POINT

  102. static const spx_float_t MIN_LEAK = {20972, -22};

  103. 

  104. /* Constants for the two-path filter */

  105. static const spx_float_t VAR1_SMOOTH = {23593, -16};

  106. static const spx_float_t VAR2_SMOOTH = {23675, -15};

  107. static const spx_float_t VAR1_UPDATE = {16384, -15};

  108. static const spx_float_t VAR2_UPDATE = {16384, -16};

  109. static const spx_float_t VAR_BACKTRACK = {16384, -12};

  110. #define TOP16(x) ((x)>>16)

  111. 

  112. #else

  113. 

  114. static const spx_float_t MIN_LEAK = .005f;

  115. 

  116. /* Constants for the two-path filter */

  117. static const spx_float_t VAR1_SMOOTH = .36f;

  118. static const spx_float_t VAR2_SMOOTH = .7225f;

  119. static const spx_float_t VAR1_UPDATE = .5f;

  120. static const spx_float_t VAR2_UPDATE = .25f;

  121. static const spx_float_t VAR_BACKTRACK = 4.f;

  122. #define TOP16(x) (x)

  123. #endif

  124. 

  125. 

  126. #define PLAYBACK_DELAY 2

  127. 

  128. void speex_echo_get_residual(SpeexEchoState *st, spx_word32_t *Yout, int len);

  129. 

  130. 

  131. /** Speex echo cancellation state. */

  132. struct SpeexEchoState_ {

  133.    int frame_size;           /**< Number of samples processed each time */

  134.    int window_size;

  135.    int M;

  136.    int cancel_count;

  137.    int adapted;

  138.    int saturated;

  139.    int screwed_up;

  140.    int C;                    /** Number of input channels (microphones) */

  141.    int K;                    /** Number of output channels (loudspeakers) */

  142.    spx_int32_t sampling_rate;

  143.    spx_word16_t spec_average;

  144.    spx_word16_t beta0;

  145.    spx_word16_t beta_max;

  146.    spx_word32_t sum_adapt;

  147.    spx_word16_t leak_estimate;

  148.    

  149.    spx_word16_t *e;      /* scratch */

  150.    spx_word16_t *x;      /* Far-end input buffer (2N) */

  151.    spx_word16_t *X;      /* Far-end buffer (M+1 frames) in frequency domain */

  152.    spx_word16_t *input;  /* scratch */

  153.    spx_word16_t *y;      /* scratch */

  154.    spx_word16_t *last_y;

  155.    spx_word16_t *Y;      /* scratch */

  156.    spx_word16_t *E;

  157.    spx_word32_t *PHI;    /* scratch */

  158.    spx_word32_t *W;      /* (Background) filter weights */

  159. #ifdef TWO_PATH

  160.    spx_word16_t *foreground; /* Foreground filter weights */

  161.    spx_word32_t  Davg1;  /* 1st recursive average of the residual power difference */

  162.    spx_word32_t  Davg2;  /* 2nd recursive average of the residual power difference */

  163.    spx_float_t   Dvar1;  /* Estimated variance of 1st estimator */

  164.    spx_float_t   Dvar2;  /* Estimated variance of 2nd estimator */

  165. #endif

  166.    spx_word32_t *power;  /* Power of the far-end signal */

  167.    spx_float_t  *power_1;/* Inverse power of far-end */

  168.    spx_word16_t *wtmp;   /* scratch */

  169. #ifdef FIXED_POINT

  170.    spx_word16_t *wtmp2;  /* scratch */

  171. #endif

  172.    spx_word32_t *Rf;     /* scratch */

  173.    spx_word32_t *Yf;     /* scratch */

  174.    spx_word32_t *Xf;     /* scratch */

  175.    spx_word32_t *Eh;

  176.    spx_word32_t *Yh;

  177.    spx_float_t   Pey;

  178.    spx_float_t   Pyy;

  179.    spx_word16_t *window;

  180.    spx_word16_t *prop;

  181.    void *fft_table;

  182.    spx_word16_t *memX, *memD, *memE;

  183.    spx_word16_t preemph;

  184.    spx_word16_t notch_radius;

  185.    spx_mem_t *notch_mem;

  186. 

  187.    /* NOTE: If you only use speex_echo_cancel() and want to save some memory, remove this */

  188.    spx_int16_t *play_buf;

  189.    int play_buf_pos;

  190.    int play_buf_started;

  191. };

  192. 

  193. static inline void filter_dc_notch16(const spx_int16_t *in, spx_word16_t radius, spx_word16_t *out, int len, spx_mem_t *mem, int stride)

  194. {

  195.    int i;

  196.    spx_word16_t den2;

  197. #ifdef FIXED_POINT

  198.    den2 = MULT16_16_Q15(radius,radius) + MULT16_16_Q15(QCONST16(.7,15),MULT16_16_Q15(32767-radius,32767-radius));

  199. #else

  200.    den2 = radius*radius + .7*(1-radius)*(1-radius);

  201. #endif   

  202.    /*printf ("%d %d %d %d %d %d\n", num[0], num[1], num[2], den[0], den[1], den[2]);*/

  203.    for (i=0;i<len;i++)

  204.    {

  205.       spx_word16_t vin = in[i*stride];

  206.       spx_word32_t vout = mem[0] + SHL32(EXTEND32(vin),15);

  207. #ifdef FIXED_POINT

  208.       mem[0] = mem[1] + SHL32(SHL32(-EXTEND32(vin),15) + MULT16_32_Q15(radius,vout),1);

  209. #else

  210.       mem[0] = mem[1] + 2*(-vin + radius*vout);

  211. #endif

  212.       mem[1] = SHL32(EXTEND32(vin),15) - MULT16_32_Q15(den2,vout);

  213.       out[i] = SATURATE32(PSHR32(MULT16_32_Q15(radius,vout),15),32767);

  214.    }

  215. }

  216. 

  217. /* This inner product is slightly different from the codec version because of fixed-point */

  218. static inline spx_word32_t mdf_inner_prod(const spx_word16_t *x, const spx_word16_t *y, int len)

  219. {

  220.    spx_word32_t sum=0;

  221.    len >>= 1;

  222.    while(len--)

  223.    {

  224.       spx_word32_t part=0;

  225.       part = MAC16_16(part,*x++,*y++);

  226.       part = MAC16_16(part,*x++,*y++);

  227.       /* HINT: If you had a 40-bit accumulator, you could shift only at the end */

  228.       sum = ADD32(sum,SHR32(part,6));

  229.    }

  230.    return sum;

  231. }

  232. 

  233. /** Compute power spectrum of a half-complex (packed) vector */

  234. static inline void power_spectrum(const spx_word16_t *X, spx_word32_t *ps, int N)

  235. {

  236.    int i, j;

  237.    ps[0]=MULT16_16(X[0],X[0]);

  238.    for (i=1,j=1;i<N-1;i+=2,j++)

  239.    {

  240.       ps[j] =  MULT16_16(X[i],X[i]) + MULT16_16(X[i+1],X[i+1]);

  241.    }

  242.    ps[j]=MULT16_16(X[i],X[i]);

  243. }

  244. 

  245. /** Compute power spectrum of a half-complex (packed) vector and accumulate */

  246. static inline void power_spectrum_accum(const spx_word16_t *X, spx_word32_t *ps, int N)

  247. {

  248.    int i, j;

  249.    ps[0]+=MULT16_16(X[0],X[0]);

  250.    for (i=1,j=1;i<N-1;i+=2,j++)

  251.    {

  252.       ps[j] +=  MULT16_16(X[i],X[i]) + MULT16_16(X[i+1],X[i+1]);

  253.    }

  254.    ps[j]+=MULT16_16(X[i],X[i]);

  255. }

  256. 

  257. /** Compute cross-power spectrum of a half-complex (packed) vectors and add to acc */

  258. #ifdef FIXED_POINT

  259. static inline void spectral_mul_accum(const spx_word16_t *X, const spx_word32_t *Y, spx_word16_t *acc, int N, int M)

  260. {

  261.    int i,j;

  262.    spx_word32_t tmp1=0,tmp2=0;

  263.    for (j=0;j<M;j++)

  264.    {

  265.       tmp1 = MAC16_16(tmp1, X[j*N],TOP16(Y[j*N]));

  266.    }

  267.    acc[0] = PSHR32(tmp1,WEIGHT_SHIFT);

  268.    for (i=1;i<N-1;i+=2)

  269.    {

  270.       tmp1 = tmp2 = 0;

  271.       for (j=0;j<M;j++)

  272.       {

  273.          tmp1 = SUB32(MAC16_16(tmp1, X[j*N+i],TOP16(Y[j*N+i])), MULT16_16(X[j*N+i+1],TOP16(Y[j*N+i+1])));

  274.          tmp2 = MAC16_16(MAC16_16(tmp2, X[j*N+i+1],TOP16(Y[j*N+i])), X[j*N+i], TOP16(Y[j*N+i+1]));

  275.       }

  276.       acc[i] = PSHR32(tmp1,WEIGHT_SHIFT);

  277.       acc[i+1] = PSHR32(tmp2,WEIGHT_SHIFT);

  278.    }

  279.    tmp1 = tmp2 = 0;

  280.    for (j=0;j<M;j++)

  281.    {

  282.       tmp1 = MAC16_16(tmp1, X[(j+1)*N-1],TOP16(Y[(j+1)*N-1]));

  283.    }

  284.    acc[N-1] = PSHR32(tmp1,WEIGHT_SHIFT);

  285. }

  286. static inline void spectral_mul_accum16(const spx_word16_t *X, const spx_word16_t *Y, spx_word16_t *acc, int N, int M)

  287. {

  288.    int i,j;

  289.    spx_word32_t tmp1=0,tmp2=0;

  290.    for (j=0;j<M;j++)

  291.    {

  292.       tmp1 = MAC16_16(tmp1, X[j*N],Y[j*N]);

  293.    }

  294.    acc[0] = PSHR32(tmp1,WEIGHT_SHIFT);

  295.    for (i=1;i<N-1;i+=2)

  296.    {

  297.       tmp1 = tmp2 = 0;

  298.       for (j=0;j<M;j++)

  299.       {

  300.          tmp1 = SUB32(MAC16_16(tmp1, X[j*N+i],Y[j*N+i]), MULT16_16(X[j*N+i+1],Y[j*N+i+1]));

  301.          tmp2 = MAC16_16(MAC16_16(tmp2, X[j*N+i+1],Y[j*N+i]), X[j*N+i], Y[j*N+i+1]);

  302.       }

  303.       acc[i] = PSHR32(tmp1,WEIGHT_SHIFT);

  304.       acc[i+1] = PSHR32(tmp2,WEIGHT_SHIFT);

  305.    }

  306.    tmp1 = tmp2 = 0;

  307.    for (j=0;j<M;j++)

  308.    {

  309.       tmp1 = MAC16_16(tmp1, X[(j+1)*N-1],Y[(j+1)*N-1]);

  310.    }

  311.    acc[N-1] = PSHR32(tmp1,WEIGHT_SHIFT);

  312. }

  313. 

  314. #else

  315. static inline void spectral_mul_accum(const spx_word16_t *X, const spx_word32_t *Y, spx_word16_t *acc, int N, int M)

  316. {

  317.    int i,j;

  318.    for (i=0;i<N;i++)

  319.       acc[i] = 0;

  320.    for (j=0;j<M;j++)

  321.    {

  322.       acc[0] += X[0]*Y[0];

  323.       for (i=1;i<N-1;i+=2)

  324.       {

  325.          acc[i] += (X[i]*Y[i] - X[i+1]*Y[i+1]);

  326.          acc[i+1] += (X[i+1]*Y[i] + X[i]*Y[i+1]);

  327.       }

  328.       acc[i] += X[i]*Y[i];

  329.       X += N;

  330.       Y += N;

  331.    }

  332. }

  333. #define spectral_mul_accum16 spectral_mul_accum

  334. #endif

  335. 

  336. /** Compute weighted cross-power spectrum of a half-complex (packed) vector with conjugate */

  337. static inline void weighted_spectral_mul_conj(const spx_float_t *w, const spx_float_t p, const spx_word16_t *X, const spx_word16_t *Y, spx_word32_t *prod, int N)

  338. {

  339.    int i, j;

  340.    spx_float_t W;

  341.    W = FLOAT_AMULT(p, w[0]);

  342.    prod[0] = FLOAT_MUL32(W,MULT16_16(X[0],Y[0]));

  343.    for (i=1,j=1;i<N-1;i+=2,j++)

  344.    {

  345.       W = FLOAT_AMULT(p, w[j]);

  346.       prod[i] = FLOAT_MUL32(W,MAC16_16(MULT16_16(X[i],Y[i]), X[i+1],Y[i+1]));

  347.       prod[i+1] = FLOAT_MUL32(W,MAC16_16(MULT16_16(-X[i+1],Y[i]), X[i],Y[i+1]));

  348.    }

  349.    W = FLOAT_AMULT(p, w[j]);

  350.    prod[i] = FLOAT_MUL32(W,MULT16_16(X[i],Y[i]));

  351. }

  352. 

  353. static inline void mdf_adjust_prop(const spx_word32_t *W, int N, int M, int P, spx_word16_t *prop)

  354. {

  355.    int i, j, p;

  356.    spx_word16_t max_sum = 1;

  357.    spx_word32_t prop_sum = 1;

  358.    for (i=0;i<M;i++)

  359.    {

  360.       spx_word32_t tmp = 1;

  361.       for (p=0;p<P;p++)

  362.          for (j=0;j<N;j++)

  363.             tmp += MULT16_16(EXTRACT16(SHR32(W[p*N*M + i*N+j],18)), EXTRACT16(SHR32(W[p*N*M + i*N+j],18)));

  364. #ifdef FIXED_POINT

  365.       /* Just a security in case an overflow were to occur */

  366.       tmp = MIN32(ABS32(tmp), 536870912);

  367. #endif

  368.       prop[i] = spx_sqrt(tmp);

  369.       if (prop[i] > max_sum)

  370.          max_sum = prop[i];

  371.    }

  372.    for (i=0;i<M;i++)

  373.    {

  374.       prop[i] += MULT16_16_Q15(QCONST16(.1f,15),max_sum);

  375.       prop_sum += EXTEND32(prop[i]);

  376.    }

  377.    for (i=0;i<M;i++)

  378.    {

  379.       prop[i] = DIV32(MULT16_16(QCONST16(.99f,15), prop[i]),prop_sum);

  380.       /*printf ("%f ", prop[i]);*/

  381.    }

  382.    /*printf ("\n");*/

  383. }

  384. 

  385. #ifdef DUMP_ECHO_CANCEL_DATA

  386. #include <stdio.h>

  387. static FILE *rFile=NULL, *pFile=NULL, *oFile=NULL;

  388. 

  389. static void dump_audio(const spx_int16_t *rec, const spx_int16_t *play, const spx_int16_t *out, int len)

  390. {

  391.    if (!(rFile && pFile && oFile))

  392.    {

  393.       speex_fatal("Dump files not open");

  394.    }

  395.    fwrite(rec, sizeof(spx_int16_t), len, rFile);

  396.    fwrite(play, sizeof(spx_int16_t), len, pFile);

  397.    fwrite(out, sizeof(spx_int16_t), len, oFile);

  398. }

  399. #endif

  400. 

  401. /** Creates a new echo canceller state */

  402. EXPORT SpeexEchoState *speex_echo_state_init(int frame_size, int filter_length)

  403. {

  404.    return speex_echo_state_init_mc(frame_size, filter_length, 1, 1);

  405. }

  406. 

  407. EXPORT SpeexEchoState *speex_echo_state_init_mc(int frame_size, int filter_length, int nb_mic, int nb_speakers)

  408. {

  409.    int i,N,M, C, K;

  410.    SpeexEchoState *st = (SpeexEchoState *)speex_alloc(sizeof(SpeexEchoState));

  411. 

  412.    st->K = nb_speakers;

  413.    st->C = nb_mic;

  414.    C=st->C;

  415.    K=st->K;

  416. #ifdef DUMP_ECHO_CANCEL_DATA

  417.    if (rFile || pFile || oFile)

  418.       speex_fatal("Opening dump files twice");

  419.    rFile = fopen("aec_rec.sw", "wb");

  420.    pFile = fopen("aec_play.sw", "wb");

  421.    oFile = fopen("aec_out.sw", "wb");

  422. #endif

  423.    

  424.    st->frame_size = frame_size;

  425.    st->window_size = 2*frame_size;

  426.    N = st->window_size;

  427.    M = st->M = (filter_length+st->frame_size-1)/frame_size;

  428.    st->cancel_count=0;

  429.    st->sum_adapt = 0;

  430.    st->saturated = 0;

  431.    st->screwed_up = 0;

  432.    /* This is the default sampling rate */

  433.    st->sampling_rate = 8000;

  434.    st->spec_average = DIV32_16(SHL32(EXTEND32(st->frame_size), 15), st->sampling_rate);

  435. #ifdef FIXED_POINT

  436.    st->beta0 = DIV32_16(SHL32(EXTEND32(st->frame_size), 16), st->sampling_rate);

  437.    st->beta_max = DIV32_16(SHL32(EXTEND32(st->frame_size), 14), st->sampling_rate);

  438. #else

  439.    st->beta0 = (2.0f*st->frame_size)/st->sampling_rate;

  440.    st->beta_max = (.5f*st->frame_size)/st->sampling_rate;

  441. #endif

  442.    st->leak_estimate = 0;

  443. 

  444.    st->fft_table = spx_fft_init(N);

  445.    

  446.    st->e = (spx_word16_t*)speex_alloc(C*N*sizeof(spx_word16_t));

  447.    st->x = (spx_word16_t*)speex_alloc(K*N*sizeof(spx_word16_t));

  448.    st->input = (spx_word16_t*)speex_alloc(C*st->frame_size*sizeof(spx_word16_t));

  449.    st->y = (spx_word16_t*)speex_alloc(C*N*sizeof(spx_word16_t));

  450.    st->last_y = (spx_word16_t*)speex_alloc(C*N*sizeof(spx_word16_t));

  451.    st->Yf = (spx_word32_t*)speex_alloc((st->frame_size+1)*sizeof(spx_word32_t));

  452.    st->Rf = (spx_word32_t*)speex_alloc((st->frame_size+1)*sizeof(spx_word32_t));

  453.    st->Xf = (spx_word32_t*)speex_alloc((st->frame_size+1)*sizeof(spx_word32_t));

  454.    st->Yh = (spx_word32_t*)speex_alloc((st->frame_size+1)*sizeof(spx_word32_t));

  455.    st->Eh = (spx_word32_t*)speex_alloc((st->frame_size+1)*sizeof(spx_word32_t));

  456. 

  457.    st->X = (spx_word16_t*)speex_alloc(K*(M+1)*N*sizeof(spx_word16_t));

  458.    st->Y = (spx_word16_t*)speex_alloc(C*N*sizeof(spx_word16_t));

  459.    st->E = (spx_word16_t*)speex_alloc(C*N*sizeof(spx_word16_t));

  460.    st->W = (spx_word32_t*)speex_alloc(C*K*M*N*sizeof(spx_word32_t));

  461. #ifdef TWO_PATH

  462.    st->foreground = (spx_word16_t*)speex_alloc(M*N*C*K*sizeof(spx_word16_t));

  463. #endif

  464.    st->PHI = (spx_word32_t*)speex_alloc(N*sizeof(spx_word32_t));

  465.    st->power = (spx_word32_t*)speex_alloc((frame_size+1)*sizeof(spx_word32_t));

  466.    st->power_1 = (spx_float_t*)speex_alloc((frame_size+1)*sizeof(spx_float_t));

  467.    st->window = (spx_word16_t*)speex_alloc(N*sizeof(spx_word16_t));

  468.    st->prop = (spx_word16_t*)speex_alloc(M*sizeof(spx_word16_t));

  469.    st->wtmp = (spx_word16_t*)speex_alloc(N*sizeof(spx_word16_t));

  470. #ifdef FIXED_POINT

  471.    st->wtmp2 = (spx_word16_t*)speex_alloc(N*sizeof(spx_word16_t));

  472.    for (i=0;i<N>>1;i++)

  473.    {

  474.       st->window[i] = (16383-SHL16(spx_cos(DIV32_16(MULT16_16(25736,i<<1),N)),1));

  475.       st->window[N-i-1] = st->window[i];

  476.    }

  477. #else

  478.    for (i=0;i<N;i++)

  479.       st->window[i] = .5-.5*cos(2*M_PI*i/N);

  480. #endif

  481.    for (i=0;i<=st->frame_size;i++)

  482.       st->power_1[i] = FLOAT_ONE;

  483.    for (i=0;i<N*M*K*C;i++)

  484.       st->W[i] = 0;

  485.    {

  486.       spx_word32_t sum = 0;

  487.       /* Ratio of ~10 between adaptation rate of first and last block */

  488.       spx_word16_t decay = SHR32(spx_exp(NEG16(DIV32_16(QCONST16(2.4,11),M))),1);

  489.       st->prop[0] = QCONST16(.7, 15);

  490.       sum = EXTEND32(st->prop[0]);

  491.       for (i=1;i<M;i++)

  492.       {

  493.          st->prop[i] = MULT16_16_Q15(st->prop[i-1], decay);

  494.          sum = ADD32(sum, EXTEND32(st->prop[i]));

  495.       }

  496.       for (i=M-1;i>=0;i--)

  497.       {

  498.          st->prop[i] = DIV32(MULT16_16(QCONST16(.8f,15), st->prop[i]),sum);

  499.       }

  500.    }

  501.    

  502.    st->memX = (spx_word16_t*)speex_alloc(K*sizeof(spx_word16_t));

  503.    st->memD = (spx_word16_t*)speex_alloc(C*sizeof(spx_word16_t));

  504.    st->memE = (spx_word16_t*)speex_alloc(C*sizeof(spx_word16_t));

  505.    st->preemph = QCONST16(.9,15);

  506.    if (st->sampling_rate<12000)

  507.       st->notch_radius = QCONST16(.9, 15);

  508.    else if (st->sampling_rate<24000)

  509.       st->notch_radius = QCONST16(.982, 15);

  510.    else

  511.       st->notch_radius = QCONST16(.992, 15);

  512. 

  513.    st->notch_mem = (spx_mem_t*)speex_alloc(2*C*sizeof(spx_mem_t));

  514.    st->adapted = 0;

  515.    st->Pey = st->Pyy = FLOAT_ONE;

  516.    

  517. #ifdef TWO_PATH

  518.    st->Davg1 = st->Davg2 = 0;

  519.    st->Dvar1 = st->Dvar2 = FLOAT_ZERO;

  520. #endif

  521.    

  522.    st->play_buf = (spx_int16_t*)speex_alloc(K*(PLAYBACK_DELAY+1)*st->frame_size*sizeof(spx_int16_t));

  523.    st->play_buf_pos = PLAYBACK_DELAY*st->frame_size;

  524.    st->play_buf_started = 0;

  525.    

  526.    return st;

  527. }

  528. 

  529. /** Resets echo canceller state */

  530. EXPORT void speex_echo_state_reset(SpeexEchoState *st)

  531. {

  532.    int i, M, N, C, K;

  533.    st->cancel_count=0;

  534.    st->screwed_up = 0;

  535.    N = st->window_size;

  536.    M = st->M;

  537.    C=st->C;

  538.    K=st->K;

  539.    for (i=0;i<N*M;i++)

  540.       st->W[i] = 0;

  541. #ifdef TWO_PATH

  542.    for (i=0;i<N*M;i++)

  543.       st->foreground[i] = 0;

  544. #endif

  545.    for (i=0;i<N*(M+1);i++)

  546.       st->X[i] = 0;

  547.    for (i=0;i<=st->frame_size;i++)

  548.    {

  549.       st->power[i] = 0;

  550.       st->power_1[i] = FLOAT_ONE;

  551.       st->Eh[i] = 0;

  552.       st->Yh[i] = 0;

  553.    }

  554.    for (i=0;i<st->frame_size;i++)

  555.    {

  556.       st->last_y[i] = 0;

  557.    }

  558.    for (i=0;i<N*C;i++)

  559.    {

  560.       st->E[i] = 0;

  561.    }

  562.    for (i=0;i<N*K;i++)

  563.    {

  564.       st->x[i] = 0;

  565.    }

  566.    for (i=0;i<2*C;i++)

  567.       st->notch_mem[i] = 0;

  568.    for (i=0;i<C;i++)

  569.       st->memD[i]=st->memE[i]=0;

  570.    for (i=0;i<K;i++)

  571.       st->memX[i]=0;

  572. 

  573.    st->saturated = 0;

  574.    st->adapted = 0;

  575.    st->sum_adapt = 0;

  576.    st->Pey = st->Pyy = FLOAT_ONE;

  577. #ifdef TWO_PATH

  578.    st->Davg1 = st->Davg2 = 0;

  579.    st->Dvar1 = st->Dvar2 = FLOAT_ZERO;

  580. #endif

  581.    for (i=0;i<3*st->frame_size;i++)

  582.       st->play_buf[i] = 0;

  583.    st->play_buf_pos = PLAYBACK_DELAY*st->frame_size;

  584.    st->play_buf_started = 0;

  585. 

  586. }

  587. 

  588. /** Destroys an echo canceller state */

  589. EXPORT void speex_echo_state_destroy(SpeexEchoState *st)

  590. {

  591.    spx_fft_destroy(st->fft_table);

  592. 

  593.    speex_free(st->e);

  594.    speex_free(st->x);

  595.    speex_free(st->input);

  596.    speex_free(st->y);

  597.    speex_free(st->last_y);

  598.    speex_free(st->Yf);

  599.    speex_free(st->Rf);

  600.    speex_free(st->Xf);

  601.    speex_free(st->Yh);

  602.    speex_free(st->Eh);

  603. 

  604.    speex_free(st->X);

  605.    speex_free(st->Y);

  606.    speex_free(st->E);

  607.    speex_free(st->W);

  608. #ifdef TWO_PATH

  609.    speex_free(st->foreground);

  610. #endif

  611.    speex_free(st->PHI);

  612.    speex_free(st->power);

  613.    speex_free(st->power_1);

  614.    speex_free(st->window);

  615.    speex_free(st->prop);

  616.    speex_free(st->wtmp);

  617. #ifdef FIXED_POINT

  618.    speex_free(st->wtmp2);

  619. #endif

  620.    speex_free(st->memX);

  621.    speex_free(st->memD);

  622.    speex_free(st->memE);

  623.    speex_free(st->notch_mem);

  624. 

  625.    speex_free(st->play_buf);

  626.    speex_free(st);

  627.    

  628. #ifdef DUMP_ECHO_CANCEL_DATA

  629.    fclose(rFile);

  630.    fclose(pFile);

  631.    fclose(oFile);

  632.    rFile = pFile = oFile = NULL;

  633. #endif

  634. }

  635. 

  636. EXPORT void speex_echo_capture(SpeexEchoState *st, const spx_int16_t *rec, spx_int16_t *out)

  637. {

  638.    int i;

  639.    /*speex_warning_int("capture with fill level ", st->play_buf_pos/st->frame_size);*/

  640.    st->play_buf_started = 1;

  641.    if (st->play_buf_pos>=st->frame_size)

  642.    {

  643.       speex_echo_cancellation(st, rec, st->play_buf, out);

  644.       st->play_buf_pos -= st->frame_size;

  645.       for (i=0;i<st->play_buf_pos;i++)

  646.          st->play_buf[i] = st->play_buf[i+st->frame_size];

  647.    } else {

  648.       speex_warning("No playback frame available (your application is buggy and/or got xruns)");

  649.       if (st->play_buf_pos!=0)

  650.       {

  651.          speex_warning("internal playback buffer corruption?");

  652.          st->play_buf_pos = 0;

  653.       }

  654.       for (i=0;i<st->frame_size;i++)

  655.          out[i] = rec[i];

  656.    }

  657. }

  658. 

  659. EXPORT void speex_echo_playback(SpeexEchoState *st, const spx_int16_t *play)

  660. {

  661.    /*speex_warning_int("playback with fill level ", st->play_buf_pos/st->frame_size);*/

  662.    if (!st->play_buf_started)

  663.    {

  664.       speex_warning("discarded first playback frame");

  665.       return;

  666.    }

  667.    if (st->play_buf_pos<=PLAYBACK_DELAY*st->frame_size)

  668.    {

  669.       int i;

  670.       for (i=0;i<st->frame_size;i++)

  671.          st->play_buf[st->play_buf_pos+i] = play[i];

  672.       st->play_buf_pos += st->frame_size;

  673.       if (st->play_buf_pos <= (PLAYBACK_DELAY-1)*st->frame_size)

  674.       {

  675.          speex_warning("Auto-filling the buffer (your application is buggy and/or got xruns)");

  676.          for (i=0;i<st->frame_size;i++)

  677.             st->play_buf[st->play_buf_pos+i] = play[i];

  678.          st->play_buf_pos += st->frame_size;

  679.       }

  680.    } else {

  681.       speex_warning("Had to discard a playback frame (your application is buggy and/or got xruns)");

  682.    }

  683. }

  684. 

  685. /** Performs echo cancellation on a frame (deprecated, last arg now ignored) */

  686. EXPORT void speex_echo_cancel(SpeexEchoState *st, const spx_int16_t *in, const spx_int16_t *far_end, spx_int16_t *out, spx_int32_t *Yout)

  687. {

  688.    speex_echo_cancellation(st, in, far_end, out);

  689. }

  690. 

  691. /** Performs echo cancellation on a frame */

  692. EXPORT void speex_echo_cancellation(SpeexEchoState *st, const spx_int16_t *in, const spx_int16_t *far_end, spx_int16_t *out)

  693. {

  694.    int i,j, chan, speak;

  695.    int N,M, C, K;

  696.    spx_word32_t Syy,See,Sxx,Sdd, Sff;

  697. #ifdef TWO_PATH

  698.    spx_word32_t Dbf;

  699.    int update_foreground;

  700. #endif

  701.    spx_word32_t Sey;

  702.    spx_word16_t ss, ss_1;

  703.    spx_float_t Pey = FLOAT_ONE, Pyy=FLOAT_ONE;

  704.    spx_float_t alpha, alpha_1;

  705.    spx_word16_t RER;

  706.    spx_word32_t tmp32;

  707.    

  708.    N = st->window_size;

  709.    M = st->M;

  710.    C = st->C;

  711.    K = st->K;

  712. 

  713.    st->cancel_count++;

  714. #ifdef FIXED_POINT

  715.    ss=DIV32_16(11469,M);

  716.    ss_1 = SUB16(32767,ss);

  717. #else

  718.    ss=.35/M;

  719.    ss_1 = 1-ss;

  720. #endif

  721. 

  722.    for (chan = 0; chan < C; chan++)

  723.    {

  724.       /* Apply a notch filter to make sure DC doesn't end up causing problems */

  725.       filter_dc_notch16(in+chan, st->notch_radius, st->input+chan*st->frame_size, st->frame_size, st->notch_mem+2*chan, C);

  726.       /* Copy input data to buffer and apply pre-emphasis */

  727.       /* Copy input data to buffer */

  728.       for (i=0;i<st->frame_size;i++)

  729.       {

  730.          spx_word32_t tmp32;

  731.          /* FIXME: This core has changed a bit, need to merge properly */

  732.          tmp32 = SUB32(EXTEND32(st->input[chan*st->frame_size+i]), EXTEND32(MULT16_16_P15(st->preemph, st->memD[chan])));

  733. #ifdef FIXED_POINT

  734.          if (tmp32 > 32767)

  735.          {

  736.             tmp32 = 32767;

  737.             if (st->saturated == 0)

  738.                st->saturated = 1;

  739.          }      

  740.          if (tmp32 < -32767)

  741.          {

  742.             tmp32 = -32767;

  743.             if (st->saturated == 0)

  744.                st->saturated = 1;

  745.          }

  746. #endif

  747.          st->memD[chan] = st->input[chan*st->frame_size+i];

  748.          st->input[chan*st->frame_size+i] = EXTRACT16(tmp32);

  749.       }

  750.    }

  751. 

  752.    for (speak = 0; speak < K; speak++)

  753.    {

  754.       for (i=0;i<st->frame_size;i++)

  755.       {

  756.          spx_word32_t tmp32;

  757.          st->x[speak*N+i] = st->x[speak*N+i+st->frame_size];

  758.          tmp32 = SUB32(EXTEND32(far_end[i*K+speak]), EXTEND32(MULT16_16_P15(st->preemph, st->memX[speak])));

  759. #ifdef FIXED_POINT

  760.          /*FIXME: If saturation occurs here, we need to freeze adaptation for M frames (not just one) */

  761.          if (tmp32 > 32767)

  762.          {

  763.             tmp32 = 32767;

  764.             st->saturated = M+1;

  765.          }      

  766.          if (tmp32 < -32767)

  767.          {

  768.             tmp32 = -32767;

  769.             st->saturated = M+1;

  770.          }      

  771. #endif

  772.          st->x[speak*N+i+st->frame_size] = EXTRACT16(tmp32);

  773.          st->memX[speak] = far_end[i*K+speak];

  774.       }

  775.    }   

  776.    

  777.    for (speak = 0; speak < K; speak++)

  778.    {

  779.       /* Shift memory: this could be optimized eventually*/

  780.       for (j=M-1;j>=0;j--)

  781.       {

  782.          for (i=0;i<N;i++)

  783.             st->X[(j+1)*N*K+speak*N+i] = st->X[j*N*K+speak*N+i];

  784.       }

  785.       /* Convert x (echo input) to frequency domain */

  786.       spx_fft(st->fft_table, st->x+speak*N, &st->X[speak*N]);

  787.    }

  788.    

  789.    Sxx = 0;

  790.    for (speak = 0; speak < K; speak++)

  791.    {

  792.       Sxx += mdf_inner_prod(st->x+speak*N+st->frame_size, st->x+speak*N+st->frame_size, st->frame_size);

  793.       power_spectrum_accum(st->X+speak*N, st->Xf, N);

  794.    }

  795.    

  796.    Sff = 0;  

  797.    for (chan = 0; chan < C; chan++)

  798.    {

  799. #ifdef TWO_PATH

  800.       /* Compute foreground filter */

  801.       spectral_mul_accum16(st->X, st->foreground+chan*N*K*M, st->Y+chan*N, N, M*K);

  802.       spx_ifft(st->fft_table, st->Y+chan*N, st->e+chan*N);

  803.       for (i=0;i<st->frame_size;i++)

  804.          st->e[chan*N+i] = SUB16(st->input[chan*st->frame_size+i], st->e[chan*N+i+st->frame_size]);

  805.       Sff += mdf_inner_prod(st->e+chan*N, st->e+chan*N, st->frame_size);

  806. #endif

  807.    }

  808.    

  809.    /* Adjust proportional adaption rate */

  810.    /* FIXME: Adjust that for C, K*/

  811.    if (st->adapted)

  812.       mdf_adjust_prop (st->W, N, M, C*K, st->prop);

  813.    /* Compute weight gradient */

  814.    if (st->saturated == 0)

  815.    {

  816.       for (chan = 0; chan < C; chan++)

  817.       {

  818.          for (speak = 0; speak < K; speak++)

  819.          {

  820.             for (j=M-1;j>=0;j--)

  821.             {

  822.                weighted_spectral_mul_conj(st->power_1, FLOAT_SHL(PSEUDOFLOAT(st->prop[j]),-15), &st->X[(j+1)*N*K+speak*N], st->E+chan*N, st->PHI, N);

  823.                for (i=0;i<N;i++)

  824.                   st->W[chan*N*K*M + j*N*K + speak*N + i] += st->PHI[i];

  825.             }

  826.          }

  827.       }

  828.    } else {

  829.       st->saturated--;

  830.    }

  831.    

  832.    /* FIXME: MC conversion required */ 

  833.    /* Update weight to prevent circular convolution (MDF / AUMDF) */

  834.    for (chan = 0; chan < C; chan++)

  835.    {

  836.       for (speak = 0; speak < K; speak++)

  837.       {

  838.          for (j=0;j<M;j++)

  839.          {

  840.             /* This is a variant of the Alternatively Updated MDF (AUMDF) */

  841.             /* Remove the "if" to make this an MDF filter */

  842.             if (j==0 || st->cancel_count%(M-1) == j-1)

  843.             {

  844. #ifdef FIXED_POINT

  845.                for (i=0;i<N;i++)

  846.                   st->wtmp2[i] = EXTRACT16(PSHR32(st->W[chan*N*K*M + j*N*K + speak*N + i],NORMALIZE_SCALEDOWN+16));

  847.                spx_ifft(st->fft_table, st->wtmp2, st->wtmp);

  848.                for (i=0;i<st->frame_size;i++)

  849.                {

  850.                   st->wtmp[i]=0;

  851.                }

  852.                for (i=st->frame_size;i<N;i++)

  853.                {

  854.                   st->wtmp[i]=SHL16(st->wtmp[i],NORMALIZE_SCALEUP);

  855.                }

  856.                spx_fft(st->fft_table, st->wtmp, st->wtmp2);

  857.                /* The "-1" in the shift is a sort of kludge that trades less efficient update speed for decrease noise */

  858.                for (i=0;i<N;i++)

  859.                   st->W[chan*N*K*M + j*N*K + speak*N + i] -= SHL32(EXTEND32(st->wtmp2[i]),16+NORMALIZE_SCALEDOWN-NORMALIZE_SCALEUP-1);

  860. #else

  861.                spx_ifft(st->fft_table, &st->W[chan*N*K*M + j*N*K + speak*N], st->wtmp);

  862.                for (i=st->frame_size;i<N;i++)

  863.                {

  864.                   st->wtmp[i]=0;

  865.                }

  866.                spx_fft(st->fft_table, st->wtmp, &st->W[chan*N*K*M + j*N*K + speak*N]);

  867. #endif

  868.             }

  869.          }

  870.       }

  871.    }

  872.    

  873.    /* So we can use power_spectrum_accum */ 

  874.    for (i=0;i<=st->frame_size;i++)

  875.       st->Rf[i] = st->Yf[i] = st->Xf[i] = 0;

  876.       

  877.    Dbf = 0;

  878.    See = 0;    

  879. #ifdef TWO_PATH

  880.    /* Difference in response, this is used to estimate the variance of our residual power estimate */

  881.    for (chan = 0; chan < C; chan++)

  882.    {

  883.       spectral_mul_accum(st->X, st->W+chan*N*K*M, st->Y+chan*N, N, M*K);

  884.       spx_ifft(st->fft_table, st->Y+chan*N, st->y+chan*N);

  885.       for (i=0;i<st->frame_size;i++)

  886.          st->e[chan*N+i] = SUB16(st->e[chan*N+i+st->frame_size], st->y[chan*N+i+st->frame_size]);

  887.       Dbf += 10+mdf_inner_prod(st->e+chan*N, st->e+chan*N, st->frame_size);

  888.       for (i=0;i<st->frame_size;i++)

  889.          st->e[chan*N+i] = SUB16(st->input[chan*st->frame_size+i], st->y[chan*N+i+st->frame_size]);

  890.       See += mdf_inner_prod(st->e+chan*N, st->e+chan*N, st->frame_size);

  891.    }

  892. #endif

  893. 

  894. #ifndef TWO_PATH

  895.    Sff = See;

  896. #endif

  897. 

  898. #ifdef TWO_PATH

  899.    /* Logic for updating the foreground filter */

  900.    

  901.    /* For two time windows, compute the mean of the energy difference, as well as the variance */

  902.    st->Davg1 = ADD32(MULT16_32_Q15(QCONST16(.6f,15),st->Davg1), MULT16_32_Q15(QCONST16(.4f,15),SUB32(Sff,See)));

  903.    st->Davg2 = ADD32(MULT16_32_Q15(QCONST16(.85f,15),st->Davg2), MULT16_32_Q15(QCONST16(.15f,15),SUB32(Sff,See)));

  904.    st->Dvar1 = FLOAT_ADD(FLOAT_MULT(VAR1_SMOOTH, st->Dvar1), FLOAT_MUL32U(MULT16_32_Q15(QCONST16(.4f,15),Sff), MULT16_32_Q15(QCONST16(.4f,15),Dbf)));

  905.    st->Dvar2 = FLOAT_ADD(FLOAT_MULT(VAR2_SMOOTH, st->Dvar2), FLOAT_MUL32U(MULT16_32_Q15(QCONST16(.15f,15),Sff), MULT16_32_Q15(QCONST16(.15f,15),Dbf)));

  906.    

  907.    /* Equivalent float code:

  908.    st->Davg1 = .6*st->Davg1 + .4*(Sff-See);

  909.    st->Davg2 = .85*st->Davg2 + .15*(Sff-See);

  910.    st->Dvar1 = .36*st->Dvar1 + .16*Sff*Dbf;

  911.    st->Dvar2 = .7225*st->Dvar2 + .0225*Sff*Dbf;

  912.    */

  913.    

  914.    update_foreground = 0;

  915.    /* Check if we have a statistically significant reduction in the residual echo */

  916.    /* Note that this is *not* Gaussian, so we need to be careful about the longer tail */

  917.    if (FLOAT_GT(FLOAT_MUL32U(SUB32(Sff,See),ABS32(SUB32(Sff,See))), FLOAT_MUL32U(Sff,Dbf)))

  918.       update_foreground = 1;

  919.    else if (FLOAT_GT(FLOAT_MUL32U(st->Davg1, ABS32(st->Davg1)), FLOAT_MULT(VAR1_UPDATE,(st->Dvar1))))

  920.       update_foreground = 1;

  921.    else if (FLOAT_GT(FLOAT_MUL32U(st->Davg2, ABS32(st->Davg2)), FLOAT_MULT(VAR2_UPDATE,(st->Dvar2))))

  922.       update_foreground = 1;

  923.    

  924.    /* Do we update? */

  925.    if (update_foreground)

  926.    {

  927.       st->Davg1 = st->Davg2 = 0;

  928.       st->Dvar1 = st->Dvar2 = FLOAT_ZERO;

  929.       /* Copy background filter to foreground filter */

  930.       for (i=0;i<N*M*C*K;i++)

  931.          st->foreground[i] = EXTRACT16(PSHR32(st->W[i],16));

  932.       /* Apply a smooth transition so as to not introduce blocking artifacts */

  933.       for (chan = 0; chan < C; chan++)

  934.          for (i=0;i<st->frame_size;i++)

  935.             st->e[chan*N+i+st->frame_size] = MULT16_16_Q15(st->window[i+st->frame_size],st->e[chan*N+i+st->frame_size]) + MULT16_16_Q15(st->window[i],st->y[chan*N+i+st->frame_size]);

  936.    } else {

  937.       int reset_background=0;

  938.       /* Otherwise, check if the background filter is significantly worse */

  939.       if (FLOAT_GT(FLOAT_MUL32U(NEG32(SUB32(Sff,See)),ABS32(SUB32(Sff,See))), FLOAT_MULT(VAR_BACKTRACK,FLOAT_MUL32U(Sff,Dbf))))

  940.          reset_background = 1;

  941.       if (FLOAT_GT(FLOAT_MUL32U(NEG32(st->Davg1), ABS32(st->Davg1)), FLOAT_MULT(VAR_BACKTRACK,st->Dvar1)))

  942.          reset_background = 1;

  943.       if (FLOAT_GT(FLOAT_MUL32U(NEG32(st->Davg2), ABS32(st->Davg2)), FLOAT_MULT(VAR_BACKTRACK,st->Dvar2)))

  944.          reset_background = 1;

  945.       if (reset_background)

  946.       {

  947.          /* Copy foreground filter to background filter */

  948.          for (i=0;i<N*M*C*K;i++)

  949.             st->W[i] = SHL32(EXTEND32(st->foreground[i]),16);

  950.          /* We also need to copy the output so as to get correct adaptation */

  951.          for (chan = 0; chan < C; chan++)

  952.          {        

  953.             for (i=0;i<st->frame_size;i++)

  954.                st->y[chan*N+i+st->frame_size] = st->e[chan*N+i+st->frame_size];

  955.             for (i=0;i<st->frame_size;i++)

  956.                st->e[chan*N+i] = SUB16(st->input[chan*st->frame_size+i], st->y[chan*N+i+st->frame_size]);

  957.          }        

  958.          See = Sff;

  959.          st->Davg1 = st->Davg2 = 0;

  960.          st->Dvar1 = st->Dvar2 = FLOAT_ZERO;

  961.       }

  962.    }

  963. #endif

  964. 

  965.    Sey = Syy = Sdd = 0;  

  966.    for (chan = 0; chan < C; chan++)

  967.    {    

  968.       /* Compute error signal (for the output with de-emphasis) */ 

  969.       for (i=0;i<st->frame_size;i++)

  970.       {

  971.          spx_word32_t tmp_out;

  972. #ifdef TWO_PATH

  973.          tmp_out = SUB32(EXTEND32(st->input[chan*st->frame_size+i]), EXTEND32(st->e[chan*N+i+st->frame_size]));

  974. #else

  975.          tmp_out = SUB32(EXTEND32(st->input[chan*st->frame_size+i]), EXTEND32(st->y[chan*N+i+st->frame_size]));

  976. #endif

  977.          tmp_out = ADD32(tmp_out, EXTEND32(MULT16_16_P15(st->preemph, st->memE[chan])));

  978.       /* This is an arbitrary test for saturation in the microphone signal */

  979.          if (in[i*C+chan] <= -32000 || in[i*C+chan] >= 32000)

  980.          {

  981.          if (st->saturated == 0)

  982.             st->saturated = 1;

  983.          }

  984.          out[i*C+chan] = WORD2INT(tmp_out);

  985.          st->memE[chan] = tmp_out;

  986.       }

  987. 

  988. #ifdef DUMP_ECHO_CANCEL_DATA

  989.       dump_audio(in, far_end, out, st->frame_size);

  990. #endif

  991.    

  992.       /* Compute error signal (filter update version) */ 

  993.       for (i=0;i<st->frame_size;i++)

  994.       {

  995.          st->e[chan*N+i+st->frame_size] = st->e[chan*N+i];

  996.          st->e[chan*N+i] = 0;

  997.       }

  998.       

  999.       /* Compute a bunch of correlations */

  1000.       /* FIXME: bad merge */

  1001.       Sey += mdf_inner_prod(st->e+chan*N+st->frame_size, st->y+chan*N+st->frame_size, st->frame_size);

  1002.       Syy += mdf_inner_prod(st->y+chan*N+st->frame_size, st->y+chan*N+st->frame_size, st->frame_size);

  1003.       Sdd += mdf_inner_prod(st->input+chan*st->frame_size, st->input+chan*st->frame_size, st->frame_size);

  1004.       

  1005.       /* Convert error to frequency domain */

  1006.       spx_fft(st->fft_table, st->e+chan*N, st->E+chan*N);

  1007.       for (i=0;i<st->frame_size;i++)

  1008.          st->y[i+chan*N] = 0;

  1009.       spx_fft(st->fft_table, st->y+chan*N, st->Y+chan*N);

  1010.    

  1011.       /* Compute power spectrum of echo (X), error (E) and filter response (Y) */

  1012.       power_spectrum_accum(st->E+chan*N, st->Rf, N);

  1013.       power_spectrum_accum(st->Y+chan*N, st->Yf, N);

  1014.     

  1015.    }

  1016.    

  1017.    /*printf ("%f %f %f %f\n", Sff, See, Syy, Sdd, st->update_cond);*/

  1018.    

  1019.    /* Do some sanity check */

  1020.    if (!(Syy>=0 && Sxx>=0 && See >= 0)

  1021. #ifndef FIXED_POINT

  1022.        || !(Sff < N*1e9 && Syy < N*1e9 && Sxx < N*1e9)

  1023. #endif

  1024.       )

  1025.    {

  1026.       /* Things have gone really bad */

  1027.       st->screwed_up += 50;

  1028.       for (i=0;i<st->frame_size*C;i++)

  1029.          out[i] = 0;

  1030.    } else if (SHR32(Sff, 2) > ADD32(Sdd, SHR32(MULT16_16(N, 10000),6)))

  1031.    {

  1032.       /* AEC seems to add lots of echo instead of removing it, let's see if it will improve */

  1033.       st->screwed_up++;

  1034.    } else {

  1035.       /* Everything's fine */

  1036.       st->screwed_up=0;

  1037.    }

  1038.    if (st->screwed_up>=50)

  1039.    {

  1040.       speex_warning("The echo canceller started acting funny and got slapped (reset). It swears it will behave now.");

  1041.       speex_echo_state_reset(st);

  1042.       return;

  1043.    }

  1044. 

  1045.    /* Add a small noise floor to make sure not to have problems when dividing */

  1046.    See = MAX32(See, SHR32(MULT16_16(N, 100),6));

  1047.      

  1048.    for (speak = 0; speak < K; speak++)

  1049.    {

  1050.       Sxx += mdf_inner_prod(st->x+speak*N+st->frame_size, st->x+speak*N+st->frame_size, st->frame_size);

  1051.       power_spectrum_accum(st->X+speak*N, st->Xf, N);

  1052.    }

  1053. 

  1054.    

  1055.    /* Smooth far end energy estimate over time */

  1056.    for (j=0;j<=st->frame_size;j++)

  1057.       st->power[j] = MULT16_32_Q15(ss_1,st->power[j]) + 1 + MULT16_32_Q15(ss,st->Xf[j]);

  1058. 

  1059.    /* Compute filtered spectra and (cross-)correlations */

  1060.    for (j=st->frame_size;j>=0;j--)

  1061.    {

  1062.       spx_float_t Eh, Yh;

  1063.       Eh = PSEUDOFLOAT(st->Rf[j] - st->Eh[j]);

  1064.       Yh = PSEUDOFLOAT(st->Yf[j] - st->Yh[j]);

  1065.       Pey = FLOAT_ADD(Pey,FLOAT_MULT(Eh,Yh));

  1066.       Pyy = FLOAT_ADD(Pyy,FLOAT_MULT(Yh,Yh));

  1067. #ifdef FIXED_POINT

  1068.       st->Eh[j] = MAC16_32_Q15(MULT16_32_Q15(SUB16(32767,st->spec_average),st->Eh[j]), st->spec_average, st->Rf[j]);

  1069.       st->Yh[j] = MAC16_32_Q15(MULT16_32_Q15(SUB16(32767,st->spec_average),st->Yh[j]), st->spec_average, st->Yf[j]);

  1070. #else

  1071.       st->Eh[j] = (1-st->spec_average)*st->Eh[j] + st->spec_average*st->Rf[j];

  1072.       st->Yh[j] = (1-st->spec_average)*st->Yh[j] + st->spec_average*st->Yf[j];

  1073. #endif

  1074.    }

  1075.    

  1076.    Pyy = FLOAT_SQRT(Pyy);

  1077.    Pey = FLOAT_DIVU(Pey,Pyy);

  1078. 

  1079.    /* Compute correlation updatete rate */

  1080.    tmp32 = MULT16_32_Q15(st->beta0,Syy);

  1081.    if (tmp32 > MULT16_32_Q15(st->beta_max,See))

  1082.       tmp32 = MULT16_32_Q15(st->beta_max,See);

  1083.    alpha = FLOAT_DIV32(tmp32, See);

  1084.    alpha_1 = FLOAT_SUB(FLOAT_ONE, alpha);

  1085.    /* Update correlations (recursive average) */

  1086.    st->Pey = FLOAT_ADD(FLOAT_MULT(alpha_1,st->Pey) , FLOAT_MULT(alpha,Pey));

  1087.    st->Pyy = FLOAT_ADD(FLOAT_MULT(alpha_1,st->Pyy) , FLOAT_MULT(alpha,Pyy));

  1088.    if (FLOAT_LT(st->Pyy, FLOAT_ONE))

  1089.       st->Pyy = FLOAT_ONE;

  1090.    /* We don't really hope to get better than 33 dB (MIN_LEAK-3dB) attenuation anyway */

  1091.    if (FLOAT_LT(st->Pey, FLOAT_MULT(MIN_LEAK,st->Pyy)))

  1092.       st->Pey = FLOAT_MULT(MIN_LEAK,st->Pyy);

  1093.    if (FLOAT_GT(st->Pey, st->Pyy))

  1094.       st->Pey = st->Pyy;

  1095.    /* leak_estimate is the linear regression result */

  1096.    st->leak_estimate = FLOAT_EXTRACT16(FLOAT_SHL(FLOAT_DIVU(st->Pey, st->Pyy),14));

  1097.    /* This looks like a stupid bug, but it's right (because we convert from Q14 to Q15) */

  1098.    if (st->leak_estimate > 16383)

  1099.       st->leak_estimate = 32767;

  1100.    else

  1101.       st->leak_estimate = SHL16(st->leak_estimate,1);

  1102.    /*printf ("%f\n", st->leak_estimate);*/

  1103.    

  1104.    /* Compute Residual to Error Ratio */

  1105. #ifdef FIXED_POINT

  1106.    tmp32 = MULT16_32_Q15(st->leak_estimate,Syy);

  1107.    tmp32 = ADD32(SHR32(Sxx,13), ADD32(tmp32, SHL32(tmp32,1)));

  1108.    /* Check for y in e (lower bound on RER) */

  1109.    {

  1110.       spx_float_t bound = PSEUDOFLOAT(Sey);

  1111.       bound = FLOAT_DIVU(FLOAT_MULT(bound, bound), PSEUDOFLOAT(ADD32(1,Syy)));

  1112.       if (FLOAT_GT(bound, PSEUDOFLOAT(See)))

  1113.          tmp32 = See;

  1114.       else if (tmp32 < FLOAT_EXTRACT32(bound))

  1115.          tmp32 = FLOAT_EXTRACT32(bound);

  1116.    }

  1117.    if (tmp32 > SHR32(See,1))

  1118.       tmp32 = SHR32(See,1);

  1119.    RER = FLOAT_EXTRACT16(FLOAT_SHL(FLOAT_DIV32(tmp32,See),15));

  1120. #else

  1121.    RER = (.0001*Sxx + 3.*MULT16_32_Q15(st->leak_estimate,Syy)) / See;

  1122.    /* Check for y in e (lower bound on RER) */

  1123.    if (RER < Sey*Sey/(1+See*Syy))

  1124.       RER = Sey*Sey/(1+See*Syy);

  1125.    if (RER > .5)

  1126.       RER = .5;

  1127. #endif

  1128. 

  1129.    /* We consider that the filter has had minimal adaptation if the following is true*/

  1130.    if (!st->adapted && st->sum_adapt > SHL32(EXTEND32(M),15) && MULT16_32_Q15(st->leak_estimate,Syy) > MULT16_32_Q15(QCONST16(.03f,15),Syy))

  1131.    {

  1132.       st->adapted = 1;

  1133.    }

  1134. 

  1135.    if (st->adapted)

  1136.    {

  1137.       /* Normal learning rate calculation once we're past the minimal adaptation phase */

  1138.       for (i=0;i<=st->frame_size;i++)

  1139.       {

  1140.          spx_word32_t r, e;

  1141.          /* Compute frequency-domain adaptation mask */

  1142.          r = MULT16_32_Q15(st->leak_estimate,SHL32(st->Yf[i],3));

  1143.          e = SHL32(st->Rf[i],3)+1;

  1144. #ifdef FIXED_POINT

  1145.          if (r>SHR32(e,1))

  1146.             r = SHR32(e,1);

  1147. #else

  1148.          if (r>.5*e)

  1149.             r = .5*e;

  1150. #endif

  1151.          r = MULT16_32_Q15(QCONST16(.7,15),r) + MULT16_32_Q15(QCONST16(.3,15),(spx_word32_t)(MULT16_32_Q15(RER,e)));

  1152.          /*st->power_1[i] = adapt_rate*r/(e*(1+st->power[i]));*/

  1153.          st->power_1[i] = FLOAT_SHL(FLOAT_DIV32_FLOAT(r,FLOAT_MUL32U(e,st->power[i]+10)),WEIGHT_SHIFT+16);

  1154.       }

  1155.    } else {

  1156.       /* Temporary adaption rate if filter is not yet adapted enough */

  1157.       spx_word16_t adapt_rate=0;

  1158. 

  1159.       if (Sxx > SHR32(MULT16_16(N, 1000),6)) 

  1160.       {

  1161.          tmp32 = MULT16_32_Q15(QCONST16(.25f, 15), Sxx);

  1162. #ifdef FIXED_POINT

  1163.          if (tmp32 > SHR32(See,2))

  1164.             tmp32 = SHR32(See,2);

  1165. #else

  1166.          if (tmp32 > .25*See)

  1167.             tmp32 = .25*See;

  1168. #endif

  1169.          adapt_rate = FLOAT_EXTRACT16(FLOAT_SHL(FLOAT_DIV32(tmp32, See),15));

  1170.       }

  1171.       for (i=0;i<=st->frame_size;i++)

  1172.          st->power_1[i] = FLOAT_SHL(FLOAT_DIV32(EXTEND32(adapt_rate),ADD32(st->power[i],10)),WEIGHT_SHIFT+1);

  1173. 

  1174. 

  1175.       /* How much have we adapted so far? */

  1176.       st->sum_adapt = ADD32(st->sum_adapt,adapt_rate);

  1177.    }

  1178. 

  1179.    /* FIXME: MC conversion required */ 

  1180.       for (i=0;i<st->frame_size;i++)

  1181.          st->last_y[i] = st->last_y[st->frame_size+i];

  1182.    if (st->adapted)

  1183.    {

  1184.       /* If the filter is adapted, take the filtered echo */

  1185.       for (i=0;i<st->frame_size;i++)

  1186.          st->last_y[st->frame_size+i] = in[i]-out[i];

  1187.    } else {

  1188.       /* If filter isn't adapted yet, all we can do is take the far end signal directly */

  1189.       /* moved earlier: for (i=0;i<N;i++)

  1190.       st->last_y[i] = st->x[i];*/

  1191.    }

  1192. 

  1193. }

  1194. 

  1195. /* Compute spectrum of estimated echo for use in an echo post-filter */

  1196. void speex_echo_get_residual(SpeexEchoState *st, spx_word32_t *residual_echo, int len)

  1197. {

  1198.    int i;

  1199.    spx_word16_t leak2;

  1200.    int N;

  1201.    

  1202.    N = st->window_size;

  1203. 

  1204.    /* Apply hanning window (should pre-compute it)*/

  1205.    for (i=0;i<N;i++)

  1206.       st->y[i] = MULT16_16_Q15(st->window[i],st->last_y[i]);

  1207.       

  1208.    /* Compute power spectrum of the echo */

  1209.    spx_fft(st->fft_table, st->y, st->Y);

  1210.    power_spectrum(st->Y, residual_echo, N);

  1211.       

  1212. #ifdef FIXED_POINT

  1213.    if (st->leak_estimate > 16383)

  1214.       leak2 = 32767;

  1215.    else

  1216.       leak2 = SHL16(st->leak_estimate, 1);

  1217. #else

  1218.    if (st->leak_estimate>.5)

  1219.       leak2 = 1;

  1220.    else

  1221.       leak2 = 2*st->leak_estimate;

  1222. #endif

  1223.    /* Estimate residual echo */

  1224.    for (i=0;i<=st->frame_size;i++)

  1225.       residual_echo[i] = (spx_int32_t)MULT16_32_Q15(leak2,residual_echo[i]);

  1226.    

  1227. }

  1228. 

  1229. EXPORT int speex_echo_ctl(SpeexEchoState *st, int request, void *ptr)

  1230. {

  1231.    switch(request)

  1232.    {

  1233.       

  1234.       case SPEEX_ECHO_GET_FRAME_SIZE:

  1235.          (*(int*)ptr) = st->frame_size;

  1236.          break;

  1237.       case SPEEX_ECHO_SET_SAMPLING_RATE:

  1238.          st->sampling_rate = (*(int*)ptr);

  1239.          st->spec_average = DIV32_16(SHL32(EXTEND32(st->frame_size), 15), st->sampling_rate);

  1240. #ifdef FIXED_POINT

  1241.          st->beta0 = DIV32_16(SHL32(EXTEND32(st->frame_size), 16), st->sampling_rate);

  1242.          st->beta_max = DIV32_16(SHL32(EXTEND32(st->frame_size), 14), st->sampling_rate);

  1243. #else

  1244.          st->beta0 = (2.0f*st->frame_size)/st->sampling_rate;

  1245.          st->beta_max = (.5f*st->frame_size)/st->sampling_rate;

  1246. #endif

  1247.          if (st->sampling_rate<12000)

  1248.             st->notch_radius = QCONST16(.9, 15);

  1249.          else if (st->sampling_rate<24000)

  1250.             st->notch_radius = QCONST16(.982, 15);

  1251.          else

  1252.             st->notch_radius = QCONST16(.992, 15);

  1253.          break;

  1254.       case SPEEX_ECHO_GET_SAMPLING_RATE:

  1255.          (*(int*)ptr) = st->sampling_rate;

  1256.          break;

  1257.       case SPEEX_ECHO_GET_IMPULSE_RESPONSE_SIZE:

  1258.          /*FIXME: Implement this for multiple channels */

  1259.          *((spx_int32_t *)ptr) = st->M * st->frame_size;

  1260.          break;

  1261.       case SPEEX_ECHO_GET_IMPULSE_RESPONSE:

  1262.       {

  1263.          int M = st->M, N = st->window_size, n = st->frame_size, i, j;

  1264.          spx_int32_t *filt = (spx_int32_t *) ptr;

  1265.          for(j=0;j<M;j++)

  1266.          {

  1267.             /*FIXME: Implement this for multiple channels */

  1268. #ifdef FIXED_POINT

  1269.             for (i=0;i<N;i++)

  1270.                st->wtmp2[i] = EXTRACT16(PSHR32(st->W[j*N+i],16+NORMALIZE_SCALEDOWN));

  1271.             spx_ifft(st->fft_table, st->wtmp2, st->wtmp);

  1272. #else

  1273.             spx_ifft(st->fft_table, &st->W[j*N], st->wtmp);

  1274. #endif

  1275.             for(i=0;i<n;i++)

  1276.                filt[j*n+i] = PSHR32(MULT16_16(32767,st->wtmp[i]), WEIGHT_SHIFT-NORMALIZE_SCALEDOWN);

  1277.          }

  1278.       }

  1279.          break;

  1280.       default:

  1281.          speex_warning_int("Unknown speex_echo_ctl request: ", request);

  1282.          return -1;

  1283.    }

  1284.    return 0;

  1285. }