src/analysis.c

/* Copyright (c) 2011 Xiph.Org Foundation
   Written by Jean-Marc Valin */
/*
   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

   - Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

   - Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "kiss_fft.h"
#include "celt.h"
#include "modes.h"
#include "arch.h"
#include "quant_bands.h"
#include <stdio.h>
#ifndef FIXED_POINT
#include "mlp.c"
#include "mlp_data.c"
#endif

#ifndef M_PI
#define M_PI 3.141592653
#endif

float dct_table[128] = {
        0.250000, 0.250000, 0.250000, 0.250000, 0.250000, 0.250000, 0.250000, 0.250000,
        0.250000, 0.250000, 0.250000, 0.250000, 0.250000, 0.250000, 0.250000, 0.250000,
        0.351851, 0.338330, 0.311806, 0.273300, 0.224292, 0.166664, 0.102631, 0.034654,
        -0.034654, -0.102631, -0.166664, -0.224292, -0.273300, -0.311806, -0.338330, -0.351851,
        0.346760, 0.293969, 0.196424, 0.068975, -0.068975, -0.196424, -0.293969, -0.346760,
        -0.346760, -0.293969, -0.196424, -0.068975, 0.068975, 0.196424, 0.293969, 0.346760,
        0.338330, 0.224292, 0.034654, -0.166664, -0.311806, -0.351851, -0.273300, -0.102631,
        0.102631, 0.273300, 0.351851, 0.311806, 0.166664, -0.034654, -0.224292, -0.338330,
        0.326641, 0.135299, -0.135299, -0.326641, -0.326641, -0.135299, 0.135299, 0.326641,
        0.326641, 0.135299, -0.135299, -0.326641, -0.326641, -0.135299, 0.135299, 0.326641,
        0.311806, 0.034654, -0.273300, -0.338330, -0.102631, 0.224292, 0.351851, 0.166664,
        -0.166664, -0.351851, -0.224292, 0.102631, 0.338330, 0.273300, -0.034654, -0.311806,
        0.293969, -0.068975, -0.346760, -0.196424, 0.196424, 0.346760, 0.068975, -0.293969,
        -0.293969, 0.068975, 0.346760, 0.196424, -0.196424, -0.346760, -0.068975, 0.293969,
        0.273300, -0.166664, -0.338330, 0.034654, 0.351851, 0.102631, -0.311806, -0.224292,
        0.224292, 0.311806, -0.102631, -0.351851, -0.034654, 0.338330, 0.166664, -0.273300,
};

#define NB_FRAMES 8

#define NB_TBANDS 18
static const int tbands[NB_TBANDS+1] = {
       2,  4,  6,  8, 10, 12, 14, 16, 20, 24, 28, 32, 40, 48, 56, 68, 80, 96, 120
};

static const float tweight[NB_TBANDS+1] = {
      .3, .4, .5, .6, .7, .8, .9, 1., 1., 1., 1., 1., 1., 1., .8, .7, .6, .5
};

#define NB_TONAL_SKIP_BANDS 0

typedef struct {
   float angle[240];
   float d_angle[240];
   float d2_angle[240];
   float prev_band_tonality[NB_TBANDS];
   float prev_tonality;
   float E[NB_FRAMES][NB_TBANDS];
   float lowE[NB_TBANDS], highE[NB_TBANDS];
   float meanE[NB_TBANDS], meanRE[NB_TBANDS];
   float mem[32];
   float cmean[8];
   float std[9];
   float music_prob;
   float Etracker;
   float lowECount;
   int E_count;
   int last_music;
   int last_transition;
   int count;
   int opus_bandwidth;
} TonalityAnalysisState;

void tonality_analysis(TonalityAnalysisState *tonal, AnalysisInfo *info, CELTEncoder *celt_enc, const opus_val16 *x, int C)
{
    int i, b;
    const CELTMode *mode;
    const kiss_fft_state *kfft;
    kiss_fft_cpx in[480], out[480];
    int N = 480, N2=240;
    float * restrict A = tonal->angle;
    float * restrict dA = tonal->d_angle;
    float * restrict d2A = tonal->d2_angle;
    float tonality[240];
    float noisiness[240];
    float band_tonality[NB_TBANDS];
    float logE[NB_TBANDS];
    float BFCC[8];
    float features[100];
    float frame_tonality;
    float max_frame_tonality;
    float tw_sum=0;
    float frame_noisiness;
    const float pi4 = M_PI*M_PI*M_PI*M_PI;
    float slope=0;
    float frame_stationarity;
    float relativeE;
    float frame_prob;
    float alpha, alphaE, alphaE2;
    float frame_loudness;
    float bandwidth_mask;
    int bandwidth=0;
    float bandE[NB_TBANDS];
    celt_encoder_ctl(celt_enc, CELT_GET_MODE(&mode));

    tonal->last_transition++;
    alpha = 1.f/IMIN(20, 1+tonal->count);
    alphaE = 1.f/IMIN(50, 1+tonal->count);
    alphaE2 = 1.f/IMIN(6000, 1+tonal->count);

    if (tonal->count<4)
       tonal->music_prob = .5;
    kfft = mode->mdct.kfft[0];
    if (C==1)
    {
       for (i=0;i<N2;i++)
       {
          float w = .5-.5*cos(M_PI*(i+1)/N2);
          in[i].r = MULT16_16(w, x[i]);
          in[i].i = MULT16_16(w, x[N-N2+i]);
          in[N-i-1].r = MULT16_16(w, x[N-i-1]);
          in[N-i-1].i = MULT16_16(w, x[2*N-N2-i-1]);
       }
    } else {
       for (i=0;i<N2;i++)
       {
          float w = .5-.5*cos(M_PI*(i+1)/N2);
          in[i].r = MULT16_16(w, x[2*i]+x[2*i+1]);
          in[i].i = MULT16_16(w, x[2*(N-N2+i)]+x[2*(N-N2+i)+1]);
          in[N-i-1].r = MULT16_16(w, x[2*(N-i-1)]+x[2*(N-i-1)+1]);
          in[N-i-1].i = MULT16_16(w, x[2*(2*N-N2-i-1)]+x[2*(2*N-N2-i-1)+1]);
       }
    }
    opus_fft(kfft, in, out);

    for (i=1;i<N2;i++)
    {
       float X1r, X2r, X1i, X2i;
       float angle, d_angle, d2_angle;
       float angle2, d_angle2, d2_angle2;
       float mod1, mod2, avg_mod;
       X1r = out[i].r+out[N-i].r;
       X1i = out[i].i-out[N-i].i;
       X2r = out[i].i+out[N-i].i;
       X2i = out[N-i].r-out[i].r;

       angle = (.5/M_PI)*atan2(X1i, X1r);
       d_angle = angle - A[i];
       d2_angle = d_angle - dA[i];

       angle2 = (.5/M_PI)*atan2(X2i, X2r);
       d_angle2 = angle2 - angle;
       d2_angle2 = d_angle2 - d_angle;

       mod1 = d2_angle - floor(.5+d2_angle);
       noisiness[i] = fabs(mod1);
       mod1 *= mod1;
       mod1 *= mod1;

       mod2 = d2_angle2 - floor(.5+d2_angle2);
       noisiness[i] += fabs(mod2);
       mod2 *= mod2;
       mod2 *= mod2;

       avg_mod = .25*(d2A[i]+2*mod1+mod2);
       tonality[i] = 1./(1+40*16*pi4*avg_mod)-.015;

       A[i] = angle2;
       dA[i] = d_angle2;
       d2A[i] = mod2;
    }

    frame_tonality = 0;
    max_frame_tonality = 0;
    tw_sum = 0;
    info->activity = 0;
    frame_noisiness = 0;
    frame_stationarity = 0;
    if (!tonal->count)
    {
       for (b=0;b<NB_TBANDS;b++)
       {
          tonal->lowE[b] = 1e10;
          tonal->highE[b] = -1e10;
       }
    }
    relativeE = 0;
    info->boost_amount[0]=info->boost_amount[1]=0;
    info->boost_band[0]=info->boost_band[1]=0;
    frame_loudness = 0;
    bandwidth_mask = 0;
    for (b=0;b<NB_TBANDS;b++)
    {
       float E=0, tE=0, nE=0;
       float L1, L2;
       float stationarity;
       for (i=tbands[b];i<tbands[b+1];i++)
       {
          float binE = out[i].r*out[i].r + out[N-i].r*out[N-i].r
                     + out[i].i*out[i].i + out[N-i].i*out[N-i].i;
          E += binE;
          tE += binE*tonality[i];
          nE += binE*2*(.5-noisiness[i]);
       }
       bandE[b] = E;
       tonal->E[tonal->E_count][b] = E;
       frame_noisiness += nE/(1e-15+E);

       frame_loudness += sqrt(E+1e-10);
       /* Add a reasonable noise floor */
       tonal->meanE[b] = (1-alphaE2)*tonal->meanE[b] + alphaE2*E;
       tonal->meanRE[b] = (1-alphaE2)*tonal->meanRE[b] + alphaE2*sqrt(E);
       /* 13 dB slope for spreading function */
       bandwidth_mask = MAX32(.05*bandwidth_mask, E);
       /* Checks if band looks like stationary noise or if it's below a (trivial) masking curve */
       if (tonal->meanRE[b]*tonal->meanRE[b] < tonal->meanE[b]*.95 && E>.1*bandwidth_mask)
          bandwidth = b;
       logE[b] = log(E+1e-10);
       tonal->lowE[b] = MIN32(logE[b], tonal->lowE[b]+.01);
       tonal->highE[b] = MAX32(logE[b], tonal->highE[b]-.1);
       if (tonal->highE[b] < tonal->lowE[b]+1)
       {
          tonal->highE[b]+=.5;
          tonal->lowE[b]-=.5;
       }
       relativeE += (logE[b]-tonal->lowE[b])/(EPSILON+tonal->highE[b]-tonal->lowE[b]);

       L1=L2=0;
       for (i=0;i<NB_FRAMES;i++)
       {
          L1 += sqrt(tonal->E[i][b]);
          L2 += tonal->E[i][b];
       }

       stationarity = MIN16(0.99,L1/sqrt(EPSILON+NB_FRAMES*L2));
       stationarity *= stationarity;
       stationarity *= stationarity;
       frame_stationarity += stationarity;
       /*band_tonality[b] = tE/(1e-15+E)*/;
       band_tonality[b] = MAX16(tE/(EPSILON+E), stationarity*tonal->prev_band_tonality[b]);
       //printf("%f ", band_tonality[b]);
#if 1
       if (b>=NB_TONAL_SKIP_BANDS)
       {
          frame_tonality += tweight[b]*band_tonality[b];
          tw_sum += tweight[b];
       }
#else
       frame_tonality += band_tonality[b];
       if (b>=NB_TBANDS-NB_TONAL_SKIP_BANDS)
          frame_tonality -= band_tonality[b-NB_TBANDS+NB_TONAL_SKIP_BANDS];
#endif
       max_frame_tonality = MAX16(max_frame_tonality, frame_tonality);
       slope += band_tonality[b]*(b-8);
       /*printf("%f %f ", band_tonality[b], stationarity);*/
       if (band_tonality[b] > info->boost_amount[1] && b>=7 && b < NB_TBANDS-1)
       {
          if (band_tonality[b] > info->boost_amount[0])
          {
             info->boost_amount[1] = info->boost_amount[0];
             info->boost_band[1] = info->boost_band[0];
             info->boost_amount[0] = band_tonality[b];
             info->boost_band[0] = b;
          } else {
             info->boost_amount[1] = band_tonality[b];
             info->boost_band[1] = b;
          }
       }
       tonal->prev_band_tonality[b] = band_tonality[b];
    }
    //printf("\n");
    frame_loudness = 20*log10(frame_loudness);
    tonal->Etracker = MAX32(tonal->Etracker-.03, frame_loudness);
    tonal->lowECount *= (1-alphaE);
    if (frame_loudness < tonal->Etracker-30)
       tonal->lowECount += alphaE;

    for (i=0;i<8;i++)
    {
       float sum=0;
       for (b=0;b<16;b++)
          sum += dct_table[i*16+b]*logE[b];
       BFCC[i] = sum;
    }

    frame_stationarity /= NB_TBANDS;
    relativeE /= NB_TBANDS;
    if (tonal->count<10)
       relativeE = .5;
    frame_noisiness /= NB_TBANDS;
#if 1
    info->activity = frame_noisiness + (1-frame_noisiness)*relativeE;
#else
    info->activity = .5*(1+frame_noisiness-frame_stationarity);
#endif
    frame_tonality = (max_frame_tonality/(tw_sum));
    frame_tonality = MAX16(frame_tonality, tonal->prev_tonality*.8);
    tonal->prev_tonality = frame_tonality;
    info->boost_amount[0] -= frame_tonality+.2;
    info->boost_amount[1] -= frame_tonality+.2;
    if (band_tonality[info->boost_band[0]] < band_tonality[info->boost_band[0]+1]+.15
        || band_tonality[info->boost_band[0]] < band_tonality[info->boost_band[0]-1]+.15)
       info->boost_amount[0]=0;
    if (band_tonality[info->boost_band[1]] < band_tonality[info->boost_band[1]+1]+.15
        || band_tonality[info->boost_band[1]] < band_tonality[info->boost_band[1]-1]+.15)
       info->boost_amount[1]=0;

    slope /= 8*8;
    info->tonality_slope = slope;

    tonal->E_count = (tonal->E_count+1)%NB_FRAMES;
    tonal->count++;
    info->tonality = frame_tonality;

    for (i=0;i<4;i++)
       features[i] = -0.12299*(BFCC[i]+tonal->mem[i+24]) + 0.49195*(tonal->mem[i]+tonal->mem[i+16]) + 0.69693*tonal->mem[i+8] - 1.4349*tonal->cmean[i];

    for (i=0;i<4;i++)
       tonal->cmean[i] = (1-alpha)*tonal->cmean[i] + alpha*BFCC[i];

    for (i=0;i<4;i++)
        features[4+i] = 0.63246*(BFCC[i]-tonal->mem[i+24]) + 0.31623*(tonal->mem[i]-tonal->mem[i+16]);
    for (i=0;i<3;i++)
        features[8+i] = 0.53452*(BFCC[i]+tonal->mem[i+24]) - 0.26726*(tonal->mem[i]+tonal->mem[i+16]) -0.53452*tonal->mem[i+8];

    if (tonal->count > 5)
    {
       for (i=0;i<9;i++)
          tonal->std[i] = (1-alpha)*tonal->std[i] + alpha*features[i]*features[i];
    }

    for (i=0;i<8;i++)
    {
       tonal->mem[i+24] = tonal->mem[i+16];
       tonal->mem[i+16] = tonal->mem[i+8];
       tonal->mem[i+8] = tonal->mem[i];
       tonal->mem[i] = BFCC[i];
    }
    for (i=0;i<9;i++)
       features[11+i] = sqrt(tonal->std[i]);
    features[20] = info->tonality;
    features[21] = info->activity;
    features[22] = frame_stationarity;
    features[23] = info->tonality_slope;
    features[24] = tonal->lowECount;

#ifndef FIXED_POINT
    mlp_process(&net, features, &frame_prob);
    /* Adds a "probability dead zone", with a cap on certainty */
    frame_prob = .90*frame_prob*frame_prob*frame_prob;

    frame_prob = .5*(frame_prob+1);

    /*printf("%f\n", frame_prob);*/
    {
       float tau, beta;
       float p0, p1;
       float max_certainty;
       /* One transition every 3 minutes */
       tau = .00005;
       beta = .1;
       max_certainty = 1.f/(10+1*tonal->last_transition);
       p0 = (1-tonal->music_prob)*(1-tau) +    tonal->music_prob *tau;
       p1 =    tonal->music_prob *(1-tau) + (1-tonal->music_prob)*tau;
       p0 *= pow(1-frame_prob, beta);
       p1 *= pow(frame_prob, beta);
       tonal->music_prob = MAX16(max_certainty, MIN16(1-max_certainty, p1/(p0+p1)));
       info->music_prob = tonal->music_prob;
       /*printf("%f %f\n", frame_prob, info->music_prob);*/
    }
    if (tonal->last_music != (tonal->music_prob>.5))
       tonal->last_transition=0;
    tonal->last_music = tonal->music_prob>.5;
#else
    info->music_prob = 0;
#endif
    /*for (i=0;i<25;i++)
       printf("%f ", features[i]);
    printf("\n");*/

    /* FIXME: Can't detect SWB for now because the last band ends at 12 kHz */
    if (bandwidth == NB_TBANDS-1 || tonal->count<100)
    {
       tonal->opus_bandwidth = OPUS_BANDWIDTH_FULLBAND;
    } else {
       int close_enough = 0;
       if (bandE[bandwidth-1] < 3000*bandE[NB_TBANDS-1] && bandwidth < NB_TBANDS-1)
          close_enough=1;
       if (bandwidth<=11 || (bandwidth==12 && close_enough))
          tonal->opus_bandwidth = OPUS_BANDWIDTH_NARROWBAND;
       else if (bandwidth<=13)
          tonal->opus_bandwidth = OPUS_BANDWIDTH_MEDIUMBAND;
       else if (bandwidth<=15 || (bandwidth==16 && close_enough))
          tonal->opus_bandwidth = OPUS_BANDWIDTH_WIDEBAND;
    }
    info->noisiness = frame_noisiness;
    info->valid = 1;
}