src/flac/analyze.c

   1 /* flac - Command-line FLAC encoder/decoder
   2  * Copyright (C) 2000,2001  Josh Coalson
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #include <math.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include "FLAC/all.h"
  24 #include "analyze.h"
  25
  26 typedef struct {
  27         FLAC__int32 residual;
  28         unsigned count;
  29 } pair_t;
  30
  31 typedef struct {
  32         pair_t buckets[FLAC__MAX_BLOCK_SIZE];
  33         int peak_index;
  34         unsigned nbuckets;
  35         unsigned nsamples;
  36         double sum, sos;
  37         double variance;
  38         double mean;
  39         double stddev;
  40 } subframe_stats_t;
  41
  42 static subframe_stats_t all_;
  43
  44 static void init_stats(subframe_stats_t *stats);
  45 static void update_stats(subframe_stats_t *stats, FLAC__int32 residual, unsigned incr);
  46 static void compute_stats(subframe_stats_t *stats);
  47 static FLAC__bool dump_stats(const subframe_stats_t *stats, const char *filename);
  48
  49 void flac__analyze_init(analysis_options aopts)
  50 {
  51         if(aopts.do_residual_gnuplot) {
  52                 init_stats(&all_);
  53         }
  54 }
  55
  56 void flac__analyze_frame(const FLAC__Frame *frame, unsigned frame_number, analysis_options aopts, FILE *fout)
  57 {
  58         const unsigned channels = frame->header.channels;
  59         char outfilename[1024];
  60         subframe_stats_t stats;
  61         unsigned i, channel;
  62
  63         /* do the human-readable part first */
  64         fprintf(fout, "frame=%u\tblocksize=%u\tsample_rate=%u\tchannels=%u\tchannel_assignment=%s\n", frame_number, frame->header.blocksize, frame->header.sample_rate, channels, FLAC__ChannelAssignmentString[frame->header.channel_assignment]);
  65         for(channel = 0; channel < channels; channel++) {
  66                 const FLAC__Subframe *subframe = frame->subframes+channel;
  67                 fprintf(fout, "\tsubframe=%u\twasted_bits=%u\ttype=%s", channel, subframe->wasted_bits, FLAC__SubframeTypeString[subframe->type]);
  68                 switch(subframe->type) {
  69                         case FLAC__SUBFRAME_TYPE_CONSTANT:
  70                                 fprintf(fout, "\tvalue=%d\n", subframe->data.constant.value);
  71                                 break;
  72                         case FLAC__SUBFRAME_TYPE_FIXED:
  73                                 fprintf(fout, "\torder=%u\tpartition_order=%u\n", subframe->data.fixed.order, subframe->data.fixed.entropy_coding_method.data.partitioned_rice.order); /*@@@ assumes method is partitioned-rice */
  74                                 for(i = 0; i < subframe->data.fixed.order; i++)
  75                                         fprintf(fout, "\t\twarmup[%u]=%d\n", i, subframe->data.fixed.warmup[i]);
  76                                 if(aopts.do_residual_text) {
  77                                         for(i = 0; i < frame->header.blocksize-subframe->data.fixed.order; i++)
  78                                                 fprintf(fout, "\t\tresidual[%u]=%d\n", i, subframe->data.fixed.residual[i]);
  79                                 }
  80                                 break;
  81                         case FLAC__SUBFRAME_TYPE_LPC:
  82                                 fprintf(fout, "\torder=%u\tpartition_order=%u\tqlp_coeff_precision=%u\tquantization_level=%d\n", subframe->data.lpc.order, subframe->data.lpc.entropy_coding_method.data.partitioned_rice.order, subframe->data.lpc.qlp_coeff_precision, subframe->data.lpc.quantization_level); /*@@@ assumes method is partitioned-rice */
  83                                 for(i = 0; i < subframe->data.lpc.order; i++)
  84                                         fprintf(fout, "\t\twarmup[%u]=%d\n", i, subframe->data.lpc.warmup[i]);
  85                                 if(aopts.do_residual_text) {
  86                                         for(i = 0; i < frame->header.blocksize-subframe->data.lpc.order; i++)
  87                                                 fprintf(fout, "\t\tresidual[%u]=%d\n", i, subframe->data.lpc.residual[i]);
  88                                 }
  89                                 break;
  90                         case FLAC__SUBFRAME_TYPE_VERBATIM:
  91                                 fprintf(fout, "\n");
  92                                 break;
  93                 }
  94         }
  95
  96         /* now do the residual distributions if requested */
  97         if(aopts.do_residual_gnuplot) {
  98                 for(channel = 0; channel < channels; channel++) {
  99                         const FLAC__Subframe *subframe = frame->subframes+channel;
 100                         unsigned residual_samples;
 101
 102                         init_stats(&stats);
 103
 104                         switch(subframe->type) {
 105                                 case FLAC__SUBFRAME_TYPE_FIXED:
 106                                         residual_samples = frame->header.blocksize - subframe->data.fixed.order;
 107                                         for(i = 0; i < residual_samples; i++)
 108                                                 update_stats(&stats, subframe->data.fixed.residual[i], 1);
 109                                         break;
 110                                 case FLAC__SUBFRAME_TYPE_LPC:
 111                                         residual_samples = frame->header.blocksize - subframe->data.lpc.order;
 112                                         for(i = 0; i < residual_samples; i++)
 113                                                 update_stats(&stats, subframe->data.lpc.residual[i], 1);
 114                                         break;
 115                                 default:
 116                                         break;
 117                         }
 118
 119                         /* update all_ */
 120                         for(i = 0; i < stats.nbuckets; i++) {
 121                                 update_stats(&all_, stats.buckets[i].residual, stats.buckets[i].count);
 122                         }
 123
 124                         /* write the subframe */
 125                         sprintf(outfilename, "f%06u.s%u.gp", frame_number, channel);
 126                         compute_stats(&stats);
 127
 128                         (void)dump_stats(&stats, outfilename);
 129                 }
 130         }
 131 }
 132
 133 void flac__analyze_finish(analysis_options aopts)
 134 {
 135         if(aopts.do_residual_gnuplot) {
 136                 compute_stats(&all_);
 137                 (void)dump_stats(&all_, "all");
 138         }
 139 }
 140
 141 void init_stats(subframe_stats_t *stats)
 142 {
 143         stats->peak_index = -1;
 144         stats->nbuckets = 0;
 145         stats->nsamples = 0;
 146         stats->sum = 0.0;
 147         stats->sos = 0.0;
 148 }
 149
 150 void update_stats(subframe_stats_t *stats, FLAC__int32 residual, unsigned incr)
 151 {
 152         unsigned i;
 153         const double r = (double)residual, a = r*incr;
 154
 155         stats->nsamples += incr;
 156         stats->sum += a;
 157         stats->sos += (a*r);
 158
 159         for(i = 0; i < stats->nbuckets; i++) {
 160                 if(stats->buckets[i].residual == residual) {
 161                         stats->buckets[i].count += incr;
 162                         goto find_peak;
 163                 }
 164         }
 165         /* not found, make a new bucket */
 166         i = stats->nbuckets;
 167         stats->buckets[i].residual = residual;
 168         stats->buckets[i].count = incr;
 169         stats->nbuckets++;
 170 find_peak:
 171         if(stats->peak_index < 0 || stats->buckets[i].count > stats->buckets[stats->peak_index].count)
 172                 stats->peak_index = i;
 173 }
 174
 175 void compute_stats(subframe_stats_t *stats)
 176 {
 177         stats->mean = stats->sum / (double)stats->nsamples;
 178         stats->variance = (stats->sos - (stats->sum * stats->sum / stats->nsamples)) / stats->nsamples;
 179         stats->stddev = sqrt(stats->variance);
 180 }
 181
 182 FLAC__bool dump_stats(const subframe_stats_t *stats, const char *filename)
 183 {
 184         FILE *outfile;
 185         unsigned i;
 186         const double m = stats->mean;
 187         const double s1 = stats->stddev, s2 = s1*2, s3 = s1*3, s4 = s1*4, s5 = s1*5, s6 = s1*6;
 188         const double p = stats->buckets[stats->peak_index].count;
 189
 190         outfile = fopen(filename, "w");
 191
 192         if(0 == outfile) {
 193                 fprintf(stderr, "ERROR opening %s\n", filename);
 194                 return false;
 195         }
 196
 197         fprintf(outfile, "plot '-' title 'PDF', '-' title 'mean' with impulses, '-' title '1-stddev' with histeps, '-' title '2-stddev' with histeps, '-' title '3-stddev' with histeps, '-' title '4-stddev' with histeps, '-' title '5-stddev' with histeps, '-' title '6-stddev' with histeps\n");
 198
 199         for(i = 0; i < stats->nbuckets; i++) {
 200                 fprintf(outfile, "%d %u\n", stats->buckets[i].residual, stats->buckets[i].count);
 201         }
 202         fprintf(outfile, "e\n");
 203
 204         fprintf(outfile, "%f %f\ne\n", stats->mean, p);
 205         fprintf(outfile, "%f %f\n%f %f\ne\n", m-s1, p*0.8, m+s1, p*0.8);
 206         fprintf(outfile, "%f %f\n%f %f\ne\n", m-s2, p*0.7, m+s2, p*0.7);
 207         fprintf(outfile, "%f %f\n%f %f\ne\n", m-s3, p*0.6, m+s3, p*0.6);
 208         fprintf(outfile, "%f %f\n%f %f\ne\n", m-s4, p*0.5, m+s4, p*0.5);
 209         fprintf(outfile, "%f %f\n%f %f\ne\n", m-s5, p*0.4, m+s5, p*0.4);
 210         fprintf(outfile, "%f %f\n%f %f\ne\n", m-s6, p*0.3, m+s6, p*0.3);
 211
 212         fprintf(outfile, "pause -1 'waiting...'\n");
 213
 214         fclose(outfile);
 215         return true;
 216 }