libaf/af_volnorm.c

   1 /*
   2  * Copyright (C) 2004 Alex Beregszaszi & Pierre Lombard
   3  *
   4  * This file is part of MPlayer.
   5  *
   6  * MPlayer is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * MPlayer is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include <inttypes.h>
  26 #include <math.h>
  27 #include <limits.h>
  28
  29 #include "af.h"
  30
  31 // Methods:
  32 // 1: uses a 1 value memory and coefficients new=a*old+b*cur (with a+b=1)
  33 // 2: uses several samples to smooth the variations (standard weighted mean
  34 //    on past samples)
  35
  36 // Size of the memory array
  37 // FIXME: should depend on the frequency of the data (should be a few seconds)
  38 #define NSAMPLES 128
  39
  40 // If summing all the mem[].len is lower than MIN_SAMPLE_SIZE bytes, then we
  41 // choose to ignore the computed value as it's not significant enough
  42 // FIXME: should depend on the frequency of the data (0.5s maybe)
  43 #define MIN_SAMPLE_SIZE 32000
  44
  45 // mul is the value by which the samples are scaled
  46 // and has to be in [MUL_MIN, MUL_MAX]
  47 #define MUL_INIT 1.0
  48 #define MUL_MIN 0.1
  49 #define MUL_MAX 5.0
  50
  51 // Silence level
  52 // FIXME: should be relative to the level of the samples
  53 #define SIL_S16 (SHRT_MAX * 0.01)
  54 #define SIL_FLOAT 0.01
  55
  56 // smooth must be in ]0.0, 1.0[
  57 #define SMOOTH_MUL 0.06
  58 #define SMOOTH_LASTAVG 0.06
  59
  60 #define DEFAULT_TARGET 0.25
  61
  62 // Data for specific instances of this filter
  63 typedef struct af_volume_s
  64 {
  65     int method; // method used
  66     float mul;
  67     // method 1
  68     float lastavg; // history value of the filter
  69     // method 2
  70     int idx;
  71     struct {
  72         float avg; // average level of the sample
  73         int len; // sample size (weight)
  74     } mem[NSAMPLES];
  75     // "Ideal" level
  76     float mid_s16;
  77     float mid_float;
  78 }af_volnorm_t;
  79
  80 // Initialization and runtime control
  81 static int control(struct af_instance_s* af, int cmd, void* arg)
  82 {
  83   af_volnorm_t* s   = (af_volnorm_t*)af->setup;
  84
  85   switch(cmd){
  86   case AF_CONTROL_REINIT:
  87     // Sanity check
  88     if(!arg) return AF_ERROR;
  89
  90     af->data->rate   = ((af_data_t*)arg)->rate;
  91     af->data->nch    = ((af_data_t*)arg)->nch;
  92
  93     if(((af_data_t*)arg)->format == (AF_FORMAT_S16_NE)){
  94       af->data->format = AF_FORMAT_S16_NE;
  95       af->data->bps    = 2;
  96     }else{
  97       af->data->format = AF_FORMAT_FLOAT_NE;
  98       af->data->bps    = 4;
  99     }
 100     return af_test_output(af,(af_data_t*)arg);
 101   case AF_CONTROL_COMMAND_LINE:{
 102     int   i = 0;
 103     float target = DEFAULT_TARGET;
 104     sscanf((char*)arg,"%d:%f", &i, &target);
 105     if (i != 1 && i != 2)
 106         return AF_ERROR;
 107     s->method = i-1;
 108     s->mid_s16 = ((float)SHRT_MAX) * target;
 109     s->mid_float = target;
 110     return AF_OK;
 111   }
 112   }
 113   return AF_UNKNOWN;
 114 }
 115
 116 // Deallocate memory
 117 static void uninit(struct af_instance_s* af)
 118 {
 119     free(af->data);
 120     free(af->setup);
 121 }
 122
 123 static void method1_int16(af_volnorm_t *s, af_data_t *c)
 124 {
 125   register int i = 0;
 126   int16_t *data = (int16_t*)c->audio;   // Audio data
 127   int len = c->len/2;           // Number of samples
 128   float curavg = 0.0, newavg, neededmul;
 129   int tmp;
 130
 131   for (i = 0; i < len; i++)
 132   {
 133     tmp = data[i];
 134     curavg += tmp * tmp;
 135   }
 136   curavg = sqrt(curavg / (float) len);
 137
 138   // Evaluate an adequate 'mul' coefficient based on previous state, current
 139   // samples level, etc
 140
 141   if (curavg > SIL_S16)
 142   {
 143     neededmul = s->mid_s16 / (curavg * s->mul);
 144     s->mul = (1.0 - SMOOTH_MUL) * s->mul + SMOOTH_MUL * neededmul;
 145
 146     // clamp the mul coefficient
 147     s->mul = clamp(s->mul, MUL_MIN, MUL_MAX);
 148   }
 149
 150   // Scale & clamp the samples
 151   for (i = 0; i < len; i++)
 152   {
 153     tmp = s->mul * data[i];
 154     tmp = clamp(tmp, SHRT_MIN, SHRT_MAX);
 155     data[i] = tmp;
 156   }
 157
 158   // Evaulation of newavg (not 100% accurate because of values clamping)
 159   newavg = s->mul * curavg;
 160
 161   // Stores computed values for future smoothing
 162   s->lastavg = (1.0 - SMOOTH_LASTAVG) * s->lastavg + SMOOTH_LASTAVG * newavg;
 163 }
 164
 165 static void method1_float(af_volnorm_t *s, af_data_t *c)
 166 {
 167   register int i = 0;
 168   float *data = (float*)c->audio;       // Audio data
 169   int len = c->len/4;           // Number of samples
 170   float curavg = 0.0, newavg, neededmul, tmp;
 171
 172   for (i = 0; i < len; i++)
 173   {
 174     tmp = data[i];
 175     curavg += tmp * tmp;
 176   }
 177   curavg = sqrt(curavg / (float) len);
 178
 179   // Evaluate an adequate 'mul' coefficient based on previous state, current
 180   // samples level, etc
 181
 182   if (curavg > SIL_FLOAT) // FIXME
 183   {
 184     neededmul = s->mid_float / (curavg * s->mul);
 185     s->mul = (1.0 - SMOOTH_MUL) * s->mul + SMOOTH_MUL * neededmul;
 186
 187     // clamp the mul coefficient
 188     s->mul = clamp(s->mul, MUL_MIN, MUL_MAX);
 189   }
 190
 191   // Scale & clamp the samples
 192   for (i = 0; i < len; i++)
 193     data[i] *= s->mul;
 194
 195   // Evaulation of newavg (not 100% accurate because of values clamping)
 196   newavg = s->mul * curavg;
 197
 198   // Stores computed values for future smoothing
 199   s->lastavg = (1.0 - SMOOTH_LASTAVG) * s->lastavg + SMOOTH_LASTAVG * newavg;
 200 }
 201
 202 static void method2_int16(af_volnorm_t *s, af_data_t *c)
 203 {
 204   register int i = 0;
 205   int16_t *data = (int16_t*)c->audio;   // Audio data
 206   int len = c->len/2;           // Number of samples
 207   float curavg = 0.0, newavg, avg = 0.0;
 208   int tmp, totallen = 0;
 209
 210   for (i = 0; i < len; i++)
 211   {
 212     tmp = data[i];
 213     curavg += tmp * tmp;
 214   }
 215   curavg = sqrt(curavg / (float) len);
 216
 217   // Evaluate an adequate 'mul' coefficient based on previous state, current
 218   // samples level, etc
 219   for (i = 0; i < NSAMPLES; i++)
 220   {
 221     avg += s->mem[i].avg * (float)s->mem[i].len;
 222     totallen += s->mem[i].len;
 223   }
 224
 225   if (totallen > MIN_SAMPLE_SIZE)
 226   {
 227     avg /= (float)totallen;
 228     if (avg >= SIL_S16)
 229     {
 230         s->mul = s->mid_s16 / avg;
 231         s->mul = clamp(s->mul, MUL_MIN, MUL_MAX);
 232     }
 233   }
 234
 235   // Scale & clamp the samples
 236   for (i = 0; i < len; i++)
 237   {
 238     tmp = s->mul * data[i];
 239     tmp = clamp(tmp, SHRT_MIN, SHRT_MAX);
 240     data[i] = tmp;
 241   }
 242
 243   // Evaulation of newavg (not 100% accurate because of values clamping)
 244   newavg = s->mul * curavg;
 245
 246   // Stores computed values for future smoothing
 247   s->mem[s->idx].len = len;
 248   s->mem[s->idx].avg = newavg;
 249   s->idx = (s->idx + 1) % NSAMPLES;
 250 }
 251
 252 static void method2_float(af_volnorm_t *s, af_data_t *c)
 253 {
 254   register int i = 0;
 255   float *data = (float*)c->audio;       // Audio data
 256   int len = c->len/4;           // Number of samples
 257   float curavg = 0.0, newavg, avg = 0.0, tmp;
 258   int totallen = 0;
 259
 260   for (i = 0; i < len; i++)
 261   {
 262     tmp = data[i];
 263     curavg += tmp * tmp;
 264   }
 265   curavg = sqrt(curavg / (float) len);
 266
 267   // Evaluate an adequate 'mul' coefficient based on previous state, current
 268   // samples level, etc
 269   for (i = 0; i < NSAMPLES; i++)
 270   {
 271     avg += s->mem[i].avg * (float)s->mem[i].len;
 272     totallen += s->mem[i].len;
 273   }
 274
 275   if (totallen > MIN_SAMPLE_SIZE)
 276   {
 277     avg /= (float)totallen;
 278     if (avg >= SIL_FLOAT)
 279     {
 280         s->mul = s->mid_float / avg;
 281         s->mul = clamp(s->mul, MUL_MIN, MUL_MAX);
 282     }
 283   }
 284
 285   // Scale & clamp the samples
 286   for (i = 0; i < len; i++)
 287     data[i] *= s->mul;
 288
 289   // Evaulation of newavg (not 100% accurate because of values clamping)
 290   newavg = s->mul * curavg;
 291
 292   // Stores computed values for future smoothing
 293   s->mem[s->idx].len = len;
 294   s->mem[s->idx].avg = newavg;
 295   s->idx = (s->idx + 1) % NSAMPLES;
 296 }
 297
 298 // Filter data through filter
 299 static af_data_t* play(struct af_instance_s* af, af_data_t* data)
 300 {
 301   af_volnorm_t *s = af->setup;
 302
 303   if(af->data->format == (AF_FORMAT_S16_NE))
 304   {
 305     if (s->method)
 306         method2_int16(s, data);
 307     else
 308         method1_int16(s, data);
 309   }
 310   else if(af->data->format == (AF_FORMAT_FLOAT_NE))
 311   {
 312     if (s->method)
 313         method2_float(s, data);
 314     else
 315         method1_float(s, data);
 316   }
 317   return data;
 318 }
 319
 320 // Allocate memory and set function pointers
 321 static int af_open(af_instance_t* af){
 322   int i = 0;
 323   af->control=control;
 324   af->uninit=uninit;
 325   af->play=play;
 326   af->mul=1;
 327   af->data=calloc(1,sizeof(af_data_t));
 328   af->setup=calloc(1,sizeof(af_volnorm_t));
 329   if(af->data == NULL || af->setup == NULL)
 330     return AF_ERROR;
 331
 332   ((af_volnorm_t*)af->setup)->mul = MUL_INIT;
 333   ((af_volnorm_t*)af->setup)->lastavg = ((float)SHRT_MAX) * DEFAULT_TARGET;
 334   ((af_volnorm_t*)af->setup)->idx = 0;
 335   ((af_volnorm_t*)af->setup)->mid_s16 = ((float)SHRT_MAX) * DEFAULT_TARGET;
 336   ((af_volnorm_t*)af->setup)->mid_float = DEFAULT_TARGET;
 337   for (i = 0; i < NSAMPLES; i++)
 338   {
 339      ((af_volnorm_t*)af->setup)->mem[i].len = 0;
 340      ((af_volnorm_t*)af->setup)->mem[i].avg = 0;
 341   }
 342   return AF_OK;
 343 }
 344
 345 // Description of this filter
 346 af_info_t af_info_volnorm = {
 347     "Volume normalizer filter",
 348     "volnorm",
 349     "Alex Beregszaszi & Pierre Lombard",
 350     "",
 351     AF_FLAGS_NOT_REENTRANT,
 352     af_open
 353 };