Alc/hrtf.c

   1 /**
   2  * OpenAL cross platform audio library
   3  * Copyright (C) 2011 by Chris Robinson
   4  * This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Library General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library 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 GNU
  12  *  Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  *  License along with this library; if not, write to the
  16  *  Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  *  Boston, MA  02111-1307, USA.
  18  * Or go to http://www.gnu.org/copyleft/lgpl.html
  19  */
  20
  21 #include "config.h"
  22
  23 #include <stdlib.h>
  24 #include <ctype.h>
  25
  26 #include "AL/al.h"
  27 #include "AL/alc.h"
  28 #include "alMain.h"
  29 #include "alSource.h"
  30 #include "alu.h"
  31
  32
  33 #ifndef PATH_MAX
  34 #define PATH_MAX 4096
  35 #endif
  36
  37
  38 /* Current data set limits defined by the makehrtf utility. */
  39 #define MIN_IR_SIZE                  (8)
  40 #define MAX_IR_SIZE                  (128)
  41 #define MOD_IR_SIZE                  (8)
  42
  43 #define MIN_EV_COUNT                 (5)
  44 #define MAX_EV_COUNT                 (128)
  45
  46 #define MIN_AZ_COUNT                 (1)
  47 #define MAX_AZ_COUNT                 (128)
  48
  49 struct Hrtf {
  50     ALuint sampleRate;
  51     ALuint irSize;
  52     ALubyte evCount;
  53
  54     const ALubyte *azCount;
  55     const ALushort *evOffset;
  56     const ALshort *coeffs;
  57     const ALubyte *delays;
  58
  59     struct Hrtf *next;
  60 };
  61
  62 static const ALchar magicMarker00[8] = "MinPHR00";
  63 static const ALchar magicMarker01[8] = "MinPHR01";
  64
  65 /* Define the default HRTF:
  66  *  ALubyte  defaultAzCount  [DefaultHrtf.evCount]
  67  *  ALushort defaultEvOffset [DefaultHrtf.evCount]
  68  *  ALshort  defaultCoeffs   [DefaultHrtf.irCount * defaultHrtf.irSize]
  69  *  ALubyte  defaultDelays   [DefaultHrtf.irCount]
  70  *
  71  *  struct Hrtf DefaultHrtf
  72  */
  73 #include "hrtf_tables.inc"
  74
  75 static struct Hrtf *LoadedHrtfs = NULL;
  76
  77 /* Calculate the elevation indices given the polar elevation in radians.
  78  * This will return two indices between 0 and (Hrtf->evCount - 1) and an
  79  * interpolation factor between 0.0 and 1.0.
  80  */
  81 static void CalcEvIndices(const struct Hrtf *Hrtf, ALfloat ev, ALuint *evidx, ALfloat *evmu)
  82 {
  83     ev = (F_PI_2 + ev) * (Hrtf->evCount-1) / F_PI;
  84     evidx[0] = fastf2u(ev);
  85     evidx[1] = minu(evidx[0] + 1, Hrtf->evCount-1);
  86     *evmu = ev - evidx[0];
  87 }
  88
  89 /* Calculate the azimuth indices given the polar azimuth in radians.  This
  90  * will return two indices between 0 and (Hrtf->azCount[ei] - 1) and an
  91  * interpolation factor between 0.0 and 1.0.
  92  */
  93 static void CalcAzIndices(const struct Hrtf *Hrtf, ALuint evidx, ALfloat az, ALuint *azidx, ALfloat *azmu)
  94 {
  95     az = (F_PI*2.0f + az) * Hrtf->azCount[evidx] / (F_PI*2.0f);
  96     azidx[0] = fastf2u(az) % Hrtf->azCount[evidx];
  97     azidx[1] = (azidx[0] + 1) % Hrtf->azCount[evidx];
  98     *azmu = az - floorf(az);
  99 }
 100
 101 /* Calculates the normalized HRTF transition factor (delta) from the changes
 102  * in gain and listener to source angle between updates.  The result is a
 103  * normalized delta factor that can be used to calculate moving HRIR stepping
 104  * values.
 105  */
 106 ALfloat CalcHrtfDelta(ALfloat oldGain, ALfloat newGain, const ALfloat olddir[3], const ALfloat newdir[3])
 107 {
 108     ALfloat gainChange, angleChange, change;
 109
 110     // Calculate the normalized dB gain change.
 111     newGain = maxf(newGain, 0.0001f);
 112     oldGain = maxf(oldGain, 0.0001f);
 113     gainChange = fabsf(log10f(newGain / oldGain) / log10f(0.0001f));
 114
 115     // Calculate the normalized listener to source angle change when there is
 116     // enough gain to notice it.
 117     angleChange = 0.0f;
 118     if(gainChange > 0.0001f || newGain > 0.0001f)
 119     {
 120         // No angle change when the directions are equal or degenerate (when
 121         // both have zero length).
 122         if(newdir[0]-olddir[0] || newdir[1]-olddir[1] || newdir[2]-olddir[2])
 123             angleChange = acosf(olddir[0]*newdir[0] +
 124                                 olddir[1]*newdir[1] +
 125                                 olddir[2]*newdir[2]) / F_PI;
 126
 127     }
 128
 129     // Use the largest of the two changes for the delta factor, and apply a
 130     // significance shaping function to it.
 131     change = maxf(angleChange * 25.0f, gainChange) * 2.0f;
 132     return minf(change, 1.0f);
 133 }
 134
 135 /* Calculates static HRIR coefficients and delays for the given polar
 136  * elevation and azimuth in radians.  Linear interpolation is used to
 137  * increase the apparent resolution of the HRIR data set.  The coefficients
 138  * are also normalized and attenuated by the specified gain.
 139  */
 140 void GetLerpedHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat gain, ALfloat (*coeffs)[2], ALuint *delays)
 141 {
 142     ALuint evidx[2], azidx[2];
 143     ALuint lidx[4], ridx[4];
 144     ALfloat mu[3], blend[4];
 145     ALuint i;
 146
 147     // Claculate elevation indices and interpolation factor.
 148     CalcEvIndices(Hrtf, elevation, evidx, &mu[2]);
 149
 150     // Calculate azimuth indices and interpolation factor for the first
 151     // elevation.
 152     CalcAzIndices(Hrtf, evidx[0], azimuth, azidx, &mu[0]);
 153
 154     // Calculate the first set of linear HRIR indices for left and right
 155     // channels.
 156     lidx[0] = Hrtf->evOffset[evidx[0]] + azidx[0];
 157     lidx[1] = Hrtf->evOffset[evidx[0]] + azidx[1];
 158     ridx[0] = Hrtf->evOffset[evidx[0]] + ((Hrtf->azCount[evidx[0]]-azidx[0]) % Hrtf->azCount[evidx[0]]);
 159     ridx[1] = Hrtf->evOffset[evidx[0]] + ((Hrtf->azCount[evidx[0]]-azidx[1]) % Hrtf->azCount[evidx[0]]);
 160
 161     // Calculate azimuth indices and interpolation factor for the second
 162     // elevation.
 163     CalcAzIndices(Hrtf, evidx[1], azimuth, azidx, &mu[1]);
 164
 165     // Calculate the second set of linear HRIR indices for left and right
 166     // channels.
 167     lidx[2] = Hrtf->evOffset[evidx[1]] + azidx[0];
 168     lidx[3] = Hrtf->evOffset[evidx[1]] + azidx[1];
 169     ridx[2] = Hrtf->evOffset[evidx[1]] + ((Hrtf->azCount[evidx[1]]-azidx[0]) % Hrtf->azCount[evidx[1]]);
 170     ridx[3] = Hrtf->evOffset[evidx[1]] + ((Hrtf->azCount[evidx[1]]-azidx[1]) % Hrtf->azCount[evidx[1]]);
 171
 172     /* Calculate 4 blending weights for 2D bilinear interpolation. */
 173     blend[0] = (1.0f-mu[0]) * (1.0f-mu[2]);
 174     blend[1] = (     mu[0]) * (1.0f-mu[2]);
 175     blend[2] = (1.0f-mu[1]) * (     mu[2]);
 176     blend[3] = (     mu[1]) * (     mu[2]);
 177
 178     /* Calculate the HRIR delays using linear interpolation. */
 179     delays[0] = fastf2u(Hrtf->delays[lidx[0]]*blend[0] + Hrtf->delays[lidx[1]]*blend[1] +
 180                         Hrtf->delays[lidx[2]]*blend[2] + Hrtf->delays[lidx[3]]*blend[3] +
 181                         0.5f) << HRTFDELAY_BITS;
 182     delays[1] = fastf2u(Hrtf->delays[ridx[0]]*blend[0] + Hrtf->delays[ridx[1]]*blend[1] +
 183                         Hrtf->delays[ridx[2]]*blend[2] + Hrtf->delays[ridx[3]]*blend[3] +
 184                         0.5f) << HRTFDELAY_BITS;
 185
 186     /* Calculate the sample offsets for the HRIR indices. */
 187     lidx[0] *= Hrtf->irSize;
 188     lidx[1] *= Hrtf->irSize;
 189     lidx[2] *= Hrtf->irSize;
 190     lidx[3] *= Hrtf->irSize;
 191     ridx[0] *= Hrtf->irSize;
 192     ridx[1] *= Hrtf->irSize;
 193     ridx[2] *= Hrtf->irSize;
 194     ridx[3] *= Hrtf->irSize;
 195
 196     /* Calculate the normalized and attenuated HRIR coefficients using linear
 197      * interpolation when there is enough gain to warrant it.  Zero the
 198      * coefficients if gain is too low.
 199      */
 200     if(gain > 0.0001f)
 201     {
 202         gain *= 1.0f/32767.0f;
 203         for(i = 0;i < Hrtf->irSize;i++)
 204         {
 205             coeffs[i][0] = (Hrtf->coeffs[lidx[0]+i]*blend[0] +
 206                             Hrtf->coeffs[lidx[1]+i]*blend[1] +
 207                             Hrtf->coeffs[lidx[2]+i]*blend[2] +
 208                             Hrtf->coeffs[lidx[3]+i]*blend[3]) * gain;
 209             coeffs[i][1] = (Hrtf->coeffs[ridx[0]+i]*blend[0] +
 210                             Hrtf->coeffs[ridx[1]+i]*blend[1] +
 211                             Hrtf->coeffs[ridx[2]+i]*blend[2] +
 212                             Hrtf->coeffs[ridx[3]+i]*blend[3]) * gain;
 213         }
 214     }
 215     else
 216     {
 217         for(i = 0;i < Hrtf->irSize;i++)
 218         {
 219             coeffs[i][0] = 0.0f;
 220             coeffs[i][1] = 0.0f;
 221         }
 222     }
 223 }
 224
 225 /* Calculates the moving HRIR target coefficients, target delays, and
 226  * stepping values for the given polar elevation and azimuth in radians.
 227  * Linear interpolation is used to increase the apparent resolution of the
 228  * HRIR data set.  The coefficients are also normalized and attenuated by the
 229  * specified gain.  Stepping resolution and count is determined using the
 230  * given delta factor between 0.0 and 1.0.
 231  */
 232 ALuint GetMovingHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat gain, ALfloat delta, ALint counter, ALfloat (*coeffs)[2], ALuint *delays, ALfloat (*coeffStep)[2], ALint *delayStep)
 233 {
 234     ALuint evidx[2], azidx[2];
 235     ALuint lidx[4], ridx[4];
 236     ALfloat mu[3], blend[4];
 237     ALfloat left, right;
 238     ALfloat step;
 239     ALuint i;
 240
 241     // Claculate elevation indices and interpolation factor.
 242     CalcEvIndices(Hrtf, elevation, evidx, &mu[2]);
 243
 244     // Calculate azimuth indices and interpolation factor for the first
 245     // elevation.
 246     CalcAzIndices(Hrtf, evidx[0], azimuth, azidx, &mu[0]);
 247
 248     // Calculate the first set of linear HRIR indices for left and right
 249     // channels.
 250     lidx[0] = Hrtf->evOffset[evidx[0]] + azidx[0];
 251     lidx[1] = Hrtf->evOffset[evidx[0]] + azidx[1];
 252     ridx[0] = Hrtf->evOffset[evidx[0]] + ((Hrtf->azCount[evidx[0]]-azidx[0]) % Hrtf->azCount[evidx[0]]);
 253     ridx[1] = Hrtf->evOffset[evidx[0]] + ((Hrtf->azCount[evidx[0]]-azidx[1]) % Hrtf->azCount[evidx[0]]);
 254
 255     // Calculate azimuth indices and interpolation factor for the second
 256     // elevation.
 257     CalcAzIndices(Hrtf, evidx[1], azimuth, azidx, &mu[1]);
 258
 259     // Calculate the second set of linear HRIR indices for left and right
 260     // channels.
 261     lidx[2] = Hrtf->evOffset[evidx[1]] + azidx[0];
 262     lidx[3] = Hrtf->evOffset[evidx[1]] + azidx[1];
 263     ridx[2] = Hrtf->evOffset[evidx[1]] + ((Hrtf->azCount[evidx[1]]-azidx[0]) % Hrtf->azCount[evidx[1]]);
 264     ridx[3] = Hrtf->evOffset[evidx[1]] + ((Hrtf->azCount[evidx[1]]-azidx[1]) % Hrtf->azCount[evidx[1]]);
 265
 266     // Calculate the stepping parameters.
 267     delta = maxf(floorf(delta*(Hrtf->sampleRate*0.015f) + 0.5f), 1.0f);
 268     step = 1.0f / delta;
 269
 270     /* Calculate 4 blending weights for 2D bilinear interpolation. */
 271     blend[0] = (1.0f-mu[0]) * (1.0f-mu[2]);
 272     blend[1] = (     mu[0]) * (1.0f-mu[2]);
 273     blend[2] = (1.0f-mu[1]) * (     mu[2]);
 274     blend[3] = (     mu[1]) * (     mu[2]);
 275
 276     /* Calculate the HRIR delays using linear interpolation.  Then calculate
 277      * the delay stepping values using the target and previous running
 278      * delays.
 279      */
 280     left = (ALfloat)(delays[0] - (delayStep[0] * counter));
 281     right = (ALfloat)(delays[1] - (delayStep[1] * counter));
 282
 283     delays[0] = fastf2u(Hrtf->delays[lidx[0]]*blend[0] + Hrtf->delays[lidx[1]]*blend[1] +
 284                         Hrtf->delays[lidx[2]]*blend[2] + Hrtf->delays[lidx[3]]*blend[3] +
 285                         0.5f) << HRTFDELAY_BITS;
 286     delays[1] = fastf2u(Hrtf->delays[ridx[0]]*blend[0] + Hrtf->delays[ridx[1]]*blend[1] +
 287                         Hrtf->delays[ridx[2]]*blend[2] + Hrtf->delays[ridx[3]]*blend[3] +
 288                         0.5f) << HRTFDELAY_BITS;
 289
 290     delayStep[0] = fastf2i(step * (delays[0] - left));
 291     delayStep[1] = fastf2i(step * (delays[1] - right));
 292
 293     /* Calculate the sample offsets for the HRIR indices. */
 294     lidx[0] *= Hrtf->irSize;
 295     lidx[1] *= Hrtf->irSize;
 296     lidx[2] *= Hrtf->irSize;
 297     lidx[3] *= Hrtf->irSize;
 298     ridx[0] *= Hrtf->irSize;
 299     ridx[1] *= Hrtf->irSize;
 300     ridx[2] *= Hrtf->irSize;
 301     ridx[3] *= Hrtf->irSize;
 302
 303     /* Calculate the normalized and attenuated target HRIR coefficients using
 304      * linear interpolation when there is enough gain to warrant it.  Zero
 305      * the target coefficients if gain is too low.  Then calculate the
 306      * coefficient stepping values using the target and previous running
 307      * coefficients.
 308      */
 309     if(gain > 0.0001f)
 310     {
 311         gain *= 1.0f/32767.0f;
 312         for(i = 0;i < HRIR_LENGTH;i++)
 313         {
 314             left = coeffs[i][0] - (coeffStep[i][0] * counter);
 315             right = coeffs[i][1] - (coeffStep[i][1] * counter);
 316
 317             coeffs[i][0] = (Hrtf->coeffs[lidx[0]+i]*blend[0] +
 318                             Hrtf->coeffs[lidx[1]+i]*blend[1] +
 319                             Hrtf->coeffs[lidx[2]+i]*blend[2] +
 320                             Hrtf->coeffs[lidx[3]+i]*blend[3]) * gain;
 321             coeffs[i][1] = (Hrtf->coeffs[ridx[0]+i]*blend[0] +
 322                             Hrtf->coeffs[ridx[1]+i]*blend[1] +
 323                             Hrtf->coeffs[ridx[2]+i]*blend[2] +
 324                             Hrtf->coeffs[ridx[3]+i]*blend[3]) * gain;
 325
 326             coeffStep[i][0] = step * (coeffs[i][0] - left);
 327             coeffStep[i][1] = step * (coeffs[i][1] - right);
 328         }
 329     }
 330     else
 331     {
 332         for(i = 0;i < HRIR_LENGTH;i++)
 333         {
 334             left = coeffs[i][0] - (coeffStep[i][0] * counter);
 335             right = coeffs[i][1] - (coeffStep[i][1] * counter);
 336
 337             coeffs[i][0] = 0.0f;
 338             coeffs[i][1] = 0.0f;
 339
 340             coeffStep[i][0] = step * -left;
 341             coeffStep[i][1] = step * -right;
 342         }
 343     }
 344
 345     /* The stepping count is the number of samples necessary for the HRIR to
 346      * complete its transition.  The mixer will only apply stepping for this
 347      * many samples.
 348      */
 349     return fastf2u(delta);
 350 }
 351
 352
 353 static struct Hrtf *LoadHrtf00(FILE *f, ALuint deviceRate)
 354 {
 355     const ALubyte maxDelay = SRC_HISTORY_LENGTH-1;
 356     struct Hrtf *Hrtf = NULL;
 357     ALboolean failed = AL_FALSE;
 358     ALuint rate = 0, irCount = 0;
 359     ALushort irSize = 0, evCount = 0;
 360     ALubyte *azCount = NULL;
 361     ALushort *evOffset = NULL;
 362     ALshort *coeffs = NULL;
 363     ALubyte *delays = NULL;
 364     ALuint i, j;
 365
 366     rate  = fgetc(f);
 367     rate |= fgetc(f)<<8;
 368     rate |= fgetc(f)<<16;
 369     rate |= fgetc(f)<<24;
 370
 371     irCount  = fgetc(f);
 372     irCount |= fgetc(f)<<8;
 373
 374     irSize  = fgetc(f);
 375     irSize |= fgetc(f)<<8;
 376
 377     evCount = fgetc(f);
 378
 379     if(rate != deviceRate)
 380     {
 381         ERR("HRIR rate does not match device rate: rate=%d (%d)\n",
 382             rate, deviceRate);
 383         failed = AL_TRUE;
 384     }
 385     if(irSize < MIN_IR_SIZE || irSize > MAX_IR_SIZE || (irSize%MOD_IR_SIZE))
 386     {
 387         ERR("Unsupported HRIR size: irSize=%d (%d to %d by %d)\n",
 388             irSize, MIN_IR_SIZE, MAX_IR_SIZE, MOD_IR_SIZE);
 389         failed = AL_TRUE;
 390     }
 391     if(evCount < MIN_EV_COUNT || evCount > MAX_EV_COUNT)
 392     {
 393         ERR("Unsupported elevation count: evCount=%d (%d to %d)\n",
 394             evCount, MIN_EV_COUNT, MAX_EV_COUNT);
 395         failed = AL_TRUE;
 396     }
 397
 398     if(failed)
 399         return NULL;
 400
 401     azCount = malloc(sizeof(azCount[0])*evCount);
 402     evOffset = malloc(sizeof(evOffset[0])*evCount);
 403     if(azCount == NULL || evOffset == NULL)
 404     {
 405         ERR("Out of memory.\n");
 406         failed = AL_TRUE;
 407     }
 408
 409     if(!failed)
 410     {
 411         evOffset[0]  = fgetc(f);
 412         evOffset[0] |= fgetc(f)<<8;
 413         for(i = 1;i < evCount;i++)
 414         {
 415             evOffset[i]  = fgetc(f);
 416             evOffset[i] |= fgetc(f)<<8;
 417             if(evOffset[i] <= evOffset[i-1])
 418             {
 419                 ERR("Invalid evOffset: evOffset[%d]=%d (last=%d)\n",
 420                     i, evOffset[i], evOffset[i-1]);
 421                 failed = AL_TRUE;
 422             }
 423
 424             azCount[i-1] = evOffset[i] - evOffset[i-1];
 425             if(azCount[i-1] < MIN_AZ_COUNT || azCount[i-1] > MAX_AZ_COUNT)
 426             {
 427                 ERR("Unsupported azimuth count: azCount[%d]=%d (%d to %d)\n",
 428                     i-1, azCount[i-1], MIN_AZ_COUNT, MAX_AZ_COUNT);
 429                 failed = AL_TRUE;
 430             }
 431         }
 432         if(irCount <= evOffset[i-1])
 433         {
 434             ERR("Invalid evOffset: evOffset[%d]=%d (irCount=%d)\n",
 435                 i-1, evOffset[i-1], irCount);
 436             failed = AL_TRUE;
 437         }
 438
 439         azCount[i-1] = irCount - evOffset[i-1];
 440         if(azCount[i-1] < MIN_AZ_COUNT || azCount[i-1] > MAX_AZ_COUNT)
 441         {
 442             ERR("Unsupported azimuth count: azCount[%d]=%d (%d to %d)\n",
 443                 i-1, azCount[i-1], MIN_AZ_COUNT, MAX_AZ_COUNT);
 444             failed = AL_TRUE;
 445         }
 446     }
 447
 448     if(!failed)
 449     {
 450         coeffs = malloc(sizeof(coeffs[0])*irSize*irCount);
 451         delays = malloc(sizeof(delays[0])*irCount);
 452         if(coeffs == NULL || delays == NULL)
 453         {
 454             ERR("Out of memory.\n");
 455             failed = AL_TRUE;
 456         }
 457     }
 458
 459     if(!failed)
 460     {
 461         for(i = 0;i < irCount*irSize;i+=irSize)
 462         {
 463             for(j = 0;j < irSize;j++)
 464             {
 465                 ALshort coeff;
 466                 coeff  = fgetc(f);
 467                 coeff |= fgetc(f)<<8;
 468                 coeffs[i+j] = coeff;
 469             }
 470         }
 471         for(i = 0;i < irCount;i++)
 472         {
 473             delays[i] = fgetc(f);
 474             if(delays[i] > maxDelay)
 475             {
 476                 ERR("Invalid delays[%d]: %d (%d)\n", i, delays[i], maxDelay);
 477                 failed = AL_TRUE;
 478             }
 479         }
 480
 481         if(feof(f))
 482         {
 483             ERR("Premature end of data\n");
 484             failed = AL_TRUE;
 485         }
 486     }
 487
 488     if(!failed)
 489     {
 490         Hrtf = malloc(sizeof(struct Hrtf));
 491         if(Hrtf == NULL)
 492         {
 493             ERR("Out of memory.\n");
 494             failed = AL_TRUE;
 495         }
 496     }
 497
 498     if(!failed)
 499     {
 500         Hrtf->sampleRate = rate;
 501         Hrtf->irSize = irSize;
 502         Hrtf->evCount = evCount;
 503         Hrtf->azCount = azCount;
 504         Hrtf->evOffset = evOffset;
 505         Hrtf->coeffs = coeffs;
 506         Hrtf->delays = delays;
 507         Hrtf->next = NULL;
 508         return Hrtf;
 509     }
 510
 511     free(azCount);
 512     free(evOffset);
 513     free(coeffs);
 514     free(delays);
 515     return NULL;
 516 }
 517
 518
 519 static struct Hrtf *LoadHrtf01(FILE *f, ALuint deviceRate)
 520 {
 521     const ALubyte maxDelay = SRC_HISTORY_LENGTH-1;
 522     struct Hrtf *Hrtf = NULL;
 523     ALboolean failed = AL_FALSE;
 524     ALuint rate = 0, irCount = 0;
 525     ALubyte irSize = 0, evCount = 0;
 526     ALubyte *azCount = NULL;
 527     ALushort *evOffset = NULL;
 528     ALshort *coeffs = NULL;
 529     ALubyte *delays = NULL;
 530     ALuint i, j;
 531
 532     rate  = fgetc(f);
 533     rate |= fgetc(f)<<8;
 534     rate |= fgetc(f)<<16;
 535     rate |= fgetc(f)<<24;
 536
 537     irSize = fgetc(f);
 538
 539     evCount = fgetc(f);
 540
 541     if(rate != deviceRate)
 542     {
 543         ERR("HRIR rate does not match device rate: rate=%d (%d)\n",
 544                 rate, deviceRate);
 545         failed = AL_TRUE;
 546     }
 547     if(irSize < MIN_IR_SIZE || irSize > MAX_IR_SIZE || (irSize%MOD_IR_SIZE))
 548     {
 549         ERR("Unsupported HRIR size: irSize=%d (%d to %d by %d)\n",
 550             irSize, MIN_IR_SIZE, MAX_IR_SIZE, MOD_IR_SIZE);
 551         failed = AL_TRUE;
 552     }
 553     if(evCount < MIN_EV_COUNT || evCount > MAX_EV_COUNT)
 554     {
 555         ERR("Unsupported elevation count: evCount=%d (%d to %d)\n",
 556             evCount, MIN_EV_COUNT, MAX_EV_COUNT);
 557         failed = AL_TRUE;
 558     }
 559
 560     if(failed)
 561         return NULL;
 562
 563     azCount = malloc(sizeof(azCount[0])*evCount);
 564     evOffset = malloc(sizeof(evOffset[0])*evCount);
 565     if(azCount == NULL || evOffset == NULL)
 566     {
 567         ERR("Out of memory.\n");
 568         failed = AL_TRUE;
 569     }
 570
 571     if(!failed)
 572     {
 573         for(i = 0;i < evCount;i++)
 574         {
 575             azCount[i] = fgetc(f);
 576             if(azCount[i] < MIN_AZ_COUNT || azCount[i] > MAX_AZ_COUNT)
 577             {
 578                 ERR("Unsupported azimuth count: azCount[%d]=%d (%d to %d)\n",
 579                     i, azCount[i], MIN_AZ_COUNT, MAX_AZ_COUNT);
 580                 failed = AL_TRUE;
 581             }
 582         }
 583     }
 584
 585     if(!failed)
 586     {
 587         evOffset[0] = 0;
 588         irCount = azCount[0];
 589         for(i = 1;i < evCount;i++)
 590         {
 591             evOffset[i] = evOffset[i-1] + azCount[i-1];
 592             irCount += azCount[i];
 593         }
 594
 595         coeffs = malloc(sizeof(coeffs[0])*irSize*irCount);
 596         delays = malloc(sizeof(delays[0])*irCount);
 597         if(coeffs == NULL || delays == NULL)
 598         {
 599             ERR("Out of memory.\n");
 600             failed = AL_TRUE;
 601         }
 602     }
 603
 604     if(!failed)
 605     {
 606         for(i = 0;i < irCount*irSize;i+=irSize)
 607         {
 608             for(j = 0;j < irSize;j++)
 609             {
 610                 ALshort coeff;
 611                 coeff  = fgetc(f);
 612                 coeff |= fgetc(f)<<8;
 613                 coeffs[i+j] = coeff;
 614             }
 615         }
 616         for(i = 0;i < irCount;i++)
 617         {
 618             delays[i] = fgetc(f);
 619             if(delays[i] > maxDelay)
 620             {
 621                 ERR("Invalid delays[%d]: %d (%d)\n", i, delays[i], maxDelay);
 622                 failed = AL_TRUE;
 623             }
 624         }
 625
 626         if(feof(f))
 627         {
 628             ERR("Premature end of data\n");
 629             failed = AL_TRUE;
 630         }
 631     }
 632
 633     if(!failed)
 634     {
 635         Hrtf = malloc(sizeof(struct Hrtf));
 636         if(Hrtf == NULL)
 637         {
 638             ERR("Out of memory.\n");
 639             failed = AL_TRUE;
 640         }
 641     }
 642
 643     if(!failed)
 644     {
 645         Hrtf->sampleRate = rate;
 646         Hrtf->irSize = irSize;
 647         Hrtf->evCount = evCount;
 648         Hrtf->azCount = azCount;
 649         Hrtf->evOffset = evOffset;
 650         Hrtf->coeffs = coeffs;
 651         Hrtf->delays = delays;
 652         Hrtf->next = NULL;
 653         return Hrtf;
 654     }
 655
 656     free(azCount);
 657     free(evOffset);
 658     free(coeffs);
 659     free(delays);
 660     return NULL;
 661 }
 662
 663
 664 static struct Hrtf *LoadHrtf(ALuint deviceRate)
 665 {
 666     const char *fnamelist = NULL;
 667
 668     if(!ConfigValueStr(NULL, "hrtf_tables", &fnamelist))
 669         return NULL;
 670     while(*fnamelist != '\0')
 671     {
 672         struct Hrtf *Hrtf = NULL;
 673         char fname[PATH_MAX];
 674         ALchar magic[8];
 675         ALuint i;
 676         FILE *f;
 677
 678         while(isspace(*fnamelist) || *fnamelist == ',')
 679             fnamelist++;
 680         i = 0;
 681         while(*fnamelist != '\0' && *fnamelist != ',')
 682         {
 683             const char *next = strpbrk(fnamelist, "%,");
 684             while(fnamelist != next && *fnamelist && i < sizeof(fname))
 685                 fname[i++] = *(fnamelist++);
 686
 687             if(!next || *next == ',')
 688                 break;
 689
 690             /* *next == '%' */
 691             next++;
 692             if(*next == 'r')
 693             {
 694                 int wrote = snprintf(&fname[i], sizeof(fname)-i, "%u", deviceRate);
 695                 i += minu(wrote, sizeof(fname)-i);
 696                 next++;
 697             }
 698             else if(*next == '%')
 699             {
 700                 if(i < sizeof(fname))
 701                     fname[i++] = '%';
 702                 next++;
 703             }
 704             else
 705                 ERR("Invalid marker '%%%c'\n", *next);
 706             fnamelist = next;
 707         }
 708         i = minu(i, sizeof(fname)-1);
 709         fname[i] = '\0';
 710         while(i > 0 && isspace(fname[i-1]))
 711             i--;
 712         fname[i] = '\0';
 713
 714         if(fname[0] == '\0')
 715             continue;
 716
 717         TRACE("Loading %s...\n", fname);
 718         f = fopen(fname, "rb");
 719         if(f == NULL)
 720         {
 721             ERR("Could not open %s\n", fname);
 722             continue;
 723         }
 724
 725         if(fread(magic, 1, sizeof(magic), f) != sizeof(magic))
 726             ERR("Failed to read magic marker\n");
 727         else
 728         {
 729             if(memcmp(magic, magicMarker00, sizeof(magicMarker00)) == 0)
 730             {
 731                 TRACE("Detected data set format v0\n");
 732                 Hrtf = LoadHrtf00(f, deviceRate);
 733             }
 734             else if(memcmp(magic, magicMarker01, sizeof(magicMarker01)) == 0)
 735             {
 736                 TRACE("Detected data set format v1\n");
 737                 Hrtf = LoadHrtf01(f, deviceRate);
 738             }
 739             else
 740                 ERR("Invalid magic marker: \"%.8s\"\n", magic);
 741         }
 742
 743         fclose(f);
 744         f = NULL;
 745
 746         if(Hrtf)
 747         {
 748             Hrtf->next = LoadedHrtfs;
 749             LoadedHrtfs = Hrtf;
 750             TRACE("Loaded HRTF support for format: %s %uhz\n",
 751                   DevFmtChannelsString(DevFmtStereo), Hrtf->sampleRate);
 752             return Hrtf;
 753         }
 754
 755         ERR("Failed to load %s\n", fname);
 756     }
 757
 758     return NULL;
 759 }
 760
 761 const struct Hrtf *GetHrtf(ALCdevice *device)
 762 {
 763     if(device->FmtChans == DevFmtStereo)
 764     {
 765         struct Hrtf *Hrtf = LoadedHrtfs;
 766         while(Hrtf != NULL)
 767         {
 768             if(device->Frequency == Hrtf->sampleRate)
 769                 return Hrtf;
 770             Hrtf = Hrtf->next;
 771         }
 772
 773         Hrtf = LoadHrtf(device->Frequency);
 774         if(Hrtf != NULL)
 775             return Hrtf;
 776
 777         if(device->Frequency == DefaultHrtf.sampleRate)
 778             return &DefaultHrtf;
 779     }
 780     ERR("Incompatible format: %s %uhz\n",
 781         DevFmtChannelsString(device->FmtChans), device->Frequency);
 782     return NULL;
 783 }
 784
 785 void FreeHrtfs(void)
 786 {
 787     struct Hrtf *Hrtf = NULL;
 788
 789     while((Hrtf=LoadedHrtfs) != NULL)
 790     {
 791         LoadedHrtfs = Hrtf->next;
 792         free((void*)Hrtf->azCount);
 793         free((void*)Hrtf->evOffset);
 794         free((void*)Hrtf->coeffs);
 795         free((void*)Hrtf->delays);
 796         free(Hrtf);
 797     }
 798 }
 799
 800 ALuint GetHrtfIrSize (const struct Hrtf *Hrtf)
 801 {
 802     return Hrtf->irSize;
 803 }