Mercurial > audio-send
view Alc/hrtf.c @ 0:f9476ff7637e
initial forking of open-al to create multiple listeners
author | Robert McIntyre <rlm@mit.edu> |
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date | Tue, 25 Oct 2011 13:02:31 -0700 |
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1 /**2 * OpenAL cross platform audio library3 * Copyright (C) 2011 by Chris Robinson4 * This library is free software; you can redistribute it and/or5 * modify it under the terms of the GNU Library General Public6 * License as published by the Free Software Foundation; either7 * 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 of11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU12 * Library General Public License for more details.13 *14 * You should have received a copy of the GNU Library General Public15 * License along with this library; if not, write to the16 * 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.html19 */21 #include "config.h"23 #include "AL/al.h"24 #include "AL/alc.h"25 #include "alMain.h"26 #include "alSource.h"28 /* External HRTF file format (LE byte order):29 *30 * ALchar magic[8] = "MinPHR00";31 * ALuint sampleRate;32 *33 * ALushort hrirCount; // Required value: 82834 * ALushort hrirSize; // Required value: 3235 * ALubyte evCount; // Required value: 1936 *37 * ALushort evOffset[evCount]; // Required values:38 * { 0, 1, 13, 37, 73, 118, 174, 234, 306, 378, 450, 522, 594, 654, 710, 755, 791, 815, 827 }39 *40 * ALushort coefficients[hrirCount][hrirSize];41 * ALubyte delays[hrirCount]; // Element values must not exceed 12742 */44 static const ALchar magicMarker[8] = "MinPHR00";46 #define HRIR_COUNT 82847 #define ELEV_COUNT 1949 static const ALushort evOffset[ELEV_COUNT] = { 0, 1, 13, 37, 73, 118, 174, 234, 306, 378, 450, 522, 594, 654, 710, 755, 791, 815, 827 };50 static const ALubyte azCount[ELEV_COUNT] = { 1, 12, 24, 36, 45, 56, 60, 72, 72, 72, 72, 72, 60, 56, 45, 36, 24, 12, 1 };52 static struct Hrtf {53 ALuint sampleRate;54 ALshort coeffs[HRIR_COUNT][HRIR_LENGTH];55 ALubyte delays[HRIR_COUNT];56 } Hrtf = {57 44100,58 #include "hrtf_tables.inc"59 };61 // Calculate the elevation indices given the polar elevation in radians.62 // This will return two indices between 0 and (ELEV_COUNT-1) and an63 // interpolation factor between 0.0 and 1.0.64 static void CalcEvIndices(ALfloat ev, ALuint *evidx, ALfloat *evmu)65 {66 ev = (M_PI/2.0f + ev) * (ELEV_COUNT-1) / M_PI;67 evidx[0] = (ALuint)ev;68 evidx[1] = minu(evidx[0] + 1, ELEV_COUNT-1);69 *evmu = ev - evidx[0];70 }72 // Calculate the azimuth indices given the polar azimuth in radians. This73 // will return two indices between 0 and (azCount [ei] - 1) and an74 // interpolation factor between 0.0 and 1.0.75 static void CalcAzIndices(ALuint evidx, ALfloat az, ALuint *azidx, ALfloat *azmu)76 {77 az = (M_PI*2.0f + az) * azCount[evidx] / (M_PI*2.0f);78 azidx[0] = (ALuint)az % azCount[evidx];79 azidx[1] = (azidx[0] + 1) % azCount[evidx];80 *azmu = az - floor(az);81 }83 // Calculates the normalized HRTF transition factor (delta) from the changes84 // in gain and listener to source angle between updates. The result is a85 // normalized delta factor than can be used to calculate moving HRIR stepping86 // values.87 ALfloat CalcHrtfDelta(ALfloat oldGain, ALfloat newGain, const ALfloat olddir[3], const ALfloat newdir[3])88 {89 ALfloat gainChange, angleChange;91 // Calculate the normalized dB gain change.92 newGain = maxf(newGain, 0.0001f);93 oldGain = maxf(oldGain, 0.0001f);94 gainChange = aluFabs(log10(newGain / oldGain) / log10(0.0001f));96 // Calculate the normalized listener to source angle change when there is97 // enough gain to notice it.98 angleChange = 0.0f;99 if(gainChange > 0.0001f || newGain > 0.0001f)100 {101 // No angle change when the directions are equal or degenerate (when102 // both have zero length).103 if(newdir[0]-olddir[0] || newdir[1]-olddir[1] || newdir[2]-olddir[2])104 angleChange = aluAcos(olddir[0]*newdir[0] +105 olddir[1]*newdir[1] +106 olddir[2]*newdir[2]) / M_PI;108 }110 // Use the largest of the two changes for the delta factor, and apply a111 // significance shaping function to it.112 return clampf(angleChange*2.0f, gainChange*2.0f, 1.0f);113 }115 // Calculates static HRIR coefficients and delays for the given polar116 // elevation and azimuth in radians. Linear interpolation is used to117 // increase the apparent resolution of the HRIR dataset. The coefficients118 // are also normalized and attenuated by the specified gain.119 void GetLerpedHrtfCoeffs(ALfloat elevation, ALfloat azimuth, ALfloat gain, ALfloat (*coeffs)[2], ALuint *delays)120 {121 ALuint evidx[2], azidx[2];122 ALfloat mu[3];123 ALuint lidx[4], ridx[4];124 ALuint i;126 // Claculate elevation indices and interpolation factor.127 CalcEvIndices(elevation, evidx, &mu[2]);129 // Calculate azimuth indices and interpolation factor for the first130 // elevation.131 CalcAzIndices(evidx[0], azimuth, azidx, &mu[0]);133 // Calculate the first set of linear HRIR indices for left and right134 // channels.135 lidx[0] = evOffset[evidx[0]] + azidx[0];136 lidx[1] = evOffset[evidx[0]] + azidx[1];137 ridx[0] = evOffset[evidx[0]] + ((azCount[evidx[0]]-azidx[0]) % azCount[evidx[0]]);138 ridx[1] = evOffset[evidx[0]] + ((azCount[evidx[0]]-azidx[1]) % azCount[evidx[0]]);140 // Calculate azimuth indices and interpolation factor for the second141 // elevation.142 CalcAzIndices(evidx[1], azimuth, azidx, &mu[1]);144 // Calculate the second set of linear HRIR indices for left and right145 // channels.146 lidx[2] = evOffset[evidx[1]] + azidx[0];147 lidx[3] = evOffset[evidx[1]] + azidx[1];148 ridx[2] = evOffset[evidx[1]] + ((azCount[evidx[1]]-azidx[0]) % azCount[evidx[1]]);149 ridx[3] = evOffset[evidx[1]] + ((azCount[evidx[1]]-azidx[1]) % azCount[evidx[1]]);151 // Calculate the normalized and attenuated HRIR coefficients using linear152 // interpolation when there is enough gain to warrant it. Zero the153 // coefficients if gain is too low.154 if(gain > 0.0001f)155 {156 ALdouble scale = gain * (1.0/32767.0);157 for(i = 0;i < HRIR_LENGTH;i++)158 {159 coeffs[i][0] = lerp(lerp(Hrtf.coeffs[lidx[0]][i], Hrtf.coeffs[lidx[1]][i], mu[0]),160 lerp(Hrtf.coeffs[lidx[2]][i], Hrtf.coeffs[lidx[3]][i], mu[1]),161 mu[2]) * scale;162 coeffs[i][1] = lerp(lerp(Hrtf.coeffs[ridx[0]][i], Hrtf.coeffs[ridx[1]][i], mu[0]),163 lerp(Hrtf.coeffs[ridx[2]][i], Hrtf.coeffs[ridx[3]][i], mu[1]),164 mu[2]) * scale;165 }166 }167 else168 {169 for(i = 0;i < HRIR_LENGTH;i++)170 {171 coeffs[i][0] = 0.0f;172 coeffs[i][1] = 0.0f;173 }174 }176 // Calculate the HRIR delays using linear interpolation.177 delays[0] = (ALuint)(lerp(lerp(Hrtf.delays[lidx[0]], Hrtf.delays[lidx[1]], mu[0]),178 lerp(Hrtf.delays[lidx[2]], Hrtf.delays[lidx[3]], mu[1]),179 mu[2]) * 65536.0f);180 delays[1] = (ALuint)(lerp(lerp(Hrtf.delays[ridx[0]], Hrtf.delays[ridx[1]], mu[0]),181 lerp(Hrtf.delays[ridx[2]], Hrtf.delays[ridx[3]], mu[1]),182 mu[2]) * 65536.0f);183 }185 // Calculates the moving HRIR target coefficients, target delays, and186 // stepping values for the given polar elevation and azimuth in radians.187 // Linear interpolation is used to increase the apparent resolution of the188 // HRIR dataset. The coefficients are also normalized and attenuated by the189 // specified gain. Stepping resolution and count is determined using the190 // given delta factor between 0.0 and 1.0.191 ALuint GetMovingHrtfCoeffs(ALfloat elevation, ALfloat azimuth, ALfloat gain, ALfloat delta, ALint counter, ALfloat (*coeffs)[2], ALuint *delays, ALfloat (*coeffStep)[2], ALint *delayStep)192 {193 ALuint evidx[2], azidx[2];194 ALuint lidx[4], ridx[4];195 ALfloat left, right;196 ALfloat mu[3];197 ALfloat step;198 ALuint i;200 // Claculate elevation indices and interpolation factor.201 CalcEvIndices(elevation, evidx, &mu[2]);203 // Calculate azimuth indices and interpolation factor for the first204 // elevation.205 CalcAzIndices(evidx[0], azimuth, azidx, &mu[0]);207 // Calculate the first set of linear HRIR indices for left and right208 // channels.209 lidx[0] = evOffset[evidx[0]] + azidx[0];210 lidx[1] = evOffset[evidx[0]] + azidx[1];211 ridx[0] = evOffset[evidx[0]] + ((azCount[evidx[0]]-azidx[0]) % azCount[evidx[0]]);212 ridx[1] = evOffset[evidx[0]] + ((azCount[evidx[0]]-azidx[1]) % azCount[evidx[0]]);214 // Calculate azimuth indices and interpolation factor for the second215 // elevation.216 CalcAzIndices(evidx[1], azimuth, azidx, &mu[1]);218 // Calculate the second set of linear HRIR indices for left and right219 // channels.220 lidx[2] = evOffset[evidx[1]] + azidx[0];221 lidx[3] = evOffset[evidx[1]] + azidx[1];222 ridx[2] = evOffset[evidx[1]] + ((azCount[evidx[1]]-azidx[0]) % azCount[evidx[1]]);223 ridx[3] = evOffset[evidx[1]] + ((azCount[evidx[1]]-azidx[1]) % azCount[evidx[1]]);225 // Calculate the stepping parameters.226 delta = maxf(floor(delta*(Hrtf.sampleRate*0.015f) + 0.5), 1.0f);227 step = 1.0f / delta;229 // Calculate the normalized and attenuated target HRIR coefficients using230 // linear interpolation when there is enough gain to warrant it. Zero231 // the target coefficients if gain is too low. Then calculate the232 // coefficient stepping values using the target and previous running233 // coefficients.234 if(gain > 0.0001f)235 {236 ALdouble scale = gain * (1.0/32767.0);237 for(i = 0;i < HRIR_LENGTH;i++)238 {239 left = coeffs[i][0] - (coeffStep[i][0] * counter);240 right = coeffs[i][1] - (coeffStep[i][1] * counter);242 coeffs[i][0] = lerp(lerp(Hrtf.coeffs[lidx[0]][i], Hrtf.coeffs[lidx[1]][i], mu[0]),243 lerp(Hrtf.coeffs[lidx[2]][i], Hrtf.coeffs[lidx[3]][i], mu[1]),244 mu[2]) * scale;245 coeffs[i][1] = lerp(lerp(Hrtf.coeffs[ridx[0]][i], Hrtf.coeffs[ridx[1]][i], mu[0]),246 lerp(Hrtf.coeffs[ridx[2]][i], Hrtf.coeffs[ridx[3]][i], mu[1]),247 mu[2]) * scale;249 coeffStep[i][0] = step * (coeffs[i][0] - left);250 coeffStep[i][1] = step * (coeffs[i][1] - right);251 }252 }253 else254 {255 for(i = 0;i < HRIR_LENGTH;i++)256 {257 left = coeffs[i][0] - (coeffStep[i][0] * counter);258 right = coeffs[i][1] - (coeffStep[i][1] * counter);260 coeffs[i][0] = 0.0f;261 coeffs[i][1] = 0.0f;263 coeffStep[i][0] = step * -left;264 coeffStep[i][1] = step * -right;265 }266 }268 // Calculate the HRIR delays using linear interpolation. Then calculate269 // the delay stepping values using the target and previous running270 // delays.271 left = delays[0] - (delayStep[0] * counter);272 right = delays[1] - (delayStep[1] * counter);274 delays[0] = (ALuint)(lerp(lerp(Hrtf.delays[lidx[0]], Hrtf.delays[lidx[1]], mu[0]),275 lerp(Hrtf.delays[lidx[2]], Hrtf.delays[lidx[3]], mu[1]),276 mu[2]) * 65536.0f);277 delays[1] = (ALuint)(lerp(lerp(Hrtf.delays[ridx[0]], Hrtf.delays[ridx[1]], mu[0]),278 lerp(Hrtf.delays[ridx[2]], Hrtf.delays[ridx[3]], mu[1]),279 mu[2]) * 65536.0f);281 delayStep[0] = (ALint)(step * (delays[0] - left));282 delayStep[1] = (ALint)(step * (delays[1] - right));284 // The stepping count is the number of samples necessary for the HRIR to285 // complete its transition. The mixer will only apply stepping for this286 // many samples.287 return (ALuint)delta;288 }290 ALCboolean IsHrtfCompatible(ALCdevice *device)291 {292 if(device->FmtChans == DevFmtStereo && device->Frequency == Hrtf.sampleRate)293 return ALC_TRUE;294 ERR("Incompatible HRTF format: %s %uhz (%s %uhz needed)\n",295 DevFmtChannelsString(device->FmtChans), device->Frequency,296 DevFmtChannelsString(DevFmtStereo), Hrtf.sampleRate);297 return ALC_FALSE;298 }300 void InitHrtf(void)301 {302 const char *fname;303 FILE *f = NULL;305 fname = GetConfigValue(NULL, "hrtf_tables", "");306 if(fname[0] != '\0')307 {308 f = fopen(fname, "rb");309 if(f == NULL)310 ERR("Could not open %s\n", fname);311 }312 if(f != NULL)313 {314 const ALubyte maxDelay = SRC_HISTORY_LENGTH-1;315 ALboolean failed = AL_FALSE;316 struct Hrtf newdata;317 ALchar magic[9];318 ALsizei i, j;320 if(fread(magic, 1, sizeof(magicMarker), f) != sizeof(magicMarker))321 {322 ERR("Failed to read magic marker\n");323 failed = AL_TRUE;324 }325 else if(memcmp(magic, magicMarker, sizeof(magicMarker)) != 0)326 {327 magic[8] = 0;328 ERR("Invalid magic marker: \"%s\"\n", magic);329 failed = AL_TRUE;330 }332 if(!failed)333 {334 ALushort hrirCount, hrirSize;335 ALubyte evCount;337 newdata.sampleRate = fgetc(f);338 newdata.sampleRate |= fgetc(f)<<8;339 newdata.sampleRate |= fgetc(f)<<16;340 newdata.sampleRate |= fgetc(f)<<24;342 hrirCount = fgetc(f);343 hrirCount |= fgetc(f)<<8;345 hrirSize = fgetc(f);346 hrirSize |= fgetc(f)<<8;348 evCount = fgetc(f);350 if(hrirCount != HRIR_COUNT || hrirSize != HRIR_LENGTH || evCount != ELEV_COUNT)351 {352 ERR("Unsupported value: hrirCount=%d (%d), hrirSize=%d (%d), evCount=%d (%d)\n",353 hrirCount, HRIR_COUNT, hrirSize, HRIR_LENGTH, evCount, ELEV_COUNT);354 failed = AL_TRUE;355 }356 }358 if(!failed)359 {360 for(i = 0;i < HRIR_COUNT;i++)361 {362 ALushort offset;363 offset = fgetc(f);364 offset |= fgetc(f)<<8;365 if(offset != evOffset[i])366 {367 ERR("Unsupported evOffset[%d] value: %d (%d)\n", i, offset, evOffset[i]);368 failed = AL_TRUE;369 }370 }371 }373 if(!failed)374 {375 for(i = 0;i < HRIR_COUNT;i++)376 {377 for(j = 0;j < HRIR_LENGTH;j++)378 {379 ALshort coeff;380 coeff = fgetc(f);381 coeff |= fgetc(f)<<8;382 newdata.coeffs[i][j] = coeff;383 }384 }385 for(i = 0;i < HRIR_COUNT;i++)386 {387 ALubyte delay;388 delay = fgetc(f);389 newdata.delays[i] = delay;390 if(delay > maxDelay)391 {392 ERR("Invalid delay[%d]: %d (%d)\n", i, delay, maxDelay);393 failed = AL_TRUE;394 }395 }397 if(feof(f))398 {399 ERR("Premature end of data\n");400 failed = AL_TRUE;401 }402 }404 fclose(f);405 f = NULL;407 if(!failed)408 Hrtf = newdata;409 else410 ERR("Failed to load %s\n", fname);411 }412 }