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/**
* OpenAL cross platform audio library
* Copyright (C) 2011 by Chris Robinson
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
* Or go to http://www.gnu.org/copyleft/lgpl.html
*/
#include "config.h"
#include <stdlib.h>
#include <ctype.h>
#include "AL/al.h"
#include "AL/alc.h"
#include "alMain.h"
#include "alSource.h"
static const ALchar magicMarker[8] = "MinPHR00";
#define HRIR_COUNT 828
#define ELEV_COUNT 19
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 };
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 };
static const struct Hrtf {
ALuint sampleRate;
ALshort coeffs[HRIR_COUNT][HRIR_LENGTH];
ALubyte delays[HRIR_COUNT];
} DefaultHrtf = {
44100,
#include "hrtf_tables.inc"
};
static struct Hrtf *LoadedHrtfs = NULL;
static ALuint NumLoadedHrtfs = 0;
// Calculate the elevation indices given the polar elevation in radians.
// This will return two indices between 0 and (ELEV_COUNT-1) and an
// interpolation factor between 0.0 and 1.0.
static void CalcEvIndices(ALfloat ev, ALuint *evidx, ALfloat *evmu)
{
ev = (F_PI_2 + ev) * (ELEV_COUNT-1) / F_PI;
evidx[0] = fastf2u(ev);
evidx[1] = minu(evidx[0] + 1, ELEV_COUNT-1);
*evmu = ev - evidx[0];
}
// Calculate the azimuth indices given the polar azimuth in radians. This
// will return two indices between 0 and (azCount [ei] - 1) and an
// interpolation factor between 0.0 and 1.0.
static void CalcAzIndices(ALuint evidx, ALfloat az, ALuint *azidx, ALfloat *azmu)
{
az = (F_PI*2.0f + az) * azCount[evidx] / (F_PI*2.0f);
azidx[0] = fastf2u(az) % azCount[evidx];
azidx[1] = (azidx[0] + 1) % azCount[evidx];
*azmu = az - aluFloor(az);
}
// Calculates the normalized HRTF transition factor (delta) from the changes
// in gain and listener to source angle between updates. The result is a
// normalized delta factor than can be used to calculate moving HRIR stepping
// values.
ALfloat CalcHrtfDelta(ALfloat oldGain, ALfloat newGain, const ALfloat olddir[3], const ALfloat newdir[3])
{
ALfloat gainChange, angleChange;
// Calculate the normalized dB gain change.
newGain = maxf(newGain, 0.0001f);
oldGain = maxf(oldGain, 0.0001f);
gainChange = aluFabs(aluLog10(newGain / oldGain) / aluLog10(0.0001f));
// Calculate the normalized listener to source angle change when there is
// enough gain to notice it.
angleChange = 0.0f;
if(gainChange > 0.0001f || newGain > 0.0001f)
{
// No angle change when the directions are equal or degenerate (when
// both have zero length).
if(newdir[0]-olddir[0] || newdir[1]-olddir[1] || newdir[2]-olddir[2])
angleChange = aluAcos(olddir[0]*newdir[0] +
olddir[1]*newdir[1] +
olddir[2]*newdir[2]) / F_PI;
}
// Use the largest of the two changes for the delta factor, and apply a
// significance shaping function to it.
return clampf(angleChange*2.0f, gainChange*2.0f, 1.0f);
}
// Calculates static HRIR coefficients and delays for the given polar
// elevation and azimuth in radians. Linear interpolation is used to
// increase the apparent resolution of the HRIR dataset. The coefficients
// are also normalized and attenuated by the specified gain.
void GetLerpedHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat gain, ALfloat (*coeffs)[2], ALuint *delays)
{
ALuint evidx[2], azidx[2];
ALfloat mu[3];
ALuint lidx[4], ridx[4];
ALuint i;
// Claculate elevation indices and interpolation factor.
CalcEvIndices(elevation, evidx, &mu[2]);
// Calculate azimuth indices and interpolation factor for the first
// elevation.
CalcAzIndices(evidx[0], azimuth, azidx, &mu[0]);
// Calculate the first set of linear HRIR indices for left and right
// channels.
lidx[0] = evOffset[evidx[0]] + azidx[0];
lidx[1] = evOffset[evidx[0]] + azidx[1];
ridx[0] = evOffset[evidx[0]] + ((azCount[evidx[0]]-azidx[0]) % azCount[evidx[0]]);
ridx[1] = evOffset[evidx[0]] + ((azCount[evidx[0]]-azidx[1]) % azCount[evidx[0]]);
// Calculate azimuth indices and interpolation factor for the second
// elevation.
CalcAzIndices(evidx[1], azimuth, azidx, &mu[1]);
// Calculate the second set of linear HRIR indices for left and right
// channels.
lidx[2] = evOffset[evidx[1]] + azidx[0];
lidx[3] = evOffset[evidx[1]] + azidx[1];
ridx[2] = evOffset[evidx[1]] + ((azCount[evidx[1]]-azidx[0]) % azCount[evidx[1]]);
ridx[3] = evOffset[evidx[1]] + ((azCount[evidx[1]]-azidx[1]) % azCount[evidx[1]]);
// Calculate the normalized and attenuated HRIR coefficients using linear
// interpolation when there is enough gain to warrant it. Zero the
// coefficients if gain is too low.
if(gain > 0.0001f)
{
gain *= 1.0f/32767.0f;
for(i = 0;i < HRIR_LENGTH;i++)
{
coeffs[i][0] = lerp(lerp(Hrtf->coeffs[lidx[0]][i], Hrtf->coeffs[lidx[1]][i], mu[0]),
lerp(Hrtf->coeffs[lidx[2]][i], Hrtf->coeffs[lidx[3]][i], mu[1]),
mu[2]) * gain;
coeffs[i][1] = lerp(lerp(Hrtf->coeffs[ridx[0]][i], Hrtf->coeffs[ridx[1]][i], mu[0]),
lerp(Hrtf->coeffs[ridx[2]][i], Hrtf->coeffs[ridx[3]][i], mu[1]),
mu[2]) * gain;
}
}
else
{
for(i = 0;i < HRIR_LENGTH;i++)
{
coeffs[i][0] = 0.0f;
coeffs[i][1] = 0.0f;
}
}
// Calculate the HRIR delays using linear interpolation.
delays[0] = fastf2u(lerp(lerp(Hrtf->delays[lidx[0]], Hrtf->delays[lidx[1]], mu[0]),
lerp(Hrtf->delays[lidx[2]], Hrtf->delays[lidx[3]], mu[1]),
mu[2]) * 65536.0f);
delays[1] = fastf2u(lerp(lerp(Hrtf->delays[ridx[0]], Hrtf->delays[ridx[1]], mu[0]),
lerp(Hrtf->delays[ridx[2]], Hrtf->delays[ridx[3]], mu[1]),
mu[2]) * 65536.0f);
}
// Calculates the moving HRIR target coefficients, target delays, and
// stepping values for the given polar elevation and azimuth in radians.
// Linear interpolation is used to increase the apparent resolution of the
// HRIR dataset. The coefficients are also normalized and attenuated by the
// specified gain. Stepping resolution and count is determined using the
// given delta factor between 0.0 and 1.0.
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)
{
ALuint evidx[2], azidx[2];
ALuint lidx[4], ridx[4];
ALfloat left, right;
ALfloat mu[3];
ALfloat step;
ALuint i;
// Claculate elevation indices and interpolation factor.
CalcEvIndices(elevation, evidx, &mu[2]);
// Calculate azimuth indices and interpolation factor for the first
// elevation.
CalcAzIndices(evidx[0], azimuth, azidx, &mu[0]);
// Calculate the first set of linear HRIR indices for left and right
// channels.
lidx[0] = evOffset[evidx[0]] + azidx[0];
lidx[1] = evOffset[evidx[0]] + azidx[1];
ridx[0] = evOffset[evidx[0]] + ((azCount[evidx[0]]-azidx[0]) % azCount[evidx[0]]);
ridx[1] = evOffset[evidx[0]] + ((azCount[evidx[0]]-azidx[1]) % azCount[evidx[0]]);
// Calculate azimuth indices and interpolation factor for the second
// elevation.
CalcAzIndices(evidx[1], azimuth, azidx, &mu[1]);
// Calculate the second set of linear HRIR indices for left and right
// channels.
lidx[2] = evOffset[evidx[1]] + azidx[0];
lidx[3] = evOffset[evidx[1]] + azidx[1];
ridx[2] = evOffset[evidx[1]] + ((azCount[evidx[1]]-azidx[0]) % azCount[evidx[1]]);
ridx[3] = evOffset[evidx[1]] + ((azCount[evidx[1]]-azidx[1]) % azCount[evidx[1]]);
// Calculate the stepping parameters.
delta = maxf(aluFloor(delta*(Hrtf->sampleRate*0.015f) + 0.5f), 1.0f);
step = 1.0f / delta;
// Calculate the normalized and attenuated target HRIR coefficients using
// linear interpolation when there is enough gain to warrant it. Zero
// the target coefficients if gain is too low. Then calculate the
// coefficient stepping values using the target and previous running
// coefficients.
if(gain > 0.0001f)
{
gain *= 1.0f/32767.0f;
for(i = 0;i < HRIR_LENGTH;i++)
{
left = coeffs[i][0] - (coeffStep[i][0] * counter);
right = coeffs[i][1] - (coeffStep[i][1] * counter);
coeffs[i][0] = lerp(lerp(Hrtf->coeffs[lidx[0]][i], Hrtf->coeffs[lidx[1]][i], mu[0]),
lerp(Hrtf->coeffs[lidx[2]][i], Hrtf->coeffs[lidx[3]][i], mu[1]),
mu[2]) * gain;
coeffs[i][1] = lerp(lerp(Hrtf->coeffs[ridx[0]][i], Hrtf->coeffs[ridx[1]][i], mu[0]),
lerp(Hrtf->coeffs[ridx[2]][i], Hrtf->coeffs[ridx[3]][i], mu[1]),
mu[2]) * gain;
coeffStep[i][0] = step * (coeffs[i][0] - left);
coeffStep[i][1] = step * (coeffs[i][1] - right);
}
}
else
{
for(i = 0;i < HRIR_LENGTH;i++)
{
left = coeffs[i][0] - (coeffStep[i][0] * counter);
right = coeffs[i][1] - (coeffStep[i][1] * counter);
coeffs[i][0] = 0.0f;
coeffs[i][1] = 0.0f;
coeffStep[i][0] = step * -left;
coeffStep[i][1] = step * -right;
}
}
// Calculate the HRIR delays using linear interpolation. Then calculate
// the delay stepping values using the target and previous running
// delays.
left = (ALfloat)(delays[0] - (delayStep[0] * counter));
right = (ALfloat)(delays[1] - (delayStep[1] * counter));
delays[0] = fastf2u(lerp(lerp(Hrtf->delays[lidx[0]], Hrtf->delays[lidx[1]], mu[0]),
lerp(Hrtf->delays[lidx[2]], Hrtf->delays[lidx[3]], mu[1]),
mu[2]) * 65536.0f);
delays[1] = fastf2u(lerp(lerp(Hrtf->delays[ridx[0]], Hrtf->delays[ridx[1]], mu[0]),
lerp(Hrtf->delays[ridx[2]], Hrtf->delays[ridx[3]], mu[1]),
mu[2]) * 65536.0f);
delayStep[0] = fastf2i(step * (delays[0] - left));
delayStep[1] = fastf2i(step * (delays[1] - right));
// The stepping count is the number of samples necessary for the HRIR to
// complete its transition. The mixer will only apply stepping for this
// many samples.
return fastf2u(delta);
}
const struct Hrtf *GetHrtf(ALCdevice *device)
{
if(device->FmtChans == DevFmtStereo)
{
ALuint i;
for(i = 0;i < NumLoadedHrtfs;i++)
{
if(device->Frequency == LoadedHrtfs[i].sampleRate)
return &LoadedHrtfs[i];
}
if(device->Frequency == DefaultHrtf.sampleRate)
return &DefaultHrtf;
}
ERR("Incompatible format: %s %uhz\n",
DevFmtChannelsString(device->FmtChans), device->Frequency);
return NULL;
}
void InitHrtf(void)
{
char *fnamelist=NULL, *next=NULL;
const char *val;
if(ConfigValueStr(NULL, "hrtf_tables", &val))
next = fnamelist = strdup(val);
while(next && *next)
{
const ALubyte maxDelay = SRC_HISTORY_LENGTH-1;
struct Hrtf newdata;
ALboolean failed;
ALchar magic[9];
ALsizei i, j;
char *fname;
FILE *f;
fname = next;
next = strchr(fname, ',');
if(next)
{
while(next != fname)
{
next--;
if(!isspace(*next))
{
*(next++) = '\0';
break;
}
}
while(isspace(*next) || *next == ',')
next++;
}
if(!fname[0])
continue;
TRACE("Loading %s\n", fname);
f = fopen(fname, "rb");
if(f == NULL)
{
ERR("Could not open %s\n", fname);
continue;
}
failed = AL_FALSE;
if(fread(magic, 1, sizeof(magicMarker), f) != sizeof(magicMarker))
{
ERR("Failed to read magic marker\n");
failed = AL_TRUE;
}
else if(memcmp(magic, magicMarker, sizeof(magicMarker)) != 0)
{
magic[8] = 0;
ERR("Invalid magic marker: \"%s\"\n", magic);
failed = AL_TRUE;
}
if(!failed)
{
ALushort hrirCount, hrirSize;
ALubyte evCount;
newdata.sampleRate = fgetc(f);
newdata.sampleRate |= fgetc(f)<<8;
newdata.sampleRate |= fgetc(f)<<16;
newdata.sampleRate |= fgetc(f)<<24;
hrirCount = fgetc(f);
hrirCount |= fgetc(f)<<8;
hrirSize = fgetc(f);
hrirSize |= fgetc(f)<<8;
evCount = fgetc(f);
if(hrirCount != HRIR_COUNT || hrirSize != HRIR_LENGTH || evCount != ELEV_COUNT)
{
ERR("Unsupported value: hrirCount=%d (%d), hrirSize=%d (%d), evCount=%d (%d)\n",
hrirCount, HRIR_COUNT, hrirSize, HRIR_LENGTH, evCount, ELEV_COUNT);
failed = AL_TRUE;
}
}
if(!failed)
{
for(i = 0;i < HRIR_COUNT;i++)
{
ALushort offset;
offset = fgetc(f);
offset |= fgetc(f)<<8;
if(offset != evOffset[i])
{
ERR("Unsupported evOffset[%d] value: %d (%d)\n", i, offset, evOffset[i]);
failed = AL_TRUE;
}
}
}
if(!failed)
{
for(i = 0;i < HRIR_COUNT;i++)
{
for(j = 0;j < HRIR_LENGTH;j++)
{
ALshort coeff;
coeff = fgetc(f);
coeff |= fgetc(f)<<8;
newdata.coeffs[i][j] = coeff;
}
}
for(i = 0;i < HRIR_COUNT;i++)
{
ALubyte delay;
delay = fgetc(f);
newdata.delays[i] = delay;
if(delay > maxDelay)
{
ERR("Invalid delay[%d]: %d (%d)\n", i, delay, maxDelay);
failed = AL_TRUE;
}
}
if(feof(f))
{
ERR("Premature end of data\n");
failed = AL_TRUE;
}
}
fclose(f);
f = NULL;
if(!failed)
{
void *temp = realloc(LoadedHrtfs, (NumLoadedHrtfs+1)*sizeof(LoadedHrtfs[0]));
if(temp != NULL)
{
LoadedHrtfs = temp;
TRACE("Loaded HRTF support for format: %s %uhz\n",
DevFmtChannelsString(DevFmtStereo), newdata.sampleRate);
LoadedHrtfs[NumLoadedHrtfs++] = newdata;
}
}
else
ERR("Failed to load %s\n", fname);
}
free(fnamelist);
fnamelist = NULL;
}
void FreeHrtf(void)
{
NumLoadedHrtfs = 0;
free(LoadedHrtfs);
LoadedHrtfs = NULL;
}
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