Dima353/openal-soft
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Add a utility to generate OpenAL Soft's HRTF data from the MIT KEMAR data

Browse Source
This commit is contained in:
Chris Robinson
2012-03-22 22:45:03 -07:00
parent 5a43cd3b64
commit b51afb74da
2 changed files with 746 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
CMakeLists.txt
+7 -1
View File
@@ -743,7 +743,13 @@ ENDIF()
IF(UTILS)
ADD_EXECUTABLE(openal-info utils/openal-info.c)
TARGET_LINK_LIBRARIES(openal-info ${LIBNAME})
INSTALL(TARGETS openal-info
ADD_EXECUTABLE(makehrtf utils/makehrtf.c)
IF(HAVE_LIBM)
TARGET_LINK_LIBRARIES(makehrtf m)
ENDIF()
INSTALL(TARGETS openal-info makehrtf
RUNTIME DESTINATION bin
LIBRARY DESTINATION "lib${LIB_SUFFIX}"
ARCHIVE DESTINATION "lib${LIB_SUFFIX}"
utils/makehrtf.c
+739
View File
@@ -0,0 +1,739 @@
/**
* HRTF utility for producing and demonstrating the process of creating an
* OpenAL Soft compatible HRIR data set.
*
* It can currently make use of the 44.1 KHz diffuse and compact KEMAR HRIRs
* provided by MIT at:
*
* http://sound.media.mit.edu/resources/KEMAR.html
*/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
// The sample rate of the MIT HRIR data sets.
#define MIT_IR_RATE (44100)
// The total number of used impulse responses from the MIT HRIR data sets.
#define MIT_IR_COUNT (828)
// The size (in samples) of each HRIR in the MIT data sets.
#define MIT_IR_SIZE (128)
// The total number of elevations given a step of 10 degrees.
#define MIT_EV_COUNT (19)
// The first elevation that the MIT data sets have HRIRs for.
#define MIT_EV_START (5)
// The head radius (in meters) used by the MIT data sets.
#define MIT_RADIUS (0.09f)
// The source to listener distance (in meters) used by the MIT data sets.
#define MIT_DISTANCE (1.4f)
// The resulting size (in samples) of a mininum-phase reconstructed HRIR.
#define MIN_IR_SIZE (32)
// The size (in samples) of the real cepstrum used in reconstruction. This
// needs to be large enough to reduce inaccuracy.
#define CEP_SIZE (8192)
// The OpenAL Soft HRTF format marker. It stands for minimum-phase head
// response protocol 00.
#define MHR_FORMAT ("MinPHR00")
typedef struct ComplexT ComplexT;
typedef struct HrirDataT HrirDataT;
// A complex number type.
struct ComplexT {
float mVec [2];
};
// The HRIR data definition. This can be used to add support for new HRIR
// sources in the future.
struct HrirDataT {
int mIrRate,
mIrCount,
mIrSize,
mEvCount,
mEvStart;
const int * mEvOffset,
* mAzCount;
float mRadius,
mDistance,
* mHrirs,
* mHrtds,
mMaxHrtd;
};
// The linear index of the first HRIR for each elevation of the MIT data set.
static const int MIT_EV_OFFSET [MIT_EV_COUNT] = {
0, 1, 13, 37, 73, 118, 174, 234, 306, 378, 450, 522, 594, 654, 710, 755, 791, 815, 827
},
// The count of distinct azimuth steps for each elevation in the MIT data
// set.
MIT_AZ_COUNT [MIT_EV_COUNT] = {
1, 12, 24, 36, 45, 56, 60, 72, 72, 72, 72, 72, 60, 56, 45, 36, 24, 12, 1
};
// Performs a forward Fast Fourier Transform.
static void FftProc (int n, const ComplexT * fftIn, ComplexT * fftOut) {
int m2, rk, k, m;
float a, b;
int i;
float wx, wy;
int j, km2;
float tx, ty, wyd;
// Data copy and bit-reversal ordering.
m2 = (n >> 1);
rk = 0;
for (k = 0; k < n; k ++) {
fftOut [rk] . mVec [0] = fftIn [k] . mVec [0];
fftOut [rk] . mVec [1] = fftIn [k] . mVec [1];
if (k < (n - 1)) {
m = m2;
while (rk >= m) {
rk -= m;
m >>= 1;
}
rk += m;
}
}
// Perform the FFT.
m2 = 1;
for (m = 2; m <= n; m <<= 1) {
a = sin (M_PI / m);
a = 2.0f * a * a;
b = sin (2.0f * M_PI / m);
for (i = 0; i < n; i += m) {
wx = 1.0f;
wy = 0.0f;
for (k = i, j = 0; j < m2; k ++, j ++) {
km2 = k + m2;
tx = (wx * fftOut [km2] . mVec [0]) - (wy * fftOut [km2] . mVec [1]);
ty = (wx * fftOut [km2] . mVec [1]) + (wy * fftOut [km2] . mVec [0]);
fftOut [km2] . mVec [0] = fftOut [k] . mVec [0] - tx;
fftOut [km2] . mVec [1] = fftOut [k] . mVec [1] - ty;
fftOut [k] . mVec [0] += tx;
fftOut [k] . mVec [1] += ty;
wyd = (a * wy) - (b * wx);
wx -= (a * wx) + (b * wy);
wy -= wyd;
}
}
m2 = m;
}
}
// Performs an inverse Fast Fourier Transform.
static void FftInvProc (int n, const ComplexT * fftIn, ComplexT * fftOut) {
int m2, rk, k, m;
float a, b;
int i;
float wx, wy;
int j, km2;
float tx, ty, wyd, invn;
// Data copy and bit-reversal ordering.
m2 = (n >> 1);
rk = 0;
for (k = 0; k < n; k ++) {
fftOut [rk] . mVec [0] = fftIn [k] . mVec [0];
fftOut [rk] . mVec [1] = fftIn [k] . mVec [1];
if (k < (n - 1)) {
m = m2;
while (rk >= m) {
rk -= m;
m >>= 1;
}
rk += m;
}
}
// Perform the IFFT.
m2 = 1;
for (m = 2; m <= n; m <<= 1) {
a = sin (M_PI / m);
a = 2.0f * a * a;
b = -sin (2.0f * M_PI / m);
for (i = 0; i < n; i += m) {
wx = 1.0f;
wy = 0.0f;
for (k = i, j = 0; j < m2; k ++, j ++) {
km2 = k + m2;
tx = (wx * fftOut [km2] . mVec [0]) - (wy * fftOut [km2] . mVec [1]);
ty = (wx * fftOut [km2] . mVec [1]) + (wy * fftOut [km2] . mVec [0]);
fftOut [km2] . mVec [0] = fftOut [k] . mVec [0] - tx;
fftOut [km2] . mVec [1] = fftOut [k] . mVec [1] - ty;
fftOut [k] . mVec [0] += tx;
fftOut [k] . mVec [1] += ty;
wyd = (a * wy) - (b * wx);
wx -= (a * wx) + (b * wy);
wy -= wyd;
}
}
m2 = m;
}
// Normalize the samples.
invn = 1.0f / n;
for (i = 0; i < n; i ++) {
fftOut [i] . mVec [0] *= invn;
fftOut [i] . mVec [1] *= invn;
}
}
// Complex absolute value.
static void ComplexAbs (const ComplexT * in, ComplexT * out) {
out -> mVec [0] = sqrt ((in -> mVec [0] * in -> mVec [0]) + (in -> mVec [1] * in -> mVec [1]));
out -> mVec [1] = 0.0f;
}
// Complex logarithm.
static void ComplexLog (const ComplexT * in, ComplexT * out) {
float r, t;
r = sqrt ((in -> mVec [0] * in -> mVec [0]) + (in -> mVec [1] * in -> mVec [1]));
t = atan2 (in -> mVec [1], in -> mVec [0]);
if (t < 0.0f)
t += 2.0f * M_PI;
out -> mVec [0] = log (r);
out -> mVec [1] = t;
}
// Complex exponent.
static void ComplexExp (const ComplexT * in, ComplexT * out) {
float e;
e = exp (in -> mVec [0]);
out -> mVec [0] = e * cos (in -> mVec [1]);
out -> mVec [1] = e * sin (in -> mVec [1]);
}
// Calculates the real cepstrum of a given impulse response. It currently
// uses a fixed cepstrum size. To make this more robust, it should be
// rewritten to handle a variable size cepstrum.
static void RealCepstrum (int irSize, const float * ir, float cep [CEP_SIZE]) {
ComplexT in [CEP_SIZE], out [CEP_SIZE];
int index;
for (index = 0; index < irSize; index ++) {
in [index] . mVec [0] = ir [index];
in [index] . mVec [1] = 0.0f;
}
for (; index < CEP_SIZE; index ++) {
in [index] . mVec [0] = 0.0f;
in [index] . mVec [1] = 0.0f;
}
FftProc (CEP_SIZE, in, out);
for (index = 0; index < CEP_SIZE; index ++) {
ComplexAbs (& out [index], & out [index]);
if (out [index] . mVec [0] < 0.000001f)
out [index] . mVec [0] = 0.000001f;
ComplexLog (& out [index], & in [index]);
}
FftInvProc (CEP_SIZE, in, out);
for (index = 0; index < CEP_SIZE; index ++)
cep [index] = out [index] . mVec [0];
}
// Reconstructs the minimum-phase impulse response for a given real cepstrum.
// Like the above function, this should eventually be modified to handle a
// variable size cepstrum.
static void MinimumPhase (const float cep [CEP_SIZE], int irSize, float * mpIr) {
ComplexT in [CEP_SIZE], out [CEP_SIZE];
int index;
in [0] . mVec [0] = cep [0];
for (index = 1; index < (CEP_SIZE / 2); index ++)
in [index] . mVec [0] = 2.0f * cep [index];
if ((CEP_SIZE % 2) != 1) {
in [index] . mVec [0] = cep [index];
index ++;
}
for (; index < CEP_SIZE; index ++)
in [index] . mVec [0] = 0.0f;
for (index = 0; index < CEP_SIZE; index ++)
in [index] . mVec [1] = 0.0f;
FftProc (CEP_SIZE, in, out);
for (index = 0; index < CEP_SIZE; index ++)
ComplexExp (& out [index], & in [index]);
FftInvProc (CEP_SIZE, in, out);
for (index = 0; index < irSize; index ++)
mpIr [index] = out [index] . mVec [0];
}
// Calculate the left-ear time delay using a spherical head model.
static float CalcLTD (float ev, float az, float rad, float dist) {
float azp, dlp, l, al;
azp = asin (cos (ev) * sin (az));
dlp = sqrt ((dist * dist) + (rad * rad) + (2.0f * dist * rad * sin (azp)));
l = sqrt ((dist * dist) - (rad * rad));
al = (0.5f * M_PI) + azp;
if (dlp > l)
dlp = l + (rad * (al - acos (rad / dist)));
return (dlp / 343.3f);
}
// Read a 16-bit little-endian integer from a file and convert it to a 32-bit
// floating-point value in the range of -1.0 to 1.0.
static int ReadInt16LeAsFloat32 (const char * fileName, FILE * fp, float * val) {
uint8_t vb [2];
uint16_t vw;
if (fread (vb, 1, sizeof (vb), fp) != sizeof (vb)) {
fclose (fp);
fprintf (stderr, "Error reading from file, '%s'.\n", fileName);
return (0);
}
vw = (((uint16_t) vb [1]) << 8) | vb [0];
(* val) = ((int16_t) vw) / 32768.0f;
return (1);
}
// Write a string to a file.
static int WriteString (const char * val, const char * fileName, FILE * fp) {
size_t len;
len = strlen (val);
if (fwrite (val, 1, len, fp) != len) {
fclose (fp);
fprintf (stderr, "Error writing to file, '%s'.\n", fileName);
return (0);
}
return (1);
}
// Write a 32-bit floating-point value in the range of -1.0 to 1.0 to a file
// as a 16-bit little-endian integer.
static int WriteFloat32AsInt16Le (float val, const char * fileName, FILE * fp) {
int16_t vw;
uint8_t vb [2];
vw = (short) round (32767.0f * val);
vb [0] = vw & 0x00FF;
vb [1] = (vw >> 8) & 0x00FF;
if (fwrite (vb, 1, sizeof (vb), fp) != sizeof (vb)) {
fclose (fp);
fprintf (stderr, "Error writing to file, '%s'.\n", fileName);
return (0);
}
return (1);
}
// Write a 32-bit little-endian unsigned integer to a file.
static int WriteUInt32Le (uint32_t val, const char * fileName, FILE * fp) {
uint8_t vb [4];
vb [0] = val & 0x000000FF;
vb [1] = (val >> 8) & 0x000000FF;
vb [2] = (val >> 16) & 0x000000FF;
vb [3] = (val >> 24) & 0x000000FF;
if (fwrite (vb, 1, sizeof (vb), fp) != sizeof (vb)) {
fclose (fp);
fprintf (stderr, "Error writing to file, '%s'.\n", fileName);
return (0);
}
return (1);
}
// Write a 16-bit little-endian unsigned integer to a file.
static int WriteUInt16Le (uint16_t val, const char * fileName, FILE * fp) {
uint8_t vb [2];
vb [0] = val & 0x00FF;
vb [1] = (val >> 8) & 0x00FF;
if (fwrite (vb, 1, sizeof (vb), fp) != sizeof (vb)) {
fclose (fp);
fprintf (stderr, "Error writing to file, '%s'.\n", fileName);
return (0);
}
return (1);
}
// Write an 8-bit unsigned integer to a file.
static int WriteUInt8 (uint8_t val, const char * fileName, FILE * fp) {
if (fwrite (& val, 1, sizeof (val), fp) != sizeof (val)) {
fclose (fp);
fprintf (stderr, "Error writing to file, '%s'.\n", fileName);
return (0);
}
return (1);
}
// Load the MIT HRIRs. This loads the entire diffuse or compact set starting
// counter-clockwise up at the bottom elevation and clockwise at the forward
// azimuth.
static int LoadMitHrirs (const char * baseName, HrirDataT * hData) {
const int EV_ANGLE [MIT_EV_COUNT] = {
-90, -80, -70, -60, -50, -40, -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90
};
int e, a;
char fileName [1024];
FILE * fp = NULL;
int j0, j1, i;
float s;
for (e = MIT_EV_START; e < MIT_EV_COUNT; e ++) {
for (a = 0; a < MIT_AZ_COUNT [e]; a ++) {
// The data packs the first 180 degrees in the left channel, and
// the last 180 degrees in the right channel.
if (round ((360.0f / MIT_AZ_COUNT [e]) * a) > 180.0f)
break;
// Determine which file to open.
snprintf (fileName, 1023, "%s%d/H%de%03da.wav", baseName, EV_ANGLE [e], EV_ANGLE [e], (int) round ((360.0f / MIT_AZ_COUNT [e]) * a));
if ((fp = fopen (fileName, "rb")) == NULL) {
fprintf (stderr, "Could not open file, '%s'.\n", fileName);
return (0);
}
// Assuming they have not changed format, skip the .WAV header.
fseek (fp, 44, SEEK_SET);
// Map the left and right channels to their appropriate azimuth
// offsets.
j0 = (MIT_EV_OFFSET [e] + a) * MIT_IR_SIZE;
j1 = (MIT_EV_OFFSET [e] + ((MIT_AZ_COUNT [e] - a) % MIT_AZ_COUNT [e])) * MIT_IR_SIZE;
// Read in the data, converting it to floating-point.
for (i = 0; i < MIT_IR_SIZE; i ++) {
if (! ReadInt16LeAsFloat32 (fileName, fp, & s))
return (0);
hData -> mHrirs [j0 + i] = s;
if (! ReadInt16LeAsFloat32 (fileName, fp, & s))
return (0);
hData -> mHrirs [j1 + i] = s;
}
fclose (fp);
}
}
return (1);
}
// Performs the minimum phase reconstruction for a given HRIR data set. The
// cepstrum size should be made configureable at some point in the future.
static void ReconstructHrirs (int minIrSize, HrirDataT * hData) {
int start, end, step, j;
float cep [CEP_SIZE];
start = hData -> mEvOffset [hData -> mEvStart];
end = hData -> mIrCount;
step = hData -> mIrSize;
for (j = start; j < end; j ++) {
RealCepstrum (step, & hData -> mHrirs [j * step], cep);
MinimumPhase (cep, minIrSize, & hData -> mHrirs [j * minIrSize]);
}
hData -> mIrSize = minIrSize;
}
// Renormalize the entire HRIR data set, and attenutate it slightly.
static void RenormalizeHrirs (const HrirDataT * hData) {
int step, start, end;
float norm;
int j, i;
step = hData -> mIrSize;
start = hData -> mEvOffset [hData -> mEvStart] * step;
end = hData -> mIrCount * step;
norm = 0.0f;
for (j = start; j < end; j += step) {
for (i = 0; i < step; i ++) {
if (fabs (hData -> mHrirs [j + i]) > norm)
norm = fabs (hData -> mHrirs [j + i]);
}
}
if (norm > 0.000001f)
norm = 1.0f / norm;
norm *= 0.95f;
for (j = start; j < end; j += step) {
for (i = 0; i < step; i ++)
hData -> mHrirs [j + i] *= norm;
}
}
// Given an elevation offset and azimuth, calculates two offsets for
// addressing the HRIRs buffer and their interpolation factor.
static void CalcAzIndices (const HrirDataT * hData, int oi, float az, int * j0, int * j1, float * jf) {
int ai;
az = fmod ((2.0f * M_PI) + az, 2.0f * M_PI) * hData -> mAzCount [oi] / (2.0f * M_PI);
ai = (int) az;
az -= ai;
(* j0) = hData -> mEvOffset [oi] + ai;
(* j1) = hData -> mEvOffset [oi] + ((ai + 1) % hData -> mAzCount [oi]);
(* jf) = az;
}
// Perform a linear interpolation.
static float Lerp (float a, float b, float f) {
return (a + (f * (b - a)));
}
// Attempt to synthesize any missing HRIRs at the bottom elevations. Right
// now this just blends the lowest elevation HRIRs together and applies some
// attenuates and high frequency damping. It's not a realistic model to use,
// but it is simple.
static void SynthesizeHrirs (HrirDataT * hData) {
int step, oi, i, a, j, e;
float of;
int j0, j1;
float jf;
float lp [4], s0, s1;
if (hData -> mEvStart <= 0)
return;
step = hData -> mIrSize;
oi = hData -> mEvStart;
for (i = 0; i < step; i ++)
hData -> mHrirs [i] = 0.0f;
for (a = 0; a < hData -> mAzCount [oi]; a ++) {
j = (hData -> mEvOffset [oi] + a) * step;
for (i = 0; i < step; i ++)
hData -> mHrirs [i] += hData -> mHrirs [j + i] / hData -> mAzCount [oi];
}
for (e = 1; e < hData -> mEvStart; e ++) {
of = ((float) e) / hData -> mEvStart;
for (a = 0; a < hData -> mAzCount [e]; a ++) {
j = (hData -> mEvOffset [e] + a) * step;
CalcAzIndices (hData, oi, a * 2.0f * M_PI / hData -> mAzCount [e], & j0, & j1, & jf);
j0 *= step;
j1 *= step;
lp [0] = 0.0f;
lp [1] = 0.0f;
lp [2] = 0.0f;
lp [3] = 0.0f;
for (i = 0; i < step; i ++) {
s0 = hData -> mHrirs [i];
s1 = Lerp (hData -> mHrirs [j0 + i], hData -> mHrirs [j1 + i], jf);
s0 = Lerp (s0, s1, of);
lp [0] = Lerp (s0, lp [0], 0.15f - (0.15f * of));
lp [1] = Lerp (lp [0], lp [1], 0.15f - (0.15f * of));
lp [2] = Lerp (lp [1], lp [2], 0.15f - (0.15f * of));
lp [3] = Lerp (lp [2], lp [3], 0.15f - (0.15f * of));
hData -> mHrirs [j + i] = lp [3];
}
}
}
lp [0] = 0.0f;
lp [1] = 0.0f;
lp [2] = 0.0f;
lp [3] = 0.0f;
for (i = 0; i < step; i ++) {
s0 = hData -> mHrirs [i];
lp [0] = Lerp (s0, lp [0], 0.15f);
lp [1] = Lerp (lp [0], lp [1], 0.15f);
lp [2] = Lerp (lp [1], lp [2], 0.15f);
lp [3] = Lerp (lp [2], lp [3], 0.15f);
hData -> mHrirs [i] = lp [3];
}
hData -> mEvStart = 0;
}
// Calculate the effective head-related time delays for the each HRIR, now
// that they are minimum-phase.
static void CalculateHrtds (HrirDataT * hData) {
float minHrtd, maxHrtd;
int e, a, j;
float t;
minHrtd = 1000.0f;
maxHrtd = -1000.0f;
for (e = 0; e < hData -> mEvCount; e ++) {
for (a = 0; a < hData -> mAzCount [e]; a ++) {
j = hData -> mEvOffset [e] + a;
t = CalcLTD ((-90.0f + (e * 180.0f / (hData -> mEvCount - 1))) * M_PI / 180.0f,
(a * 360.0f / hData -> mAzCount [e]) * M_PI / 180.0f,
hData -> mRadius, hData -> mDistance);
hData -> mHrtds [j] = t;
if (t > maxHrtd)
maxHrtd = t;
if (t < minHrtd)
minHrtd = t;
}
}
maxHrtd -= minHrtd;
for (j = 0; j < hData -> mIrCount; j ++)
hData -> mHrtds [j] -= minHrtd;
hData -> mMaxHrtd = maxHrtd;
}
// Save the OpenAL Soft HRTF data set.
static int SaveMhr (const HrirDataT * hData, const char * fileName) {
FILE * fp = NULL;
int e, step, end, j, i;
if ((fp = fopen (fileName, "wb")) == NULL) {
fprintf (stderr, "Could not create file, '%s'.\n", fileName);
return (0);
}
if (! WriteString (MHR_FORMAT, fileName, fp))
return (0);
if (! WriteUInt32Le ((uint32_t) hData -> mIrRate, fileName, fp))
return (0);
if (! WriteUInt16Le ((uint16_t) hData -> mIrCount, fileName, fp))
return (0);
if (! WriteUInt16Le ((uint16_t) hData -> mIrSize, fileName, fp))
return (0);
if (! WriteUInt8 ((uint8_t) hData -> mEvCount, fileName, fp))
return (0);
for (e = 0; e < hData -> mEvCount; e ++) {
if (! WriteUInt16Le ((uint16_t) hData -> mEvOffset [e], fileName, fp))
return (0);
}
step = hData -> mIrSize;
end = hData -> mIrCount * step;
for (j = 0; j < end; j += step) {
for (i = 0; i < step; i ++) {
if (! WriteFloat32AsInt16Le (hData -> mHrirs [j + i], fileName, fp))
return (0);
}
}
for (j = 0; j < hData -> mIrCount; j ++) {
i = (int) round (44100.0f * hData -> mHrtds [j]);
if (i > 127)
i = 127;
if (! WriteUInt8 ((uint8_t) i, fileName, fp))
return (0);
}
fclose (fp);
return (1);
}
// Save the OpenAL Soft built-in table.
static int SaveTab (const HrirDataT * hData, const char * fileName) {
FILE * fp = NULL;
int step, end, j, i;
char text [16];
if ((fp = fopen (fileName, "wb")) == NULL) {
fprintf (stderr, "Could not create file, '%s'.\n", fileName);
return (0);
}
if (! WriteString ("/* This data is Copyright 1994 by the MIT Media Laboratory. It is provided free\n"
" * with no restrictions on use, provided the authors are cited when the data is\n"
" * used in any research or commercial application. */\n"
"/* Bill Gardner <billg@media.mit.edu> and Keith Martin <kdm@media.mit.edu> */\n"
"\n"
" /* HRIR Coefficients */\n"
" {\n", fileName, fp))
return (0);
step = hData -> mIrSize;
end = hData -> mIrCount * step;
for (j = 0; j < end; j += step) {
if (! WriteString (" { ", fileName, fp))
return (0);
for (i = 0; i < step; i ++) {
snprintf (text, 15, "%+d, ", (int) round (32767.0f * hData -> mHrirs [j + i]));
if (! WriteString (text, fileName, fp))
return (0);
}
if (! WriteString ("},\n", fileName, fp))
return (0);
}
if (! WriteString (" },\n"
"\n"
" /* HRIR Delays */\n"
" { ", fileName, fp))
return (0);
for (j = 0; j < hData -> mIrCount; j ++) {
snprintf (text, 15, "%d, ", (int) round (44100.0f * hData -> mHrtds [j]));
if (! WriteString (text, fileName, fp))
return (0);
}
if (! WriteString ("}\n", fileName, fp))
return (0);
fclose (fp);
return (1);
}
// Loads and processes an MIT data set. At present, the HRIR and HRTD data
// is loaded and processed in a static buffer. That should change to using
// heap allocated memory in the future. A cleanup function will then be
// required.
static int MakeMit(const char *baseInName, HrirDataT *hData)
{
static float hrirs[MIT_IR_COUNT * MIT_IR_SIZE];
static float hrtds[MIT_IR_COUNT];
hData->mIrRate = MIT_IR_RATE;
hData->mIrCount = MIT_IR_COUNT;
hData->mIrSize = MIT_IR_SIZE;
hData->mEvCount = MIT_EV_COUNT;
hData->mEvStart = MIT_EV_START;
hData->mEvOffset = MIT_EV_OFFSET;
hData->mAzCount = MIT_AZ_COUNT;
hData->mRadius = MIT_RADIUS;
hData->mDistance = MIT_DISTANCE;
hData->mHrirs = hrirs;
hData->mHrtds = hrtds;
fprintf(stderr, "Loading base HRIR data...\n");
if(!LoadMitHrirs(baseInName, hData))
return 0;
fprintf(stderr, "Performing minimum phase reconstruction and truncation...\n");
ReconstructHrirs(MIN_IR_SIZE, hData);
fprintf(stderr, "Renormalizing minimum phase HRIR data...\n");
RenormalizeHrirs(hData);
fprintf(stderr, "Synthesizing missing elevations...\n");
SynthesizeHrirs(hData);
fprintf(stderr, "Calculating impulse delays...\n");
CalculateHrtds(hData);
return 1;
}
// Simple dispatch. Provided a command, the path to the MIT set of choice,
// and an optional output filename, this will produce an OpenAL Soft
// compatible HRTF set in the chosen format.
int main(int argc, char *argv[])
{
char baseName[1024];
const char *outName = NULL;
HrirDataT hData;
if(argc < 3 || strcmp(argv [1], "-h") == 0 || strcmp (argv [1], "--help") == 0)
{
fprintf(stderr, "Usage: %s <command> <path of MIT set> [ <output file> ]\n\n", argv[0]);
fprintf(stderr, "Commands:\n");
fprintf(stderr, " -m, --make-mhr Makes an OpenAL Soft compatible HRTF data set.\n");
fprintf(stderr, " Defaults output to: ./oal_soft_hrtf_44100.mhr\n");
fprintf(stderr, " -t, --make-tab Makes the built-in table used when compiling OpenAL Soft.\n");
fprintf(stderr, " Defaults output to: ./hrtf_tables.inc\n");
fprintf(stderr, " -h, --help Displays this help information.\n");
return 0;
}
snprintf(baseName, sizeof(baseName), "%s/elev", argv[2]);
if(strcmp(argv[1], "-m") == 0 || strcmp(argv[1], "--make-mhr") == 0)
{
if(argc > 3)
outName = argv[3];
else
outName = "./oal_soft_hrtf_44100.mhr";
if(!MakeMit(baseName, &hData))
return -1;
fprintf(stderr, "Creating data set file...\n");
if(!SaveMhr(&hData, outName))
return -1;
}
else if(strcmp(argv[1], "-t") == 0 || strcmp(argv[1], "--make-tab") == 0)
{
if(argc > 3)
outName = argv[3];
else
outName = "./hrtf_tables.inc";
if(!MakeMit(baseName, &hData))
return -1;
fprintf(stderr, "Creating table file...\n");
if(!SaveTab(&hData, outName))
return -1;
}
else
{
fprintf(stderr, "Invalid command '%s'\n", argv[1]);
return -1;
}
fprintf(stderr, "Done.\n");
return 0;
}