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AuroraOpenALSoft/Alc/hrtf.h

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Move HRTF macros and function declarations to a separate header
2014-02-24 05:11:01 +00:00
#ifndef ALC_HRTF_H
#define ALC_HRTF_H
#include "AL/al.h"
#include "AL/alc.h"
Move the B-Format HRTF virtual speaker stuff to InitHrtfPanning This keeps the decoder matrices and coefficient mapping together for if it changes in the future.
2017-01-19 03:16:24 +00:00
#include "alMain.h"
Allow the hrtf_tables option to be device-specific
2015-09-20 11:10:21 +00:00
#include "alstring.h"
Reference count HRTFs and unload them when unused
2017-04-06 20:00:29 +00:00
#include "atomic.h"
Allow the hrtf_tables option to be device-specific
2015-09-20 11:10:21 +00:00
Avoid function calls to get the HRTF sample rate and IR size
2016-07-07 17:26:42 +00:00
Store the loaded hrtf entry container in the enumerated hrtf entry
2017-04-05 18:29:58 +00:00
/* The maximum number of virtual speakers used to generate HRTF coefficients
* for decoding B-Format.
*/
#define HRTF_AMBI_MAX_CHANNELS 16
Load HRTF files as needed Currently only applies to external files, rather than embedded datasets. Also, HRTFs aren't unloaded after being loaded, until library shutdown.
2017-04-05 19:27:30 +00:00
struct HrtfEntry;
Avoid function calls to get the HRTF sample rate and IR size
2016-07-07 17:26:42 +00:00
struct Hrtf {
Reference count HRTFs and unload them when unused
2017-04-06 20:00:29 +00:00
RefCount ref;
Avoid function calls to get the HRTF sample rate and IR size
2016-07-07 17:26:42 +00:00
ALuint sampleRate;
Use ALsizei for sizes and offsets with the mixer Unsigned 32-bit offsets actually have some potential overhead on 64-bit targets for pointer/array accesses due to rules on integer wrapping. No idea how much impact it has in practice, but it's nice to be correct about it.
2017-01-16 15:45:07 +00:00
ALsizei irSize;
Store the HRTF distance in the Hrtf handle
2017-10-23 20:26:35 +00:00
ALfloat distance;
Avoid function calls to get the HRTF sample rate and IR size
2016-07-07 17:26:42 +00:00
ALubyte evCount;
const ALubyte *azCount;
const ALushort *evOffset;
Store the HRTF coeffs as a stereo pair This will make it easier to handle HRTF data sets that have separate left and right ear responses. Will need an mhr version update to take advantage of that.
2017-04-07 15:46:50 +00:00
const ALfloat (*coeffs)[2];
const ALubyte (*delays)[2];
Avoid function calls to get the HRTF sample rate and IR size
2016-07-07 17:26:42 +00:00
};
Move HRTF macros and function declarations to a separate header
2014-02-24 05:11:01 +00:00
Move the B-Format HRTF virtual speaker stuff to InitHrtfPanning This keeps the decoder matrices and coefficient mapping together for if it changes in the future.
2017-01-19 03:16:24 +00:00
Use the enumerated HRTF list for selecting an HRTF Also report the proper specifier of the one currently in use.
2015-10-06 13:48:53 +00:00
void FreeHrtfs(void);
Store the loaded hrtf entry container in the enumerated hrtf entry
2017-04-05 18:29:58 +00:00
vector_EnumeratedHrtf EnumerateHrtf(const_al_string devname);
void FreeHrtfList(vector_EnumeratedHrtf *list);
Load HRTF files as needed Currently only applies to external files, rather than embedded datasets. Also, HRTFs aren't unloaded after being loaded, until library shutdown.
2017-04-05 19:27:30 +00:00
struct Hrtf *GetLoadedHrtf(struct HrtfEntry *entry);
Reference count HRTFs and unload them when unused
2017-04-06 20:00:29 +00:00
void Hrtf_IncRef(struct Hrtf *hrtf);
void Hrtf_DecRef(struct Hrtf *hrtf);
Enumerate and list HRTFs per-device
2015-10-06 07:23:11 +00:00
Rework HRTF coefficient fading This improves fading between HRIRs as sources pan around. In particular, it improves the issue with individual coefficients having various rounding errors in the stepping values, as well as issues with interpolating delay values. It does this by doing two mixing passes for each source. First using the last coefficients that fade to silence, and then again using the new coefficients that fade from silence. When added together, it creates a linear fade from one to the other. Additionally, the gain is applied separately so the individual coefficients don't step with rounding errors. Although this does increase CPU cost since it's doing two mixes per source, each mix is a bit cheaper now since the stepping is simplified to a single gain value, and the overall quality is improved.
2017-03-12 02:04:06 +00:00
void GetHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat spread, ALfloat (*coeffs)[2], ALsizei *delays);
Move HRTF macros and function declarations to a separate header
2014-02-24 05:11:01 +00:00
Move the B-Format HRTF virtual speaker stuff to InitHrtfPanning This keeps the decoder matrices and coefficient mapping together for if it changes in the future.
2017-01-19 03:16:24 +00:00
/**
* Produces HRTF filter coefficients for decoding B-Format, given a set of
* virtual speaker positions and HF/LF matrices for decoding to them. The
* returned coefficients are ordered and scaled according to the matrices.
Decode directly from B-Format to HRTF instead of a cube Last time this attempted to average the HRIRs according to their contribution to a given B-Format channel as if they were loudspeakers, as well as averaging the HRIR delays. The latter part resulted in the loss of the ITD (inter-aural time delay), a key component of HRTF. This time, the HRIRs are averaged similar to above, except instead of averaging the delays, they're applied to the resulting coefficients (for example, a delay of 8 would apply the HRIR starting at the 8th sample of the target HRIR). This does roughly double the IR length, as the largest delay is about 35 samples while the filter is normally 32 samples. However, this is still smaller the original data set IR (which was 256 samples), it also only needs to be applied to 4 channels for first-order ambisonics, rather than the 8-channel cube. So it's doing twice as much work per sample, but only working on half the number of samples. Additionally, since the resulting HRIRs no longer rely on an extra delay line, a more efficient HRTF mixing function can be made that doesn't use one. Such a function can also avoid the per-sample stepping parameters the original uses.
2016-08-12 06:20:35 +00:00
*/
Don't bother returning the IR length for B-Format decoding
2017-07-31 08:20:42 +00:00
void BuildBFormatHrtf(const struct Hrtf *Hrtf, DirectHrtfState *state, ALsizei NumChannels, const ALfloat (*restrict AmbiPoints)[2], const ALfloat (*restrict AmbiMatrix)[2][MAX_AMBI_COEFFS], ALsizei AmbiCount);
Decode directly from B-Format to HRTF instead of a cube Last time this attempted to average the HRIRs according to their contribution to a given B-Format channel as if they were loudspeakers, as well as averaging the HRIR delays. The latter part resulted in the loss of the ITD (inter-aural time delay), a key component of HRTF. This time, the HRIRs are averaged similar to above, except instead of averaging the delays, they're applied to the resulting coefficients (for example, a delay of 8 would apply the HRIR starting at the 8th sample of the target HRIR). This does roughly double the IR length, as the largest delay is about 35 samples while the filter is normally 32 samples. However, this is still smaller the original data set IR (which was 256 samples), it also only needs to be applied to 4 channels for first-order ambisonics, rather than the 8-channel cube. So it's doing twice as much work per sample, but only working on half the number of samples. Additionally, since the resulting HRIRs no longer rely on an extra delay line, a more efficient HRTF mixing function can be made that doesn't use one. Such a function can also avoid the per-sample stepping parameters the original uses.
2016-08-12 06:20:35 +00:00
Move HRTF macros and function declarations to a separate header
2014-02-24 05:11:01 +00:00
#endif /* ALC_HRTF_H */
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