Alc/hrtf.h

   1 #ifndef ALC_HRTF_H
   2 #define ALC_HRTF_H
   3
   4 #include "AL/al.h"
   5 #include "AL/alc.h"
   6
   7 #include "alMain.h"
   8 #include "alstring.h"
   9 #include "atomic.h"
  10
  11
  12 #define HRTFDELAY_BITS    (20)
  13 #define HRTFDELAY_FRACONE (1<<HRTFDELAY_BITS)
  14 #define HRTFDELAY_MASK    (HRTFDELAY_FRACONE-1)
  15
  16 /* The maximum number of virtual speakers used to generate HRTF coefficients
  17  * for decoding B-Format.
  18  */
  19 #define HRTF_AMBI_MAX_CHANNELS 16
  20
  21
  22 struct HrtfEntry;
  23
  24 struct Hrtf {
  25     RefCount ref;
  26
  27     ALuint sampleRate;
  28     ALsizei irSize;
  29     ALubyte evCount;
  30
  31     const ALubyte *azCount;
  32     const ALushort *evOffset;
  33     const ALfloat (*coeffs)[2];
  34     const ALubyte (*delays)[2];
  35 };
  36
  37
  38 void FreeHrtfs(void);
  39
  40 vector_EnumeratedHrtf EnumerateHrtf(const_al_string devname);
  41 void FreeHrtfList(vector_EnumeratedHrtf *list);
  42 struct Hrtf *GetLoadedHrtf(struct HrtfEntry *entry);
  43 void Hrtf_IncRef(struct Hrtf *hrtf);
  44 void Hrtf_DecRef(struct Hrtf *hrtf);
  45
  46 void GetHrtfCoeffs(const struct Hrtf *Hrtf, ALfloat elevation, ALfloat azimuth, ALfloat spread, ALfloat (*coeffs)[2], ALsizei *delays);
  47
  48 /**
  49  * Produces HRTF filter coefficients for decoding B-Format, given a set of
  50  * virtual speaker positions and HF/LF matrices for decoding to them. The
  51  * returned coefficients are ordered and scaled according to the matrices.
  52  * Returns the maximum impulse-response length of the generated coefficients.
  53  */
  54 ALsizei BuildBFormatHrtf(const struct Hrtf *Hrtf, DirectHrtfState *state, ALsizei NumChannels, const ALfloat (*restrict AmbiPoints)[2], const ALfloat (*restrict AmbiMatrix)[2][MAX_AMBI_COEFFS], ALsizei AmbiCount);
  55
  56 #endif /* ALC_HRTF_H */