binauraliser_internal.h File Reference

Convolves input audio (up to 64 channels) with interpolated HRTFs in the time-frequency domain. More...

#include "binauraliser.h"
#include "saf.h"
#include "saf_externals.h"

Go to the source code of this file.

Data Structures
struct	binauraliser_data
	Main structure for binauraliser. More...

Macros
#define	BINAURALISER_FRAME_SIZE   ( 128 )
	Framesize, in time-domain samples.
#define	HOP_SIZE   ( 128 )
	STFT hop size.
#define	HYBRID_BANDS   ( HOP_SIZE + 5 )
	Number of frequency bands.
#define	TIME_SLOTS   ( BINAURALISER_FRAME_SIZE / HOP_SIZE )
	Number of STFT timeslots.

Functions
void	binauraliser_setCodecStatus (void *const hBin, CODEC_STATUS newStatus)
	Sets codec status (see CODEC_STATUS enum)
void	binauraliser_interpHRTFs (void *const hBin, INTERP_MODES mode, float azimuth_deg, float elevation_deg, float_complex h_intrp[HYBRID_BANDS][NUM_EARS])
	Interpolates between (up to) 3 HRTFs via amplitude-normalised VBAP gains.
void	binauraliser_initHRTFsAndGainTables (void *const hBin)
	Initialise the HRTFs: either loading the default set or loading from a SOFA file; and then generate a VBAP gain table for interpolation.
void	binauraliser_initTFT (void *const hBin)
	Initialise the filterbank used by binauraliser.
void	binauraliser_loadPreset (SOURCE_CONFIG_PRESETS preset, float dirs_deg[MAX_NUM_INPUTS][2], int *newNCH, int *nDims)
	Returns the source directions for a specified source config preset.

Detailed Description

Convolves input audio (up to 64 channels) with interpolated HRTFs in the time-frequency domain.

The HRTFs are interpolated by applying amplitude-preserving VBAP gains to the HRTF magnitude responses and inter-aural time differences (ITDs) individually, before being re-combined. The example also allows the user to specify an external SOFA file for the convolution, and rotations of the source directions to accomodate head-tracking.

Author

Leo McCormack

Date

25.09.2017

License

ISC

Definition in file binauraliser_internal.h.

Macro Definition Documentation

BINAURALISER_FRAME_SIZE

#define BINAURALISER_FRAME_SIZE   ( 128 )

Framesize, in time-domain samples.

Definition at line 52 of file binauraliser_internal.h.

HOP_SIZE

#define HOP_SIZE   ( 128 )

STFT hop size.

Definition at line 55 of file binauraliser_internal.h.

HYBRID_BANDS

#define HYBRID_BANDS   ( HOP_SIZE + 5 )

Number of frequency bands.

Definition at line 56 of file binauraliser_internal.h.

TIME_SLOTS

#define TIME_SLOTS   ( BINAURALISER_FRAME_SIZE / HOP_SIZE )

Number of STFT timeslots.

Definition at line 57 of file binauraliser_internal.h.

Function Documentation

binauraliser_initHRTFsAndGainTables()

void binauraliser_initHRTFsAndGainTables

(

void *const

hBin

)

Initialise the HRTFs: either loading the default set or loading from a SOFA file; and then generate a VBAP gain table for interpolation.

Note

Call binauraliser_initTFT() (if needed) before calling this function

Definition at line 125 of file binauraliser_internal.c.

binauraliser_initTFT()

void binauraliser_initTFT

(

void *const

hBin

)

Initialise the filterbank used by binauraliser.

Note

Call this function before binauraliser_initHRTFsAndGainTables()

Definition at line 267 of file binauraliser_internal.c.

binauraliser_interpHRTFs()

void binauraliser_interpHRTFs	(	void *const	hBin,
		INTERP_MODES	mode,
		float	azimuth_deg,
		float	elevation_deg,
		float_complex	h_intrp[HYBRID_BANDS][NUM_EARS] )

Interpolates between (up to) 3 HRTFs via amplitude-normalised VBAP gains.

The HRTF magnitude responses and HRIR ITDs are interpolated seperately before re-introducing the phase.

Parameters

[in]	hBin	binauraliser handle
[in]	mode	see INTERP_MODES
[in]	azimuth_deg	Source azimuth in DEGREES
[in]	elevation_deg	Source elevation in DEGREES
[out]	h_intrp	Interpolated HRTF

Definition at line 46 of file binauraliser_internal.c.

binauraliser_loadPreset()

void binauraliser_loadPreset	(	SOURCE_CONFIG_PRESETS	preset,
		float	dirs_deg[MAX_NUM_INPUTS][2],
		int *	newNCH,
		int *	nDims )

Returns the source directions for a specified source config preset.

The function also returns the number of source in the configuration Note: default uniformly distributed points are used to pad the dirs_deg matrix up to the MAX_NUM_INPUTS, if nCH is less than this. This can help avoid scenarios of many sources being panned in the same direction, or triangulations errors.

Parameters

[in]	preset	See SOURCE_CONFIG_PRESETS enum.
[out]	dirs_deg	Source directions, [azimuth elevation] convention, in DEGREES;
[out]	newNCH	(&) new number of channels
[out]	nDims	(&) estimate of the number of dimensions (2 or 3)

Definition at line 283 of file binauraliser_internal.c.

binauraliser_setCodecStatus()

void binauraliser_setCodecStatus	(	void *const	hBin,
		CODEC_STATUS	newStatus )

Sets codec status (see CODEC_STATUS enum)

Definition at line 35 of file binauraliser_internal.c.