Single Pass Spectrogram Inversion

Functions
int	spsi (const LTFAT_REAL s[], ltfat_int L, ltfat_int W, ltfat_int a, ltfat_int M, LTFAT_REAL initphase[], LTFAT_COMPLEX c[])
int	spsi_withmask (const LTFAT_COMPLEX cin[], const int mask[], ltfat_int L, ltfat_int W, ltfat_int a, ltfat_int M, LTFAT_REAL initphase[], LTFAT_COMPLEX c[])

Detailed Description

Algorithm Description

The implementation follows papers [1] .

Function Documentation

int spsi	(	const LTFAT_REAL	s[],
		ltfat_int	L,
		ltfat_int	W,
		ltfat_int	a,
		ltfat_int	M,
		LTFAT_REAL	initphase[],
		LTFAT_COMPLEX	c[]
	)

SPSI algorithm implementation

M2 = M/2 + 1, N = L/a

Parameters

[in]	s	Target magnitude, size M2 x N x W
[in]	L	Transform length
[in]	W	Number of signal channels
[in]	a	Hop factor
[in]	M	Number of frequency channels
[in,out]	initphase	[in] phase of -1 frame, [out] phase of [N-1] frame, size M2 x W or NULL, but then a memory allocation will occur.
[out]	c	Coefficients with reconstructed phase, size M2 x N x W

Versions

phaseret_spsi_d(const double s[], ltfat_int L, ltfat_int W, ltfat_int a, ltfat_int M, double initphase[], ltfat_complex_d c[]);

phaseret_spsi_s(const float s[], ltfat_int L, ltfat_int W, ltfat_int a, ltfat_int M, float initphase[], ltfat_complex_s c[]);

Returns

Status code	Description
LTFATERR_SUCCESS	No error occurred
LTFATERR_NULLPOINTER	s or c was NULL
LTFATERR_NOTPOSARG	At least one of the following was not positive: L, W, a, M
LTFATERR_NOMEM	Heap allocation failed

int spsi_withmask	(	const LTFAT_COMPLEX	cin[],
		const int	mask[],
		ltfat_int	L,
		ltfat_int	W,
		ltfat_int	a,
		ltfat_int	M,
		LTFAT_REAL	initphase[],
		LTFAT_COMPLEX	c[]
	)

Masked SPSI algorithm implementation

Works as spsi() except c[ii]=cinit[ii] if mask[ii] evaluates to true.

M2 = M/2 + 1, N = L/a

Parameters

[in]	cinit	Initial coefficients, size M2 x N x W
[in]	mask	Mask of known coefficients
[in]	L	Transform length
[in]	W	Number of signal channels
[in]	a	Hop factor
[in]	M	Number of frequency channels
[in,out]	initphase	[in] phase of -1 frame, [out] phase of [N-1] frame, size M2 x W or NULL, but then a memory allocation will occur.
[out]	c	Coefficients with reconstructed phase, size M2 x N x W

Versions

phaseret_spsi_withmask_d(const ltfat_complex_d cin[], const int mask[], ltfat_int L, ltfat_int W, ltfat_int a, ltfat_int M, double initphase[], ltfat_complex_d c[]);

phaseret_spsi_withmask_s(const ltfat_complex_s cin[], const int mask[], ltfat_int L, ltfat_int W, ltfat_int a, ltfat_int M, float initphase[], ltfat_complex_s c[]);

Returns

Status code	Description
LTFATERR_SUCCESS	No error occurred
LTFATERR_NULLPOINTER	cinit, c or mask was NULL
LTFATERR_NOTPOSARG	At least one of the following was not positive: L, W, a, M
LTFATERR_NOMEM	Heap allocation failed