MFCC F32

Functions
void	arm_mfcc_f32 (const arm_mfcc_instance_f32 *S, float32_t *pSrc, float32_t *pDst, float32_t *pTmp)
	MFCC F32. More...
arm_status	arm_mfcc_init_f32 (arm_mfcc_instance_f32 *S, uint32_t fftLen, uint32_t nbMelFilters, uint32_t nbDctOutputs, const float32_t *dctCoefs, const uint32_t *filterPos, const uint32_t *filterLengths, const float32_t *filterCoefs, const float32_t *windowCoefs)
	Generic initialization of the MFCC F32 instance structure. More...
arm_status	arm_mfcc_init_32_f32 (arm_mfcc_instance_f32 *S, uint32_t nbMelFilters, uint32_t nbDctOutputs, const float32_t *dctCoefs, const uint32_t *filterPos, const uint32_t *filterLengths, const float32_t *filterCoefs, const float32_t *windowCoefs)
	Initialization of the MFCC F32 instance structure for 32 samples MFCC. More...
arm_status	arm_mfcc_init_64_f32 (arm_mfcc_instance_f32 *S, uint32_t nbMelFilters, uint32_t nbDctOutputs, const float32_t *dctCoefs, const uint32_t *filterPos, const uint32_t *filterLengths, const float32_t *filterCoefs, const float32_t *windowCoefs)
	Initialization of the MFCC F32 instance structure for 64 samples MFCC. More...
arm_status	arm_mfcc_init_128_f32 (arm_mfcc_instance_f32 *S, uint32_t nbMelFilters, uint32_t nbDctOutputs, const float32_t *dctCoefs, const uint32_t *filterPos, const uint32_t *filterLengths, const float32_t *filterCoefs, const float32_t *windowCoefs)
	Initialization of the MFCC F32 instance structure for 128 samples MFCC. More...
arm_status	arm_mfcc_init_256_f32 (arm_mfcc_instance_f32 *S, uint32_t nbMelFilters, uint32_t nbDctOutputs, const float32_t *dctCoefs, const uint32_t *filterPos, const uint32_t *filterLengths, const float32_t *filterCoefs, const float32_t *windowCoefs)
	Initialization of the MFCC F32 instance structure for 256 samples MFCC. More...
arm_status	arm_mfcc_init_512_f32 (arm_mfcc_instance_f32 *S, uint32_t nbMelFilters, uint32_t nbDctOutputs, const float32_t *dctCoefs, const uint32_t *filterPos, const uint32_t *filterLengths, const float32_t *filterCoefs, const float32_t *windowCoefs)
	Initialization of the MFCC F32 instance structure for 512 samples MFCC. More...
arm_status	arm_mfcc_init_1024_f32 (arm_mfcc_instance_f32 *S, uint32_t nbMelFilters, uint32_t nbDctOutputs, const float32_t *dctCoefs, const uint32_t *filterPos, const uint32_t *filterLengths, const float32_t *filterCoefs, const float32_t *windowCoefs)
	Initialization of the MFCC F32 instance structure for 1024 samples MFCC. More...
arm_status	arm_mfcc_init_2048_f32 (arm_mfcc_instance_f32 *S, uint32_t nbMelFilters, uint32_t nbDctOutputs, const float32_t *dctCoefs, const uint32_t *filterPos, const uint32_t *filterLengths, const float32_t *filterCoefs, const float32_t *windowCoefs)
	Initialization of the MFCC F32 instance structure for 2048 samples MFCC. More...
arm_status	arm_mfcc_init_4096_f32 (arm_mfcc_instance_f32 *S, uint32_t nbMelFilters, uint32_t nbDctOutputs, const float32_t *dctCoefs, const uint32_t *filterPos, const uint32_t *filterLengths, const float32_t *filterCoefs, const float32_t *windowCoefs)
	Initialization of the MFCC F32 instance structure for 4096 samples MFCC. More...

Description

Function Documentation

arm_mfcc_f32()

void arm_mfcc_f32	(	const arm_mfcc_instance_f32 *	S,
		float32_t *	pSrc,
		float32_t *	pDst,
		float32_t *	pTmp
	)

Parameters

[in]	S	points to the mfcc instance structure
[in]	pSrc	points to the input samples
[out]	pDst	points to the output MFCC values
[in,out]	pTmp	points to a temporary buffer of complex

Returns

none

Description

The number of input samples if the FFT length used when initializing the instance data structure.

The temporary buffer has a 2*fft length size when MFCC is implemented with CFFT. It has length FFT Length + 2 when implemented with RFFT (default implementation).

The source buffer is modified by this function.

arm_mfcc_init_1024_f32()

arm_status arm_mfcc_init_1024_f32	(	arm_mfcc_instance_f32 *	S,
		uint32_t	nbMelFilters,
		uint32_t	nbDctOutputs,
		const float32_t *	dctCoefs,
		const uint32_t *	filterPos,
		const uint32_t *	filterLengths,
		const float32_t *	filterCoefs,
		const float32_t *	windowCoefs
	)

Parameters

[out]	S	points to the mfcc instance structure
[in]	nbMelFilters	number of Mel filters
[in]	nbDctOutputs	number of Dct outputs
[in]	dctCoefs	points to an array of DCT coefficients
[in]	filterPos	points of the array of filter positions
[in]	filterLengths	points to the array of filter lengths
[in]	filterCoefs	points to the array of filter coefficients
[in]	windowCoefs	points to the array of window coefficients

Returns

error status

Description

The matrix of Mel filter coefficients is sparse. Most of the coefficients are zero. To avoid multiplying the spectrogram by those zeros, the filter is applied only to a given position in the spectrogram and on a given number of FFT bins (the filter length). It is the reason for the arrays filterPos and filterLengths.

window coefficients can describe (for instance) a Hamming window. The array has the same size as the FFT length.

The folder Scripts is containing a Python script which can be used to generate the filter, dct and window arrays.

arm_mfcc_init_128_f32()

arm_status arm_mfcc_init_128_f32	(	arm_mfcc_instance_f32 *	S,
		uint32_t	nbMelFilters,
		uint32_t	nbDctOutputs,
		const float32_t *	dctCoefs,
		const uint32_t *	filterPos,
		const uint32_t *	filterLengths,
		const float32_t *	filterCoefs,
		const float32_t *	windowCoefs
	)

Parameters

[out]	S	points to the mfcc instance structure
[in]	nbMelFilters	number of Mel filters
[in]	nbDctOutputs	number of Dct outputs
[in]	dctCoefs	points to an array of DCT coefficients
[in]	filterPos	points of the array of filter positions
[in]	filterLengths	points to the array of filter lengths
[in]	filterCoefs	points to the array of filter coefficients
[in]	windowCoefs	points to the array of window coefficients

Returns

error status

Description

The matrix of Mel filter coefficients is sparse. Most of the coefficients are zero. To avoid multiplying the spectrogram by those zeros, the filter is applied only to a given position in the spectrogram and on a given number of FFT bins (the filter length). It is the reason for the arrays filterPos and filterLengths.

window coefficients can describe (for instance) a Hamming window. The array has the same size as the FFT length.

The folder Scripts is containing a Python script which can be used to generate the filter, dct and window arrays.

arm_mfcc_init_2048_f32()

arm_status arm_mfcc_init_2048_f32	(	arm_mfcc_instance_f32 *	S,
		uint32_t	nbMelFilters,
		uint32_t	nbDctOutputs,
		const float32_t *	dctCoefs,
		const uint32_t *	filterPos,
		const uint32_t *	filterLengths,
		const float32_t *	filterCoefs,
		const float32_t *	windowCoefs
	)

Parameters

[out]	S	points to the mfcc instance structure
[in]	nbMelFilters	number of Mel filters
[in]	nbDctOutputs	number of Dct outputs
[in]	dctCoefs	points to an array of DCT coefficients
[in]	filterPos	points of the array of filter positions
[in]	filterLengths	points to the array of filter lengths
[in]	filterCoefs	points to the array of filter coefficients
[in]	windowCoefs	points to the array of window coefficients

Returns

error status

Description

The matrix of Mel filter coefficients is sparse. Most of the coefficients are zero. To avoid multiplying the spectrogram by those zeros, the filter is applied only to a given position in the spectrogram and on a given number of FFT bins (the filter length). It is the reason for the arrays filterPos and filterLengths.

window coefficients can describe (for instance) a Hamming window. The array has the same size as the FFT length.

The folder Scripts is containing a Python script which can be used to generate the filter, dct and window arrays.

arm_mfcc_init_256_f32()

arm_status arm_mfcc_init_256_f32	(	arm_mfcc_instance_f32 *	S,
		uint32_t	nbMelFilters,
		uint32_t	nbDctOutputs,
		const float32_t *	dctCoefs,
		const uint32_t *	filterPos,
		const uint32_t *	filterLengths,
		const float32_t *	filterCoefs,
		const float32_t *	windowCoefs
	)

Parameters

[out]	S	points to the mfcc instance structure
[in]	nbMelFilters	number of Mel filters
[in]	nbDctOutputs	number of Dct outputs
[in]	dctCoefs	points to an array of DCT coefficients
[in]	filterPos	points of the array of filter positions
[in]	filterLengths	points to the array of filter lengths
[in]	filterCoefs	points to the array of filter coefficients
[in]	windowCoefs	points to the array of window coefficients

Returns

error status

Description

The matrix of Mel filter coefficients is sparse. Most of the coefficients are zero. To avoid multiplying the spectrogram by those zeros, the filter is applied only to a given position in the spectrogram and on a given number of FFT bins (the filter length). It is the reason for the arrays filterPos and filterLengths.

window coefficients can describe (for instance) a Hamming window. The array has the same size as the FFT length.

The folder Scripts is containing a Python script which can be used to generate the filter, dct and window arrays.

arm_mfcc_init_32_f32()

arm_status arm_mfcc_init_32_f32	(	arm_mfcc_instance_f32 *	S,
		uint32_t	nbMelFilters,
		uint32_t	nbDctOutputs,
		const float32_t *	dctCoefs,
		const uint32_t *	filterPos,
		const uint32_t *	filterLengths,
		const float32_t *	filterCoefs,
		const float32_t *	windowCoefs
	)

Parameters

[out]	S	points to the mfcc instance structure
[in]	nbMelFilters	number of Mel filters
[in]	nbDctOutputs	number of Dct outputs
[in]	dctCoefs	points to an array of DCT coefficients
[in]	filterPos	points of the array of filter positions
[in]	filterLengths	points to the array of filter lengths
[in]	filterCoefs	points to the array of filter coefficients
[in]	windowCoefs	points to the array of window coefficients

Returns

error status

Description

The matrix of Mel filter coefficients is sparse. Most of the coefficients are zero. To avoid multiplying the spectrogram by those zeros, the filter is applied only to a given position in the spectrogram and on a given number of FFT bins (the filter length). It is the reason for the arrays filterPos and filterLengths.

window coefficients can describe (for instance) a Hamming window. The array has the same size as the FFT length.

The folder Scripts is containing a Python script which can be used to generate the filter, dct and window arrays.

arm_mfcc_init_4096_f32()

arm_status arm_mfcc_init_4096_f32	(	arm_mfcc_instance_f32 *	S,
		uint32_t	nbMelFilters,
		uint32_t	nbDctOutputs,
		const float32_t *	dctCoefs,
		const uint32_t *	filterPos,
		const uint32_t *	filterLengths,
		const float32_t *	filterCoefs,
		const float32_t *	windowCoefs
	)

Parameters

[out]	S	points to the mfcc instance structure
[in]	nbMelFilters	number of Mel filters
[in]	nbDctOutputs	number of Dct outputs
[in]	dctCoefs	points to an array of DCT coefficients
[in]	filterPos	points of the array of filter positions
[in]	filterLengths	points to the array of filter lengths
[in]	filterCoefs	points to the array of filter coefficients
[in]	windowCoefs	points to the array of window coefficients

Returns

error status

Description

The matrix of Mel filter coefficients is sparse. Most of the coefficients are zero. To avoid multiplying the spectrogram by those zeros, the filter is applied only to a given position in the spectrogram and on a given number of FFT bins (the filter length). It is the reason for the arrays filterPos and filterLengths.

window coefficients can describe (for instance) a Hamming window. The array has the same size as the FFT length.

The folder Scripts is containing a Python script which can be used to generate the filter, dct and window arrays.

arm_mfcc_init_512_f32()

arm_status arm_mfcc_init_512_f32	(	arm_mfcc_instance_f32 *	S,
		uint32_t	nbMelFilters,
		uint32_t	nbDctOutputs,
		const float32_t *	dctCoefs,
		const uint32_t *	filterPos,
		const uint32_t *	filterLengths,
		const float32_t *	filterCoefs,
		const float32_t *	windowCoefs
	)

Parameters

[out]	S	points to the mfcc instance structure
[in]	nbMelFilters	number of Mel filters
[in]	nbDctOutputs	number of Dct outputs
[in]	dctCoefs	points to an array of DCT coefficients
[in]	filterPos	points of the array of filter positions
[in]	filterLengths	points to the array of filter lengths
[in]	filterCoefs	points to the array of filter coefficients
[in]	windowCoefs	points to the array of window coefficients

Returns

error status

Description

The matrix of Mel filter coefficients is sparse. Most of the coefficients are zero. To avoid multiplying the spectrogram by those zeros, the filter is applied only to a given position in the spectrogram and on a given number of FFT bins (the filter length). It is the reason for the arrays filterPos and filterLengths.

window coefficients can describe (for instance) a Hamming window. The array has the same size as the FFT length.

The folder Scripts is containing a Python script which can be used to generate the filter, dct and window arrays.

arm_mfcc_init_64_f32()

arm_status arm_mfcc_init_64_f32	(	arm_mfcc_instance_f32 *	S,
		uint32_t	nbMelFilters,
		uint32_t	nbDctOutputs,
		const float32_t *	dctCoefs,
		const uint32_t *	filterPos,
		const uint32_t *	filterLengths,
		const float32_t *	filterCoefs,
		const float32_t *	windowCoefs
	)

Parameters

[out]	S	points to the mfcc instance structure
[in]	nbMelFilters	number of Mel filters
[in]	nbDctOutputs	number of Dct outputs
[in]	dctCoefs	points to an array of DCT coefficients
[in]	filterPos	points of the array of filter positions
[in]	filterLengths	points to the array of filter lengths
[in]	filterCoefs	points to the array of filter coefficients
[in]	windowCoefs	points to the array of window coefficients

Returns

error status

Description

The matrix of Mel filter coefficients is sparse. Most of the coefficients are zero. To avoid multiplying the spectrogram by those zeros, the filter is applied only to a given position in the spectrogram and on a given number of FFT bins (the filter length). It is the reason for the arrays filterPos and filterLengths.

window coefficients can describe (for instance) a Hamming window. The array has the same size as the FFT length.

The folder Scripts is containing a Python script which can be used to generate the filter, dct and window arrays.

arm_mfcc_init_f32()

arm_status arm_mfcc_init_f32	(	arm_mfcc_instance_f32 *	S,
		uint32_t	fftLen,
		uint32_t	nbMelFilters,
		uint32_t	nbDctOutputs,
		const float32_t *	dctCoefs,
		const uint32_t *	filterPos,
		const uint32_t *	filterLengths,
		const float32_t *	filterCoefs,
		const float32_t *	windowCoefs
	)

Parameters

[out]	S	points to the mfcc instance structure
[in]	fftLen	fft length
[in]	nbMelFilters	number of Mel filters
[in]	nbDctOutputs	number of Dct outputs
[in]	dctCoefs	points to an array of DCT coefficients
[in]	filterPos	points of the array of filter positions
[in]	filterLengths	points to the array of filter lengths
[in]	filterCoefs	points to the array of filter coefficients
[in]	windowCoefs	points to the array of window coefficients

Returns

error status

Description

The matrix of Mel filter coefficients is sparse. Most of the coefficients are zero. To avoid multiplying the spectrogram by those zeros, the filter is applied only to a given position in the spectrogram and on a given number of FFT bins (the filter length). It is the reason for the arrays filterPos and filterLengths.

window coefficients can describe (for instance) a Hamming window. The array has the same size as the FFT length.

The folder Scripts is containing a Python script which can be used to generate the filter, dct and window arrays.

This function should be used only if you don't know the FFT sizes that you'll need at build time. The use of this function will prevent the linker from removing the FFT tables that are not needed and the library code size will be bigger than needed.

If you use CMSIS-DSP as a static library, and if you know the MFCC sizes that you need at build time, then it is better to use the initialization functions defined for each MFCC size.