Partial Convolution [Filtering Functions]

Functions
arm_status	arm_conv_partial_f32 (float32_t *pSrcA, uint32_t srcALen, float32_t *pSrcB, uint32_t srcBLen, float32_t *pDst, uint32_t firstIndex, uint32_t numPoints)
arm_status	arm_conv_partial_q31 (q31_t *pSrcA, uint32_t srcALen, q31_t *pSrcB, uint32_t srcBLen, q31_t *pDst, uint32_t firstIndex, uint32_t numPoints)
arm_status	arm_conv_partial_fast_q31 (q31_t *pSrcA, uint32_t srcALen, q31_t *pSrcB, uint32_t srcBLen, q31_t *pDst, uint32_t firstIndex, uint32_t numPoints)
arm_status	arm_conv_partial_q15 (q15_t *pSrcA, uint32_t srcALen, q15_t *pSrcB, uint32_t srcBLen, q15_t *pDst, uint32_t firstIndex, uint32_t numPoints, q15_t *pScratch1, q15_t *pScratch2)
arm_status	arm_conv_partial_fast_q15 (q15_t *pSrcA, uint32_t srcALen, q15_t *pSrcB, uint32_t srcBLen, q15_t *pDst, uint32_t firstIndex, uint32_t numPoints, q15_t *pScratch1, q15_t *pScratch2)
arm_status	arm_conv_partial_q7 (q7_t *pSrcA, uint32_t srcALen, q7_t *pSrcB, uint32_t srcBLen, q7_t *pDst, uint32_t firstIndex, uint32_t numPoints, q15_t *pScratch1, q15_t *pScratch2)

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Detailed Description

Partial Convolution is equivalent to Convolution except that a subset of the output samples is generated. Each function has two additional arguments. firstIndex specifies the starting index of the subset of output samples. numPoints is the number of output samples to compute. The function computes the output in the range [firstIndex, ..., firstIndex+numPoints-1]. The output array pDst contains numPoints values.

The allowable range of output indices is [0 srcALen+srcBLen-2]. If the requested subset does not fall in this range then the functions return ARM_MATH_ARGUMENT_ERROR. Otherwise the functions return ARM_MATH_SUCCESS.

Note:

Refer arm_conv_f32() for details on fixed point behavior.

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Function Documentation

arm_status arm_conv_partial_f32	(	float32_t *	pSrcA,
		uint32_t	srcALen,
		float32_t *	pSrcB,
		uint32_t	srcBLen,
		float32_t *	pDst,
		uint32_t	firstIndex,
		uint32_t	numPoints
	)

Partial convolution of floating-point sequences.

Parameters:

[in]	*pSrcA	points to the first input sequence.
[in]	srcALen	length of the first input sequence.
[in]	*pSrcB	points to the second input sequence.
[in]	srcBLen	length of the second input sequence.
[out]	*pDst	points to the location where the output result is written.
[in]	firstIndex	is the first output sample to start with.
[in]	numPoints	is the number of output points to be computed.

Returns:

Returns either ARM_MATH_SUCCESS if the function completed correctly or ARM_MATH_ARGUMENT_ERROR if the requested subset is not in the range [0 srcALen+srcBLen-2].

Definition at line 65 of file arm_conv_partial_f32.c.

arm_status arm_conv_partial_q31	(	q31_t *	pSrcA,
		uint32_t	srcALen,
		q31_t *	pSrcB,
		uint32_t	srcBLen,
		q31_t *	pDst,
		uint32_t	firstIndex,
		uint32_t	numPoints
	)

Partial convolution of Q31 sequences.

Parameters:

[in]	*pSrcA	points to the first input sequence.
[in]	srcALen	length of the first input sequence.
[in]	*pSrcB	points to the second input sequence.
[in]	srcBLen	length of the second input sequence.
[out]	*pDst	points to the location where the output result is written.
[in]	firstIndex	is the first output sample to start with.
[in]	numPoints	is the number of output points to be computed.

Returns:

Returns either ARM_MATH_SUCCESS if the function completed correctly or ARM_MATH_ARGUMENT_ERROR if the requested subset is not in the range [0 srcALen+srcBLen-2].

See arm_conv_partial_fast_q31() for a faster but less precise implementation of this function.

* Read y[srcBLen - 4] sample */

* Read x[6] sample */

* acc1 += x[4] * y[srcBLen - 4] */

* acc2 += x[5] * y[srcBLen - 4] */

* acc3 += x[6] * y[srcBLen - 4] */

Definition at line 50 of file arm_conv_partial_q31.c.

arm_status arm_conv_partial_fast_q31	(	q31_t *	pSrcA,
		uint32_t	srcALen,
		q31_t *	pSrcB,
		uint32_t	srcBLen,
		q31_t *	pDst,
		uint32_t	firstIndex,
		uint32_t	numPoints
	)

Partial convolution of Q31 sequences (fast version)

Partial convolution of Q31 sequences (fast version).

Parameters:

[in]	*pSrcA	points to the first input sequence.
[in]	srcALen	length of the first input sequence.
[in]	*pSrcB	points to the second input sequence.
[in]	srcBLen	length of the second input sequence.
[out]	*pDst	points to the location where the output result is written.
[in]	firstIndex	is the first output sample to start with.
[in]	numPoints	is the number of output points to be computed.

Returns:

Returns either ARM_MATH_SUCCESS if the function completed correctly or ARM_MATH_ARGUMENT_ERROR if the requested subset is not in the range [0 srcALen+srcBLen-2].

See arm_conv_partial_q31() for a slower implementation of this function which uses a 64-bit accumulator to provide higher precision.

Definition at line 50 of file arm_conv_partial_fast_q31.c.

arm_status arm_conv_partial_q15	(	q15_t *	pSrcA,
		uint32_t	srcALen,
		q15_t *	pSrcB,
		uint32_t	srcBLen,
		q15_t *	pDst,
		uint32_t	firstIndex,
		uint32_t	numPoints,
		q15_t *	pScratch1,
		q15_t *	pScratch2
	)

Partial convolution of Q15 sequences.

Parameters:

[in]	*pSrcA	points to the first input sequence.
[in]	srcALen	length of the first input sequence.
[in]	*pSrcB	points to the second input sequence.
[in]	srcBLen	length of the second input sequence.
[out]	*pDst	points to the location where the output result is written.
[in]	firstIndex	is the first output sample to start with.
[in]	numPoints	is the number of output points to be computed.
[in]	*pScratch1	points to scratch buffer of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen) - 2.
[in]	*pScratch2	points to scratch buffer of size min(srcALen, srcBLen).

Returns:

Returns either ARM_MATH_SUCCESS if the function completed correctly or ARM_MATH_ARGUMENT_ERROR if the requested subset is not in the range [0 srcALen+srcBLen-2].

Alignment of buffers

To get best performance of cycles input, output, scratch1 and scratch2 buffers should be aligned by 32-bit

Refer to arm_conv_partial_fast_q15() for a faster but less precise version of this function.

Conditions for optimum performance

Input, output, state buffers should be aligned by 32-bit

Restrictions

If the silicon does not support unaligned memory access enable the macro UNALIGNED_SUPPORT_DISABLE In this case input, output, state buffers should be aligned by 32-bit

Definition at line 65 of file arm_conv_partial_q15.c.

arm_status arm_conv_partial_fast_q15	(	q15_t *	pSrcA,
		uint32_t	srcALen,
		q15_t *	pSrcB,
		uint32_t	srcBLen,
		q15_t *	pDst,
		uint32_t	firstIndex,
		uint32_t	numPoints,
		q15_t *	pScratch1,
		q15_t *	pScratch2
	)

Partial convolution of Q15 sequences (fast version)

Partial convolution of Q15 sequences (fast version).

Parameters:

[in]	*pSrcA	points to the first input sequence.
[in]	srcALen	length of the first input sequence.
[in]	*pSrcB	points to the second input sequence.
[in]	srcBLen	length of the second input sequence.
[out]	*pDst	points to the location where the output result is written.
[in]	firstIndex	is the first output sample to start with.
[in]	numPoints	is the number of output points to be computed.
[in]	*pScratch1	points to scratch buffer of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen) - 2.
[in]	*pScratch2	points to scratch buffer of size min(srcALen, srcBLen).

Returns:

Returns either ARM_MATH_SUCCESS if the function completed correctly or ARM_MATH_ARGUMENT_ERROR if the requested subset is not in the range [0 srcALen+srcBLen-2].

See arm_conv_partial_q15() for a slower implementation of this function which uses a 64-bit accumulator to avoid wrap around distortion.

Conditions for optimum performance

Input, output, scratch1 and scratch2 buffers should be aligned by 32-bit

Restrictions

If the silicon does not support unaligned memory access enable the macro UNALIGNED_SUPPORT_DISABLE In this case input, output, scratch1 and scratch2 buffers should be aligned by 32-bit

Definition at line 61 of file arm_conv_partial_fast_q15.c.

arm_status arm_conv_partial_q7	(	q7_t *	pSrcA,
		uint32_t	srcALen,
		q7_t *	pSrcB,
		uint32_t	srcBLen,
		q7_t *	pDst,
		uint32_t	firstIndex,
		uint32_t	numPoints,
		q15_t *	pScratch1,
		q15_t *	pScratch2
	)

Partial convolution of Q7 sequences.

Parameters:

[in]	*pSrcA	points to the first input sequence.
[in]	srcALen	length of the first input sequence.
[in]	*pSrcB	points to the second input sequence.
[in]	srcBLen	length of the second input sequence.
[out]	*pDst	points to the location where the output result is written.
[in]	firstIndex	is the first output sample to start with.
[in]	numPoints	is the number of output points to be computed.
[in]	*pScratch1	points to scratch buffer(of type q15_t) of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen) - 2.
[in]	*pScratch2	points to scratch buffer (of type q15_t) of size min(srcALen, srcBLen).

Returns:

Returns either ARM_MATH_SUCCESS if the function completed correctly or ARM_MATH_ARGUMENT_ERROR if the requested subset is not in the range [0 srcALen+srcBLen-2].

Conditions for optimum performance

Input, output, scratch1 and scratch2 buffers should be aligned by 32-bit

Restrictions

If the silicon does not support unaligned memory access enable the macro UNALIGNED_SUPPORT_DISABLE In this case input, output, scratch1 and scratch2 buffers should be aligned by 32-bit

Definition at line 60 of file arm_conv_partial_q7.c.