VXLIB_channelExtract_1of4_i8u_o8u

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Detailed Description

Functions
VXLIB_STATUS	VXLIB_channelExtract_1of4_i8u_o8u (const uint8_t src[restrict], const VXLIB_bufParams2D_t *src_addr, uint8_t dst[restrict], const VXLIB_bufParams2D_t *dst_addr, uint8_t channelOffset)
VXLIB_STATUS	VXLIB_channelExtract_1of4_i8u_o8u_checkParams (const uint8_t src[], const VXLIB_bufParams2D_t *src_addr, const uint8_t dst[], const VXLIB_bufParams2D_t *dst_addr, uint8_t channelOffset)

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Function Documentation

VXLIB_STATUS VXLIB_channelExtract_1of4_i8u_o8u	(	const uint8_t	src[restrict],
		const VXLIB_bufParams2D_t *	src_addr,
		uint8_t	dst[restrict],
		const VXLIB_bufParams2D_t *	dst_addr,
		uint8_t	channelOffset
	)

Description:

Extracts a single channel from a 4-channel interleaved image format.

Method:

The channel extract is computed using the following equation:

    dst(x) = src(4*x + channelOffset)

   

Parameters:

[in]	src[]	Pointer to array containing input image (UQ8.0)
[in]	src_addr[]	Pointer to structure containing dimensional information of src
[out]	dst[]	Pointer to array containing output image (UQ8.0)
[in]	dst_addr[]	Pointer to structure containing dimensional information of dst
[in]	channelOffset	Identifies which channel to extract (0, 1, 2, or 3)

Assumptions:

• I/O buffer pointers are assumed to be not aliased.

Performance Considerations:

• For best performance, the following parameter settings are recommended:
  • Set widths equal to strides
  • Align all pointers to 8 byte boundaries
  • Set all stride values to a multiple of 8
  • Set all width values to a multiple of 8

VXLIB_STATUS VXLIB_channelExtract_1of4_i8u_o8u_checkParams	(	const uint8_t	src[],
		const VXLIB_bufParams2D_t *	src_addr,
		const uint8_t	dst[],
		const VXLIB_bufParams2D_t *	dst_addr,
		uint8_t	channelOffset
	)

Description:

Checks the parameters for programming errors for the VXLIB_channelExtract_1of4_i8u_o8u function.

Method:

The following checks are made:

• There shall be no NULL pointers
• The src image can be VXLIB_UINT16 or VXLIB_UINT32
  • If VXLIB_UINT16:
    • The dim_x of the src image shall be 2 * dim_x of dst image
  • If VXLIB_UINT32:
    • The dim_x of the src image shall be equal to the dim_x of dst image
• The stride_y of the src image shall be equal to or greater than dst image dim_x * 4
• The stride_y of the dst image shall be equal to or greater than dim_x
• The channelOffset shall be in the range [0..3]

Parameters:

[in]	src[]	Pointer to array containing first input image (UQ8.0)
[in]	src_addr[]	Pointer to structure containing dimensional information of src
[out]	dst[]	Pointer to array containing output image (UQ8.0)
[in]	dst_addr[]	Pointer to structure containing dimensional information of dst
[in]	channelOffset	Identifies which channel to extract (0, 1, 2, or 3)

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