Performs an inverse DCT on a 2D buffer of 8x8 size.
Syntax
Case 1: Not-in-place operation
IppStatus ippiDCT8x8Inv_<mod>(const Ipp<datatype>* pSrc, Ipp<datatype>* pDst);
Supported values for mod:
16s_C1 |
32f_C1 |
IppStatus ippiDCT8x8Inv_A10_16s_C1(const Ipp16s* pSrc, Ipp16s* pDst);
Case 2: Not-in-place operation with ROI
IppStatus ippiDCT8x8Inv_<mod>(const Ipp<srcDatatype>* pSrc, Ipp<dstDatatype>* pDst, int dstStep);
Supported values for mod:
16s_C1R |
16s8u_C1R |
Case 3: In-place operation
IppStatus ippiDCT8x8Inv_<mod>(Ipp<datatype>* pSrcDst);
Supported values for mod:
16s_C1I |
32f_C1I |
IppStatus ippiDCT8x8Inv_A10_16s_C1I( Ipp16s* pSrcDst);
Parameters
pSrc |
Pointer to the source image. |
pDst |
Pointer to the destination buffer. |
dstStep |
Distance in bytes between starts of consecutive lines in the destination buffer for operations with ROI. |
pSrcDst |
Pointer to the source and destination image for in-place operations. |
Description
The function ippiDCT8x8Inv is declared in the ippi.h file. Some flavors operate with ROI (see Regions of Interest in Intel IPP).
This function computes the inverse discrete cosine transform of data in a 2D buffer of 8x8 size. No prerequisites are needed to use this transform function.
Caution
Source data for 16s functions must be the result of the forward discrete cosine transform of data from the range [-512, 511] for flavors with A10 modifier (ippiDCT8x8Inv_A10), and from the range [-256, 255] for flavors without A10 modifier (ippiDCT8x8Inv); they cannot be arbitrary data from the range [-32768, 32767].
Return Values
ippStsNoErr |
Indicates no error. Any other value indicates an error or a warning. |
ippStsNullPtrErr |
Indicates an error condition if pSrc, pDst, or pSrcDst pointer is NULL. |
ippStsStepErr |
Indicates an error condition if dstStep value is zero or negative. |