Developer Reference

  • 2020
  • 10/21/2020
  • Public Content
Contents

DCT8x8InvLSClip

Performs an inverse DCT on a 2D buffer of 8x8 size with further data conversion and level shift.

Syntax

IppStatus ippiDCT8x8InvLSClip_16s8u_C1R(const Ipp16s*
pSrc
, Ipp8u*
pDst
, int
dstStep
, Ipp16s
addVal
, Ipp8u
clipDown
, Ipp8u
clipUp
);
Include Files
ippi.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
,
ipps.h
Libraries:
ippcore.lib
,
ippvm.lib
,
ipps.lib
Parameters
pSrc
Pointer to the source image buffer.
pDst
Pointer to the destination image buffer.
dstStep
Distance in bytes between starts of consecutive lines in the destination image buffer.
addVal
The level shift value.
clipDown
The lower bound for the range of output values.
clipUp
The upper bound for the range of output values.
Description
This function operates with ROI (see Regions of Interest in Intel IPP) that is a 2D buffer of 8x8 size in this case, thus there is no need to specify its size.
This function performs the inverse discrete cosine transform of the buffer
pSrc
. After completing the DCT, this function performs level shift operation by adding the constant value
addVal
to each sample. Finally, the function converts data from the signed
Ipp16s
type to the unsigned
Ipp8u
type. The output data are clipped to the range
[
clipDown
..
clipUp
]
. The result is stored in the destination buffer
pDst
.
Source data for 16s flavors must be the result of the forward discrete cosine transform of data from the range [-256, 255], 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
or
pDst
pointer is
NULL
.
ippStsStepErr
Indicates an error condition if
dstStep
value is zero or negative.

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.