Decodes DCT coefficients for intra coded block.
IppStatus ippiDecodeCoeffsIntra_MPEG4_1u16s(Ipp8u** ppBitStream, int* pBitOffset, Ipp16s* pCoeffs, int* pIndxLastNonZero, int rvlcFlag, int noDCFlag, int scan);
ppBitStream |
Pointer to the pointer to the current byte in the bitstream buffer. The pointer is updated by the function. |
||||||||
pBitOffset |
Pointer to the bit position in the byte pointed by **ppBitStream. The pointer is updated by the function. |
||||||||
pCoeffs |
Pointer to the output coefficients. |
||||||||
pIndxLastNonZero |
Pointer to the index of the last non-zero coefficient. In case of error during decoding, the index of the previous successfully decoded coefficient is stored in it. |
||||||||
rvlcFlag |
Flag, when set to ‘0' indicates that VLC tables B.16, B.18, B.19, and B.21 [ISO14496] are used in decoding DCT coefficients, otherwise the reversible variable length tables B.23, B.24, and B.25 [ISO14496] are used. |
||||||||
noDCFlag |
Flag, when set to ‘0' indicates that pCoeffs is set starting with zero element, otherwise - with the first element. |
||||||||
scan |
Type of the scan, takes one of the following values:
See the corresponding enumerator in the introduction to the General Functions. |
The function ippiDecodeCoeffsIntra_MPEG4_1u16s is declared in the ippvc.h header file. This function performs VLC decoding of the DC coefficient (if noDCFlag is 0) and AC coefficients for one intra coded block using VLC decoding process as specified in [ISO14496], subclause 7.4.1. Additionally, the function can perform inverse scan.
This function is used in the MPEG-4 decoder included into Intel IPP Samples. See introduction to MPEG-4.
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error when at least one input pointer is NULL. |
ippStsBitOffsetErr |
Indicates an error condition if* pBitOffset is out of the range [0, 7]. |
ippStsVLCCodeErr |
Indicates an error condition if an illegal code is detected through the decoding. |
Copyright © 2000 - 2011, Intel Corporation. All rights reserved.