Developer Reference

  • 2020
  • 07/15/2020
  • Public Content
Contents

DeflateLZ77

Performs LZ77 encoding according to the specified compression level.

Syntax

IppStatus ippsDeflateLZ77_8u(const Ipp8u**
ppSrc
, Ipp32u*
pSrcLen
, Ipp32u*
pSrcIdx
, const Ipp8u*
pWindow
, Ipp32u
winSize
, Ipp32s*
pHashHead
, Ipp32s*
pHashPrev
, Ipp32u
hashSize
, IppDeflateFreqTable
pLitFreqTable
[286], IppDeflateFreqTable
pDistFreqTable
[30], Ipp8u*
pLitDst
, Ipp16u*
pDistDst
, Ipp32u*
pDstLen
, int
comprLevel
, IppLZ77Flush
flush
);
Include Files
ippdc.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
,
ipps.h
Libraries:
ippcore.lib
,
ippvm.lib
,
ipps.lib
Parameters
ppSrc
Double pointer to the source vector.
pSrcLen
Pointer to the length of the source vector.
pSrcIdx
Pointer to the index of the current position in the source vector.
pWindow
Pointer to the sliding window (the dictionary for the LZ77 algorithm).
winSize
Size of the sliding window and the
pHashPrev
table.
pHashHead
Pointer to the table containing heads of the hash chains.
pHashPrev
Pointer to the table contating indexes to the previous strings with the same hash key.
hashSize
Size of the
pHashHead
table.
pLitFreqTable
Pointer to the literals/lengths frequency table.
pDistFreqTable
Pointer to the distances frequency table.
pLitDst
Pointer to the destination vector containing literals/lengths.
pDistDst
Pointer to the destination vector containing distances.
pDstLen
Pointer to the length of the destination vectors.
comprLevel
Compression level in range [0..9] in accordance with ZLIB.
flush
Specifies the encoding mode for data blocks (see flush parameter ).
Description
This function performs LZ77 encoding of source data
ppSrc
according to the compression level
comprLevel
, which is similar to the ZLIB compression level.
To correctly process the first bytes of the source vector, initialize the
pHashHead
table with the
winSize
value.
The
pSrcIdx
parameter returns the index of the current position in the source vector, and is used to establish a correlation between the current position in the source vector and indexes in hash tables. After processing each 2GB of source data, the index and hash tables must be normalized (instead of 64K of source data in ZLIB).
Return Values
ippStsNoErr
Indicates no error.
ippStsNullPtrErr
Indicates an error when at least one of the specified pointers is
NULL
.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804