Visible to Intel only — GUID: GUID-106379FF-BB64-4DE8-B448-AB75CC4D5458
Visible to Intel only — GUID: GUID-106379FF-BB64-4DE8-B448-AB75CC4D5458
DecodeLZ4
Performs LZ4 decoding.
Syntax
IppStatus ippsDecodeLZ4_8u(const Ipp8u* pSrc, int srcLen, Ipp8u* pDst, int* pDstLen);
IppStatus ippsDecodeLZ4Dict_8u(const Ipp8u* pSrc, int* pSrcLen, Ipp8u* pDst, int dstIdx, int* pDstLen, const Ipp8u* pDict, int dictSize);
Include Files
ippdc.h
Domain Dependencies
Headers: ippcore.h, ippvm.h, ipps.h
Libraries: ippcore.lib, ippvm.lib, ipps.lib
Parameters
pSrc |
Pointer to the source data. |
srcLen |
Length of the source data for decompression. |
pSrcLen |
Pointer to the length of the source data for decompression. |
pDst |
Pointer to the compressed data. |
pDstLen |
Pointer to the length of the uncompressed data. |
dstIdx |
Index of the starting byte in the destination vector. |
pDict |
Pointer to the dictionary. |
dictSize |
Length of the dictionary. |
Description
This function performs decoding of the source data pSrc using the LZ4 algorithm. The destination buffer must have sufficient length for the operation. The length of the uncompressed data is set to pDstLen.
Return Values
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error if at lease one of the specified pointers is NULL. |
ippStsSizeErr |
Indicates an error if the srcLen value is less than, or equal to zero. |
ippStsMemAllocErr |
Indicates an error if the size of the allocated memory is not sufficient for decompression. |
Example
/*******************************************************************************
* Copyright 2015 Intel Corporation.
*
*
* This software and the related documents are Intel copyrighted materials, and your use of them is governed by
* the express license under which they were provided to you ('License'). Unless the License provides otherwise,
* you may not use, modify, copy, publish, distribute, disclose or transmit this software or the related
* documents without Intel's prior written permission.
* This software and the related documents are provided as is, with no express or implied warranties, other than
* those that are expressly stated in the License.
*******************************************************************************/
/*
The example below shows how to use the functions:
ippsEncodeLZ4HashTableGetSize_8u
ippsEncodeLZ4HashTableInit_8u
ippsEncodeLZ4_8u
ippsDecodeLZ4_8u
*/
#include <stdio.h>
#include <string.h>
#include <ipp/ippdc.h>
#include <ipp/ipps.h>
/* Next two defines are created to simplify code reading and understanding */
#define EXIT_MAIN exitLine: /* Label for Exit */
#define check_sts(st) if((st) != ippStsNoErr) goto exitLine; /* Go to Exit if Intel(R) Integrated Performance Primitives (Intel(R) IPP) function returned status different from ippStsNoErr */
#define TEST_SIZE (1024)
int main(void)
{
Ipp8u *srcBuf = NULL, *comprBuf = NULL, *decomprBuf = NULL, *hashTable = NULL;
IppStatus st = ippStsNoErr;
int hashSize = 0,
comprLen = TEST_SIZE + TEST_SIZE / 255 + 16, /* Extra bytes for
uncompressible data */
decomprLen = TEST_SIZE + 33;
int i;
srcBuf = ippsMalloc_8u(TEST_SIZE);
decomprBuf = ippsMalloc_8u(decomprLen); /* Spare bytes for "wild"
(non-safe) decompression */
comprBuf = ippsMalloc_8u(comprLen);
/* Initialize source buffer */
check_sts( st = ippsVectorJaehne_8u(srcBuf, TEST_SIZE, IPP_MAX_8U) )
for(i = 0; i < TEST_SIZE; i++)
srcBuf[i] >>= 6; /* Decrease source data entropy */
/* Init and allocate hash table */
check_sts( st = ippsEncodeLZ4HashTableGetSize_8u(&hashSize) )
hashTable = ippsMalloc_8u(hashSize);
check_sts( st = ippsEncodeLZ4HashTableInit_8u(hashTable, TEST_SIZE) )
/* Compress source data */
check_sts( st = ippsEncodeLZ4_8u((const Ipp8u*)srcBuf, TEST_SIZE, comprBuf,
&comprLen, hashTable) )
/* Print compression result */
printf("Compression: %d bytes compressed into %d bytes\n", TEST_SIZE, comprLen);
/* Decompression */
decomprLen = TEST_SIZE + 33;
check_sts( st = ippsDecodeLZ4_8u((const Ipp8u*)comprBuf, comprLen, decomprBuf,
&decomprLen) )
/* Check */
if(decomprLen == TEST_SIZE)/* Decompressed size must be equal to source data size */
{
if(memcmp(srcBuf, decomprBuf, TEST_SIZE) != 0)
{
printf("Wrong decompression!\n");
st = ippStsErr;
}
else
printf("Decompressed by ippsDecodeLZ4_8u OK\n");
}
else
printf("Invalid decompressed length %d\n", decomprLen);
EXIT_MAIN
ippsFree(srcBuf);
ippsFree(comprBuf);
ippsFree(decomprBuf);
ippsFree(hashTable);
return (int)st;
}