EncodeLZOInit

Initializes LZO encoding structure.

Syntax

IppStatus ippsEncodeLZOInit_8u(IppLZOMethod method, Ipp32u maxInputLen, IppLZOState_8u* pLZOState);

Include Files

ippdc.h

Domain Dependencies

Headers: ippcore.h, ippvm.h, ipps.h

Libraries: ippcore.lib, ippvm.lib, ipps.lib

Parameters

method	Specifies required LZO compression method, possible values are listed in Table "method Parameter").
maxInputLen	Specifies the maximum length of the input data buffer during compression operations. Not required for the IppLZO1XST and IppLZO1X1ST compression methods.
pLZOState	Pointer to the LZO encoding structure.

Description

This function initializes the LZO encoding structure in the external buffer. Its size must be calculated by calling the function ippsEncodeLZOGetSize beforehand.

The parameter method must be the same for both functions.

Return Values

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error if the pointer pLZOState is NULL.
ippStsBadArgErr I	ndicates an error if the parameter method has an illegal value.

Example

/*******************************************************************************
* Copyright 2017 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:
        ippsEncodeLZOGetSize
        ippsEncodeLZO_8u
        ippsEncodeLZOInit_8u
        ippsDecodeLZO_8u
        ippsDecodeLZOSafe_8u
*/

#include <stdio.h>
#include <string.h>

#include <ippdc.h>      /* Data compression functions       */
#include <ipps.h>       /* Malloc/vector initialization function   */

/* 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® Integrated Primitives (Intel® IPP) function returned status different from ippStsNoErr */

#define TEST_SIZE (1024 * 4)
#define DECOMPR_MAX (TEST_SIZE + 64)

int main(void)
{
    Ipp8u           *srcBuf = NULL, *comprBuf = NULL, *decomprBuf = NULL;
    IppStatus       st;
    int             i;
    Ipp32u          stateSize;
    IppLZOState_8u  *lzoState = NULL;
    Ipp32u          comprLen, decomprLen;

    /* Allocate buffers */
    srcBuf      = ippsMalloc_8u(TEST_SIZE);
    decomprBuf  = ippsMalloc_8u(DECOMPR_MAX);    /* Extra 64 bytes may be required
                                                       for non-safe decompression       */
    comprBuf    = ippsMalloc_8u(TEST_SIZE + TEST_SIZE/10);
    /* 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 */
    /* Allocate and initialize LZO structure */
    check_sts(  st = ippsEncodeLZOGetSize(IppLZO1XST, TEST_SIZE, &stateSize)    )
    lzoState = (IppLZOState_8u*)ippsMalloc_8u(stateSize);
    check_sts(  st = ippsEncodeLZOInit_8u(IppLZO1XST, TEST_SIZE, lzoState)      )
    /* LZO compress, decompress and compare */
    comprLen = (TEST_SIZE + TEST_SIZE/10);
    check_sts(  st = ippsEncodeLZO_8u(srcBuf, TEST_SIZE, comprBuf, &comprLen, lzoState)   )
    printf("LZO compress: %d bytes compressed into %d bytes\n", TEST_SIZE, (int)comprLen);
    decomprLen = DECOMPR_MAX;
    check_sts(  st = ippsDecodeLZO_8u(comprBuf, comprLen, decomprBuf, &decomprLen)    )
    if(decomprLen != TEST_SIZE || memcmp(decomprBuf, srcBuf, TEST_SIZE) != 0)
    {
        printf("Non-safe decompress failed!\n");
        st = ippStsErr;
        goto exitLine;
    }
    else
        printf("Non-safe decompress verified.\n");
    /* Decompress using safe function */
    ippsZero_8u(decomprBuf, DECOMPR_MAX);
    decomprLen = TEST_SIZE;                         /* Can specify exact size */
    check_sts(  st = ippsDecodeLZOSafe_8u(comprBuf, comprLen, decomprBuf, &decomprLen)  )
    if(decomprLen != TEST_SIZE || memcmp(decomprBuf, srcBuf, TEST_SIZE) != 0)
    {
        printf("Safe decompress failed!\n");
        st = ippStsErr;
        goto exitLine;
    }
    else
        printf("Safe decompress verified.\n");

EXIT_MAIN
    ippsFree(srcBuf);
    ippsFree(decomprBuf);
    ippsFree(comprBuf);
    ippsFree(lzoState);
    return (int)st;
}