I found the API ippsDecodeLZO_8u definition in Ippdc.h:
/* /////////////////////////////////////////////////////////////////////////////
// Name: ippsDecodeLZO_8u
// Purpose: decompresses specified input buffer to output buffer, returns decompressed data length
//
// Arguments:
// pSrc pointer to input buffer
// srcLen input data length
// pDst pointer to output buffer
// pDstLen pointer to output data length variable. Initially contains output buffer length
//
// Return:
// ippStsNullPtrErr one of the pointers is NULL
// ippStsDstSizeLessExpected output buffer is too short for compressed data
// ippStsSrcSizeLessExpected input buffer data is not complete, i.e. no EOF found
// ippStsBrokenLzoStream ippsDecodeLZOSafe_8u detected output buffer boundary violation
// ippStsNoErr no error detected
//
*/
If I passed the argument pDstlen (value = 0), the performance of ippsDecodeLZO_8u is very low. But If I passed the pDstlen (value = real output buffer length ), the performance is improved.
some misunderstanding:
- I don't kown why the return code is always 'ippStsNoErr' when I passed the argument pDstlen (value = 0), is right?
- If IPP allows user call the API ippsDecodeLZO_8u by passing the argument pDstlen (value = 0), why the performance is lower than I passed the real output buffer length . I think IPP will malloc additional buffer to support the situation that given argument pDstlen < decompressed_len. So this action willmake performance decline. Is right?
Regards,
Haixiao
