Determines the type of encoded data block.
Syntax
IppStatus ippsDecodeLZ77GetBlockType_8u(Ipp8u** ppSrc, int* pSrcLen, IppLZ77HuffMode* pHuffMode, IppLZ77State_8u* pLZ77State);
Parameters
ppSrc |
Double pointer to the source buffer. |
pSrcLen |
Pointer to the length of the source buffer. |
pHuffMode |
Pointer to the value of the parameter that indicates the encoding mode. Possible values are: |
| IppLZ77UseFixed Encoding with fixed Huffman codes. | |
| IppLZ77UseDynamic Encoding with dynamic Huffman codes. | |
| IppLZ77UseStored Stored block without Huffman coding. | |
pLZ77State |
Pointer to the LZ77 decoding state structure. |
Description
The function ippsDecodeLZ77GetBlockType is declared in the ippdc.h file. This function analyzes the source data ppSrc and returns the parameter pHuffMode which value indicates what Huffman decoding mode must be used for decoding the source bit stream. In accordance with this value the one of the functions ippsDecodeLZ77FixedHuff, ippsDecodeLZ77DynamicHuff, or ippsDecodeLZ77StoredBlockippsDecodeLZ77StoredBlock must be used.
Note
If you use only one specified encoding mode, then type of the input data for decoding is known, and this function is not necessary.
Return Values
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error if the pointer ppLZ77State is NULL. |
ippStsSizeErr |
Indicates an error if SrcLen is less than or equal to 0. |
ippStsSrcSizeLessExpected |
Indicates a warning that the source buffer is insufficient (internal bit stream and source buffer do not contain enought bits to decode the type of block). |