ZLIB Coding Functions

This section describes Intel IPP data compression functions that implement compression methods and data formats defined by the following specifications: [RFC1950], [RFC1951], and [RFC1952]. These formats are also known as ZLIB, DEFLATE, and GZIP, respectively.

A basic algorithm for these data compression methods is based on the Lempel-Ziv (LZ77) [Ziv77] dictionary-based compression.

The structure of ZLIB data is schematically shown in Figure "ZLIB Data Structure".

Figure "Encoding Data Block with Intel IPP ZLIB Functions" and Figure "Decoding Data Block with Intel IPP ZLIB Functions" show the schemes of applying the Intel IPP ZLIB functions for encoding and decoding, respectively. The functions which names are bolded are the mandatory functions for the specified stage.

The full version of the zlib library based on the Intel IPP is presented as the Intel IPP Sample downloadable form http://www.intel.com/cd/software/products/asmo-na/eng/perflib/ipp/index.htm.

• Special Parameters
  
• EncodeLZ77Init
  Initializes the LZ77 encoding state structure.
• EncodeLZ77GetSize
  Computes the size of the LZ77 encoding state structure.
• EncodeLZ77InitAlloc
  Allocates memory and initializes the encoding state structure.
• LZ77Free
  Frees memory allocated for the LZ77 encoding and decoding structures.
• EncodeLZ77
  Performs LZ77 encoding.
• EncodeLZ77SelectHuffMode
  Determines the optimal encoding mode.
• EncodeLZ77FixedHuff
  Performs fixed Huffman encoding.
• EncodeLZ77DynamicHuff
  Performs dynamic Huffman encoding.
• EncodeLZ77StoredBlock
  Stores the data block without compression.
• EncodeLZ77Flush
  Writes the checksum and total length of the input data to the end of the stream.
• EncodeLZ77GetPairs
  Retrieves pair data from the LZ77 encoding state structure.
• EncodeLZ77SetPairs
  Sets pair data in the LZ77 encoding state structure.
• EncodeLZ77GetStatus
  Reads the deflate status value from the LZ77 encoding state structure.
• EncodeLZ77SetStatus
  Sets the deflate status to the desired value in the LZ77 encoding state structure.
• EncodeLZ77Reset
  Resets the LZ77 encoding state structure.
• DecodeLZ77Init
  Initializes the LZ77 decoding structure.
• DecodeLZ77GetSize
  Computes the size of the LZ77 decoding structure.
• DecodeLZ77InitAlloc
  Allocates memory and initializes the LZ77 decoding structure.
• DecodeLZ77
  Performs LZ77 decoding.
• DecodeLZ77GetBlockType
  Determines the type of encoded data block.
• DecodeLZ77FixedHuff
  Performs fixed Huffman decoding.
• DecodeLZ77DynamicHuff
  Performs dynamic Huffman decoding.
• DecodeLZ77StoredBlock
  Performs decoding of the block stored without compression.
• DecodeLZ77GetPairs
  Retrieves pair data from the LZ77 decoding state structure.
• DecodeLZ77SetPairs
  Sets pair data in the LZ77 decoding state structure.
• DecodeLZ77GetStatus
  Reads the inflate status value from the LZ77 decoding state structure.
• DecodeLZ77SetStatus
  Sets the inflate status to the desired value in the LZ77 decoding state structure.
• DecodeLZ77Reset
  Resets the LZ77 decoding state structure.
• Adler32
  Computes the Adler32 checksum for the source data buffer.
• CRC32, CRC32C
  Computes the CRC32 checksum for the source data buffer.
• DeflateLZ77
  Performs LZ77 encoding according to the specified compression level.
• DeflateDictionarySet
  Presets the user's dictionary for LZ77 encoding.
• DeflateUpdate Hash
  Performs LZ77 encoding according to the specified compression level.
• DeflateHuff
  Performs Huffman encoding .
• InflateBuildHuffTable
  Builds the Huffman code table for compressed block in the “deflate” format.
• Inflate
  Decodes data in the “deflate” format.
• Example of Using Intel IPP ZLIB Coding Functions
  

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