# MI_GetCompressionType

## C Specification

  `#include <nitro/mi.h>`
  `MICompressionType MI_GetCompressionType( const void* srcp );`

## Arguments

srcp | Source address where the compressed data is stored.

## Return Values

The compression format.

## Description

This function obtains the compression format by checking the data header information of the compressed data. This function does not check the contents of the compressed data but only reads the compression format included in the beginning of the data.

This function is compatible with all compression formats supported by the NITRO-SDK.

The return values have the following definitions in the `MICompressType` enumerated type.

`MI_COMPRESSION_LZ` | Data compressed using the LZ77 format.
`MI_COMPRESSION_HUFFMAN` | Data compressed using the Huffman format.
`MI_COMPRESSION_RL` | Data compressed using the Run Length format.
`MI_COMPRESSION_DIFF` | Data compressed with the difference filter applied.

## Internal Operation

Determines the compression type by reading the first four bytes of the data header.

## See Also

`MI_UncompressLZ*, MI_UncompressHuffman, MI_UncompressRL*, MI_UnfilterDiff*, MI_GetUncompressedSize`

## Revision History

06/18/2004 Initial version.