Edit File: delta.h
/** * \file lzma/delta.h * \brief Delta filter */ /* * Author: Lasse Collin * * This file has been put into the public domain. * You can do whatever you want with this file. * * See ../lzma.h for information about liblzma as a whole. */ #ifndef LZMA_H_INTERNAL # error Never include this file directly. Use <lzma.h> instead. #endif /** * \brief Filter ID * * Filter ID of the Delta filter. This is used as lzma_filter.id. */ #define LZMA_FILTER_DELTA LZMA_VLI_C(0x03) /** * \brief Type of the delta calculation * * Currently only byte-wise delta is supported. Other possible types could * be, for example, delta of 16/32/64-bit little/big endian integers, but * these are not currently planned since byte-wise delta is almost as good. */ typedef enum { LZMA_DELTA_TYPE_BYTE } lzma_delta_type; /** * \brief Options for the Delta filter * * These options are needed by both encoder and decoder. */ typedef struct { /** For now, this must always be LZMA_DELTA_TYPE_BYTE. */ lzma_delta_type type; /** * \brief Delta distance * * With the only currently supported type, LZMA_DELTA_TYPE_BYTE, * the distance is as bytes. * * Examples: * - 16-bit stereo audio: distance = 4 bytes * - 24-bit RGB image data: distance = 3 bytes */ uint32_t dist; # define LZMA_DELTA_DIST_MIN 1 # define LZMA_DELTA_DIST_MAX 256 /* * Reserved space to allow possible future extensions without * breaking the ABI. You should not touch these, because the names * of these variables may change. These are and will never be used * when type is LZMA_DELTA_TYPE_BYTE, so it is safe to leave these * uninitialized. */ uint32_t reserved_int1; uint32_t reserved_int2; uint32_t reserved_int3; uint32_t reserved_int4; void *reserved_ptr1; void *reserved_ptr2; } lzma_options_delta;