/**
* \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;
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