jpayne@69: /* SPDX-License-Identifier: 0BSD */
jpayne@69: 
jpayne@69: /**
jpayne@69:  * \file        lzma/delta.h
jpayne@69:  * \brief       Delta filter
jpayne@69:  * \note        Never include this file directly. Use <lzma.h> instead.
jpayne@69:  */
jpayne@69: 
jpayne@69: /*
jpayne@69:  * Author: Lasse Collin
jpayne@69:  */
jpayne@69: 
jpayne@69: #ifndef LZMA_H_INTERNAL
jpayne@69: #	error Never include this file directly. Use <lzma.h> instead.
jpayne@69: #endif
jpayne@69: 
jpayne@69: 
jpayne@69: /**
jpayne@69:  * \brief       Filter ID
jpayne@69:  *
jpayne@69:  * Filter ID of the Delta filter. This is used as lzma_filter.id.
jpayne@69:  */
jpayne@69: #define LZMA_FILTER_DELTA       LZMA_VLI_C(0x03)
jpayne@69: 
jpayne@69: 
jpayne@69: /**
jpayne@69:  * \brief       Type of the delta calculation
jpayne@69:  *
jpayne@69:  * Currently only byte-wise delta is supported. Other possible types could
jpayne@69:  * be, for example, delta of 16/32/64-bit little/big endian integers, but
jpayne@69:  * these are not currently planned since byte-wise delta is almost as good.
jpayne@69:  */
jpayne@69: typedef enum {
jpayne@69: 	LZMA_DELTA_TYPE_BYTE
jpayne@69: } lzma_delta_type;
jpayne@69: 
jpayne@69: 
jpayne@69: /**
jpayne@69:  * \brief       Options for the Delta filter
jpayne@69:  *
jpayne@69:  * These options are needed by both encoder and decoder.
jpayne@69:  */
jpayne@69: typedef struct {
jpayne@69: 	/** For now, this must always be LZMA_DELTA_TYPE_BYTE. */
jpayne@69: 	lzma_delta_type type;
jpayne@69: 
jpayne@69: 	/**
jpayne@69: 	 * \brief       Delta distance
jpayne@69: 	 *
jpayne@69: 	 * With the only currently supported type, LZMA_DELTA_TYPE_BYTE,
jpayne@69: 	 * the distance is as bytes.
jpayne@69: 	 *
jpayne@69: 	 * Examples:
jpayne@69: 	 *  - 16-bit stereo audio: distance = 4 bytes
jpayne@69: 	 *  - 24-bit RGB image data: distance = 3 bytes
jpayne@69: 	 */
jpayne@69: 	uint32_t dist;
jpayne@69: 
jpayne@69: 	/**
jpayne@69: 	 * \brief       Minimum value for lzma_options_delta.dist.
jpayne@69: 	 */
jpayne@69: #	define LZMA_DELTA_DIST_MIN 1
jpayne@69: 
jpayne@69: 	/**
jpayne@69: 	 * \brief       Maximum value for lzma_options_delta.dist.
jpayne@69: 	 */
jpayne@69: #	define LZMA_DELTA_DIST_MAX 256
jpayne@69: 
jpayne@69: 	/*
jpayne@69: 	 * Reserved space to allow possible future extensions without
jpayne@69: 	 * breaking the ABI. You should not touch these, because the names
jpayne@69: 	 * of these variables may change. These are and will never be used
jpayne@69: 	 * when type is LZMA_DELTA_TYPE_BYTE, so it is safe to leave these
jpayne@69: 	 * uninitialized.
jpayne@69: 	 */
jpayne@69: 
jpayne@69: 	/** \private     Reserved member. */
jpayne@69: 	uint32_t reserved_int1;
jpayne@69: 
jpayne@69: 	/** \private     Reserved member. */
jpayne@69: 	uint32_t reserved_int2;
jpayne@69: 
jpayne@69: 	/** \private     Reserved member. */
jpayne@69: 	uint32_t reserved_int3;
jpayne@69: 
jpayne@69: 	/** \private     Reserved member. */
jpayne@69: 	uint32_t reserved_int4;
jpayne@69: 
jpayne@69: 	/** \private     Reserved member. */
jpayne@69: 	void *reserved_ptr1;
jpayne@69: 
jpayne@69: 	/** \private     Reserved member. */
jpayne@69: 	void *reserved_ptr2;
jpayne@69: 
jpayne@69: } lzma_options_delta;