ref: 7cdf839293bf3c0b5c3f52d368635156530ddf85
dir: /jpc_bs.h/
/*
* Copyright (c) 1999-2000 Image Power, Inc. and the University of
* British Columbia.
* Copyright (c) 2001-2002 Michael David Adams.
* All rights reserved.
*/
/* __START_OF_JASPER_LICENSE__
*
* JasPer License Version 2.0
*
* Copyright (c) 2001-2006 Michael David Adams
* Copyright (c) 1999-2000 Image Power, Inc.
* Copyright (c) 1999-2000 The University of British Columbia
*
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person (the
* "User") obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, and/or sell copies of the Software, and to permit
* persons to whom the Software is furnished to do so, subject to the
* following conditions:
*
* 1. The above copyright notices and this permission notice (which
* includes the disclaimer below) shall be included in all copies or
* substantial portions of the Software.
*
* 2. The name of a copyright holder shall not be used to endorse or
* promote products derived from the Software without specific prior
* written permission.
*
* THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
* LICENSE. NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
* THIS DISCLAIMER. THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
* "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
* INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. NO ASSURANCES ARE
* PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
* THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
* EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
* BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
* PROPERTY RIGHTS OR OTHERWISE. AS A CONDITION TO EXERCISING THE RIGHTS
* GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
* ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY. THE SOFTWARE
* IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
* SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
* AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
* SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
* THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
* PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
* RISK ACTIVITIES"). THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
* EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
*
* __END_OF_JASPER_LICENSE__
*/
/*
* Bit Stream Class
*
* $Id$
*/
#ifndef JPC_BS_H
#define JPC_BS_H
/******************************************************************************\
* Includes.
\******************************************************************************/
#include "jasper/jas_types.h"
#include "jasper/jas_stream.h"
/******************************************************************************\
* Constants.
\******************************************************************************/
/*
* Bit stream open mode flags.
*/
/* Bit stream open for reading. */
#define JPC_BITSTREAM_READ 0x01
/* Bit stream open for writing. */
#define JPC_BITSTREAM_WRITE 0x02
/*
* Bit stream flags.
*/
/* Do not close underlying character stream. */
#define JPC_BITSTREAM_NOCLOSE 0x01
/* End of file has been reached while reading. */
#define JPC_BITSTREAM_EOF 0x02
/* An I/O error has occured. */
#define JPC_BITSTREAM_ERR 0x04
/******************************************************************************\
* Types.
\******************************************************************************/
/* Bit stream class. */
typedef struct {
/* Some miscellaneous flags. */
int flags_;
/* The input/output buffer. */
uint_fast16_t buf_;
/* The number of bits remaining in the byte being read/written. */
int cnt_;
/* The underlying stream associated with this bit stream. */
jas_stream_t *stream_;
/* The mode in which this bit stream was opened. */
int openmode_;
} jpc_bitstream_t;
/******************************************************************************\
* Functions/macros for opening and closing bit streams..
\******************************************************************************/
/* Open a stream as a bit stream. */
jpc_bitstream_t *jpc_bitstream_sopen(jas_stream_t *stream, const char *mode);
/* Close a bit stream. */
int jpc_bitstream_close(jpc_bitstream_t *bitstream);
/******************************************************************************\
* Functions/macros for reading from and writing to bit streams..
\******************************************************************************/
/* Read a bit from a bit stream. */
#ifndef NDEBUG
#define jpc_bitstream_getbit(bitstream) \
jpc_bitstream_getbit_func(bitstream)
#else
#define jpc_bitstream_getbit(bitstream) \
jpc_bitstream_getbit_macro(bitstream)
#endif
/* Write a bit to a bit stream. */
#ifndef NDEBUG
#define jpc_bitstream_putbit(bitstream, v) \
jpc_bitstream_putbit_func(bitstream, v)
#else
#define jpc_bitstream_putbit(bitstream, v) \
jpc_bitstream_putbit_macro(bitstream, v)
#endif
/* Read one or more bits from a bit stream. */
long jpc_bitstream_getbits(jpc_bitstream_t *bitstream, int n);
/* Write one or more bits to a bit stream. */
int jpc_bitstream_putbits(jpc_bitstream_t *bitstream, int n, long v);
/******************************************************************************\
* Functions/macros for flushing and aligning bit streams.
\******************************************************************************/
/* Align the current position within the bit stream to the next byte
boundary. */
int jpc_bitstream_align(jpc_bitstream_t *bitstream);
/* Align the current position in the bit stream with the next byte boundary,
ensuring that certain bits consumed in the process match a particular
pattern. */
int jpc_bitstream_inalign(jpc_bitstream_t *bitstream, int fillmask,
int filldata);
/* Align the current position in the bit stream with the next byte boundary,
writing bits from the specified pattern (if necessary) in the process. */
int jpc_bitstream_outalign(jpc_bitstream_t *bitstream, int filldata);
/* Check if a bit stream needs alignment. */
JAS_ATTRIBUTE_PURE
int jpc_bitstream_needalign(const jpc_bitstream_t *bitstream);
/* How many additional bytes would be output if the bit stream was aligned? */
JAS_ATTRIBUTE_PURE
int jpc_bitstream_pending(const jpc_bitstream_t *bitstream);
/******************************************************************************\
* Functions/macros for querying state information for bit streams.
\******************************************************************************/
/* Has EOF been encountered on a bit stream? */
#define jpc_bitstream_eof(bitstream) \
((bitstream)->flags_ & JPC_BITSTREAM_EOF)
/******************************************************************************\
* Internals.
\******************************************************************************/
/* DO NOT DIRECTLY INVOKE ANY OF THE MACROS OR FUNCTIONS BELOW. THEY ARE
FOR INTERNAL USE ONLY. */
int jpc_bitstream_getbit_func(jpc_bitstream_t *bitstream);
int jpc_bitstream_putbit_func(jpc_bitstream_t *bitstream, int v);
int jpc_bitstream_fillbuf(jpc_bitstream_t *bitstream);
#define jpc_bitstream_getbit_macro(bitstream) \
((--(bitstream)->cnt_ >= 0) ? \
((int)(((bitstream)->buf_ >> (bitstream)->cnt_) & 1)) : \
jpc_bitstream_fillbuf(bitstream))
#define jpc_bitstream_putbit_macro(bitstream, bit) \
((--(bitstream)->cnt_ < 0) ? \
((bitstream)->buf_ = ((bitstream)->buf_ << 8) & 0xffff, \
(bitstream)->cnt_ = ((bitstream)->buf_ == 0xff00) ? 6 : 7, \
(bitstream)->buf_ |= ((bit) & 1) << (bitstream)->cnt_, \
(jas_stream_putc((bitstream)->stream_, (bitstream)->buf_ >> 8) == EOF) \
? (EOF) : ((bit) & 1)) : \
((bitstream)->buf_ |= ((bit) & 1) << (bitstream)->cnt_, \
(bit) & 1))
#endif