ref: 7cdf839293bf3c0b5c3f52d368635156530ddf85
dir: /jpc_mqdec.h/
/*
* Copyright (c) 1999-2000 Image Power, Inc. and the University of
* British Columbia.
* Copyright (c) 2001-2003 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__
*/
/*
* MQ Arithmetic Decoder
*
* $Id$
*/
#ifndef JPC_MQDEC_H
#define JPC_MQDEC_H
/******************************************************************************\
* Includes.
\******************************************************************************/
#include "jasper/jas_types.h"
#include "jasper/jas_stream.h"
#include "jpc_mqcod.h"
/******************************************************************************\
* Types.
\******************************************************************************/
/* MQ arithmetic decoder. */
typedef struct {
/* The C register. */
uint_least32_t creg;
/* The A register. */
uint_least32_t areg;
/* The CT register. */
uint_least32_t ctreg;
/* The current context. */
const jpc_mqstate_t **curctx;
/* The per-context information. */
const jpc_mqstate_t **ctxs;
/* The maximum number of contexts. */
unsigned maxctxs;
/* The stream from which to read data. */
jas_stream_t *in;
/* The last character read. */
jas_uchar inbuffer;
/* The EOF indicator. */
bool eof;
} jpc_mqdec_t;
/******************************************************************************\
* Functions/macros for construction and destruction.
\******************************************************************************/
/* Create a MQ decoder. */
jpc_mqdec_t *jpc_mqdec_create(unsigned maxctxs, jas_stream_t *in);
/* Destroy a MQ decoder. */
void jpc_mqdec_destroy(jpc_mqdec_t *dec);
/******************************************************************************\
* Functions/macros for initialization.
\******************************************************************************/
/* Set the input stream associated with a MQ decoder. */
void jpc_mqdec_setinput(jpc_mqdec_t *dec, jas_stream_t *in);
/* Initialize a MQ decoder. */
void jpc_mqdec_init(jpc_mqdec_t *dec);
/******************************************************************************\
* Functions/macros for manipulating contexts.
\******************************************************************************/
/* Set the current context for a MQ decoder. */
static inline void jpc_mqdec_setcurctx(jpc_mqdec_t *dec, unsigned ctxno)
{
dec->curctx = &dec->ctxs[ctxno];
}
/* Set the state information for all contexts of a MQ decoder. */
void jpc_mqdec_setctxs(const jpc_mqdec_t *dec, unsigned numctxs, const jpc_mqctx_t *ctxs);
/******************************************************************************\
* Functions/macros for decoding bits.
\******************************************************************************/
/* Decode a symbol. */
#ifdef NDEBUG
#define jpc_mqdec_getbit(dec) \
jpc_mqdec_getbit_macro(dec)
#else
#define jpc_mqdec_getbit(dec) \
jpc_mqdec_getbit_func(dec)
#endif
/* Decode a symbol (assuming an unskewed probability distribution). */
#ifdef NDEBUG
#define jpc_mqdec_getbitnoskew(dec) \
jpc_mqdec_getbit_macro(dec)
#else
#define jpc_mqdec_getbitnoskew(dec) \
jpc_mqdec_getbit_func(dec)
#endif
/******************************************************************************\
* EVERYTHING BELOW THIS POINT IS IMPLEMENTATION SPECIFIC AND NOT PART OF THE
* APPLICATION INTERFACE. DO NOT RELY ON ANY OF THE INTERNAL FUNCTIONS/MACROS
* GIVEN BELOW.
\******************************************************************************/
bool jpc_mqdec_mpsexchrenormd(jpc_mqdec_t *dec);
bool jpc_mqdec_lpsexchrenormd(jpc_mqdec_t *dec);
JAS_FORCE_INLINE
static bool jpc_mqdec_getbit_macro(jpc_mqdec_t *dec)
{
const jpc_mqstate_t *const state = *dec->curctx;
dec->areg -= state->qeval;
if (dec->creg >= (uint_least32_t)state->qeval << 16) {
dec->creg -= (uint_least32_t)state->qeval << 16;
return dec->areg & 0x8000
? state->mps
: jpc_mqdec_mpsexchrenormd(dec);
} else {
return jpc_mqdec_lpsexchrenormd(dec);
}
}
JAS_FORCE_INLINE
static bool jpc_mqdec_mpsexchange(uint_least32_t areg, uint_least32_t delta, const jpc_mqstate_t **curctx)
{
if (areg < delta) {
const jpc_mqstate_t *state = *curctx;
/* LPS decoded. */
*curctx = state->nlps;
return !state->mps;
} else {
const jpc_mqstate_t *state = *curctx;
/* MPS decoded. */
*curctx = state->nmps;
return state->mps;
}
}
JAS_FORCE_INLINE
static bool jpc_mqdec_lpsexchange(uint_least32_t *areg_p, uint_least32_t delta, const jpc_mqstate_t **curctx)
{
if (*areg_p >= delta) {
const jpc_mqstate_t *state = *curctx;
*areg_p = delta;
*curctx = state->nlps;
return !state->mps;
} else {
const jpc_mqstate_t *state = *curctx;
*areg_p = delta;
*curctx = state->nmps;
return state->mps;
}
}
bool jpc_mqdec_getbit_func(jpc_mqdec_t *dec);
#endif