/* * 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 * * $Id$ */ /******************************************************************************\* Includes.\******************************************************************************/ #include "jpc_mqdec.h" #include "jasper/jas_types.h"#include "jasper/jas_malloc.h"#include "jasper/jas_math.h"#include "jasper/jas_debug.h" /******************************************************************************\* Local macros.\******************************************************************************/ #ifndef NDEBUG#define	MQDEC_CALL(n, x) \	((jas_get_debug_level() >= (n)) ? ((void)(x)) : ((void)0))#else#define	MQDEC_CALL(n, x)#endif /******************************************************************************\* Local function prototypes.\******************************************************************************/ static void jpc_mqdec_bytein(jpc_mqdec_t *mqdec); /******************************************************************************\* Code for creation and destruction of a MQ decoder.\******************************************************************************/ /* Create a MQ decoder. */jpc_mqdec_t *jpc_mqdec_create(unsigned maxctxs, jas_stream_t *in){	jpc_mqdec_t *mqdec; 	/* There must be at least one context. */	assert(maxctxs > 0); 	/* Allocate memory for the MQ decoder. */	if (!(mqdec = jas_malloc(sizeof(jpc_mqdec_t)))) {		goto error;	}	mqdec->in = in;	mqdec->maxctxs = maxctxs;	/* Allocate memory for the per-context state information. */	if (!(mqdec->ctxs = jas_alloc2(mqdec->maxctxs, sizeof(jpc_mqstate_t *)))) {		goto error;	}	/* Set the current context to the first context. */	mqdec->curctx = mqdec->ctxs; 	/* If an input stream has been associated with the MQ decoder,	  initialize the decoder state from the stream. */	if (mqdec->in) {		jpc_mqdec_init(mqdec);	}	/* Initialize the per-context state information. */	jpc_mqdec_setctxs(mqdec, 0, 0); 	return mqdec; error:	/* Oops...  Something has gone wrong. */	if (mqdec) {		jpc_mqdec_destroy(mqdec);	}	return 0;} /* Destroy a MQ decoder. */void jpc_mqdec_destroy(jpc_mqdec_t *mqdec){	jas_free(mqdec->ctxs);	jas_free(mqdec);} /******************************************************************************\* Code for initialization of a MQ decoder.\******************************************************************************/ /* Initialize the state of a MQ decoder. */ void jpc_mqdec_init(jpc_mqdec_t *mqdec){	int c; 	mqdec->eof = false;	mqdec->creg = 0;	/* Get the next byte from the input stream. */	if ((c = jas_stream_getc(mqdec->in)) == EOF) {		/* We have encountered an I/O error or EOF. */		c = 0xff;		mqdec->eof = true;	}	mqdec->inbuffer = c;	mqdec->creg += mqdec->inbuffer << 16;	jpc_mqdec_bytein(mqdec);	mqdec->creg <<= 7;	mqdec->ctreg -= 7;	mqdec->areg = 0x8000;} /* Set the input stream for a MQ decoder. */ void jpc_mqdec_setinput(jpc_mqdec_t *mqdec, jas_stream_t *in){	mqdec->in = in;} /* Initialize one or more contexts. */ void jpc_mqdec_setctxs(const jpc_mqdec_t *mqdec, unsigned numctxs, const jpc_mqctx_t *ctxs){	const jpc_mqstate_t **ctx; 	ctx = mqdec->ctxs;	unsigned n = JAS_MIN(mqdec->maxctxs, numctxs);	while (n-- > 0) {		*ctx = &jpc_mqstates[2 * ctxs->ind + ctxs->mps];		++ctx;		++ctxs;	}	n = mqdec->maxctxs - numctxs;	while (n-- > 0) {		*ctx = &jpc_mqstates[0];		++ctx;	}} /******************************************************************************\* Code for decoding a bit.\******************************************************************************/ /* Decode a bit. */ bool jpc_mqdec_getbit_func(register jpc_mqdec_t *mqdec){	bool bit;	JAS_LOGDEBUGF(100, "jpc_mqdec_getbit_func(%p)\n", mqdec);	MQDEC_CALL(100, jpc_mqdec_dump(mqdec));	bit = jpc_mqdec_getbit_macro(mqdec);	MQDEC_CALL(100, jpc_mqdec_dump(mqdec));	JAS_LOGDEBUGF(100, "ctx = %d, decoded %d\n", mqdec->curctx -	  mqdec->ctxs, bit);	return bit;} static void jpc_mqdec_renormd(jpc_mqdec_t *mqdec){	do {		if (!mqdec->ctreg)			jpc_mqdec_bytein(mqdec); 		mqdec->areg <<= 1;		mqdec->creg <<= 1;		--mqdec->ctreg;	} while (!(mqdec->areg & 0x8000));} /* Apply MPS_EXCHANGE algorithm (with RENORMD). */bool jpc_mqdec_mpsexchrenormd(register jpc_mqdec_t *mqdec){	register const jpc_mqstate_t *state = *mqdec->curctx;	bool ret = jpc_mqdec_mpsexchange(mqdec->areg, state->qeval, mqdec->curctx);	jpc_mqdec_renormd(mqdec);	return ret;} /* Apply LPS_EXCHANGE algorithm (with RENORMD). */bool jpc_mqdec_lpsexchrenormd(register jpc_mqdec_t *mqdec){	register const jpc_mqstate_t *state = *mqdec->curctx;	bool ret = jpc_mqdec_lpsexchange(&mqdec->areg, state->qeval, mqdec->curctx);	jpc_mqdec_renormd(mqdec);	return ret;} /******************************************************************************\* Support code.\******************************************************************************/ /* Apply the BYTEIN algorithm. */static void jpc_mqdec_bytein(jpc_mqdec_t *mqdec){	int c;	unsigned char prevbuf; 	if (!mqdec->eof) {		if ((c = jas_stream_getc(mqdec->in)) == EOF) {			mqdec->eof = true;			c = 0xff;		}		prevbuf = mqdec->inbuffer;		mqdec->inbuffer = c;		if (prevbuf == 0xff) {			if (c > 0x8f) {				mqdec->creg += 0xff00;				mqdec->ctreg = 8;			} else {				mqdec->creg += c << 9;				mqdec->ctreg = 7;			}		} else {			mqdec->creg += c << 8;			mqdec->ctreg = 8;		}	} else {		mqdec->creg += 0xff00;		mqdec->ctreg = 8;	}} /******************************************************************************\* Code for debugging.\******************************************************************************/ /* Dump a MQ decoder to a stream for debugging. */ void jpc_mqdec_dump(const jpc_mqdec_t *mqdec){	jas_logprintf("MQDEC A = %08lx, C = %08lx, CT=%08lx, ",	  (unsigned long) mqdec->areg, (unsigned long) mqdec->creg,	  (unsigned long) mqdec->ctreg);	jas_logprintf("CTX = %" PRIdPTR ", ", mqdec->curctx - mqdec->ctxs);	jas_logprintf("IND %" PRIdPTR ", MPS %d, QEVAL %"PRIxLEAST16"\n", *mqdec->curctx -	  jpc_mqstates, (*mqdec->curctx)->mps, (*mqdec->curctx)->qeval);}