307 lines
9.8 KiB
C
307 lines
9.8 KiB
C
/*
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* Copyright (c) 1999-2000 Image Power, Inc. and the University of
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* British Columbia.
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* Copyright (c) 2001-2003 Michael David Adams.
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* All rights reserved.
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*/
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/* __START_OF_JASPER_LICENSE__
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*
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* JasPer License Version 2.0
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*
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* Copyright (c) 2001-2006 Michael David Adams
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* Copyright (c) 1999-2000 Image Power, Inc.
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* Copyright (c) 1999-2000 The University of British Columbia
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*
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* All rights reserved.
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*
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* Permission is hereby granted, free of charge, to any person (the
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* "User") obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without restriction,
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* including without limitation the rights to use, copy, modify, merge,
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* publish, distribute, and/or sell copies of the Software, and to permit
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* persons to whom the Software is furnished to do so, subject to the
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* following conditions:
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*
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* 1. The above copyright notices and this permission notice (which
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* includes the disclaimer below) shall be included in all copies or
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* substantial portions of the Software.
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*
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* 2. The name of a copyright holder shall not be used to endorse or
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* promote products derived from the Software without specific prior
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* written permission.
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*
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* THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
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* LICENSE. NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
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* THIS DISCLAIMER. THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
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* "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
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* BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
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* PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO
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* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
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* INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
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* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
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* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
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* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. NO ASSURANCES ARE
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* PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
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* THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
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* EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
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* BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
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* PROPERTY RIGHTS OR OTHERWISE. AS A CONDITION TO EXERCISING THE RIGHTS
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* GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
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* ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY. THE SOFTWARE
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* IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
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* SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
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* AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
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* SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
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* THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
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* PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
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* RISK ACTIVITIES"). THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
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* EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
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*
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* __END_OF_JASPER_LICENSE__
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*/
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/*
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* MQ Arithmetic Decoder
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*
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* $Id: jpc_mqdec.c,v 1.2 2008-05-26 09:40:52 vp153 Exp $
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*/
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/******************************************************************************\
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* Includes.
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\******************************************************************************/
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#include <assert.h>
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#include <stdlib.h>
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#include <stdarg.h>
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#include "jasper/jas_types.h"
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#include "jasper/jas_malloc.h"
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#include "jasper/jas_math.h"
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#include "jasper/jas_debug.h"
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#include "jpc_mqdec.h"
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/******************************************************************************\
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* Local macros.
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\******************************************************************************/
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#if defined(DEBUG)
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#define MQDEC_CALL(n, x) \
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((jas_getdbglevel() >= (n)) ? ((void)(x)) : ((void)0))
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#else
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#define MQDEC_CALL(n, x)
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#endif
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/******************************************************************************\
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* Local function prototypes.
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\******************************************************************************/
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static void jpc_mqdec_bytein(jpc_mqdec_t *mqdec);
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/******************************************************************************\
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* Code for creation and destruction of a MQ decoder.
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\******************************************************************************/
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/* Create a MQ decoder. */
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jpc_mqdec_t *jpc_mqdec_create(int maxctxs, jas_stream_t *in)
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{
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jpc_mqdec_t *mqdec;
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/* There must be at least one context. */
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assert(maxctxs > 0);
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/* Allocate memory for the MQ decoder. */
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if (!(mqdec = jas_malloc(sizeof(jpc_mqdec_t)))) {
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goto error;
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}
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mqdec->in = in;
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mqdec->maxctxs = maxctxs;
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/* Allocate memory for the per-context state information. */
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if (!(mqdec->ctxs = jas_alloc2(mqdec->maxctxs, sizeof(jpc_mqstate_t *)))) {
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goto error;
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}
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/* Set the current context to the first context. */
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mqdec->curctx = mqdec->ctxs;
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/* If an input stream has been associated with the MQ decoder,
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initialize the decoder state from the stream. */
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if (mqdec->in) {
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jpc_mqdec_init(mqdec);
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}
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/* Initialize the per-context state information. */
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jpc_mqdec_setctxs(mqdec, 0, 0);
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return mqdec;
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error:
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/* Oops... Something has gone wrong. */
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if (mqdec) {
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jpc_mqdec_destroy(mqdec);
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}
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return 0;
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}
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/* Destroy a MQ decoder. */
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void jpc_mqdec_destroy(jpc_mqdec_t *mqdec)
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{
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if (mqdec->ctxs) {
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jas_free(mqdec->ctxs);
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}
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jas_free(mqdec);
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}
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/******************************************************************************\
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* Code for initialization of a MQ decoder.
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\******************************************************************************/
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/* Initialize the state of a MQ decoder. */
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void jpc_mqdec_init(jpc_mqdec_t *mqdec)
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{
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int c;
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mqdec->eof = 0;
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mqdec->creg = 0;
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/* Get the next byte from the input stream. */
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if ((c = jas_stream_getc(mqdec->in)) == EOF) {
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/* We have encountered an I/O error or EOF. */
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c = 0xff;
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mqdec->eof = 1;
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}
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mqdec->inbuffer = c;
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mqdec->creg += mqdec->inbuffer << 16;
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jpc_mqdec_bytein(mqdec);
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mqdec->creg <<= 7;
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mqdec->ctreg -= 7;
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mqdec->areg = 0x8000;
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}
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/* Set the input stream for a MQ decoder. */
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void jpc_mqdec_setinput(jpc_mqdec_t *mqdec, jas_stream_t *in)
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{
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mqdec->in = in;
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}
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/* Initialize one or more contexts. */
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void jpc_mqdec_setctxs(jpc_mqdec_t *mqdec, int numctxs, jpc_mqctx_t *ctxs)
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{
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jpc_mqstate_t **ctx;
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int n;
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ctx = mqdec->ctxs;
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n = JAS_MIN(mqdec->maxctxs, numctxs);
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while (--n >= 0) {
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*ctx = &jpc_mqstates[2 * ctxs->ind + ctxs->mps];
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++ctx;
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++ctxs;
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}
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n = mqdec->maxctxs - numctxs;
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while (--n >= 0) {
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*ctx = &jpc_mqstates[0];
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++ctx;
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}
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}
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/* Initialize a context. */
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void jpc_mqdec_setctx(jpc_mqdec_t *mqdec, int ctxno, jpc_mqctx_t *ctx)
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{
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jpc_mqstate_t **ctxi;
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ctxi = &mqdec->ctxs[ctxno];
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*ctxi = &jpc_mqstates[2 * ctx->ind + ctx->mps];
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}
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/******************************************************************************\
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* Code for decoding a bit.
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\******************************************************************************/
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/* Decode a bit. */
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int jpc_mqdec_getbit_func(register jpc_mqdec_t *mqdec)
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{
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int bit;
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JAS_DBGLOG(100, ("jpc_mqdec_getbit_func(%p)\n", mqdec));
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MQDEC_CALL(100, jpc_mqdec_dump(mqdec, stderr));
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bit = jpc_mqdec_getbit_macro(mqdec);
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MQDEC_CALL(100, jpc_mqdec_dump(mqdec, stderr));
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JAS_DBGLOG(100, ("ctx = %d, decoded %d\n", mqdec->curctx -
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mqdec->ctxs, bit));
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return bit;
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}
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/* Apply MPS_EXCHANGE algorithm (with RENORMD). */
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int jpc_mqdec_mpsexchrenormd(register jpc_mqdec_t *mqdec)
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{
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int ret;
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register jpc_mqstate_t *state = *mqdec->curctx;
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jpc_mqdec_mpsexchange(mqdec->areg, state->qeval, mqdec->curctx, ret);
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jpc_mqdec_renormd(mqdec->areg, mqdec->creg, mqdec->ctreg, mqdec->in,
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mqdec->eof, mqdec->inbuffer);
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return ret;
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}
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/* Apply LPS_EXCHANGE algorithm (with RENORMD). */
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int jpc_mqdec_lpsexchrenormd(register jpc_mqdec_t *mqdec)
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{
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int ret;
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register jpc_mqstate_t *state = *mqdec->curctx;
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jpc_mqdec_lpsexchange(mqdec->areg, state->qeval, mqdec->curctx, ret);
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jpc_mqdec_renormd(mqdec->areg, mqdec->creg, mqdec->ctreg, mqdec->in,
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mqdec->eof, mqdec->inbuffer);
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return ret;
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}
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/******************************************************************************\
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* Support code.
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\******************************************************************************/
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/* Apply the BYTEIN algorithm. */
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static void jpc_mqdec_bytein(jpc_mqdec_t *mqdec)
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{
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int c;
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unsigned char prevbuf;
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if (!mqdec->eof) {
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if ((c = jas_stream_getc(mqdec->in)) == EOF) {
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mqdec->eof = 1;
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c = 0xff;
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}
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prevbuf = mqdec->inbuffer;
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mqdec->inbuffer = c;
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if (prevbuf == 0xff) {
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if (c > 0x8f) {
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mqdec->creg += 0xff00;
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mqdec->ctreg = 8;
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} else {
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mqdec->creg += c << 9;
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mqdec->ctreg = 7;
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}
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} else {
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mqdec->creg += c << 8;
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mqdec->ctreg = 8;
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}
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} else {
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mqdec->creg += 0xff00;
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mqdec->ctreg = 8;
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}
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}
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/******************************************************************************\
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* Code for debugging.
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\******************************************************************************/
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/* Dump a MQ decoder to a stream for debugging. */
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void jpc_mqdec_dump(jpc_mqdec_t *mqdec, FILE *out)
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{
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fprintf(out, "MQDEC A = %08lx, C = %08lx, CT=%08lx, ",
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(unsigned long) mqdec->areg, (unsigned long) mqdec->creg,
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(unsigned long) mqdec->ctreg);
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fprintf(out, "CTX = %d, ", (int)(mqdec->curctx - mqdec->ctxs));
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fprintf(out, "IND %d, MPS %d, QEVAL %x\n", (int)(*mqdec->curctx -
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jpc_mqstates), (int)(*mqdec->curctx)->mps, (int)(*mqdec->curctx)->qeval);
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}
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