about summary refs log tree commit diff
path: root/converter/other/jpeg2000/libjasper/jpc/jpc_t2dec.c
diff options
context:
space:
mode:
Diffstat (limited to 'converter/other/jpeg2000/libjasper/jpc/jpc_t2dec.c')
-rw-r--r--converter/other/jpeg2000/libjasper/jpc/jpc_t2dec.c626
1 files changed, 626 insertions, 0 deletions
diff --git a/converter/other/jpeg2000/libjasper/jpc/jpc_t2dec.c b/converter/other/jpeg2000/libjasper/jpc/jpc_t2dec.c
new file mode 100644
index 00000000..9aaaa55c
--- /dev/null
+++ b/converter/other/jpeg2000/libjasper/jpc/jpc_t2dec.c
@@ -0,0 +1,626 @@
+/*
+ * 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 Software License
+ * 
+ * IMAGE POWER JPEG-2000 PUBLIC LICENSE
+ * ************************************
+ * 
+ * GRANT:
+ * 
+ * Permission is hereby granted, free of charge, to any person (the "User")
+ * obtaining a copy of this software and associated documentation, to deal
+ * in the JasPer Software without restriction, including without limitation
+ * the right to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the JasPer Software (in source and binary forms),
+ * and to permit persons to whom the JasPer Software is furnished to do so,
+ * provided further that the License Conditions below are met.
+ * 
+ * License Conditions
+ * ******************
+ * 
+ * A.  Redistributions of source code must retain the above copyright notice,
+ * and this list of conditions, and the following disclaimer.
+ * 
+ * B.  Redistributions in binary form must reproduce the above copyright
+ * notice, and this list of conditions, and the following disclaimer in
+ * the documentation and/or other materials provided with the distribution.
+ * 
+ * C.  Neither the name of Image Power, Inc. nor any other contributor
+ * (including, but not limited to, the University of British Columbia and
+ * Michael David Adams) may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * 
+ * D.  User agrees that it shall not commence any action against Image Power,
+ * Inc., the University of British Columbia, Michael David Adams, or any
+ * other contributors (collectively "Licensors") for infringement of any
+ * intellectual property rights ("IPR") held by the User in respect of any
+ * technology that User owns or has a right to license or sublicense and
+ * which is an element required in order to claim compliance with ISO/IEC
+ * 15444-1 (i.e., JPEG-2000 Part 1).  "IPR" means all intellectual property
+ * rights worldwide arising under statutory or common law, and whether
+ * or not perfected, including, without limitation, all (i) patents and
+ * patent applications owned or licensable by User; (ii) rights associated
+ * with works of authorship including copyrights, copyright applications,
+ * copyright registrations, mask work rights, mask work applications,
+ * mask work registrations; (iii) rights relating to the protection of
+ * trade secrets and confidential information; (iv) any right analogous
+ * to those set forth in subsections (i), (ii), or (iii) and any other
+ * proprietary rights relating to intangible property (other than trademark,
+ * trade dress, or service mark rights); and (v) divisions, continuations,
+ * renewals, reissues and extensions of the foregoing (as and to the extent
+ * applicable) now existing, hereafter filed, issued or acquired.
+ * 
+ * E.  If User commences an infringement action against any Licensor(s) then
+ * such Licensor(s) shall have the right to terminate User's license and
+ * all sublicenses that have been granted hereunder by User to other parties.
+ * 
+ * F.  This software is for use only in hardware or software products that
+ * are compliant with ISO/IEC 15444-1 (i.e., JPEG-2000 Part 1).  No license
+ * or right to this Software is granted for products that do not comply
+ * with ISO/IEC 15444-1.  The JPEG-2000 Part 1 standard can be purchased
+ * from the ISO.
+ * 
+ * THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE.
+ * NO USE OF THE JASPER SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
+ * THIS DISCLAIMER.  THE JASPER SOFTWARE IS PROVIDED BY THE LICENSORS AND
+ * CONTRIBUTORS UNDER THIS LICENSE ON AN ``AS-IS'' BASIS, WITHOUT WARRANTY
+ * OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION,
+ * WARRANTIES THAT THE JASPER SOFTWARE IS FREE OF DEFECTS, IS MERCHANTABLE,
+ * IS FIT FOR A PARTICULAR PURPOSE OR IS NON-INFRINGING.  THOSE INTENDING
+ * TO USE THE JASPER SOFTWARE OR MODIFICATIONS THEREOF FOR USE IN HARDWARE
+ * OR SOFTWARE PRODUCTS ARE ADVISED THAT THEIR USE MAY INFRINGE EXISTING
+ * PATENTS, COPYRIGHTS, TRADEMARKS, OR OTHER INTELLECTUAL PROPERTY RIGHTS.
+ * THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE JASPER SOFTWARE
+ * IS WITH THE USER.  SHOULD ANY PART OF THE JASPER SOFTWARE PROVE DEFECTIVE
+ * IN ANY RESPECT, THE USER (AND NOT THE INITIAL DEVELOPERS, THE UNIVERSITY
+ * OF BRITISH COLUMBIA, IMAGE POWER, INC., MICHAEL DAVID ADAMS, OR ANY
+ * OTHER CONTRIBUTOR) SHALL ASSUME THE COST OF ANY NECESSARY SERVICING,
+ * REPAIR OR CORRECTION.  UNDER NO CIRCUMSTANCES AND UNDER NO LEGAL THEORY,
+ * WHETHER TORT (INCLUDING NEGLIGENCE), CONTRACT, OR OTHERWISE, SHALL THE
+ * INITIAL DEVELOPER, THE UNIVERSITY OF BRITISH COLUMBIA, IMAGE POWER, INC.,
+ * MICHAEL DAVID ADAMS, ANY OTHER CONTRIBUTOR, OR ANY DISTRIBUTOR OF THE
+ * JASPER SOFTWARE, OR ANY SUPPLIER OF ANY OF SUCH PARTIES, BE LIABLE TO
+ * THE USER OR ANY OTHER PERSON FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR
+ * CONSEQUENTIAL DAMAGES OF ANY CHARACTER INCLUDING, WITHOUT LIMITATION,
+ * DAMAGES FOR LOSS OF GOODWILL, WORK STOPPAGE, COMPUTER FAILURE OR
+ * MALFUNCTION, OR ANY AND ALL OTHER COMMERCIAL DAMAGES OR LOSSES, EVEN IF
+ * SUCH PARTY HAD BEEN INFORMED, OR OUGHT TO HAVE KNOWN, OF THE POSSIBILITY
+ * OF SUCH DAMAGES.  THE JASPER SOFTWARE AND UNDERLYING TECHNOLOGY ARE NOT
+ * FAULT-TOLERANT AND ARE NOT DESIGNED, MANUFACTURED OR INTENDED FOR USE OR
+ * RESALE AS ON-LINE CONTROL EQUIPMENT IN HAZARDOUS ENVIRONMENTS REQUIRING
+ * FAIL-SAFE PERFORMANCE, SUCH AS IN THE OPERATION OF NUCLEAR FACILITIES,
+ * AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL, DIRECT
+ * LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH THE FAILURE OF THE
+ * JASPER SOFTWARE OR UNDERLYING TECHNOLOGY OR PRODUCT COULD LEAD DIRECTLY
+ * TO DEATH, PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE
+ * ("HIGH RISK ACTIVITIES").  LICENSOR SPECIFICALLY DISCLAIMS ANY EXPRESS
+ * OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.  USER WILL NOT
+ * KNOWINGLY USE, DISTRIBUTE OR RESELL THE JASPER SOFTWARE OR UNDERLYING
+ * TECHNOLOGY OR PRODUCTS FOR HIGH RISK ACTIVITIES AND WILL ENSURE THAT ITS
+ * CUSTOMERS AND END-USERS OF ITS PRODUCTS ARE PROVIDED WITH A COPY OF THE
+ * NOTICE SPECIFIED IN THIS SECTION.
+ * 
+ * __END_OF_JASPER_LICENSE__
+ */
+
+/*
+ * Tier 2 Decoder
+ *
+ * $Id$
+ */
+
+/******************************************************************************\
+* Includes.
+\******************************************************************************/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "jasper/jas_types.h"
+#include "jasper/jas_fix.h"
+#include "jasper/jas_malloc.h"
+#include "jasper/jas_math.h"
+#include "jasper/jas_stream.h"
+#include "jasper/jas_debug.h"
+
+#include "jpc_bs.h"
+#include "jpc_dec.h"
+#include "jpc_cs.h"
+#include "jpc_mqdec.h"
+#include "jpc_t2dec.h"
+#include "jpc_t1cod.h"
+#include "jpc_math.h"
+
+/******************************************************************************\
+*
+\******************************************************************************/
+
+long jpc_dec_lookahead(jas_stream_t *in);
+static int jpc_getcommacode(jpc_bitstream_t *in);
+static int jpc_getnumnewpasses(jpc_bitstream_t *in);
+static int jpc_dec_decodepkt(jpc_dec_t *dec, jas_stream_t *pkthdrstream, jas_stream_t *in, int compno, int lvlno,
+  int prcno, int lyrno);
+
+/******************************************************************************\
+* Code.
+\******************************************************************************/
+
+static int jpc_getcommacode(jpc_bitstream_t *in)
+{
+	int n;
+	int v;
+
+	n = 0;
+	for (;;) {
+		if ((v = jpc_bitstream_getbit(in)) < 0) {
+			return -1;
+		}
+		if (jpc_bitstream_eof(in)) {
+			return -1;
+		}
+		if (!v) {
+			break;
+		}
+		++n;
+	}
+
+	return n;
+}
+
+static int jpc_getnumnewpasses(jpc_bitstream_t *in)
+{
+	int n;
+
+	if ((n = jpc_bitstream_getbit(in)) > 0) {
+		if ((n = jpc_bitstream_getbit(in)) > 0) {
+			if ((n = jpc_bitstream_getbits(in, 2)) == 3) {
+				if ((n = jpc_bitstream_getbits(in, 5)) == 31) {
+					if ((n = jpc_bitstream_getbits(in, 7)) >= 0) {
+						n += 36 + 1;
+					}
+				} else if (n >= 0) {
+					n += 5 + 1;
+				}
+			} else if (n >= 0) {
+				n += 2 + 1;
+			}
+		} else if (!n) {
+			n += 2;
+		}
+	} else if (!n) {
+		++n;
+	}
+
+	return n;
+}
+
+static int jpc_dec_decodepkt(jpc_dec_t *dec, jas_stream_t *pkthdrstream, jas_stream_t *in, int compno, int rlvlno,
+  int prcno, int lyrno)
+{
+	jpc_bitstream_t *inb;
+	jpc_dec_tcomp_t *tcomp;
+	jpc_dec_rlvl_t *rlvl;
+	jpc_dec_band_t *band;
+	jpc_dec_cblk_t *cblk;
+	int n;
+	int m;
+	int i;
+	jpc_tagtreenode_t *leaf;
+	int included;
+	int ret;
+	int numnewpasses;
+	jpc_dec_seg_t *seg;
+	int len;
+	int present;
+	int savenumnewpasses;
+	int mycounter;
+	jpc_ms_t *ms;
+	jpc_dec_tile_t *tile;
+	jpc_dec_ccp_t *ccp;
+	jpc_dec_cp_t *cp;
+	int bandno;
+	jpc_dec_prc_t *prc;
+	int usedcblkcnt;
+	int cblkno;
+	uint_fast32_t bodylen;
+	bool discard;
+	int passno;
+	int maxpasses;
+	int hdrlen;
+	int hdroffstart;
+	int hdroffend;
+
+	discard = (lyrno >= dec->maxlyrs);
+
+	tile = dec->curtile;
+	cp = tile->cp;
+	ccp = &cp->ccps[compno];
+
+	/*
+	 * Decode the packet header.
+	 */
+
+	/* Decode the SOP marker segment if present. */
+	if (cp->csty & JPC_COD_SOP) {
+		if (jpc_dec_lookahead(in) == JPC_MS_SOP) {
+			if (!(ms = jpc_getms(in, dec->cstate))) {
+				return -1;
+			}
+			if (jpc_ms_gettype(ms) != JPC_MS_SOP) {
+				jpc_ms_destroy(ms);
+				fprintf(stderr, "missing SOP marker segment\n");
+				return -1;
+			}
+			jpc_ms_destroy(ms);
+		}
+	}
+
+hdroffstart = jas_stream_getrwcount(pkthdrstream);
+
+	if (!(inb = jpc_bitstream_sopen(pkthdrstream, "r"))) {
+		return -1;
+	}
+
+	if ((present = jpc_bitstream_getbit(inb)) < 0) {
+		return 1;
+	}
+	JAS_DBGLOG(10, ("\n", present));
+	JAS_DBGLOG(10, ("present=%d ", present));
+
+	/* Is the packet non-empty? */
+	if (present) {
+		/* The packet is non-empty. */
+		tcomp = &tile->tcomps[compno];
+		rlvl = &tcomp->rlvls[rlvlno];
+		bodylen = 0;
+		for (bandno = 0, band = rlvl->bands; bandno < rlvl->numbands;
+		  ++bandno, ++band) {
+			if (!band->data) {
+				continue;
+			}
+			prc = &band->prcs[prcno];
+			if (!prc->cblks) {
+				continue;
+			}
+			usedcblkcnt = 0;
+			for (cblkno = 0, cblk = prc->cblks; cblkno < prc->numcblks;
+			  ++cblkno, ++cblk) {
+				++usedcblkcnt;
+				if (!cblk->numpasses) {
+					leaf = jpc_tagtree_getleaf(prc->incltagtree, usedcblkcnt - 1);
+					if ((included = jpc_tagtree_decode(prc->incltagtree, leaf, lyrno + 1, inb)) < 0) {
+						return -1;
+					}
+				} else {
+					if ((included = jpc_bitstream_getbit(inb)) < 0) {
+						return -1;
+					}
+				}
+				JAS_DBGLOG(10, ("\n"));
+				JAS_DBGLOG(10, ("included=%d ", included));
+				if (!included) {
+					continue;
+				}
+				if (!cblk->numpasses) {
+					i = 1;
+					leaf = jpc_tagtree_getleaf(prc->numimsbstagtree, usedcblkcnt - 1);
+					for (;;) {
+						if ((ret = jpc_tagtree_decode(prc->numimsbstagtree, leaf, i, inb)) < 0) {
+							return -1;
+						}
+						if (ret) {
+							break;
+						}
+						++i;
+					}
+					cblk->numimsbs = i - 1;
+					cblk->firstpassno = cblk->numimsbs * 3;
+				}
+				if ((numnewpasses = jpc_getnumnewpasses(inb)) < 0) {
+					return -1;
+				}
+				JAS_DBGLOG(10, ("numnewpasses=%d ", numnewpasses));
+				seg = cblk->curseg;
+				savenumnewpasses = numnewpasses;
+				mycounter = 0;
+				if (numnewpasses > 0) {
+					if ((m = jpc_getcommacode(inb)) < 0) {
+						return -1;
+					}
+					cblk->numlenbits += m;
+					JAS_DBGLOG(10, ("increment=%d ", m));
+					while (numnewpasses > 0) {
+						passno = cblk->firstpassno + cblk->numpasses + mycounter;
+	/* XXX - the maxpasses is not set precisely but this doesn't matter... */
+						maxpasses = JPC_SEGPASSCNT(passno, cblk->firstpassno, 10000, (ccp->cblkctx & JPC_COX_LAZY) != 0, (ccp->cblkctx & JPC_COX_TERMALL) != 0);
+						if (!discard && !seg) {
+							if (!(seg = jpc_seg_alloc())) {
+								return -1;
+							}
+							jpc_seglist_insert(&cblk->segs, cblk->segs.tail, seg);
+							if (!cblk->curseg) {
+								cblk->curseg = seg;
+							}
+							seg->passno = passno;
+							seg->type = JPC_SEGTYPE(seg->passno, cblk->firstpassno, (ccp->cblkctx & JPC_COX_LAZY) != 0);
+							seg->maxpasses = maxpasses;
+						}
+						n = JAS_MIN(numnewpasses, maxpasses);
+						mycounter += n;
+						numnewpasses -= n;
+						if ((len = jpc_bitstream_getbits(inb, cblk->numlenbits + jpc_floorlog2(n))) < 0) {
+							return -1;
+						}
+						JAS_DBGLOG(10, ("len=%d ", len));
+						if (!discard) {
+							seg->lyrno = lyrno;
+							seg->numpasses += n;
+							seg->cnt = len;
+							seg = seg->next;
+						}
+						bodylen += len;
+					}
+				}
+				cblk->numpasses += savenumnewpasses;
+			}
+		}
+
+		jpc_bitstream_inalign(inb, 0, 0);
+
+	} else {
+		if (jpc_bitstream_inalign(inb, 0x7f, 0)) {
+			fprintf(stderr, "alignment failed\n");
+			return -1;
+		}
+	}
+	jpc_bitstream_close(inb);
+
+	hdroffend = jas_stream_getrwcount(pkthdrstream);
+	hdrlen = hdroffend - hdroffstart;
+	if (jas_getdbglevel() >= 5) {
+		fprintf(stderr, "hdrlen=%lu bodylen=%lu \n", (unsigned long) hdrlen,
+		  (unsigned long) bodylen);
+	}
+
+	if (cp->csty & JPC_COD_EPH) {
+		if (jpc_dec_lookahead(pkthdrstream) == JPC_MS_EPH) {
+			if (!(ms = jpc_getms(pkthdrstream, dec->cstate))) {
+				fprintf(stderr, "cannot get (EPH) marker segment\n");
+				return -1;
+			}
+			if (jpc_ms_gettype(ms) != JPC_MS_EPH) {
+				jpc_ms_destroy(ms);
+				fprintf(stderr, "missing EPH marker segment\n");
+				return -1;
+			}
+			jpc_ms_destroy(ms);
+		}
+	}
+
+	/* decode the packet body. */
+
+	if (jas_getdbglevel() >= 1) {
+		fprintf(stderr, "packet body offset=%06ld\n", (long) jas_stream_getrwcount(in));
+	}
+
+	if (!discard) {
+		tcomp = &tile->tcomps[compno];
+		rlvl = &tcomp->rlvls[rlvlno];
+		for (bandno = 0, band = rlvl->bands; bandno < rlvl->numbands;
+		  ++bandno, ++band) {
+			if (!band->data) {
+				continue;
+			}
+			prc = &band->prcs[prcno];
+			if (!prc->cblks) {
+				continue;
+			}
+			for (cblkno = 0, cblk = prc->cblks; cblkno < prc->numcblks;
+			  ++cblkno, ++cblk) {
+				seg = cblk->curseg;
+				while (seg) {
+					if (!seg->stream) {
+						if (!(seg->stream = jas_stream_memopen(0, 0))) {
+							return -1;
+						}
+					}
+#if 0
+fprintf(stderr, "lyrno=%02d, compno=%02d, lvlno=%02d, prcno=%02d, bandno=%02d, cblkno=%02d, passno=%02d numpasses=%02d cnt=%d numbps=%d, numimsbs=%d\n", lyrno, compno, rlvlno, prcno, band - rlvl->bands, cblk - prc->cblks, seg->passno, seg->numpasses, seg->cnt, band->numbps, cblk->numimsbs);
+#endif
+					if (seg->cnt > 0) {
+						if (jpc_getdata(in, seg->stream, seg->cnt) < 0) {
+							return -1;
+						}
+						seg->cnt = 0;
+					}
+					if (seg->numpasses >= seg->maxpasses) {
+						cblk->curseg = seg->next;
+					}
+					seg = seg->next;
+				}
+			}
+		}
+	} else {
+		if (jas_stream_gobble(in, bodylen) != bodylen) {
+			return -1;
+		}
+	}
+	return 0;
+}
+
+/********************************************************************************************/
+/********************************************************************************************/
+
+int jpc_dec_decodepkts(jpc_dec_t *dec, jas_stream_t *pkthdrstream, jas_stream_t *in)
+{
+	jpc_dec_tile_t *tile;
+	jpc_pi_t *pi;
+	int ret;
+
+	tile = dec->curtile;
+	pi = tile->pi;
+	for (;;) {
+if (!tile->pkthdrstream || jas_stream_peekc(tile->pkthdrstream) == EOF) {
+		switch (jpc_dec_lookahead(in)) {
+		case JPC_MS_EOC:
+		case JPC_MS_SOT:
+			return 0;
+			break;
+		case JPC_MS_SOP:
+		case JPC_MS_EPH:
+		case 0:
+			break;
+		default:
+			return -1;
+			break;
+		}
+}
+		if ((ret = jpc_pi_next(pi))) {
+			return ret;
+		}
+if (dec->maxpkts >= 0 && dec->numpkts >= dec->maxpkts) {
+	fprintf(stderr, "warning: stopping decode prematurely as requested\n");
+	return 0;
+}
+		if (jas_getdbglevel() >= 1) {
+			fprintf(stderr, "packet offset=%08ld prg=%d cmptno=%02d "
+			  "rlvlno=%02d prcno=%03d lyrno=%02d\n", (long)
+			  jas_stream_getrwcount(in), jpc_pi_prg(pi), jpc_pi_cmptno(pi),
+			  jpc_pi_rlvlno(pi), jpc_pi_prcno(pi), jpc_pi_lyrno(pi));
+		}
+		if (jpc_dec_decodepkt(dec, pkthdrstream, in, jpc_pi_cmptno(pi), jpc_pi_rlvlno(pi),
+		  jpc_pi_prcno(pi), jpc_pi_lyrno(pi))) {
+			return -1;
+		}
+++dec->numpkts;
+	}
+
+	return 0;
+}
+
+jpc_pi_t *jpc_dec_pi_create(jpc_dec_t *dec, jpc_dec_tile_t *tile)
+{
+	jpc_pi_t *pi;
+	int compno;
+	jpc_picomp_t *picomp;
+	jpc_pirlvl_t *pirlvl;
+	jpc_dec_tcomp_t *tcomp;
+	int rlvlno;
+	jpc_dec_rlvl_t *rlvl;
+	int prcno;
+	int *prclyrno;
+	jpc_dec_cmpt_t *cmpt;
+
+	if (!(pi = jpc_pi_create0())) {
+		return 0;
+	}
+	pi->numcomps = dec->numcomps;
+	if (!(pi->picomps = jas_malloc(pi->numcomps * sizeof(jpc_picomp_t)))) {
+		jpc_pi_destroy(pi);
+		return 0;
+	}
+	for (compno = 0, picomp = pi->picomps; compno < pi->numcomps; ++compno,
+	  ++picomp) {
+		picomp->pirlvls = 0;
+	}
+
+	for (compno = 0, tcomp = tile->tcomps, picomp = pi->picomps;
+	  compno < pi->numcomps; ++compno, ++tcomp, ++picomp) {
+		picomp->numrlvls = tcomp->numrlvls;
+		if (!(picomp->pirlvls = jas_malloc(picomp->numrlvls *
+		  sizeof(jpc_pirlvl_t)))) {
+			jpc_pi_destroy(pi);
+			return 0;
+		}
+		for (rlvlno = 0, pirlvl = picomp->pirlvls; rlvlno <
+		  picomp->numrlvls; ++rlvlno, ++pirlvl) {
+			pirlvl->prclyrnos = 0;
+		}
+		for (rlvlno = 0, pirlvl = picomp->pirlvls, rlvl = tcomp->rlvls;
+		  rlvlno < picomp->numrlvls; ++rlvlno, ++pirlvl, ++rlvl) {
+/* XXX sizeof(long) should be sizeof different type */
+			pirlvl->numprcs = rlvl->numprcs;
+			if (!(pirlvl->prclyrnos = jas_malloc(pirlvl->numprcs *
+			  sizeof(long)))) {
+				jpc_pi_destroy(pi);
+				return 0;
+			}
+		}
+	}
+
+	pi->maxrlvls = 0;
+	for (compno = 0, tcomp = tile->tcomps, picomp = pi->picomps, cmpt =
+	  dec->cmpts; compno < pi->numcomps; ++compno, ++tcomp, ++picomp,
+	  ++cmpt) {
+		picomp->hsamp = cmpt->hstep;
+		picomp->vsamp = cmpt->vstep;
+		for (rlvlno = 0, pirlvl = picomp->pirlvls, rlvl = tcomp->rlvls;
+		  rlvlno < picomp->numrlvls; ++rlvlno, ++pirlvl, ++rlvl) {
+			pirlvl->prcwidthexpn = rlvl->prcwidthexpn;
+			pirlvl->prcheightexpn = rlvl->prcheightexpn;
+			for (prcno = 0, prclyrno = pirlvl->prclyrnos;
+			  prcno < pirlvl->numprcs; ++prcno, ++prclyrno) {
+				*prclyrno = 0;
+			}
+			pirlvl->numhprcs = rlvl->numhprcs;
+		}
+		if (pi->maxrlvls < tcomp->numrlvls) {
+			pi->maxrlvls = tcomp->numrlvls;
+		}
+	}
+
+	pi->numlyrs = tile->cp->numlyrs;
+	pi->xstart = tile->xstart;
+	pi->ystart = tile->ystart;
+	pi->xend = tile->xend;
+	pi->yend = tile->yend;
+
+	pi->picomp = 0;
+	pi->pirlvl = 0;
+	pi->x = 0;
+	pi->y = 0;
+	pi->compno = 0;
+	pi->rlvlno = 0;
+	pi->prcno = 0;
+	pi->lyrno = 0;
+	pi->xstep = 0;
+	pi->ystep = 0;
+
+	pi->pchgno = -1;
+
+	pi->defaultpchg.prgord = tile->cp->prgord;
+	pi->defaultpchg.compnostart = 0;
+	pi->defaultpchg.compnoend = pi->numcomps;
+	pi->defaultpchg.rlvlnostart = 0;
+	pi->defaultpchg.rlvlnoend = pi->maxrlvls;
+	pi->defaultpchg.lyrnoend = pi->numlyrs;
+	pi->pchg = 0;
+
+	pi->valid = 0;
+
+	return pi;
+}
+
+long jpc_dec_lookahead(jas_stream_t *in)
+{
+	uint_fast16_t x;
+	if (jpc_getuint16(in, &x)) {
+		return -1;
+	}
+	if (jas_stream_ungetc(in, x & 0xff) == EOF ||
+	  jas_stream_ungetc(in, x >> 8) == EOF) {
+		return -1;
+	}
+	if (x >= JPC_MS_INMIN && x <= JPC_MS_INMAX) {
+		return x;
+	}
+	return 0;
+}