jpc_dec.c

用C语言实现的JPEG编码

		*/
	}
	return 0;
}

static int jpc_dec_process_soc(jpc_dec_t *dec, jpc_ms_t *ms)
{
	/* Eliminate warnings about unused variables. */
	ms = 0;

	/* We should expect to encounter a SIZ marker segment next. */
	dec->state = JPC_MHSIZ;

	return 0;
}

static int jpc_dec_process_sot(jpc_dec_t *dec, jpc_ms_t *ms)
{
	jpc_dec_tile_t *tile;
	jpc_sot_t *sot = &ms->parms.sot;
	jas_image_cmptparm_t *compinfos;
	jas_image_cmptparm_t *compinfo;
	jpc_dec_cmpt_t *cmpt;
	int cmptno;

	if (dec->state == JPC_MH) {

		compinfos = jas_malloc(dec->numcomps * sizeof(jas_image_cmptparm_t));
		assert(compinfos);
		for (cmptno = 0, cmpt = dec->cmpts, compinfo = compinfos;
		  cmptno < dec->numcomps; ++cmptno, ++cmpt, ++compinfo) {
			compinfo->tlx = 0;
			compinfo->tly = 0;
			compinfo->prec = cmpt->prec;
			compinfo->sgnd = cmpt->sgnd;
			compinfo->width = cmpt->width;
			compinfo->height = cmpt->height;
			compinfo->hstep = cmpt->hstep;
			compinfo->vstep = cmpt->vstep;
		}

		if (!(dec->image = jas_image_create(dec->numcomps, compinfos,
		  JAS_CLRSPC_UNKNOWN))) {
			return -1;
		}
		jas_free(compinfos);

		/* Is the packet header information stored in PPM marker segments in
		  the main header? */
		if (dec->ppmstab) {
			/* Convert the PPM marker segment data into a collection of streams
			  (one stream per tile-part). */
			if (!(dec->pkthdrstreams = jpc_ppmstabtostreams(dec->ppmstab))) {
				abort();
			}
			jpc_ppxstab_destroy(dec->ppmstab);
			dec->ppmstab = 0;
		}
	}

	if (sot->len > 0) {
		dec->curtileendoff = jas_stream_getrwcount(dec->in) - ms->len -
		  4 + sot->len;
	} else {
		dec->curtileendoff = 0;
	}

	if (JAS_CAST(int, sot->tileno) > dec->numtiles) {
		fprintf(stderr, "invalid tile number in SOT marker segment\n");
		return -1;
	}
	/* Set the current tile. */
	dec->curtile = &dec->tiles[sot->tileno];
	tile = dec->curtile;
	/* Ensure that this is the expected part number. */
	if (sot->partno != tile->partno) {
		return -1;
	}
	if (tile->numparts > 0 && sot->partno >= tile->numparts) {
		return -1;
	}
	if (!tile->numparts && sot->numparts > 0) {
		tile->numparts = sot->numparts;
	}

	tile->pptstab = 0;

	switch (tile->state) {
	case JPC_TILE_INIT:
		/* This is the first tile-part for this tile. */
		tile->state = JPC_TILE_ACTIVE;
		assert(!tile->cp);
		if (!(tile->cp = jpc_dec_cp_copy(dec->cp))) {
			return -1;
		}
		jpc_dec_cp_resetflags(dec->cp);
		break;
	default:
		if (sot->numparts == sot->partno - 1) {
			tile->state = JPC_TILE_ACTIVELAST;
		}
		break;
	}

	/* Note: We do not increment the expected tile-part number until
	  all processing for this tile-part is complete. */

	/* We should expect to encounter other tile-part header marker
	  segments next. */
	dec->state = JPC_TPH;

	return 0;
}

static int jpc_dec_process_sod(jpc_dec_t *dec, jpc_ms_t *ms)
{
	jpc_dec_tile_t *tile;
	int pos;

	/* Eliminate compiler warnings about unused variables. */
	ms = 0;

	if (!(tile = dec->curtile)) {
		return -1;
	}

	if (!tile->partno) {
		if (!jpc_dec_cp_isvalid(tile->cp)) {
			return -1;
		}
		jpc_dec_cp_prepare(tile->cp);
		if (jpc_dec_tileinit(dec, tile)) {
			return -1;
		}
	}

	/* Are packet headers stored in the main header or tile-part header? */
	if (dec->pkthdrstreams) {
		/* Get the stream containing the packet header data for this
		  tile-part. */
		if (!(tile->pkthdrstream = jpc_streamlist_remove(dec->pkthdrstreams, 0))) {
			return -1;
		}
	}

	if (tile->pptstab) {
		if (!tile->pkthdrstream) {
			if (!(tile->pkthdrstream = jas_stream_memopen(0, 0))) {
				return -1;
			}
		}
		pos = jas_stream_tell(tile->pkthdrstream);
		jas_stream_seek(tile->pkthdrstream, 0, SEEK_END);
		if (jpc_pptstabwrite(tile->pkthdrstream, tile->pptstab)) {
			return -1;
		}
		jas_stream_seek(tile->pkthdrstream, pos, SEEK_SET);
		jpc_ppxstab_destroy(tile->pptstab);
		tile->pptstab = 0;
	}

	if (jas_getdbglevel() >= 10) {
		jpc_dec_dump(dec, stderr);
	}

	if (jpc_dec_decodepkts(dec, (tile->pkthdrstream) ? tile->pkthdrstream :
	  dec->in, dec->in)) {
		fprintf(stderr, "jpc_dec_decodepkts failed\n");
		return -1;
	}

	/* Gobble any unconsumed tile data. */
	if (dec->curtileendoff > 0) {
		long curoff;
		uint_fast32_t n;
		curoff = jas_stream_getrwcount(dec->in);
		if (curoff < dec->curtileendoff) {
			n = dec->curtileendoff - curoff;
			fprintf(stderr,
			  "warning: ignoring trailing garbage (%lu bytes)\n",
			  (unsigned long) n);

			while (n-- > 0) {
				if (jas_stream_getc(dec->in) == EOF) {
					fprintf(stderr, "read error\n");
					return -1;
				}
			}
		} else if (curoff > dec->curtileendoff) {
			fprintf(stderr,
			  "warning: not enough tile data (%lu bytes)\n",
			  (unsigned long) curoff - dec->curtileendoff);
		}

	}

	if (tile->numparts > 0 && tile->partno == tile->numparts - 1) {
		if (jpc_dec_tiledecode(dec, tile)) {
			return -1;
		}
		jpc_dec_tilefini(dec, tile);
	}

	dec->curtile = 0;

	/* Increment the expected tile-part number. */
	++tile->partno;

	/* We should expect to encounter a SOT marker segment next. */
	dec->state = JPC_TPHSOT;

	return 0;
}

static int jpc_dec_tileinit(jpc_dec_t *dec, jpc_dec_tile_t *tile)
{
	jpc_dec_tcomp_t *tcomp;
	int compno;
	int rlvlno;
	jpc_dec_rlvl_t *rlvl;
	jpc_dec_band_t *band;
	jpc_dec_prc_t *prc;
	int bndno;
	jpc_tsfb_band_t *bnd;
	int bandno;
	jpc_dec_ccp_t *ccp;
	int prccnt;
	jpc_dec_cblk_t *cblk;
	int cblkcnt;
	uint_fast32_t tlprcxstart;
	uint_fast32_t tlprcystart;
	uint_fast32_t brprcxend;
	uint_fast32_t brprcyend;
	uint_fast32_t tlcbgxstart;
	uint_fast32_t tlcbgystart;
	uint_fast32_t brcbgxend;
	uint_fast32_t brcbgyend;
	uint_fast32_t cbgxstart;
	uint_fast32_t cbgystart;
	uint_fast32_t cbgxend;
	uint_fast32_t cbgyend;
	uint_fast32_t tlcblkxstart;
	uint_fast32_t tlcblkystart;
	uint_fast32_t brcblkxend;
	uint_fast32_t brcblkyend;
	uint_fast32_t cblkxstart;
	uint_fast32_t cblkystart;
	uint_fast32_t cblkxend;
	uint_fast32_t cblkyend;
	uint_fast32_t tmpxstart;
	uint_fast32_t tmpystart;
	uint_fast32_t tmpxend;
	uint_fast32_t tmpyend;
	jpc_dec_cp_t *cp;
	jpc_tsfb_band_t bnds[64];
	jpc_pchg_t *pchg;
	int pchgno;
	jpc_dec_cmpt_t *cmpt;

	cp = tile->cp;
	tile->realmode = 0;
	if (cp->mctid == JPC_MCT_ICT) {
		tile->realmode = 1;
	}

	for (compno = 0, tcomp = tile->tcomps, cmpt = dec->cmpts; compno <
	  dec->numcomps; ++compno, ++tcomp, ++cmpt) {
		ccp = &tile->cp->ccps[compno];
		if (ccp->qmfbid == JPC_COX_INS) {
			tile->realmode = 1;
		}
		tcomp->numrlvls = ccp->numrlvls;
		if (!(tcomp->rlvls = jas_malloc(tcomp->numrlvls *
		  sizeof(jpc_dec_rlvl_t)))) {
			return -1;
		}
		if (!(tcomp->data = jas_seq2d_create(JPC_CEILDIV(tile->xstart,
		  cmpt->hstep), JPC_CEILDIV(tile->ystart, cmpt->vstep),
		  JPC_CEILDIV(tile->xend, cmpt->hstep), JPC_CEILDIV(tile->yend,
		  cmpt->vstep)))) {
			return -1;
		}
		if (!(tcomp->tsfb = jpc_cod_gettsfb(ccp->qmfbid,
		  tcomp->numrlvls - 1))) {
			return -1;
		}
{
	jpc_tsfb_getbands(tcomp->tsfb, jas_seq2d_xstart(tcomp->data), jas_seq2d_ystart(tcomp->data), jas_seq2d_xend(tcomp->data), jas_seq2d_yend(tcomp->data), bnds);
}
		for (rlvlno = 0, rlvl = tcomp->rlvls; rlvlno < tcomp->numrlvls;
		  ++rlvlno, ++rlvl) {
rlvl->bands = 0;
			rlvl->xstart = JPC_CEILDIVPOW2(tcomp->xstart,
			  tcomp->numrlvls - 1 - rlvlno);
			rlvl->ystart = JPC_CEILDIVPOW2(tcomp->ystart,
			  tcomp->numrlvls - 1 - rlvlno);
			rlvl->xend = JPC_CEILDIVPOW2(tcomp->xend,
			  tcomp->numrlvls - 1 - rlvlno);
			rlvl->yend = JPC_CEILDIVPOW2(tcomp->yend,
			  tcomp->numrlvls - 1 - rlvlno);
			rlvl->prcwidthexpn = ccp->prcwidthexpns[rlvlno];
			rlvl->prcheightexpn = ccp->prcheightexpns[rlvlno];
			tlprcxstart = JPC_FLOORDIVPOW2(rlvl->xstart,
			  rlvl->prcwidthexpn) << rlvl->prcwidthexpn;
			tlprcystart = JPC_FLOORDIVPOW2(rlvl->ystart,
			  rlvl->prcheightexpn) << rlvl->prcheightexpn;
			brprcxend = JPC_CEILDIVPOW2(rlvl->xend,
			  rlvl->prcwidthexpn) << rlvl->prcwidthexpn;
			brprcyend = JPC_CEILDIVPOW2(rlvl->yend,
			  rlvl->prcheightexpn) << rlvl->prcheightexpn;
			rlvl->numhprcs = (brprcxend - tlprcxstart) >>
			  rlvl->prcwidthexpn;
			rlvl->numvprcs = (brprcyend - tlprcystart) >>
			  rlvl->prcheightexpn;
			rlvl->numprcs = rlvl->numhprcs * rlvl->numvprcs;

			if (rlvl->xstart >= rlvl->xend || rlvl->ystart >= rlvl->yend) {
				rlvl->bands = 0;
				rlvl->numprcs = 0;
				rlvl->numhprcs = 0;
				rlvl->numvprcs = 0;
				continue;
			}	
			if (!rlvlno) {
				tlcbgxstart = tlprcxstart;
				tlcbgystart = tlprcystart;
				brcbgxend = brprcxend;
				brcbgyend = brprcyend;
				rlvl->cbgwidthexpn = rlvl->prcwidthexpn;
				rlvl->cbgheightexpn = rlvl->prcheightexpn;
			} else {
				tlcbgxstart = JPC_CEILDIVPOW2(tlprcxstart, 1);
				tlcbgystart = JPC_CEILDIVPOW2(tlprcystart, 1);
				brcbgxend = JPC_CEILDIVPOW2(brprcxend, 1);
				brcbgyend = JPC_CEILDIVPOW2(brprcyend, 1);
				rlvl->cbgwidthexpn = rlvl->prcwidthexpn - 1;
				rlvl->cbgheightexpn = rlvl->prcheightexpn - 1;
			}
			rlvl->cblkwidthexpn = JAS_MIN(ccp->cblkwidthexpn,
			  rlvl->cbgwidthexpn);
			rlvl->cblkheightexpn = JAS_MIN(ccp->cblkheightexpn,
			  rlvl->cbgheightexpn);

			rlvl->numbands = (!rlvlno) ? 1 : 3;
			if (!(rlvl->bands = jas_malloc(rlvl->numbands *
			  sizeof(jpc_dec_band_t)))) {
				return -1;
			}
			for (bandno = 0, band = rlvl->bands;
			  bandno < rlvl->numbands; ++bandno, ++band) {
				bndno = (!rlvlno) ? 0 : (3 * (rlvlno - 1) +
				  bandno + 1);
				bnd = &bnds[bndno];

				band->orient = bnd->orient;
				band->stepsize = ccp->stepsizes[bndno];
				band->analgain = JPC_NOMINALGAIN(ccp->qmfbid,
				  tcomp->numrlvls - 1, rlvlno, band->orient);
				band->absstepsize = jpc_calcabsstepsize(band->stepsize,
				  cmpt->prec + band->analgain);
				band->numbps = ccp->numguardbits +
				  JPC_QCX_GETEXPN(band->stepsize) - 1;
				band->roishift = (ccp->roishift + band->numbps >= JPC_PREC) ?
				  (JPC_PREC - 1 - band->numbps) : ccp->roishift;
				band->data = 0;
				band->prcs = 0;
				if (bnd->xstart == bnd->xend || bnd->ystart == bnd->yend) {
					continue;
				}
				if (!(band->data = jas_seq2d_create(0, 0, 0, 0))) {
					return -1;
				}
				jas_seq2d_bindsub(band->data, tcomp->data, bnd->locxstart, bnd->locystart, bnd->locxend, bnd->locyend);
				jas_seq2d_setshift(band->data, bnd->xstart, bnd->ystart);

				assert(rlvl->numprcs);

				if (!(band->prcs = jas_malloc(rlvl->numprcs * sizeof(jpc_dec_prc_t)))) {
					return -1;
				}

/************************************************/
	cbgxstart = tlcbgxstart;
	cbgystart = tlcbgystart;
	for (prccnt = rlvl->numprcs, prc = band->prcs;
	  prccnt > 0; --prccnt, ++prc) {
		cbgxend = cbgxstart + (1 << rlvl->cbgwidthexpn);
		cbgyend = cbgystart + (1 << rlvl->cbgheightexpn);
		prc->xstart = JAS_MAX(cbgxstart, JAS_CAST(uint_fast32_t, jas_seq2d_xstart(band->data)));
		prc->ystart = JAS_MAX(cbgystart, JAS_CAST(uint_fast32_t, jas_seq2d_ystart(band->data)));
		prc->xend = JAS_MIN(cbgxend, JAS_CAST(uint_fast32_t, jas_seq2d_xend(band->data)));
		prc->yend = JAS_MIN(cbgyend, JAS_CAST(uint_fast32_t, jas_seq2d_yend(band->data)));
		if (prc->xend > prc->xstart && prc->yend > prc->ystart) {
			tlcblkxstart = JPC_FLOORDIVPOW2(prc->xstart,
			  rlvl->cblkwidthexpn) << rlvl->cblkwidthexpn;
			tlcblkystart = JPC_FLOORDIVPOW2(prc->ystart,
			  rlvl->cblkheightexpn) << rlvl->cblkheightexpn;
			brcblkxend = JPC_CEILDIVPOW2(prc->xend,
			  rlvl->cblkwidthexpn) << rlvl->cblkwidthexpn;
			brcblkyend = JPC_CEILDIVPOW2(prc->yend,
			  rlvl->cblkheightexpn) << rlvl->cblkheightexpn;
			prc->numhcblks = (brcblkxend - tlcblkxstart) >>
			  rlvl->cblkwidthexpn;
			prc->numvcblks = (brcblkyend - tlcblkystart) >>
			  rlvl->cblkheightexpn;
			prc->numcblks = prc->numhcblks * prc->numvcblks;
			assert(prc->numcblks > 0);

			if (!(prc->incltagtree = jpc_tagtree_create(prc->numhcblks, prc->numvcblks))) {
				return -1;
			}
			if (!(prc->numimsbstagtree = jpc_tagtree_create(prc->numhcblks, prc->numvcblks))) {
				return -1;
			}
			if (!(prc->cblks = jas_malloc(prc->numcblks * sizeof(jpc_dec_cblk_t)))) {
				return -1;
			}

			cblkxstart = cbgxstart;
			cblkystart = cbgystart;
			for (cblkcnt = prc->numcblks, cblk = prc->cblks; cblkcnt > 0;) {
				cblkxend = cblkxstart + (1 << rlvl->cblkwidthexpn);
				cblkyend = cblkystart + (1 << rlvl->cblkheightexpn);
				tmpxstart = JAS_MAX(cblkxstart, prc->xstart);
				tmpystart = JAS_MAX(cblkystart, prc->ystart);
				tmpxend = JAS_MIN(cblkxend, prc->xend);
				tmpyend = JAS_MIN(cblkyend, prc->yend);
				if (tmpxend > tmpxstart && tmpyend > tmpystart) {
					cblk->firstpassno = -1;
					cblk->mqdec = 0;
					cblk->nulldec = 0;
					cblk->flags = 0;
					cblk->numpasses = 0;
					cblk->segs.head = 0;
					cblk->segs.tail = 0;
					cblk->curseg = 0;
					cblk->numimsbs = 0;
					cblk->numlenbits = 3;
					cblk->flags = 0;
					if (!(cblk->data = jas_seq2d_create(0, 0, 0, 0))) {
						return -1;
					}
					jas_seq2d_bindsub(cblk->data, band->data, tmpxstart, tmpystart, tmpxend, tmpyend);
					++cblk;
					--cblkcnt;
				}
				cblkxstart += 1 << rlvl->cblkwidthexpn;
				if (cblkxstart >= cbgxend) {
					cblkxstart = cbgxstart;
					cblkystart += 1 << rlvl->cblkheightexpn;
				}
			}

		} else {
			prc->cblks = 0;
			prc->incltagtree = 0;
			prc->numimsbstagtree = 0;
		}
		cbgxstart += 1 << rlvl->cbgwidthexpn;
		if (cbgxstart >= brcbgxend) {
			cbgxstart = tlcbgxstart;
			cbgystart += 1 << rlvl->cbgheightexpn;
		}

	}
/********************************************/
			}
		}
	}

if (!(tile->pi = jpc_dec_pi_create(dec, tile)))
{
	return -1;