jpc_dec.c

用C语言实现的JPEG编码

				jas_matrix_set(x, i, j, val);
			}
		}
	}
}

static jpc_dec_t *jpc_dec_create(jpc_dec_importopts_t *impopts, jas_stream_t *in)
{
	jpc_dec_t *dec;

	if (!(dec = jas_malloc(sizeof(jpc_dec_t)))) {
		return 0;
	}

	dec->image = 0;
	dec->xstart = 0;
	dec->ystart = 0;
	dec->xend = 0;
	dec->yend = 0;
	dec->tilewidth = 0;
	dec->tileheight = 0;
	dec->tilexoff = 0;
	dec->tileyoff = 0;
	dec->numhtiles = 0;
	dec->numvtiles = 0;
	dec->numtiles = 0;
	dec->tiles = 0;
	dec->curtile = 0;
	dec->numcomps = 0;
	dec->in = in;
	dec->cp = 0;
	dec->maxlyrs = impopts->maxlyrs;
	dec->maxpkts = impopts->maxpkts;
dec->numpkts = 0;
	dec->ppmseqno = 0;
	dec->state = 0;
	dec->cmpts = 0;
	dec->pkthdrstreams = 0;
	dec->ppmstab = 0;
	dec->curtileendoff = 0;

	return dec;
}

static void jpc_dec_destroy(jpc_dec_t *dec)
{
	if (dec->cstate) {
		jpc_cstate_destroy(dec->cstate);
	}
	if (dec->pkthdrstreams) {
		jpc_streamlist_destroy(dec->pkthdrstreams);
	}
	if (dec->image) {
		jas_image_destroy(dec->image);
	}

	if (dec->cp) {
		jpc_dec_cp_destroy(dec->cp);
	}

	if (dec->cmpts) {
		jas_free(dec->cmpts);
	}

	if (dec->tiles) {
		jas_free(dec->tiles);
	}

	jas_free(dec);
}

/******************************************************************************\
*
\******************************************************************************/

void jpc_seglist_insert(jpc_dec_seglist_t *list, jpc_dec_seg_t *ins, jpc_dec_seg_t *node)
{
	jpc_dec_seg_t *prev;
	jpc_dec_seg_t *next;

	prev = ins;
	node->prev = prev;
	next = prev ? (prev->next) : 0;
	node->prev = prev;
	node->next = next;
	if (prev) {
		prev->next = node;
	} else {
		list->head = node;
	}
	if (next) {
		next->prev = node;
	} else {
		list->tail = node;
	}
}

void jpc_seglist_remove(jpc_dec_seglist_t *list, jpc_dec_seg_t *seg)
{
	jpc_dec_seg_t *prev;
	jpc_dec_seg_t *next;

	prev = seg->prev;
	next = seg->next;
	if (prev) {
		prev->next = next;
	} else {
		list->head = next;
	}
	if (next) {
		next->prev = prev;
	} else {
		list->tail = prev;
	}
	seg->prev = 0;
	seg->next = 0;
}

jpc_dec_seg_t *jpc_seg_alloc()
{
	jpc_dec_seg_t *seg;

	if (!(seg = jas_malloc(sizeof(jpc_dec_seg_t)))) {
		return 0;
	}
	seg->prev = 0;
	seg->next = 0;
	seg->passno = -1;
	seg->numpasses = 0;
	seg->maxpasses = 0;
	seg->type = JPC_SEG_INVALID;
	seg->stream = 0;
	seg->cnt = 0;
	seg->complete = 0;
	seg->lyrno = -1;
	return seg;
}

void jpc_seg_destroy(jpc_dec_seg_t *seg)
{
	if (seg->stream) {
		jas_stream_close(seg->stream);
	}
	jas_free(seg);
}

static int jpc_dec_dump(jpc_dec_t *dec, FILE *out)
{
	jpc_dec_tile_t *tile;
	int tileno;
	jpc_dec_tcomp_t *tcomp;
	int compno;
	jpc_dec_rlvl_t *rlvl;
	int rlvlno;
	jpc_dec_band_t *band;
	int bandno;
	jpc_dec_prc_t *prc;
	int prcno;
	jpc_dec_cblk_t *cblk;
	int cblkno;

	for (tileno = 0, tile = dec->tiles; tileno < dec->numtiles;
	  ++tileno, ++tile) {
		for (compno = 0, tcomp = tile->tcomps; compno < dec->numcomps;
		  ++compno, ++tcomp) {
			for (rlvlno = 0, rlvl = tcomp->rlvls; rlvlno <
			  tcomp->numrlvls; ++rlvlno, ++rlvl) {
fprintf(out, "RESOLUTION LEVEL %d\n", rlvlno);
fprintf(out, "xs =%d, ys = %d, xe = %d, ye = %d, w = %d, h = %d\n",
  rlvl->xstart, rlvl->ystart, rlvl->xend, rlvl->yend, rlvl->xend -
  rlvl->xstart, rlvl->yend - rlvl->ystart);
				for (bandno = 0, band = rlvl->bands;
				  bandno < rlvl->numbands; ++bandno, ++band) {
fprintf(out, "BAND %d\n", bandno);
fprintf(out, "xs =%d, ys = %d, xe = %d, ye = %d, w = %d, h = %d\n",
  jas_seq2d_xstart(band->data), jas_seq2d_ystart(band->data), jas_seq2d_xend(band->data),
  jas_seq2d_yend(band->data), jas_seq2d_xend(band->data) - jas_seq2d_xstart(band->data),
  jas_seq2d_yend(band->data) - jas_seq2d_ystart(band->data));
					for (prcno = 0, prc = band->prcs;
					  prcno < rlvl->numprcs; ++prcno,
					  ++prc) {
fprintf(out, "CODE BLOCK GROUP %d\n", prcno);
fprintf(out, "xs =%d, ys = %d, xe = %d, ye = %d, w = %d, h = %d\n",
  prc->xstart, prc->ystart, prc->xend, prc->yend, prc->xend -
  prc->xstart, prc->yend - prc->ystart);
						for (cblkno = 0, cblk =
						  prc->cblks; cblkno <
						  prc->numcblks; ++cblkno,
						  ++cblk) {
fprintf(out, "CODE BLOCK %d\n", cblkno);
fprintf(out, "xs =%d, ys = %d, xe = %d, ye = %d, w = %d, h = %d\n",
  jas_seq2d_xstart(cblk->data), jas_seq2d_ystart(cblk->data), jas_seq2d_xend(cblk->data),
  jas_seq2d_yend(cblk->data), jas_seq2d_xend(cblk->data) - jas_seq2d_xstart(cblk->data),
  jas_seq2d_yend(cblk->data) - jas_seq2d_ystart(cblk->data));
						}
					}
				}
			}
		}
	}

	return 0;
}

jpc_streamlist_t *jpc_streamlist_create()
{
	jpc_streamlist_t *streamlist;
	int i;

	if (!(streamlist = jas_malloc(sizeof(jpc_streamlist_t)))) {
		return 0;
	}
	streamlist->numstreams = 0;
	streamlist->maxstreams = 100;
	if (!(streamlist->streams = jas_malloc(streamlist->maxstreams *
	  sizeof(jas_stream_t *)))) {
		jas_free(streamlist);
		return 0;
	}
	for (i = 0; i < streamlist->maxstreams; ++i) {
		streamlist->streams[i] = 0;
	}
	return streamlist;
}

int jpc_streamlist_insert(jpc_streamlist_t *streamlist, int streamno,
  jas_stream_t *stream)
{
	jas_stream_t **newstreams;
	int newmaxstreams;
	int i;
	/* Grow the array of streams if necessary. */
	if (streamlist->numstreams >= streamlist->maxstreams) {
		newmaxstreams = streamlist->maxstreams + 1024;
		if (!(newstreams = jas_realloc(streamlist->streams,
		  (newmaxstreams + 1024) * sizeof(jas_stream_t *)))) {
			return -1;
		}
		for (i = streamlist->numstreams; i < streamlist->maxstreams; ++i) {
			streamlist->streams[i] = 0;
		}
		streamlist->maxstreams = newmaxstreams;
		streamlist->streams = newstreams;
	}
	if (streamno != streamlist->numstreams) {
		/* Can only handle insertion at start of list. */
		return -1;
	}
	streamlist->streams[streamno] = stream;
	++streamlist->numstreams;
	return 0;
}

jas_stream_t *jpc_streamlist_remove(jpc_streamlist_t *streamlist, int streamno)
{
	jas_stream_t *stream;
	int i;
	if (streamno >= streamlist->numstreams) {
		abort();
	}
	stream = streamlist->streams[streamno];
	for (i = streamno + 1; i < streamlist->numstreams; ++i) {
		streamlist->streams[i - 1] = streamlist->streams[i];
	}
	--streamlist->numstreams;
	return stream;
}

void jpc_streamlist_destroy(jpc_streamlist_t *streamlist)
{
	int streamno;
	if (streamlist->streams) {
		for (streamno = 0; streamno < streamlist->numstreams;
		  ++streamno) {
			jas_stream_close(streamlist->streams[streamno]);
		}
		jas_free(streamlist->streams);
	}
	jas_free(streamlist);
}

jas_stream_t *jpc_streamlist_get(jpc_streamlist_t *streamlist, int streamno)
{
	assert(streamno < streamlist->numstreams);
	return streamlist->streams[streamno];
}

int jpc_streamlist_numstreams(jpc_streamlist_t *streamlist)
{
	return streamlist->numstreams;
}

jpc_ppxstab_t *jpc_ppxstab_create()
{
	jpc_ppxstab_t *tab;

	if (!(tab = jas_malloc(sizeof(jpc_ppxstab_t)))) {
		return 0;
	}
	tab->numents = 0;
	tab->maxents = 0;
	tab->ents = 0;
	return tab;
}

void jpc_ppxstab_destroy(jpc_ppxstab_t *tab)
{
	int i;
	for (i = 0; i < tab->numents; ++i) {
		jpc_ppxstabent_destroy(tab->ents[i]);
	}
	if (tab->ents) {
		jas_free(tab->ents);
	}
	jas_free(tab);
}

int jpc_ppxstab_grow(jpc_ppxstab_t *tab, int maxents)
{
	jpc_ppxstabent_t **newents;
	if (tab->maxents < maxents) {
		newents = (tab->ents) ? jas_realloc(tab->ents, maxents *
		  sizeof(jpc_ppxstabent_t *)) : jas_malloc(maxents * sizeof(jpc_ppxstabent_t *));
		if (!newents) {
			return -1;
		}
		tab->ents = newents;
		tab->maxents = maxents;
	}
	return 0;
}

int jpc_ppxstab_insert(jpc_ppxstab_t *tab, jpc_ppxstabent_t *ent)
{
	int inspt;
	int i;

	for (i = 0; i < tab->numents; ++i) {
		if (tab->ents[i]->ind > ent->ind) {
			break;
		}
	}
	inspt = i;

	if (tab->numents >= tab->maxents) {
		if (jpc_ppxstab_grow(tab, tab->maxents + 128)) {
			return -1;
		}
	}

	for (i = tab->numents; i > inspt; --i) {
		tab->ents[i] = tab->ents[i - 1];
	}
	tab->ents[i] = ent;
	++tab->numents;

	return 0;
}

jpc_streamlist_t *jpc_ppmstabtostreams(jpc_ppxstab_t *tab)
{
	jpc_streamlist_t *streams;
	uchar *dataptr;
	uint_fast32_t datacnt;
	uint_fast32_t tpcnt;
	jpc_ppxstabent_t *ent;
	int entno;
	jas_stream_t *stream;
	int n;

	if (!(streams = jpc_streamlist_create())) {
		goto error;
	}

	if (!tab->numents) {
		return streams;
	}

	entno = 0;
	ent = tab->ents[entno];
	dataptr = ent->data;
	datacnt = ent->len;
	for (;;) {

		/* Get the length of the packet header data for the current
		  tile-part. */
		if (datacnt < 4) {
			goto error;
		}
		if (!(stream = jas_stream_memopen(0, 0))) {
			goto error;
		}
		if (jpc_streamlist_insert(streams, jpc_streamlist_numstreams(streams),
		  stream)) {
			goto error;
		}
		tpcnt = (dataptr[0] << 24) | (dataptr[1] << 16) | (dataptr[2] << 8)
		  | dataptr[3];
		datacnt -= 4;
		dataptr += 4;

		/* Get the packet header data for the current tile-part. */
		while (tpcnt) {
			if (!datacnt) {
				if (++entno >= tab->numents) {
					goto error;
				}
				ent = tab->ents[entno];
				dataptr = ent->data;
				datacnt = ent->len;
			}
			n = JAS_MIN(tpcnt, datacnt);
			if (jas_stream_write(stream, dataptr, n) != n) {
				goto error;
			}
			tpcnt -= n;
			dataptr += n;
			datacnt -= n;
		}
		jas_stream_rewind(stream);
		if (!datacnt) {
			if (++entno >= tab->numents) {
				break;
			}
			ent = tab->ents[entno];
			dataptr = ent->data;
			datacnt = ent->len;
		}
	}

	return streams;

error:
	jpc_streamlist_destroy(streams);
	return 0;
}

int jpc_pptstabwrite(jas_stream_t *out, jpc_ppxstab_t *tab)
{
	int i;
	jpc_ppxstabent_t *ent;
	for (i = 0; i < tab->numents; ++i) {
		ent = tab->ents[i];
		if (jas_stream_write(out, ent->data, ent->len) != JAS_CAST(int, ent->len)) {
			return -1;
		}
	}
	return 0;
}

jpc_ppxstabent_t *jpc_ppxstabent_create()
{
	jpc_ppxstabent_t *ent;
	if (!(ent = jas_malloc(sizeof(jpc_ppxstabent_t)))) {
		return 0;
	}
	ent->data = 0;
	ent->len = 0;
	ent->ind = 0;
	return ent;
}

void jpc_ppxstabent_destroy(jpc_ppxstabent_t *ent)
{
	if (ent->data) {
		jas_free(ent->data);
	}
	jas_free(ent);
}