jpc_t2cod.c

用C语言实现的JPEG编码

	jpc_pirlvl_t *pirlvl;
	jpc_pchg_t *pchg;
	int prchind;
	int prcvind;
	int *prclyrno;
	int compno;
	jpc_picomp_t *picomp;
	int xstep;
	int ystep;
	uint_fast32_t trx0;
	uint_fast32_t try0;
	uint_fast32_t r;
	uint_fast32_t rpx;
	uint_fast32_t rpy;

	pchg = pi->pchg;
	if (!pi->prgvolfirst) {
		goto skip;
	} else {
		pi->xstep = 0;
		pi->ystep = 0;
		for (compno = 0, picomp = pi->picomps; compno < pi->numcomps;
		  ++compno, ++picomp) {
			for (rlvlno = 0, pirlvl = picomp->pirlvls; rlvlno <
			  picomp->numrlvls; ++rlvlno, ++pirlvl) {
				xstep = picomp->hsamp * (1 <<
				  (pirlvl->prcwidthexpn + picomp->numrlvls -
				  rlvlno - 1));
				ystep = picomp->vsamp * (1 <<
				  (pirlvl->prcheightexpn + picomp->numrlvls -
				  rlvlno - 1));
				pi->xstep = (!pi->xstep) ? xstep :
				  JAS_MIN(pi->xstep, xstep);
				pi->ystep = (!pi->ystep) ? ystep :
				  JAS_MIN(pi->ystep, ystep);
			}
		}
		pi->prgvolfirst = 0;
	}

	for (pi->y = pi->ystart; pi->y < pi->yend; pi->y += pi->ystep -
	  (pi->y % pi->ystep)) {
		for (pi->x = pi->xstart; pi->x < pi->xend; pi->x += pi->xstep -
		  (pi->x % pi->xstep)) {
			for (pi->compno = pchg->compnostart, pi->picomp =
			  &pi->picomps[pi->compno]; pi->compno < pi->numcomps
			  && pi->compno < JAS_CAST(int, pchg->compnoend); ++pi->compno,
			  ++pi->picomp) {
				for (pi->rlvlno = pchg->rlvlnostart,
				  pi->pirlvl = &pi->picomp->pirlvls[pi->rlvlno];
				  pi->rlvlno < pi->picomp->numrlvls &&
				  pi->rlvlno < pchg->rlvlnoend; ++pi->rlvlno,
				  ++pi->pirlvl) {
					if (pi->pirlvl->numprcs == 0) {
						continue;
					}
					r = pi->picomp->numrlvls - 1 - pi->rlvlno;
					trx0 = JPC_CEILDIV(pi->xstart, pi->picomp->hsamp << r);
					try0 = JPC_CEILDIV(pi->ystart, pi->picomp->vsamp << r);
					rpx = r + pi->pirlvl->prcwidthexpn;
					rpy = r + pi->pirlvl->prcheightexpn;
					if (((pi->x == pi->xstart && ((trx0 << r) % (1 << rpx))) ||
					  !(pi->x % (pi->picomp->hsamp << rpx))) &&
					  ((pi->y == pi->ystart && ((try0 << r) % (1 << rpy))) ||
					  !(pi->y % (pi->picomp->vsamp << rpy)))) {
						prchind = JPC_FLOORDIVPOW2(JPC_CEILDIV(pi->x, pi->picomp->hsamp
						  << r), pi->pirlvl->prcwidthexpn) - JPC_FLOORDIVPOW2(trx0,
						  pi->pirlvl->prcwidthexpn);
						prcvind = JPC_FLOORDIVPOW2(JPC_CEILDIV(pi->y, pi->picomp->vsamp
						  << r), pi->pirlvl->prcheightexpn) - JPC_FLOORDIVPOW2(try0,
						  pi->pirlvl->prcheightexpn);
						pi->prcno = prcvind * pi->pirlvl->numhprcs + prchind;
						assert(pi->prcno < pi->pirlvl->numprcs);
						for (pi->lyrno = 0; pi->lyrno < pi->numlyrs &&
						  pi->lyrno < JAS_CAST(int, pchg->lyrnoend); ++pi->lyrno) {
							prclyrno = &pi->pirlvl->prclyrnos[pi->prcno];
							if (pi->lyrno >= *prclyrno) {
								++(*prclyrno);
								return 0;
							}
skip:
							;
						}
					}
				}
			}
		}
	}
	return 1;
}

static int jpc_pi_nextcprl(register jpc_pi_t *pi)
{
	int rlvlno;
	jpc_pirlvl_t *pirlvl;
	jpc_pchg_t *pchg;
	int prchind;
	int prcvind;
	int *prclyrno;
	uint_fast32_t trx0;
	uint_fast32_t try0;
	uint_fast32_t r;
	uint_fast32_t rpx;
	uint_fast32_t rpy;

	pchg = pi->pchg;
	if (!pi->prgvolfirst) {
		goto skip;
	} else {
		pi->prgvolfirst = 0;
	}

	for (pi->compno = pchg->compnostart, pi->picomp =
	  &pi->picomps[pi->compno]; pi->compno < JAS_CAST(int, pchg->compnoend); ++pi->compno,
	  ++pi->picomp) {
		pirlvl = pi->picomp->pirlvls;
		pi->xstep = pi->picomp->hsamp * (1 << (pirlvl->prcwidthexpn +
		  pi->picomp->numrlvls - 1));
		pi->ystep = pi->picomp->vsamp * (1 << (pirlvl->prcheightexpn +
		  pi->picomp->numrlvls - 1));
		for (rlvlno = 1, pirlvl = &pi->picomp->pirlvls[1];
		  rlvlno < pi->picomp->numrlvls; ++rlvlno, ++pirlvl) {
			pi->xstep = JAS_MIN(pi->xstep, pi->picomp->hsamp * (1 <<
			  (pirlvl->prcwidthexpn + pi->picomp->numrlvls -
			  rlvlno - 1)));
			pi->ystep = JAS_MIN(pi->ystep, pi->picomp->vsamp * (1 <<
			  (pirlvl->prcheightexpn + pi->picomp->numrlvls -
			  rlvlno - 1)));
		}
		for (pi->y = pi->ystart; pi->y < pi->yend;
		  pi->y += pi->ystep - (pi->y % pi->ystep)) {
			for (pi->x = pi->xstart; pi->x < pi->xend;
			  pi->x += pi->xstep - (pi->x % pi->xstep)) {
				for (pi->rlvlno = pchg->rlvlnostart,
				  pi->pirlvl = &pi->picomp->pirlvls[pi->rlvlno];
				  pi->rlvlno < pi->picomp->numrlvls && pi->rlvlno <
				  pchg->rlvlnoend; ++pi->rlvlno, ++pi->pirlvl) {
					if (pi->pirlvl->numprcs == 0) {
						continue;
					}
					r = pi->picomp->numrlvls - 1 - pi->rlvlno;
					trx0 = JPC_CEILDIV(pi->xstart, pi->picomp->hsamp << r);
					try0 = JPC_CEILDIV(pi->ystart, pi->picomp->vsamp << r);
					rpx = r + pi->pirlvl->prcwidthexpn;
					rpy = r + pi->pirlvl->prcheightexpn;
					if (((pi->x == pi->xstart && ((trx0 << r) % (1 << rpx))) ||
					  !(pi->x % (pi->picomp->hsamp << rpx))) &&
					  ((pi->y == pi->ystart && ((try0 << r) % (1 << rpy))) ||
					  !(pi->y % (pi->picomp->vsamp << rpy)))) {
						prchind = JPC_FLOORDIVPOW2(JPC_CEILDIV(pi->x, pi->picomp->hsamp
						  << r), pi->pirlvl->prcwidthexpn) - JPC_FLOORDIVPOW2(trx0,
						  pi->pirlvl->prcwidthexpn);
						prcvind = JPC_FLOORDIVPOW2(JPC_CEILDIV(pi->y, pi->picomp->vsamp
						  << r), pi->pirlvl->prcheightexpn) - JPC_FLOORDIVPOW2(try0,
						  pi->pirlvl->prcheightexpn);
						pi->prcno = prcvind *
						  pi->pirlvl->numhprcs +
						  prchind;
						assert(pi->prcno <
						  pi->pirlvl->numprcs);
						for (pi->lyrno = 0; pi->lyrno <
						  pi->numlyrs && pi->lyrno < JAS_CAST(int, pchg->lyrnoend); ++pi->lyrno) {
							prclyrno = &pi->pirlvl->prclyrnos[pi->prcno];
							if (pi->lyrno >= *prclyrno) {
								++(*prclyrno);
								return 0;
							}
skip:
							;
						}
					}
				}
			}
		}
	}
	return 1;
}

static void pirlvl_destroy(jpc_pirlvl_t *rlvl)
{
	if (rlvl->prclyrnos) {
		jas_free(rlvl->prclyrnos);
	}
}

static void jpc_picomp_destroy(jpc_picomp_t *picomp)
{
	int rlvlno;
	jpc_pirlvl_t *pirlvl;
	if (picomp->pirlvls) {
		for (rlvlno = 0, pirlvl = picomp->pirlvls; rlvlno <
		  picomp->numrlvls; ++rlvlno, ++pirlvl) {
			pirlvl_destroy(pirlvl);
		}
		jas_free(picomp->pirlvls);
	}
}

void jpc_pi_destroy(jpc_pi_t *pi)
{
	jpc_picomp_t *picomp;
	int compno;
	if (pi->picomps) {
		for (compno = 0, picomp = pi->picomps; compno < pi->numcomps;
		  ++compno, ++picomp) {
			jpc_picomp_destroy(picomp);
		}
		jas_free(pi->picomps);
	}
	if (pi->pchglist) {
		jpc_pchglist_destroy(pi->pchglist);
	}
	jas_free(pi);
}

jpc_pi_t *jpc_pi_create0()
{
	jpc_pi_t *pi;
	if (!(pi = jas_malloc(sizeof(jpc_pi_t)))) {
		return 0;
	}
	pi->picomps = 0;
	pi->pchgno = 0;
	if (!(pi->pchglist = jpc_pchglist_create())) {
		jas_free(pi);
		return 0;
	}
	return pi;
}

int jpc_pi_addpchg(jpc_pi_t *pi, jpc_pocpchg_t *pchg)
{
	return jpc_pchglist_insert(pi->pchglist, -1, pchg);
}

jpc_pchglist_t *jpc_pchglist_create()
{
	jpc_pchglist_t *pchglist;
	if (!(pchglist = jas_malloc(sizeof(jpc_pchglist_t)))) {
		return 0;
	}
	pchglist->numpchgs = 0;
	pchglist->maxpchgs = 0;
	pchglist->pchgs = 0;
	return pchglist;
}

int jpc_pchglist_insert(jpc_pchglist_t *pchglist, int pchgno, jpc_pchg_t *pchg)
{
	int i;
	int newmaxpchgs;
	jpc_pchg_t **newpchgs;
	if (pchgno < 0) {
		pchgno = pchglist->numpchgs;
	}
	if (pchglist->numpchgs >= pchglist->maxpchgs) {
		newmaxpchgs = pchglist->maxpchgs + 128;
		if (!(newpchgs = jas_realloc(pchglist->pchgs, newmaxpchgs * sizeof(jpc_pchg_t *)))) {
			return -1;
		}
		pchglist->maxpchgs = newmaxpchgs;
		pchglist->pchgs = newpchgs;
	}
	for (i = pchglist->numpchgs; i > pchgno; --i) {
		pchglist->pchgs[i] = pchglist->pchgs[i - 1];
	}
	pchglist->pchgs[pchgno] = pchg;
	++pchglist->numpchgs;
	return 0;
}

jpc_pchg_t *jpc_pchglist_remove(jpc_pchglist_t *pchglist, int pchgno)
{
	int i;
	jpc_pchg_t *pchg;
	assert(pchgno < pchglist->numpchgs);
	pchg = pchglist->pchgs[pchgno];
	for (i = pchgno + 1; i < pchglist->numpchgs; ++i) {
		pchglist->pchgs[i - 1] = pchglist->pchgs[i];
	}
	--pchglist->numpchgs;
	return pchg;
}

jpc_pchg_t *jpc_pchg_copy(jpc_pchg_t *pchg)
{
	jpc_pchg_t *newpchg;
	if (!(newpchg = jas_malloc(sizeof(jpc_pchg_t)))) {
		return 0;
	}
	*newpchg = *pchg;
	return newpchg;
}

jpc_pchglist_t *jpc_pchglist_copy(jpc_pchglist_t *pchglist)
{
	jpc_pchglist_t *newpchglist;
	jpc_pchg_t *newpchg;
	int pchgno;
	if (!(newpchglist = jpc_pchglist_create())) {
		return 0;
	}
	for (pchgno = 0; pchgno < pchglist->numpchgs; ++pchgno) {
		if (!(newpchg = jpc_pchg_copy(pchglist->pchgs[pchgno])) ||
		  jpc_pchglist_insert(newpchglist, -1, newpchg)) {
			jpc_pchglist_destroy(newpchglist);
			return 0;
		}
	}
	return newpchglist;
}

void jpc_pchglist_destroy(jpc_pchglist_t *pchglist)
{
	int pchgno;
	if (pchglist->pchgs) {
		for (pchgno = 0; pchgno < pchglist->numpchgs; ++pchgno) {
			jpc_pchg_destroy(pchglist->pchgs[pchgno]);
		}
		jas_free(pchglist->pchgs);
	}
	jas_free(pchglist);
}

void jpc_pchg_destroy(jpc_pchg_t *pchg)
{
	jas_free(pchg);
}

jpc_pchg_t *jpc_pchglist_get(jpc_pchglist_t *pchglist, int pchgno)
{
	return pchglist->pchgs[pchgno];
}

int jpc_pchglist_numpchgs(jpc_pchglist_t *pchglist)
{
	return pchglist->numpchgs;
}

int jpc_pi_init(jpc_pi_t *pi)
{
	int compno;
	int rlvlno;
	int prcno;
	jpc_picomp_t *picomp;
	jpc_pirlvl_t *pirlvl;
	int *prclyrno;

	pi->prgvolfirst = 0;
	pi->valid = 0;
	pi->pktno = -1;
	pi->pchgno = -1;
	pi->pchg = 0;

	for (compno = 0, picomp = pi->picomps; compno < pi->numcomps;
	  ++compno, ++picomp) {
		for (rlvlno = 0, pirlvl = picomp->pirlvls; rlvlno <
		  picomp->numrlvls; ++rlvlno, ++pirlvl) {
			for (prcno = 0, prclyrno = pirlvl->prclyrnos;
			  prcno < pirlvl->numprcs; ++prcno, ++prclyrno) {
				*prclyrno = 0;
			}
		}
	}
	return 0;
}