jpc_t1enc.c

用C语言实现的JPEG编码

	one = 1 << (bitpos + JPC_NUMEXTRABITS);

	fstripestart = jas_matrix_getref(flags, 1, 1);
	dstripestart = jas_matrix_getref(data, 0, 0);
	for (i = height; i > 0; i -= 4, fstripestart += fstripestep,
	  dstripestart += dstripestep) {
		fvscanstart = fstripestart;
		dvscanstart = dstripestart;
		vscanlen = JAS_MIN(i, 4);
		for (j = width; j > 0; --j, ++fvscanstart, ++dvscanstart) {
			fp = fvscanstart;
			dp = dvscanstart;
			k = vscanlen;

			sigpass_step(fp, frowstep, dp, bitpos, one,
			  nmsedec, orient, mqenc, vcausalflag);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			sigpass_step(fp, frowstep, dp, bitpos, one,
			  nmsedec, orient, mqenc, 0);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			sigpass_step(fp, frowstep, dp, bitpos, one,
			  nmsedec, orient, mqenc, 0);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			sigpass_step(fp, frowstep, dp, bitpos, one,
			  nmsedec, orient, mqenc, 0);

		}
	}

	if (term) {
		jpc_mqenc_flush(mqenc, term - 1);
	}

	return jpc_mqenc_error(mqenc) ? (-1) : 0;
}

#define	rawsigpass_step(fp, frowstep, dp, bitpos, one, nmsedec, out, vcausalflag) \
{ \
	jpc_fix_t f = *(fp); \
	jpc_fix_t v; \
	if ((f & JPC_OTHSIGMSK) && !(f & (JPC_SIG | JPC_VISIT))) { \
		v = (abs(*(dp)) & (one)) ? 1 : 0; \
		if ((jpc_bitstream_putbit((out), v)) == EOF) { \
			return -1; \
		} \
		if (v) { \
			*(nmsedec) += JPC_GETSIGNMSEDEC(abs(*(dp)), (bitpos) + JPC_NUMEXTRABITS); \
			v = ((*(dp) < 0) ? 1 : 0); \
			if (jpc_bitstream_putbit(out, v) == EOF) { \
				return -1; \
			} \
			JPC_UPDATEFLAGS4(fp, frowstep, v, vcausalflag); \
			*(fp) |= JPC_SIG; \
		} \
		*(fp) |= JPC_VISIT; \
	} \
}

static int jpc_encrawsigpass(jpc_bitstream_t *out, int bitpos, int vcausalflag, jas_matrix_t *flags,
  jas_matrix_t *data, int term, long *nmsedec)
{
	int i;
	int j;
	int k;
	int one;
	int vscanlen;
	int width;
	int height;
	int frowstep;
	int drowstep;
	int fstripestep;
	int dstripestep;
	jpc_fix_t *fstripestart;
	jpc_fix_t *dstripestart;
	jpc_fix_t *fp;
	jpc_fix_t *dp;
	jpc_fix_t *fvscanstart;
	jpc_fix_t *dvscanstart;

	*nmsedec = 0;
	width = jas_matrix_numcols(data);
	height = jas_matrix_numrows(data);
	frowstep = jas_matrix_rowstep(flags);
	drowstep = jas_matrix_rowstep(data);
	fstripestep = frowstep << 2;
	dstripestep = drowstep << 2;

	one = 1 << (bitpos + JPC_NUMEXTRABITS);

	fstripestart = jas_matrix_getref(flags, 1, 1);
	dstripestart = jas_matrix_getref(data, 0, 0);
	for (i = height; i > 0; i -= 4, fstripestart += fstripestep,
	  dstripestart += dstripestep) {
		fvscanstart = fstripestart;
		dvscanstart = dstripestart;
		vscanlen = JAS_MIN(i, 4);
		for (j = width; j > 0; --j, ++fvscanstart, ++dvscanstart) {
			fp = fvscanstart;
			dp = dvscanstart;
			k = vscanlen;

			rawsigpass_step(fp, frowstep, dp, bitpos, one,
			  nmsedec, out, vcausalflag);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;

			rawsigpass_step(fp, frowstep, dp, bitpos, one,
			  nmsedec, out, 0);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;

			rawsigpass_step(fp, frowstep, dp, bitpos, one,
			  nmsedec, out, 0);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;

			rawsigpass_step(fp, frowstep, dp, bitpos, one,
			  nmsedec, out, 0);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;

		}
	}

	if (term) {
		jpc_bitstream_outalign(out, 0x2a);
	}

	return 0;
}

/******************************************************************************\
* Code for refinement pass.
\******************************************************************************/

#define	refpass_step(fp, dp, bitpos, one, nmsedec, mqenc, vcausalflag) \
{ \
	int v; \
	if (((*(fp)) & (JPC_SIG | JPC_VISIT)) == JPC_SIG) { \
		(d) = *(dp); \
		*(nmsedec) += JPC_GETREFNMSEDEC(abs(d), (bitpos) + JPC_NUMEXTRABITS); \
		jpc_mqenc_setcurctx((mqenc), JPC_GETMAGCTXNO(*(fp))); \
		v = (abs(d) & (one)) ? 1 : 0; \
		jpc_mqenc_putbit((mqenc), v); \
		*(fp) |= JPC_REFINE; \
	} \
}

static int jpc_encrefpass(jpc_mqenc_t *mqenc, int bitpos, int vcausalflag, jas_matrix_t *flags, jas_matrix_t *data,
  int term, long *nmsedec)
{
	int i;
	int j;
	int one;
	int vscanlen;
	int d;
	int width;
	int height;
	int frowstep;
	int drowstep;
	int fstripestep;
	int dstripestep;
	jpc_fix_t *fstripestart;
	jpc_fix_t *dstripestart;
	jpc_fix_t *fvscanstart;
	jpc_fix_t *dvscanstart;
	jpc_fix_t *dp;
	jpc_fix_t *fp;
int k;

	*nmsedec = 0;
	width = jas_matrix_numcols(data);
	height = jas_matrix_numrows(data);
	frowstep = jas_matrix_rowstep(flags);
	drowstep = jas_matrix_rowstep(data);
	fstripestep = frowstep << 2;
	dstripestep = drowstep << 2;

	one = 1 << (bitpos + JPC_NUMEXTRABITS);

	fstripestart = jas_matrix_getref(flags, 1, 1);
	dstripestart = jas_matrix_getref(data, 0, 0);
	for (i = height; i > 0; i -= 4, fstripestart += fstripestep,
	  dstripestart += dstripestep) {
		fvscanstart = fstripestart;
		dvscanstart = dstripestart;
		vscanlen = JAS_MIN(i, 4);
		for (j = width; j > 0; --j, ++fvscanstart, ++dvscanstart) {
			fp = fvscanstart;
			dp = dvscanstart;
			k = vscanlen;

			refpass_step(fp, dp, bitpos, one, nmsedec,
			  mqenc, vcausalflag);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			refpass_step(fp, dp, bitpos, one, nmsedec,
			  mqenc, 0);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			refpass_step(fp, dp, bitpos, one, nmsedec,
			  mqenc, 0);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			refpass_step(fp, dp, bitpos, one, nmsedec,
			  mqenc, 0);

		}
	}

	if (term) {
		jpc_mqenc_flush(mqenc, term - 1);
	}

	return jpc_mqenc_error(mqenc) ? (-1) : 0;
}

#define	rawrefpass_step(fp, dp, bitpos, one, nmsedec, out, vcausalflag) \
{ \
	jpc_fix_t d; \
	jpc_fix_t v; \
	if (((*(fp)) & (JPC_SIG | JPC_VISIT)) == JPC_SIG) { \
		d = *(dp); \
		*(nmsedec) += JPC_GETREFNMSEDEC(abs(d), (bitpos) + JPC_NUMEXTRABITS); \
		v = (abs(d) & (one)) ? 1 : 0; \
		if (jpc_bitstream_putbit((out), v) == EOF) { \
			return -1; \
		} \
		*(fp) |= JPC_REFINE; \
	} \
}

static int jpc_encrawrefpass(jpc_bitstream_t *out, int bitpos, int vcausalflag, jas_matrix_t *flags,
  jas_matrix_t *data, int term, long *nmsedec)
{
	int i;
	int j;
	int k;
	int one;
	int vscanlen;
	int width;
	int height;
	int frowstep;
	int drowstep;
	int fstripestep;
	int dstripestep;
	jpc_fix_t *fstripestart;
	jpc_fix_t *dstripestart;
	jpc_fix_t *fvscanstart;
	jpc_fix_t *dvscanstart;
	jpc_fix_t *dp;
	jpc_fix_t *fp;

	*nmsedec = 0;
	width = jas_matrix_numcols(data);
	height = jas_matrix_numrows(data);
	frowstep = jas_matrix_rowstep(flags);
	drowstep = jas_matrix_rowstep(data);
	fstripestep = frowstep << 2;
	dstripestep = drowstep << 2;

	one = 1 << (bitpos + JPC_NUMEXTRABITS);

	fstripestart = jas_matrix_getref(flags, 1, 1);
	dstripestart = jas_matrix_getref(data, 0, 0);
	for (i = height; i > 0; i -= 4, fstripestart += fstripestep,
	  dstripestart += dstripestep) {
		fvscanstart = fstripestart;
		dvscanstart = dstripestart;
		vscanlen = JAS_MIN(i, 4);
		for (j = width; j > 0; --j, ++fvscanstart, ++dvscanstart) {
			fp = fvscanstart;
			dp = dvscanstart;
			k = vscanlen;

			rawrefpass_step(fp, dp, bitpos, one, nmsedec,
			  out, vcausalflag);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			rawrefpass_step(fp, dp, bitpos, one, nmsedec,
			  out, vcausalflag);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			rawrefpass_step(fp, dp, bitpos, one, nmsedec,
			  out, vcausalflag);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			rawrefpass_step(fp, dp, bitpos, one, nmsedec,
			  out, vcausalflag);

		}
	}

	if (term) {
		jpc_bitstream_outalign(out, 0x2a);
	}

	return 0;
}

/******************************************************************************\
* Code for cleanup pass.
\******************************************************************************/

#define	clnpass_step(fp, frowstep, dp, bitpos, one, orient, nmsedec, mqenc, label1, label2, vcausalflag) \
{ \
	int f; \
	int v; \
label1 \
	f = *(fp); \
	if (!(f & (JPC_SIG | JPC_VISIT))) { \
		jpc_mqenc_setcurctx(mqenc, JPC_GETZCCTXNO(f, (orient))); \
		v = (abs(*(dp)) & (one)) ? 1 : 0; \
		jpc_mqenc_putbit((mqenc), v); \
		if (v) { \
label2 \
			f = *(fp); \
			/* Coefficient is significant. */ \
			*(nmsedec) += JPC_GETSIGNMSEDEC(abs(*(dp)), (bitpos) + JPC_NUMEXTRABITS); \
			jpc_mqenc_setcurctx((mqenc), JPC_GETSCCTXNO(f)); \
			v = ((*(dp) < 0) ? 1 : 0); \
			jpc_mqenc_putbit((mqenc), v ^ JPC_GETSPB(f)); \
			JPC_UPDATEFLAGS4((fp), (frowstep), v, vcausalflag); \
			*(fp) |= JPC_SIG; \
		} \
	} \
	*(fp) &= ~JPC_VISIT; \
}

static int jpc_encclnpass(jpc_mqenc_t *mqenc, int bitpos, int orient, int vcausalflag, int segsymflag, jas_matrix_t *flags,
  jas_matrix_t *data, int term, long *nmsedec)
{
	int i;
	int j;
	int k;
	int vscanlen;
	int v;
	int runlen;
	jpc_fix_t *fp;
	int width;
	int height;
	jpc_fix_t *dp;
	int one;
	int frowstep;
	int drowstep;
	int fstripestep;
	int dstripestep;
	jpc_fix_t *fstripestart;
	jpc_fix_t *dstripestart;
	jpc_fix_t *fvscanstart;
	jpc_fix_t *dvscanstart;

	*nmsedec = 0;
	width = jas_matrix_numcols(data);
	height = jas_matrix_numrows(data);
	frowstep = jas_matrix_rowstep(flags);
	drowstep = jas_matrix_rowstep(data);
	fstripestep = frowstep << 2;
	dstripestep = drowstep << 2;

	one = 1 << (bitpos + JPC_NUMEXTRABITS);

	fstripestart = jas_matrix_getref(flags, 1, 1);
	dstripestart = jas_matrix_getref(data, 0, 0);
	for (i = height; i > 0; i -= 4, fstripestart += fstripestep,
	  dstripestart += dstripestep) {
		fvscanstart = fstripestart;
		dvscanstart = dstripestart;
		vscanlen = JAS_MIN(i, 4);
		for (j = width; j > 0; --j, ++fvscanstart, ++dvscanstart) {

			fp = fvscanstart;
			if (vscanlen >= 4 && !((*fp) & (JPC_SIG | JPC_VISIT |
			  JPC_OTHSIGMSK)) && (fp += frowstep, !((*fp) & (JPC_SIG |
			  JPC_VISIT | JPC_OTHSIGMSK))) && (fp += frowstep, !((*fp) &
			  (JPC_SIG | JPC_VISIT | JPC_OTHSIGMSK))) && (fp += frowstep,
			  !((*fp) & (JPC_SIG | JPC_VISIT | JPC_OTHSIGMSK)))) {
				dp = dvscanstart;
				for (k = 0; k < vscanlen; ++k) {
					v = (abs(*dp) & one) ? 1 : 0;
					if (v) {
						break;
					}
					dp += drowstep;
				}
				runlen = k;
				if (runlen >= 4) {
					jpc_mqenc_setcurctx(mqenc, JPC_AGGCTXNO);
					jpc_mqenc_putbit(mqenc, 0);
					continue;
				}
				jpc_mqenc_setcurctx(mqenc, JPC_AGGCTXNO);
				jpc_mqenc_putbit(mqenc, 1);
				jpc_mqenc_setcurctx(mqenc, JPC_UCTXNO);
				jpc_mqenc_putbit(mqenc, runlen >> 1);
				jpc_mqenc_putbit(mqenc, runlen & 1);
				fp = fvscanstart + frowstep * runlen;
				dp = dvscanstart + drowstep * runlen;
				k = vscanlen - runlen;
				switch (runlen) {
				case 0:
					goto clnpass_partial0;
					break;
				case 1:
					goto clnpass_partial1;
					break;
				case 2:
					goto clnpass_partial2;
					break;
				case 3:
					goto clnpass_partial3;
					break;
				}
			} else {
				runlen = 0;
				fp = fvscanstart;
				dp = dvscanstart;
				k = vscanlen;
				goto clnpass_full0;
			}
			clnpass_step(fp, frowstep, dp, bitpos, one,
			  orient, nmsedec, mqenc, clnpass_full0:, clnpass_partial0:, vcausalflag);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			clnpass_step(fp, frowstep, dp, bitpos, one,
				orient, nmsedec, mqenc, ;, clnpass_partial1:, 0);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			clnpass_step(fp, frowstep, dp, bitpos, one,
				orient, nmsedec, mqenc, ;, clnpass_partial2:, 0);
			if (--k <= 0) {
				continue;
			}
			fp += frowstep;
			dp += drowstep;
			clnpass_step(fp, frowstep, dp, bitpos, one,
				orient, nmsedec, mqenc, ;, clnpass_partial3:, 0);
		}
	}

	if (segsymflag) {
		jpc_mqenc_setcurctx(mqenc, JPC_UCTXNO);
		jpc_mqenc_putbit(mqenc, 1);
		jpc_mqenc_putbit(mqenc, 0);
		jpc_mqenc_putbit(mqenc, 1);
		jpc_mqenc_putbit(mqenc, 0);
	}

	if (term) {
		jpc_mqenc_flush(mqenc, term - 1);
	}

	return jpc_mqenc_error(mqenc) ? (-1) : 0;
}