1 files changed, 461 insertions, 0 deletions

diff --git a/libtiff/tif_predict.c b/libtiff/tif_predict.c
new file mode 100644
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--- /dev/null
+++ b/libtiff/tif_predict.c
@@ -0,0 +1,461 @@
+/* $Header: /cvs/maptools/cvsroot/libtiff/libtiff/tif_predict.c,v 1.1 1999-07-27 21:50:27 mike Exp $ */
+
+/*
+ * Copyright (c) 1988-1997 Sam Leffler
+ * Copyright (c) 1991-1997 Silicon Graphics, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and 
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that (i) the above copyright notices and this permission notice appear in
+ * all copies of the software and related documentation, and (ii) the names of
+ * Sam Leffler and Silicon Graphics may not be used in any advertising or
+ * publicity relating to the software without the specific, prior written
+ * permission of Sam Leffler and Silicon Graphics.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
+ * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
+ * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
+ * 
+ * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
+ * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
+ * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+ * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
+ * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
+ * OF THIS SOFTWARE.
+ */
+
+/*
+ * TIFF Library.
+ *
+ * Predictor Tag Support (used by multiple codecs).
+ */
+#include "tiffiop.h"
+#include "tif_predict.h"
+
+#include <assert.h>
+
+#define	PredictorState(tif)	((TIFFPredictorState*) (tif)->tif_data)
+
+static	void horAcc8(TIFF*, tidata_t, tsize_t);
+static	void horAcc16(TIFF*, tidata_t, tsize_t);
+static	void swabHorAcc16(TIFF*, tidata_t, tsize_t);
+static	void horDiff8(TIFF*, tidata_t, tsize_t);
+static	void horDiff16(TIFF*, tidata_t, tsize_t);
+static	int PredictorDecodeRow(TIFF*, tidata_t, tsize_t, tsample_t);
+static	int PredictorDecodeTile(TIFF*, tidata_t, tsize_t, tsample_t);
+static	int PredictorEncodeRow(TIFF*, tidata_t, tsize_t, tsample_t);
+static	int PredictorEncodeTile(TIFF*, tidata_t, tsize_t, tsample_t);
+
+static int
+PredictorSetup(TIFF* tif)
+{
+	TIFFPredictorState* sp = PredictorState(tif);
+	TIFFDirectory* td = &tif->tif_dir;
+
+	if (sp->predictor == 1)		/* no differencing */
+		return (1);
+	if (sp->predictor != 2) {
+		TIFFError(tif->tif_name, "\"Predictor\" value %d not supported",
+		    sp->predictor);
+		return (0);
+	}
+	if (td->td_bitspersample != 8 && td->td_bitspersample != 16) {
+		TIFFError(tif->tif_name,
+    "Horizontal differencing \"Predictor\" not supported with %d-bit samples",
+		    td->td_bitspersample);
+		return (0);
+	}
+	sp->stride = (td->td_planarconfig == PLANARCONFIG_CONTIG ?
+	    td->td_samplesperpixel : 1);
+	/*
+	 * Calculate the scanline/tile-width size in bytes.
+	 */
+	if (isTiled(tif))
+		sp->rowsize = TIFFTileRowSize(tif);
+	else
+		sp->rowsize = TIFFScanlineSize(tif);
+	return (1);
+}
+
+static int
+PredictorSetupDecode(TIFF* tif)
+{
+	TIFFPredictorState* sp = PredictorState(tif);
+	TIFFDirectory* td = &tif->tif_dir;
+
+	if (!(*sp->setupdecode)(tif) || !PredictorSetup(tif))
+		return (0);
+	if (sp->predictor == 2) {
+		switch (td->td_bitspersample) {
+		case 8:  sp->pfunc = horAcc8; break;
+		case 16: sp->pfunc = horAcc16; break;
+		}
+		/*
+		 * Override default decoding method with
+		 * one that does the predictor stuff.
+		 */
+		sp->coderow = tif->tif_decoderow;
+		tif->tif_decoderow = PredictorDecodeRow;
+		sp->codestrip = tif->tif_decodestrip;
+		tif->tif_decodestrip = PredictorDecodeTile;
+		sp->codetile = tif->tif_decodetile;
+		tif->tif_decodetile = PredictorDecodeTile;
+		/*
+		 * If the data is horizontally differenced
+		 * 16-bit data that requires byte-swapping,
+		 * then it must be byte swapped before the
+		 * accumulation step.  We do this with a
+		 * special-purpose routine and override the
+		 * normal post decoding logic that the library
+		 * setup when the directory was read.
+		 */
+		if (tif->tif_flags&TIFF_SWAB) {
+			if (sp->pfunc == horAcc16) {
+				sp->pfunc = swabHorAcc16;
+				tif->tif_postdecode = _TIFFNoPostDecode;
+			} /* else handle 32-bit case... */
+		}
+	}
+	return (1);
+}
+
+static int
+PredictorSetupEncode(TIFF* tif)
+{
+	TIFFPredictorState* sp = PredictorState(tif);
+	TIFFDirectory* td = &tif->tif_dir;
+
+	if (!(*sp->setupencode)(tif) || !PredictorSetup(tif))
+		return (0);
+	if (sp->predictor == 2) {
+		switch (td->td_bitspersample) {
+		case 8:  sp->pfunc = horDiff8; break;
+		case 16: sp->pfunc = horDiff16; break;
+		}
+		/*
+		 * Override default encoding method with
+		 * one that does the predictor stuff.
+		 */
+		sp->coderow = tif->tif_encoderow;
+		tif->tif_encoderow = PredictorEncodeRow;
+		sp->codestrip = tif->tif_encodestrip;
+		tif->tif_encodestrip = PredictorEncodeTile;
+		sp->codetile = tif->tif_encodetile;
+		tif->tif_encodetile = PredictorEncodeTile;
+	}
+	return (1);
+}
+
+#define REPEAT4(n, op)		\
+    switch (n) {		\
+    default: { int i; for (i = n-4; i > 0; i--) { op; } } \
+    case 4:  op;		\
+    case 3:  op;		\
+    case 2:  op;		\
+    case 1:  op;		\
+    case 0:  ;			\
+    }
+
+static void
+horAcc8(TIFF* tif, tidata_t cp0, tsize_t cc)
+{
+	TIFFPredictorState* sp = PredictorState(tif);
+	u_int stride = sp->stride;
+
+	char* cp = (char*) cp0;
+	if (cc > stride) {
+		cc -= stride;
+		/*
+		 * Pipeline the most common cases.
+		 */
+		if (stride == 3)  {
+			u_int cr = cp[0];
+			u_int cg = cp[1];
+			u_int cb = cp[2];
+			do {
+				cc -= 3, cp += 3;
+				cp[0] = (cr += cp[0]);
+				cp[1] = (cg += cp[1]);
+				cp[2] = (cb += cp[2]);
+			} while ((int32) cc > 0);
+		} else if (stride == 4)  {
+			u_int cr = cp[0];
+			u_int cg = cp[1];
+			u_int cb = cp[2];
+			u_int ca = cp[3];
+			do {
+				cc -= 4, cp += 4;
+				cp[0] = (cr += cp[0]);
+				cp[1] = (cg += cp[1]);
+				cp[2] = (cb += cp[2]);
+				cp[3] = (ca += cp[3]);
+			} while ((int32) cc > 0);
+		} else  {
+			do {
+				REPEAT4(stride, cp[stride] += *cp; cp++)
+				cc -= stride;
+			} while ((int32) cc > 0);
+		}
+	}
+}
+
+static void
+swabHorAcc16(TIFF* tif, tidata_t cp0, tsize_t cc)
+{
+	TIFFPredictorState* sp = PredictorState(tif);
+	u_int stride = sp->stride;
+	uint16* wp = (uint16*) cp0;
+	tsize_t wc = cc / 2;
+
+	if (wc > stride) {
+		TIFFSwabArrayOfShort(wp, wc);
+		wc -= stride;
+		do {
+			REPEAT4(stride, wp[stride] += wp[0]; wp++)
+			wc -= stride;
+		} while ((int32) wc > 0);
+	}
+}
+
+static void
+horAcc16(TIFF* tif, tidata_t cp0, tsize_t cc)
+{
+	u_int stride = PredictorState(tif)->stride;
+	uint16* wp = (uint16*) cp0;
+	tsize_t wc = cc / 2;
+
+	if (wc > stride) {
+		wc -= stride;
+		do {
+			REPEAT4(stride, wp[stride] += wp[0]; wp++)
+			wc -= stride;
+		} while ((int32) wc > 0);
+	}
+}
+
+/*
+ * Decode a scanline and apply the predictor routine.
+ */
+static int
+PredictorDecodeRow(TIFF* tif, tidata_t op0, tsize_t occ0, tsample_t s)
+{
+	TIFFPredictorState *sp = PredictorState(tif);
+
+	assert(sp != NULL);
+	assert(sp->coderow != NULL);
+	assert(sp->pfunc != NULL);
+	if ((*sp->coderow)(tif, op0, occ0, s)) {
+		(*sp->pfunc)(tif, op0, occ0);
+		return (1);
+	} else
+		return (0);
+}
+
+/*
+ * Decode a tile/strip and apply the predictor routine.
+ * Note that horizontal differencing must be done on a
+ * row-by-row basis.  The width of a "row" has already
+ * been calculated at pre-decode time according to the
+ * strip/tile dimensions.
+ */
+static int
+PredictorDecodeTile(TIFF* tif, tidata_t op0, tsize_t occ0, tsample_t s)
+{
+	TIFFPredictorState *sp = PredictorState(tif);
+
+	assert(sp != NULL);
+	assert(sp->codetile != NULL);
+	if ((*sp->codetile)(tif, op0, occ0, s)) {
+		tsize_t rowsize = sp->rowsize;
+		assert(rowsize > 0);
+		assert(sp->pfunc != NULL);
+		while ((long)occ0 > 0) {
+			(*sp->pfunc)(tif, op0, (tsize_t) rowsize);
+			occ0 -= rowsize;
+			op0 += rowsize;
+		}
+		return (1);
+	} else
+		return (0);
+}
+
+static void
+horDiff8(TIFF* tif, tidata_t cp0, tsize_t cc)
+{
+	TIFFPredictorState* sp = PredictorState(tif);
+	u_int stride = sp->stride;
+	char* cp = (char*) cp0;
+
+	if (cc > stride) {
+		cc -= stride;
+		/*
+		 * Pipeline the most common cases.
+		 */
+		if (stride == 3) {
+			int r1, g1, b1;
+			int r2 = cp[0];
+			int g2 = cp[1];
+			int b2 = cp[2];
+			do {
+				r1 = cp[3]; cp[3] = r1-r2; r2 = r1;
+				g1 = cp[4]; cp[4] = g1-g2; g2 = g1;
+				b1 = cp[5]; cp[5] = b1-b2; b2 = b1;
+				cp += 3;
+			} while ((int32)(cc -= 3) > 0);
+		} else if (stride == 4) {
+			int r1, g1, b1, a1;
+			int r2 = cp[0];
+			int g2 = cp[1];
+			int b2 = cp[2];
+			int a2 = cp[3];
+			do {
+				r1 = cp[4]; cp[4] = r1-r2; r2 = r1;
+				g1 = cp[5]; cp[5] = g1-g2; g2 = g1;
+				b1 = cp[6]; cp[6] = b1-b2; b2 = b1;
+				a1 = cp[7]; cp[7] = a1-a2; a2 = a1;
+				cp += 4;
+			} while ((int32)(cc -= 4) > 0);
+		} else {
+			cp += cc - 1;
+			do {
+				REPEAT4(stride, cp[stride] -= cp[0]; cp--)
+			} while ((int32)(cc -= stride) > 0);
+		}
+	}
+}
+
+static void
+horDiff16(TIFF* tif, tidata_t cp0, tsize_t cc)
+{
+	TIFFPredictorState* sp = PredictorState(tif);
+	u_int stride = sp->stride;
+	int16 *wp = (int16*) cp0;
+	tsize_t wc = cc/2;
+
+	if (wc > stride) {
+		wc -= stride;
+		wp += wc - 1;
+		do {
+			REPEAT4(stride, wp[stride] -= wp[0]; wp--)
+			wc -= stride;
+		} while ((int32) wc > 0);
+	}
+}
+
+static int
+PredictorEncodeRow(TIFF* tif, tidata_t bp, tsize_t cc, tsample_t s)
+{
+	TIFFPredictorState *sp = PredictorState(tif);
+
+	assert(sp != NULL);
+	assert(sp->pfunc != NULL);
+	assert(sp->coderow != NULL);
+/* XXX horizontal differencing alters user's data XXX */
+	(*sp->pfunc)(tif, bp, cc);
+	return ((*sp->coderow)(tif, bp, cc, s));
+}
+
+static int
+PredictorEncodeTile(TIFF* tif, tidata_t bp0, tsize_t cc0, tsample_t s)
+{
+	TIFFPredictorState *sp = PredictorState(tif);
+	tsize_t cc = cc0, rowsize;
+	u_char* bp = bp0;
+
+	assert(sp != NULL);
+	assert(sp->pfunc != NULL);
+	assert(sp->codetile != NULL);
+	rowsize = sp->rowsize;
+	assert(rowsize > 0);
+	while ((long)cc > 0) {
+		(*sp->pfunc)(tif, bp, (tsize_t) rowsize);
+		cc -= rowsize;
+		bp += rowsize;
+	}
+	return ((*sp->codetile)(tif, bp0, cc0, s));
+}
+
+#define	FIELD_PREDICTOR	(FIELD_CODEC+0)		/* XXX */
+
+static const TIFFFieldInfo predictFieldInfo[] = {
+    { TIFFTAG_PREDICTOR,	 1, 1, TIFF_SHORT,	FIELD_PREDICTOR,
+      FALSE,	FALSE,	"Predictor" },
+};
+#define	N(a)	(sizeof (a) / sizeof (a[0]))
+
+static int
+PredictorVSetField(TIFF* tif, ttag_t tag, va_list ap)
+{
+	TIFFPredictorState *sp = PredictorState(tif);
+
+	switch (tag) {
+	case TIFFTAG_PREDICTOR:
+		sp->predictor = (uint16) va_arg(ap, int);
+		TIFFSetFieldBit(tif, FIELD_PREDICTOR);
+		break;
+	default:
+		return (*sp->vsetparent)(tif, tag, ap);
+	}
+	tif->tif_flags |= TIFF_DIRTYDIRECT;
+	return (1);
+}
+
+static int
+PredictorVGetField(TIFF* tif, ttag_t tag, va_list ap)
+{
+	TIFFPredictorState *sp = PredictorState(tif);
+
+	switch (tag) {
+	case TIFFTAG_PREDICTOR:
+		*va_arg(ap, uint16*) = sp->predictor;
+		break;
+	default:
+		return (*sp->vgetparent)(tif, tag, ap);
+	}
+	return (1);
+}
+
+static void
+PredictorPrintDir(TIFF* tif, FILE* fd, long flags)
+{
+	TIFFPredictorState* sp = PredictorState(tif);
+
+	(void) flags;
+	if (TIFFFieldSet(tif,FIELD_PREDICTOR)) {
+		fprintf(fd, "  Predictor: ");
+		switch (sp->predictor) {
+		case 1: fprintf(fd, "none "); break;
+		case 2: fprintf(fd, "horizontal differencing "); break;
+		}
+		fprintf(fd, "%u (0x%x)\n", sp->predictor, sp->predictor);
+	}
+	if (sp->printdir)
+		(*sp->printdir)(tif, fd, flags);
+}
+
+int
+TIFFPredictorInit(TIFF* tif)
+{
+	TIFFPredictorState* sp = PredictorState(tif);
+
+	/*
+	 * Merge codec-specific tag information and
+	 * override parent get/set field methods.
+	 */
+	_TIFFMergeFieldInfo(tif, predictFieldInfo, N(predictFieldInfo));
+	sp->vgetparent = tif->tif_vgetfield;
+	tif->tif_vgetfield = PredictorVGetField;/* hook for predictor tag */
+	sp->vsetparent = tif->tif_vsetfield;
+	tif->tif_vsetfield = PredictorVSetField;/* hook for predictor tag */
+	sp->printdir = tif->tif_printdir;
+	tif->tif_printdir = PredictorPrintDir;	/* hook for predictor tag */
+
+	sp->setupdecode = tif->tif_setupdecode;
+	tif->tif_setupdecode = PredictorSetupDecode;
+	sp->setupencode = tif->tif_setupencode;
+	tif->tif_setupencode = PredictorSetupEncode;
+
+	sp->predictor = 1;			/* default value */
+	sp->pfunc = NULL;			/* no predictor routine */
+	return (1);
+}