/* $Header: /cvsroot/osrs/libtiff/libtiff/tif_predict.c,v 1.2 1999/11/27 21:43:28 warmerda 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);
tsize_t 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);
tsize_t 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)
{
tsize_t 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);
tsize_t 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);
tsize_t 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);
}
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