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* libtiff/tif_predict.c: fix generation of output with 16 bit

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or 32 bit integer, when byte swapping is needed, in
horizontal predictor (#2521). Also fixes decoding when there is
a single pixel to code (unlikely case...) and byte swapping is
involved.
This commit is contained in:
Even Rouault 2015-08-31 14:36:10 +00:00
parent e9b10efff9
commit 45e29cce8d
2 changed files with 55 additions and 24 deletions
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8
ChangeLog
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@ -1,3 +1,11 @@
2015-08-31 Even Rouault <even.rouault at spatialys.com>
* libtiff/tif_predict.c: fix generation of output with 16 bit
or 32 bit integer, when byte swapping is needed, in
horizontal predictor (#2521). Also fixes decoding when there is
a single pixel to code (unlikely case...) and byte swapping is
involved.
2015-08-30 Even Rouault <even.rouault at spatialys.com>
* libtiff/tif_lzw.c: make nextdata a unsigned type to avoid

65
libtiff/tif_predict.c
View File

@ -1,4 +1,4 @@
/* $Id: tif_predict.c,v 1.33 2015-08-30 20:49:55 erouault Exp $ */
/* $Id: tif_predict.c,v 1.34 2015-08-31 14:36:10 erouault Exp $ */
/*
* Copyright (c) 1988-1997 Sam Leffler
@ -42,6 +42,8 @@ static void swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);
static void horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc);
static void horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc);
static void horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc);
static void swabHorDiff16(TIFF* tif, uint8* cp0, tmsize_t cc);
static void swabHorDiff32(TIFF* tif, uint8* cp0, tmsize_t cc);
static void fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc);
static void fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc);
static int PredictorDecodeRow(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s);
@ -207,6 +209,23 @@ PredictorSetupEncode(TIFF* tif)
sp->encodetile = tif->tif_encodetile;
tif->tif_encodetile = PredictorEncodeTile;
}
/*
* If the data is horizontally differenced 16-bit data that
* requires byte-swapping, then it must be byte swapped after
* the differenciation 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->encodepfunc == horDiff16) {
sp->encodepfunc = swabHorDiff16;
tif->tif_postdecode = _TIFFNoPostDecode;
} else if (sp->encodepfunc == horDiff32) {
sp->encodepfunc = swabHorDiff32;
tif->tif_postdecode = _TIFFNoPostDecode;
}
}
}
else if (sp->predictor == 3) {
@ -298,20 +317,11 @@ horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc)
static void
swabHorAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)
{
tmsize_t stride = PredictorState(tif)->stride;
uint16* wp = (uint16*) cp0;
tmsize_t wc = cc / 2;
assert((cc%(2*stride))==0);
if (wc > stride) {
TIFFSwabArrayOfShort(wp, wc);
wc -= stride;
do {
REPEAT4(stride, wp[stride] = (uint16)(((unsigned int)wp[stride] + (unsigned int)wp[0]) & 0xffff); wp++)
wc -= stride;
} while (wc > 0);
}
horAcc16(tif, cp0, cc);
}
static void
@ -335,20 +345,11 @@ horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)
static void
swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc)
{
tmsize_t stride = PredictorState(tif)->stride;
uint32* wp = (uint32*) cp0;
tmsize_t wc = cc / 4;
assert((cc%(4*stride))==0);
if (wc > stride) {
TIFFSwabArrayOfLong(wp, wc);
wc -= stride;
do {
REPEAT4(stride, wp[stride] += wp[0]; wp++)
wc -= stride;
} while (wc > 0);
}
horAcc32(tif, cp0, cc);
}
static void
@ -524,6 +525,17 @@ horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc)
}
}
static void
swabHorDiff16(TIFF* tif, uint8* cp0, tmsize_t cc)
{
uint16* wp = (uint16*) cp0;
tmsize_t wc = cc / 2;
horDiff16(tif, cp0, cc);
TIFFSwabArrayOfShort(wp, wc);
}
static void
horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)
{
@ -544,6 +556,17 @@ horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)
}
}
static void
swabHorDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)
{
uint32* wp = (uint32*) cp0;
tmsize_t wc = cc / 4;
horDiff32(tif, cp0, cc);
TIFFSwabArrayOfLong(wp, wc);
}
/*
* Floating point predictor differencing routine.
*/