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/* $Id: tif_strip.c,v 1.1 2005-06-17 13:54:52 vp153 Exp $ */
/*
* Copyright (c) 1991-1997 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.
*
* Strip-organized Image Support Routines.
*/
#include "tiffiop.h"
static uint32
summarize(TIFF* tif, size_t summand1, size_t summand2, const char* where)
{
/*
* XXX: We are using casting to uint32 here, bacause sizeof(size_t)
* may be larger than sizeof(uint32) on 64-bit architectures.
*/
uint32 bytes = summand1 + summand2;
if (bytes - summand1 != summand2) {
TIFFError(tif->tif_name, "Integer overflow in %s", where);
bytes = 0;
}
return (bytes);
}
static uint32
multiply(TIFF* tif, size_t nmemb, size_t elem_size, const char* where)
{
uint32 bytes = nmemb * elem_size;
if (elem_size && bytes / elem_size != nmemb) {
TIFFError(tif->tif_name, "Integer overflow in %s", where);
bytes = 0;
}
return (bytes);
}
/*
* Compute which strip a (row,sample) value is in.
*/
tstrip_t
TIFFComputeStrip(TIFF* tif, uint32 row, tsample_t sample)
{
TIFFDirectory *td = &tif->tif_dir;
tstrip_t strip;
strip = row / td->td_rowsperstrip;
if (td->td_planarconfig == PLANARCONFIG_SEPARATE) {
if (sample >= td->td_samplesperpixel) {
TIFFError(tif->tif_name,
"%lu: Sample out of range, max %lu",
(unsigned long) sample, (unsigned long) td->td_samplesperpixel);
return ((tstrip_t) 0);
}
strip += sample*td->td_stripsperimage;
}
return (strip);
}
/*
* Compute how many strips are in an image.
*/
tstrip_t
TIFFNumberOfStrips(TIFF* tif)
{
TIFFDirectory *td = &tif->tif_dir;
tstrip_t nstrips;
nstrips = (td->td_rowsperstrip == (uint32) -1 ? 1 :
TIFFhowmany(td->td_imagelength, td->td_rowsperstrip));
if (td->td_planarconfig == PLANARCONFIG_SEPARATE)
nstrips = multiply(tif, nstrips, td->td_samplesperpixel,
"TIFFNumberOfStrips");
return (nstrips);
}
/*
* Compute the # bytes in a variable height, row-aligned strip.
*/
tsize_t
TIFFVStripSize(TIFF* tif, uint32 nrows)
{
TIFFDirectory *td = &tif->tif_dir;
if (nrows == (uint32) -1)
nrows = td->td_imagelength;
if (td->td_planarconfig == PLANARCONFIG_CONTIG &&
td->td_photometric == PHOTOMETRIC_YCBCR &&
!isUpSampled(tif)) {
/*
* Packed YCbCr data contain one Cb+Cr for every
* HorizontalSampling*VerticalSampling Y values.
* Must also roundup width and height when calculating
* since images that are not a multiple of the
* horizontal/vertical subsampling area include
* YCbCr data for the extended image.
*/
uint16 ycbcrsubsampling[2];
tsize_t w, scanline, samplingarea;
TIFFGetField( tif, TIFFTAG_YCBCRSUBSAMPLING,
ycbcrsubsampling + 0,
ycbcrsubsampling + 1 );
samplingarea = ycbcrsubsampling[0]*ycbcrsubsampling[1];
if (samplingarea == 0) {
TIFFError(tif->tif_name, "Invalid YCbCr subsampling");
return 0;
}
w = TIFFroundup(td->td_imagewidth, ycbcrsubsampling[0]);
scanline = TIFFhowmany8(multiply(tif, w, td->td_bitspersample,
"TIFFVStripSize"));
nrows = TIFFroundup(nrows, ycbcrsubsampling[1]);
/* NB: don't need TIFFhowmany here 'cuz everything is rounded */
scanline = multiply(tif, nrows, scanline, "TIFFVStripSize");
return ((tsize_t)
summarize(tif, scanline,
multiply(tif, 2, scanline / samplingarea,
"TIFFVStripSize"), "TIFFVStripSize"));
} else
return ((tsize_t) multiply(tif, nrows, TIFFScanlineSize(tif),
"TIFFVStripSize"));
}
/*
* Compute the # bytes in a raw strip.
*/
tsize_t
TIFFRawStripSize(TIFF* tif, tstrip_t strip)
{
TIFFDirectory* td = &tif->tif_dir;
tsize_t bytecount = td->td_stripbytecount[strip];
if (bytecount <= 0) {
TIFFError(tif->tif_name,
"%lu: Invalid strip byte count, strip %lu",
(unsigned long) bytecount, (unsigned long) strip);
bytecount = (tsize_t) -1;
}
return bytecount;
}
/*
* Compute the # bytes in a (row-aligned) strip.
*
* Note that if RowsPerStrip is larger than the
* recorded ImageLength, then the strip size is
* truncated to reflect the actual space required
* to hold the strip.
*/
tsize_t
TIFFStripSize(TIFF* tif)
{
TIFFDirectory* td = &tif->tif_dir;
uint32 rps = td->td_rowsperstrip;
if (rps > td->td_imagelength)
rps = td->td_imagelength;
return (TIFFVStripSize(tif, rps));
}
/*
* Compute a default strip size based on the image
* characteristics and a requested value. If the
* request is <1 then we choose a strip size according
* to certain heuristics.
*/
uint32
TIFFDefaultStripSize(TIFF* tif, uint32 request)
{
return (*tif->tif_defstripsize)(tif, request);
}
uint32
_TIFFDefaultStripSize(TIFF* tif, uint32 s)
{
if ((int32) s < 1) {
/*
* If RowsPerStrip is unspecified, try to break the
* image up into strips that are approximately 8Kbytes.
*/
tsize_t scanline = TIFFScanlineSize(tif);
s = (uint32)(8*1024) / (scanline == 0 ? 1 : scanline);
if (s == 0) /* very wide images */
s = 1;
}
return (s);
}
/*
* Return the number of bytes to read/write in a call to
* one of the scanline-oriented i/o routines. Note that
* this number may be 1/samples-per-pixel if data is
* stored as separate planes.
*/
tsize_t
TIFFScanlineSize(TIFF* tif)
{
TIFFDirectory *td = &tif->tif_dir;
tsize_t scanline;
scanline = multiply (tif, td->td_bitspersample, td->td_imagewidth,
"TIFFScanlineSize");
if (td->td_planarconfig == PLANARCONFIG_CONTIG)
scanline = multiply (tif, scanline, td->td_samplesperpixel,
"TIFFScanlineSize");
return ((tsize_t) TIFFhowmany8(scanline));
}
/*
* Return the number of bytes required to store a complete
* decoded and packed raster scanline (as opposed to the
* I/O size returned by TIFFScanlineSize which may be less
* if data is store as separate planes).
*/
tsize_t
TIFFRasterScanlineSize(TIFF* tif)
{
TIFFDirectory *td = &tif->tif_dir;
tsize_t scanline;
scanline = multiply (tif, td->td_bitspersample, td->td_imagewidth,
"TIFFRasterScanlineSize");
if (td->td_planarconfig == PLANARCONFIG_CONTIG) {
scanline = multiply (tif, scanline, td->td_samplesperpixel,
"TIFFRasterScanlineSize");
return ((tsize_t) TIFFhowmany8(scanline));
} else
return ((tsize_t) multiply (tif, TIFFhowmany8(scanline),
td->td_samplesperpixel,
"TIFFRasterScanlineSize"));
}
/* vim: set ts=8 sts=8 sw=8 noet: */