/* $Header: /cvsroot/osrs/libtiff/libtiff/tif_strip.c,v 1.1.1.1 1999/07/27 21:50:27 mike 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"
/*
* 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,
"%u: Sample out of range, max %u",
sample, 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 ?
(td->td_imagelength != 0 ? 1 : 0) :
TIFFhowmany(td->td_imagelength, td->td_rowsperstrip));
if (td->td_planarconfig == PLANARCONFIG_SEPARATE)
nstrips *= td->td_samplesperpixel;
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;
#ifdef YCBCR_SUPPORT
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.
*/
tsize_t w =
TIFFroundup(td->td_imagewidth, td->td_ycbcrsubsampling[0]);
tsize_t scanline = TIFFhowmany(w*td->td_bitspersample, 8);
tsize_t samplingarea =
td->td_ycbcrsubsampling[0]*td->td_ycbcrsubsampling[1];
nrows = TIFFroundup(nrows, td->td_ycbcrsubsampling[1]);
/* NB: don't need TIFFhowmany here 'cuz everything is rounded */
return ((tsize_t)
(nrows*scanline + 2*(nrows*scanline / samplingarea)));
} else
#endif
return ((tsize_t)(nrows * TIFFScanlineSize(tif)));
}
/*
* 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 = td->td_bitspersample * td->td_imagewidth;
if (td->td_planarconfig == PLANARCONFIG_CONTIG)
scanline *= td->td_samplesperpixel;
return ((tsize_t) TIFFhowmany(scanline, 8));
}
/*
* 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 = td->td_bitspersample * td->td_imagewidth;
if (td->td_planarconfig == PLANARCONFIG_CONTIG) {
scanline *= td->td_samplesperpixel;
return ((tsize_t) TIFFhowmany(scanline, 8));
} else
return ((tsize_t)
TIFFhowmany(scanline, 8)*td->td_samplesperpixel);
}
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