/* $Id: tif_strip.c,v 1.19.2.1 2010-06-08 18:50:43 bfriesen 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) {

		TIFFErrorExt(tif->tif_clientdata, 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) {

		TIFFErrorExt(tif->tif_clientdata, 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) {

			TIFFErrorExt(tif->tif_clientdata, 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) {

			TIFFErrorExt(tif->tif_clientdata, 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) {

		TIFFErrorExt(tif->tif_clientdata, 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

		 * STRIP_SIZE_DEFAULT bytes long.

		 */

		tsize_t scanline = TIFFScanlineSize(tif);

		s = (uint32)STRIP_SIZE_DEFAULT / (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;

	if (td->td_planarconfig == PLANARCONFIG_CONTIG) {

		if (td->td_photometric == PHOTOMETRIC_YCBCR

		    && !isUpSampled(tif)) {

			uint16 ycbcrsubsampling[2];

			TIFFGetField(tif, TIFFTAG_YCBCRSUBSAMPLING,

				     ycbcrsubsampling + 0,

				     ycbcrsubsampling + 1);

			if (ycbcrsubsampling[0] == 0) {

				TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

					     "Invalid YCbCr subsampling");

				return 0;

			}

			scanline = TIFFroundup(td->td_imagewidth,

					       ycbcrsubsampling[0]);

			scanline = TIFFhowmany8(multiply(tif, scanline,

							 td->td_bitspersample,

							 "TIFFScanlineSize"));

			return ((tsize_t)

				summarize(tif, scanline,

					  multiply(tif, 2,

						scanline / ycbcrsubsampling[0],

						"TIFFVStripSize"),

					  "TIFFVStripSize"));

		} else {

			scanline = multiply(tif, td->td_imagewidth,

					    td->td_samplesperpixel,

					    "TIFFScanlineSize");

		}

	} else

		scanline = td->td_imagewidth;

	return ((tsize_t) TIFFhowmany8(multiply(tif, scanline,

						td->td_bitspersample,

						"TIFFScanlineSize")));

}

/*

 * Some stuff depends on this older version of TIFFScanlineSize

 * TODO: resolve this

 */

tsize_t

TIFFOldScanlineSize(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 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.

 * The ScanlineSize in case of YCbCrSubsampling is defined as the

 * strip size divided by the strip height, i.e. the size of a pack of vertical

 * subsampling lines divided by vertical subsampling. It should thus make

 * sense when multiplied by a multiple of vertical subsampling.

 * Some stuff depends on this newer version of TIFFScanlineSize

 * TODO: resolve this

 */

tsize_t

TIFFNewScanlineSize(TIFF* tif)

{

	TIFFDirectory *td = &tif->tif_dir;

	tsize_t scanline;

	if (td->td_planarconfig == PLANARCONFIG_CONTIG) {

		if (td->td_photometric == PHOTOMETRIC_YCBCR

		    && !isUpSampled(tif)) {

			uint16 ycbcrsubsampling[2];

			TIFFGetField(tif, TIFFTAG_YCBCRSUBSAMPLING,

				     ycbcrsubsampling + 0,

				     ycbcrsubsampling + 1);

			if (ycbcrsubsampling[0]*ycbcrsubsampling[1] == 0) {

				TIFFErrorExt(tif->tif_clientdata, tif->tif_name,

					     "Invalid YCbCr subsampling");

				return 0;

			}

			return((tsize_t) ((((td->td_imagewidth+ycbcrsubsampling[0]-1)

					    /ycbcrsubsampling[0])

					   *(ycbcrsubsampling[0]*ycbcrsubsampling[1]+2)

					   *td->td_bitspersample+7)

					  /8)/ycbcrsubsampling[1]);

		} else {

			scanline = multiply(tif, td->td_imagewidth,

					    td->td_samplesperpixel,

					    "TIFFScanlineSize");

		}

	} else

		scanline = td->td_imagewidth;

	return ((tsize_t) TIFFhowmany8(multiply(tif, scanline,

						td->td_bitspersample,

						"TIFFScanlineSize")));

}

/*

 * 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: */

/*

 * Local Variables:

 * mode: c

 * c-basic-offset: 8

 * fill-column: 78

 * End:

 */