Ejemplo n.º 1
0
/*
 * Seek to a random row+sample in a file.
 *
 * Only used by TIFFReadScanline, and is only used on
 * strip organized files.  We do some tricky stuff to try
 * and avoid reading the whole compressed raw data for big
 * strips.
 */
static int
TIFFSeek(TIFF* tif, uint32 row, uint16 sample )
{
	register TIFFDirectory *td = &tif->tif_dir;
	uint32 strip;
        int    whole_strip;
	tmsize_t read_ahead = 0;

        /*
        ** Establish what strip we are working from.
        */
	if (row >= td->td_imagelength) {	/* out of range */
		TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
		    "%lu: Row out of range, max %lu",
		    (unsigned long) row,
		    (unsigned long) td->td_imagelength);
		return (0);
	}
	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 (0);
		}
		strip = (uint32)sample*td->td_stripsperimage + row/td->td_rowsperstrip;
	} else
		strip = row / td->td_rowsperstrip;

        /*
         * Do we want to treat this strip as one whole chunk or
         * read it a few lines at a time?
         */
#if defined(CHUNKY_STRIP_READ_SUPPORT)
        if (!_TIFFFillStriles( tif ) || !tif->tif_dir.td_stripbytecount)
            return 0;
        whole_strip = tif->tif_dir.td_stripbytecount[strip] < 10
                || isMapped(tif);
#else
        whole_strip = 1;
#endif
        
        if( !whole_strip )
        {
                read_ahead = tif->tif_scanlinesize * 16 + 5000;
        }

        /*
         * If we haven't loaded this strip, do so now, possibly
         * only reading the first part.
         */
	if (strip != tif->tif_curstrip) {	/* different strip, refill */
                
                if( whole_strip )
                {
                        if (!TIFFFillStrip(tif, strip))
                                return (0);
                }
                else
                {
                        if( !TIFFFillStripPartial(tif,strip,read_ahead,1) )
                                return 0;
                }
	}

        /*
        ** If we already have some data loaded, do we need to read some more?
        */
        else if( !whole_strip )
        {
                if( ((tif->tif_rawdata + tif->tif_rawdataloaded) - tif->tif_rawcp) < read_ahead 
                    && (uint64) tif->tif_rawdataoff+tif->tif_rawdataloaded < td->td_stripbytecount[strip] )
                {
                        if( !TIFFFillStripPartial(tif,strip,read_ahead,0) )
                                return 0;
                }
        }

        if (row < tif->tif_row) {
		/*
		 * Moving backwards within the same strip: backup
		 * to the start and then decode forward (below).
		 *
		 * NB: If you're planning on lots of random access within a
		 * strip, it's better to just read and decode the entire
		 * strip, and then access the decoded data in a random fashion.
		 */

                if( tif->tif_rawdataoff != 0 )
                {
                        if( !TIFFFillStripPartial(tif,strip,read_ahead,1) )
                                return 0;
                }
                else
                {
                        if (!TIFFStartStrip(tif, strip))
                                return (0);
                }
	}
        
	if (row != tif->tif_row) {
		/*
		 * Seek forward to the desired row.
		 */

                /* TODO: Will this really work with partial buffers? */
                
		if (!(*tif->tif_seek)(tif, row - tif->tif_row))
			return (0);
		tif->tif_row = row;
	}

	return (1);
}
Ejemplo n.º 2
0
/*
 * Read the specified strip and setup for decoding. The data buffer is
 * expanded, as necessary, to hold the strip's data.
 */
int
TIFFFillStrip(TIFF* tif, uint32 strip)
{
	static const char module[] = "TIFFFillStrip";
	TIFFDirectory *td = &tif->tif_dir;

    if (!_TIFFFillStriles( tif ) || !tif->tif_dir.td_stripbytecount)
        return 0;
        
	if ((tif->tif_flags&TIFF_NOREADRAW)==0)
	{
		uint64 bytecount = td->td_stripbytecount[strip];
		if ((int64)bytecount <= 0) {
#if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
			TIFFErrorExt(tif->tif_clientdata, module,
				"Invalid strip byte count %I64u, strip %lu",
				     (unsigned __int64) bytecount,
				     (unsigned long) strip);
#else
			TIFFErrorExt(tif->tif_clientdata, module,
				"Invalid strip byte count %llu, strip %lu",
				     (unsigned long long) bytecount,
				     (unsigned long) strip);
#endif
			return (0);
		}
		if (isMapped(tif) &&
		    (isFillOrder(tif, td->td_fillorder)
		    || (tif->tif_flags & TIFF_NOBITREV))) {
			/*
			 * The image is mapped into memory and we either don't
			 * need to flip bits or the compression routine is
			 * going to handle this operation itself.  In this
			 * case, avoid copying the raw data and instead just
			 * reference the data from the memory mapped file
			 * image.  This assumes that the decompression
			 * routines do not modify the contents of the raw data
			 * buffer (if they try to, the application will get a
			 * fault since the file is mapped read-only).
			 */
			if ((tif->tif_flags & TIFF_MYBUFFER) && tif->tif_rawdata) {
				_TIFFfree(tif->tif_rawdata);
				tif->tif_rawdata = NULL;
				tif->tif_rawdatasize = 0;
			}
			tif->tif_flags &= ~TIFF_MYBUFFER;
			/*
			 * We must check for overflow, potentially causing
			 * an OOB read. Instead of simple
			 *
			 *  td->td_stripoffset[strip]+bytecount > tif->tif_size
			 *
			 * comparison (which can overflow) we do the following
			 * two comparisons:
			 */
			if (bytecount > (uint64)tif->tif_size ||
			    td->td_stripoffset[strip] > (uint64)tif->tif_size - bytecount) {
				/*
				 * This error message might seem strange, but
				 * it's what would happen if a read were done
				 * instead.
				 */
#if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
				TIFFErrorExt(tif->tif_clientdata, module,

					"Read error on strip %lu; "
					"got %I64u bytes, expected %I64u",
					(unsigned long) strip,
					(unsigned __int64) tif->tif_size - td->td_stripoffset[strip],
					(unsigned __int64) bytecount);
#else
				TIFFErrorExt(tif->tif_clientdata, module,

					"Read error on strip %lu; "
					"got %llu bytes, expected %llu",
					(unsigned long) strip,
					(unsigned long long) tif->tif_size - td->td_stripoffset[strip],
					(unsigned long long) bytecount);
#endif
				tif->tif_curstrip = NOSTRIP;
				return (0);
			}
			tif->tif_rawdatasize = (tmsize_t)bytecount;
			tif->tif_rawdata = tif->tif_base + (tmsize_t)td->td_stripoffset[strip];
                        tif->tif_rawdataoff = 0;
                        tif->tif_rawdataloaded = (tmsize_t) bytecount;

			/* 
			 * When we have tif_rawdata reference directly into the memory mapped file
			 * we need to be pretty careful about how we use the rawdata.  It is not
			 * a general purpose working buffer as it normally otherwise is.  So we
			 * keep track of this fact to avoid using it improperly.
			 */
			tif->tif_flags |= TIFF_BUFFERMMAP;
		} else {
			/*
			 * Expand raw data buffer, if needed, to hold data
			 * strip coming from file (perhaps should set upper
			 * bound on the size of a buffer we'll use?).
			 */
			tmsize_t bytecountm;
			bytecountm=(tmsize_t)bytecount;
			if ((uint64)bytecountm!=bytecount)
			{
				TIFFErrorExt(tif->tif_clientdata,module,"Integer overflow");
				return(0);
			}
			if (bytecountm > tif->tif_rawdatasize) {
				tif->tif_curstrip = NOSTRIP;
				if ((tif->tif_flags & TIFF_MYBUFFER) == 0) {
					TIFFErrorExt(tif->tif_clientdata, module,
					    "Data buffer too small to hold strip %lu",
					    (unsigned long) strip);
					return (0);
				}
				if (!TIFFReadBufferSetup(tif, 0, bytecountm))
					return (0);
			}
			if (tif->tif_flags&TIFF_BUFFERMMAP) {
				tif->tif_curstrip = NOSTRIP;
				if (!TIFFReadBufferSetup(tif, 0, bytecountm))
					return (0);
			}
			if (TIFFReadRawStrip1(tif, strip, tif->tif_rawdata,
				bytecountm, module) != bytecountm)
				return (0);

                        tif->tif_rawdataoff = 0;
                        tif->tif_rawdataloaded = bytecountm;
                        
			if (!isFillOrder(tif, td->td_fillorder) &&
			    (tif->tif_flags & TIFF_NOBITREV) == 0)
				TIFFReverseBits(tif->tif_rawdata, bytecountm);
                }
	}
	return (TIFFStartStrip(tif, strip));
}
Ejemplo n.º 3
0
static int
TIFFFillStripPartial( TIFF *tif, int strip, tmsize_t read_ahead, int restart )
{
	static const char module[] = "TIFFFillStripPartial";
	register TIFFDirectory *td = &tif->tif_dir;
        tmsize_t unused_data;
        uint64 read_offset;
        tmsize_t cc, to_read;
        /* tmsize_t bytecountm; */
        
        if (!_TIFFFillStriles( tif ) || !tif->tif_dir.td_stripbytecount)
            return 0;
        
        /*
         * Expand raw data buffer, if needed, to hold data
         * strip coming from file (perhaps should set upper
         * bound on the size of a buffer we'll use?).
         */

        /* bytecountm=(tmsize_t) td->td_stripbytecount[strip]; */
        if (read_ahead*2 > tif->tif_rawdatasize) {
                assert( restart );
                
                tif->tif_curstrip = NOSTRIP;
                if ((tif->tif_flags & TIFF_MYBUFFER) == 0) {
                        TIFFErrorExt(tif->tif_clientdata, module,
                                     "Data buffer too small to hold part of strip %lu",
                                     (unsigned long) strip);
                        return (0);
                }
                if (!TIFFReadBufferSetup(tif, 0, read_ahead*2))
                        return (0);
        }

        if( restart )
        {
                tif->tif_rawdataloaded = 0;
                tif->tif_rawdataoff = 0;
        }

        /*
        ** If we are reading more data, move any unused data to the
        ** start of the buffer.
        */
        if( tif->tif_rawdataloaded > 0 )
                unused_data = tif->tif_rawdataloaded - (tif->tif_rawcp - tif->tif_rawdata);
        else
                unused_data = 0;
        
        if( unused_data > 0 )
        {
		assert((tif->tif_flags&TIFF_BUFFERMMAP)==0);
                memmove( tif->tif_rawdata, tif->tif_rawcp, unused_data );
        }

        /*
        ** Seek to the point in the file where more data should be read.
        */
        read_offset = td->td_stripoffset[strip]
                + tif->tif_rawdataoff + tif->tif_rawdataloaded;

        if (!SeekOK(tif, read_offset)) {
                TIFFErrorExt(tif->tif_clientdata, module,
                             "Seek error at scanline %lu, strip %lu",
                             (unsigned long) tif->tif_row, (unsigned long) strip);
                return 0;
        }

        /*
        ** How much do we want to read?
        */
        to_read = tif->tif_rawdatasize - unused_data;
        if( (uint64) to_read > td->td_stripbytecount[strip] 
            - tif->tif_rawdataoff - tif->tif_rawdataloaded )
        {
                to_read = (tmsize_t) td->td_stripbytecount[strip]
                        - tif->tif_rawdataoff - tif->tif_rawdataloaded;
        }

	assert((tif->tif_flags&TIFF_BUFFERMMAP)==0);
        cc = TIFFReadFile(tif, tif->tif_rawdata + unused_data, to_read);

        if (cc != to_read) {
#if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
                TIFFErrorExt(tif->tif_clientdata, module,
                             "Read error at scanline %lu; got %I64u bytes, expected %I64u",
                             (unsigned long) tif->tif_row,
                             (unsigned __int64) cc,
                             (unsigned __int64) to_read);
#else
                TIFFErrorExt(tif->tif_clientdata, module,
                             "Read error at scanline %lu; got %llu bytes, expected %llu",
                             (unsigned long) tif->tif_row,
                             (unsigned long long) cc,
                             (unsigned long long) to_read);
#endif
                return 0;
        }
        
        tif->tif_rawdataoff = tif->tif_rawdataoff + tif->tif_rawdataloaded - unused_data ;
        tif->tif_rawdataloaded = unused_data + to_read;

        tif->tif_rawcp = tif->tif_rawdata;
                        
        if (!isFillOrder(tif, td->td_fillorder) &&
            (tif->tif_flags & TIFF_NOBITREV) == 0) {
		assert((tif->tif_flags&TIFF_BUFFERMMAP)==0);
                TIFFReverseBits(tif->tif_rawdata + unused_data, to_read );
	}

        /*
        ** When starting a strip from the beginning we need to
        ** restart the decoder.
        */
        if( restart )
                return TIFFStartStrip(tif, strip);
        else
                return 1;
}
Ejemplo n.º 4
0
/*
 * Read the specified strip and setup for decoding. 
 * The data buffer is expanded, as necessary, to
 * hold the strip's data.
 */
static int
TIFFFillStrip(TIFF* tif, tstrip_t strip)
{
	static const char module[] = "TIFFFillStrip";
	TIFFDirectory *td = &tif->tif_dir;
	tsize_t bytecount;

	bytecount = td->td_stripbytecount[strip];
	if (bytecount <= 0) {
		TIFFError(tif->tif_name,
		    "%lu: Invalid strip byte count, strip %lu",
		    (u_long) bytecount, (u_long) strip);
		return (0);
	}
	if (isMapped(tif) &&
	    (isFillOrder(tif, td->td_fillorder) || (tif->tif_flags & TIFF_NOBITREV))) {
		/*
		 * The image is mapped into memory and we either don't
		 * need to flip bits or the compression routine is going
		 * to handle this operation itself.  In this case, avoid
		 * copying the raw data and instead just reference the
		 * data from the memory mapped file image.  This assumes
		 * that the decompression routines do not modify the
		 * contents of the raw data buffer (if they try to,
		 * the application will get a fault since the file is
		 * mapped read-only).
		 */
		if ((tif->tif_flags & TIFF_MYBUFFER) && tif->tif_rawdata)
			_TIFFfree(tif->tif_rawdata);
		tif->tif_flags &= ~TIFF_MYBUFFER;
		if ( td->td_stripoffset[strip] + bytecount > tif->tif_size) {
			/*
			 * This error message might seem strange, but it's
			 * what would happen if a read were done instead.
			 */
			TIFFError(module,
		    "%s: Read error on strip %lu; got %lu bytes, expected %lu",
			    tif->tif_name,
			    (u_long) strip,
			    (u_long) tif->tif_size - td->td_stripoffset[strip],
			    (u_long) bytecount);
			tif->tif_curstrip = NOSTRIP;
			return (0);
		}
		tif->tif_rawdatasize = bytecount;
		tif->tif_rawdata = tif->tif_base + td->td_stripoffset[strip];
	} else {
		/*
		 * Expand raw data buffer, if needed, to
		 * hold data strip coming from file
		 * (perhaps should set upper bound on
		 *  the size of a buffer we'll use?).
		 */
		if (bytecount > tif->tif_rawdatasize) {
			tif->tif_curstrip = NOSTRIP;
			if ((tif->tif_flags & TIFF_MYBUFFER) == 0) {
				TIFFError(module,
				"%s: Data buffer too small to hold strip %lu",
				    tif->tif_name, (u_long) strip);
				return (0);
			}
			if (!TIFFReadBufferSetup(tif, 0,
			    TIFFroundup(bytecount, 1024)))
				return (0);
		}
		if (TIFFReadRawStrip1(tif, strip, (u_char *)tif->tif_rawdata,
		    bytecount, module) != bytecount)
			return (0);
		if (!isFillOrder(tif, td->td_fillorder) &&
		    (tif->tif_flags & TIFF_NOBITREV) == 0)
			TIFFReverseBits(tif->tif_rawdata, bytecount);
	}
	return (TIFFStartStrip(tif, strip));
}
Ejemplo n.º 5
0
/*
 * Read the specified strip and setup for decoding. The data buffer is
 * expanded, as necessary, to hold the strip's data.
 */
int
TIFFFillStrip(TIFF* tif, tstrip_t strip)
{
	static const char module[] = "TIFFFillStrip";
	TIFFDirectory *td = &tif->tif_dir;

	if ((tif->tif_flags&TIFF_NOREADRAW)==0)
	{
		/*
		 * FIXME: butecount should have tsize_t type, but for now
		 * libtiff defines tsize_t as a signed 32-bit integer and we
		 * are losing ability to read arrays larger than 2^31 bytes.
		 * So we are using uint32 instead of tsize_t here.
		 */
		uint32 bytecount = td->td_stripbytecount[strip];
		if (bytecount <= 0) {
			TIFFErrorExt(tif->tif_clientdata, module,
			    "%s: Invalid strip byte count %lu, strip %lu",
			    tif->tif_name, (unsigned long) bytecount,
			    (unsigned long) strip);
			return (0);
		}
		if (isMapped(tif) &&
		    (isFillOrder(tif, td->td_fillorder)
		    || (tif->tif_flags & TIFF_NOBITREV))) {
			/*
			 * The image is mapped into memory and we either don't
			 * need to flip bits or the compression routine is
			 * going to handle this operation itself.  In this
			 * case, avoid copying the raw data and instead just
			 * reference the data from the memory mapped file
			 * image.  This assumes that the decompression
			 * routines do not modify the contents of the raw data
			 * buffer (if they try to, the application will get a
			 * fault since the file is mapped read-only).
			 */
			if ((tif->tif_flags & TIFF_MYBUFFER) && tif->tif_rawdata)
				_TIFFfree(tif->tif_rawdata);
			tif->tif_flags &= ~TIFF_MYBUFFER;
			/*
			 * We must check for overflow, potentially causing
			 * an OOB read. Instead of simple
			 *
			 *  td->td_stripoffset[strip]+bytecount > tif->tif_size
			 *
			 * comparison (which can overflow) we do the following
			 * two comparisons:
			 */
			if (bytecount > tif->tif_size ||
			    td->td_stripoffset[strip] > tif->tif_size - bytecount) {
				/*
				 * This error message might seem strange, but
				 * it's what would happen if a read were done
				 * instead.
				 */
				TIFFErrorExt(tif->tif_clientdata, module,

					"%s: Read error on strip %lu; "
					"got %lu bytes, expected %lu",
					tif->tif_name, (unsigned long) strip,
					(unsigned long) tif->tif_size - td->td_stripoffset[strip],
					(unsigned long) bytecount);
				tif->tif_curstrip = NOSTRIP;
				return (0);
			}
			tif->tif_rawdatasize = bytecount;
			tif->tif_rawdata = tif->tif_base + td->td_stripoffset[strip];
		} else {
			/*
			 * Expand raw data buffer, if needed, to hold data
			 * strip coming from file (perhaps should set upper
			 * bound on the size of a buffer we'll use?).
			 */
			if (bytecount > (uint32)tif->tif_rawdatasize) {
				tif->tif_curstrip = NOSTRIP;
				if ((tif->tif_flags & TIFF_MYBUFFER) == 0) {
					TIFFErrorExt(tif->tif_clientdata,
						     module,
				"%s: Data buffer too small to hold strip %lu",
						     tif->tif_name,
						     (unsigned long) strip);
					return (0);
				}
				if (!TIFFReadBufferSetup(tif, 0,
				    TIFFroundup(bytecount, 1024)))
					return (0);
			}
			if ((uint32)TIFFReadRawStrip1(tif, strip,
				(unsigned char *)tif->tif_rawdata,
				bytecount, module) != bytecount)
				return (0);
			if (!isFillOrder(tif, td->td_fillorder) &&
			    (tif->tif_flags & TIFF_NOBITREV) == 0)
				TIFFReverseBits(tif->tif_rawdata, bytecount);
		}
	}
	return (TIFFStartStrip(tif, strip));
}
Ejemplo n.º 6
0
static int
TIFFFillStripPartial( TIFF *tif, int strip, tmsize_t read_ahead, int restart )
{
	static const char module[] = "TIFFFillStripPartial";
	register TIFFDirectory *td = &tif->tif_dir;
        tmsize_t unused_data;
        uint64 read_offset;
        tmsize_t to_read;
        tmsize_t read_ahead_mod;
        /* tmsize_t bytecountm; */
        
        if (!_TIFFFillStriles( tif ) || !tif->tif_dir.td_stripbytecount)
            return 0;
        
        /*
         * Expand raw data buffer, if needed, to hold data
         * strip coming from file (perhaps should set upper
         * bound on the size of a buffer we'll use?).
         */

        /* bytecountm=(tmsize_t) td->td_stripbytecount[strip]; */

        /* Not completely sure where the * 2 comes from, but probably for */
        /* an exponentional growth strategy of tif_rawdatasize */
        if( read_ahead < TIFF_TMSIZE_T_MAX / 2 )
                read_ahead_mod = read_ahead * 2;
        else
                read_ahead_mod = read_ahead;
        if (read_ahead_mod > tif->tif_rawdatasize) {
                assert( restart );
                
                tif->tif_curstrip = NOSTRIP;
                if ((tif->tif_flags & TIFF_MYBUFFER) == 0) {
                        TIFFErrorExt(tif->tif_clientdata, module,
                                     "Data buffer too small to hold part of strip %lu",
                                     (unsigned long) strip);
                        return (0);
                }
        }

        if( restart )
        {
                tif->tif_rawdataloaded = 0;
                tif->tif_rawdataoff = 0;
        }

        /*
        ** If we are reading more data, move any unused data to the
        ** start of the buffer.
        */
        if( tif->tif_rawdataloaded > 0 )
                unused_data = tif->tif_rawdataloaded - (tif->tif_rawcp - tif->tif_rawdata);
        else
                unused_data = 0;
        
        if( unused_data > 0 )
        {
		assert((tif->tif_flags&TIFF_BUFFERMMAP)==0);
                memmove( tif->tif_rawdata, tif->tif_rawcp, unused_data );
        }

        /*
        ** Seek to the point in the file where more data should be read.
        */
        read_offset = td->td_stripoffset[strip]
                + tif->tif_rawdataoff + tif->tif_rawdataloaded;

        if (!SeekOK(tif, read_offset)) {
                TIFFErrorExt(tif->tif_clientdata, module,
                             "Seek error at scanline %lu, strip %lu",
                             (unsigned long) tif->tif_row, (unsigned long) strip);
                return 0;
        }

        /*
        ** How much do we want to read?
        */
        if( read_ahead_mod > tif->tif_rawdatasize )
                to_read = read_ahead_mod - unused_data;
        else
                to_read = tif->tif_rawdatasize - unused_data;
        if( (uint64) to_read > td->td_stripbytecount[strip] 
            - tif->tif_rawdataoff - tif->tif_rawdataloaded )
        {
                to_read = (tmsize_t) td->td_stripbytecount[strip]
                        - tif->tif_rawdataoff - tif->tif_rawdataloaded;
        }

	assert((tif->tif_flags&TIFF_BUFFERMMAP)==0);
        if( !TIFFReadAndRealloc( tif, to_read, unused_data,
                                 1, /* is_strip */
                                 0, /* strip_or_tile */
                                 module) )
        {
                return 0;
        }

        tif->tif_rawdataoff = tif->tif_rawdataoff + tif->tif_rawdataloaded - unused_data ;
        tif->tif_rawdataloaded = unused_data + to_read;

        tif->tif_rawcc = tif->tif_rawdataloaded;
        tif->tif_rawcp = tif->tif_rawdata;
                        
        if (!isFillOrder(tif, td->td_fillorder) &&
            (tif->tif_flags & TIFF_NOBITREV) == 0) {
		assert((tif->tif_flags&TIFF_BUFFERMMAP)==0);
                TIFFReverseBits(tif->tif_rawdata + unused_data, to_read );
	}

        /*
        ** When starting a strip from the beginning we need to
        ** restart the decoder.
        */
        if( restart )
        {

#ifdef JPEG_SUPPORT
            /* A bit messy since breaks the codec abstraction. Ultimately */
            /* there should be a function pointer for that, but it seems */
            /* only JPEG is affected. */
            /* For JPEG, if there are multiple scans (can generally be known */
            /* with the  read_ahead used), we need to read the whole strip */
            if( tif->tif_dir.td_compression==COMPRESSION_JPEG &&
                (uint64)tif->tif_rawcc < td->td_stripbytecount[strip] )
            {
                if( TIFFJPEGIsFullStripRequired(tif) )
                {
                    return TIFFFillStrip(tif, strip);
                }
            }
#endif

            return TIFFStartStrip(tif, strip);
        }
        else
        {
                return 1;
        }
}