src/tiff/libtiff/tif_next.c

   1
   2 /*
   3  * Copyright (c) 1988-1997 Sam Leffler
   4  * Copyright (c) 1991-1997 Silicon Graphics, Inc.
   5  *
   6  * Permission to use, copy, modify, distribute, and sell this software and
   7  * its documentation for any purpose is hereby granted without fee, provided
   8  * that (i) the above copyright notices and this permission notice appear in
   9  * all copies of the software and related documentation, and (ii) the names of
  10  * Sam Leffler and Silicon Graphics may not be used in any advertising or
  11  * publicity relating to the software without the specific, prior written
  12  * permission of Sam Leffler and Silicon Graphics.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
  15  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  16  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  17  *
  18  * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
  19  * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  20  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  21  * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  22  * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  23  * OF THIS SOFTWARE.
  24  */
  25
  26 #include "tiffiop.h"
  27 #ifdef NEXT_SUPPORT
  28 /*
  29  * TIFF Library.
  30  *
  31  * NeXT 2-bit Grey Scale Compression Algorithm Support
  32  */
  33
  34 #define SETPIXEL(op, v) {                       \
  35         switch (npixels++ & 3) {                \
  36         case 0: op[0]  = (unsigned char) ((v) << 6); break;     \
  37         case 1: op[0] |= (v) << 4; break;       \
  38         case 2: op[0] |= (v) << 2; break;       \
  39         case 3: *op++ |= (v);      break;       \
  40         }                                       \
  41 }
  42
  43 #define LITERALROW      0x00
  44 #define LITERALSPAN     0x40
  45 #define WHITE           ((1<<2)-1)
  46
  47 static int
  48 NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s)
  49 {
  50         static const char module[] = "NeXTDecode";
  51         unsigned char *bp, *op;
  52         tmsize_t cc;
  53         uint8* row;
  54         tmsize_t scanline, n;
  55
  56         (void) s;
  57         /*
  58          * Each scanline is assumed to start off as all
  59          * white (we assume a PhotometricInterpretation
  60          * of ``min-is-black'').
  61          */
  62         for (op = (unsigned char*) buf, cc = occ; cc-- > 0;)
  63                 *op++ = 0xff;
  64
  65         bp = (unsigned char *)tif->tif_rawcp;
  66         cc = tif->tif_rawcc;
  67         scanline = tif->tif_scanlinesize;
  68         if (occ % scanline)
  69         {
  70                 TIFFErrorExt(tif->tif_clientdata, module, "Fractional scanlines cannot be read");
  71                 return (0);
  72         }
  73         for (row = buf; occ > 0; occ -= scanline, row += scanline) {
  74                 n = *bp++, cc--;
  75                 switch (n) {
  76                 case LITERALROW:
  77                         /*
  78                          * The entire scanline is given as literal values.
  79                          */
  80                         if (cc < scanline)
  81                                 goto bad;
  82                         _TIFFmemcpy(row, bp, scanline);
  83                         bp += scanline;
  84                         cc -= scanline;
  85                         break;
  86                 case LITERALSPAN: {
  87                         tmsize_t off;
  88                         /*
  89                          * The scanline has a literal span that begins at some
  90                          * offset.
  91                          */
  92                         off = (bp[0] * 256) + bp[1];
  93                         n = (bp[2] * 256) + bp[3];
  94                         if (cc < 4+n || off+n > scanline)
  95                                 goto bad;
  96                         _TIFFmemcpy(row+off, bp+4, n);
  97                         bp += 4+n;
  98                         cc -= 4+n;
  99                         break;
 100                 }
 101                 default: {
 102                         uint32 npixels = 0, grey;
 103                         uint32 imagewidth = tif->tif_dir.td_imagewidth;
 104
 105                         /*
 106                          * The scanline is composed of a sequence of constant
 107                          * color ``runs''.  We shift into ``run mode'' and
 108                          * interpret bytes as codes of the form
 109                          * <color><npixels> until we've filled the scanline.
 110                          */
 111                         op = row;
 112                         for (;;) {
 113                                 grey = (uint32)((n>>6) & 0x3);
 114                                 n &= 0x3f;
 115                                 /*
 116                                  * Ensure the run does not exceed the scanline
 117                                  * bounds, potentially resulting in a security
 118                                  * issue.
 119                                  */
 120                                 while (n-- > 0 && npixels < imagewidth)
 121                                         SETPIXEL(op, grey);
 122                                 if (npixels >= imagewidth)
 123                                         break;
 124                                 if (cc == 0)
 125                                         goto bad;
 126                                 n = *bp++, cc--;
 127                         }
 128                         break;
 129                 }
 130                 }
 131         }
 132         tif->tif_rawcp = (uint8*) bp;
 133         tif->tif_rawcc = cc;
 134         return (1);
 135 bad:
 136         TIFFErrorExt(tif->tif_clientdata, module, "Not enough data for scanline %ld",
 137             (long) tif->tif_row);
 138         return (0);
 139 }
 140
 141 int
 142 TIFFInitNeXT(TIFF* tif, int scheme)
 143 {
 144         (void) scheme;
 145         tif->tif_decoderow = NeXTDecode;
 146         tif->tif_decodestrip = NeXTDecode;
 147         tif->tif_decodetile = NeXTDecode;
 148         return (1);
 149 }
 150 #endif /* NEXT_SUPPORT */
 151
 152 /* vim: set ts=8 sts=8 sw=8 noet: */
 153 /*
 154  * Local Variables:
 155  * mode: c
 156  * c-basic-offset: 8
 157  * fill-column: 78
 158  * End:
 159  */