/* $Id: tif_next.c,v 1.16 2014-12-29 12:09:11 erouault Exp $ */ /* * Copyright (c) 1988-1997 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. */ #include "tiffiop.h" #ifdef NEXT_SUPPORT /* * TIFF Library. * * NeXT 2-bit Grey Scale Compression Algorithm Support */ #define SETPIXEL(op, v) { \ switch (npixels++ & 3) { \ case 0: op[0] = (unsigned char) ((v) << 6); break; \ case 1: op[0] |= (v) << 4; break; \ case 2: op[0] |= (v) << 2; break; \ case 3: *op++ |= (v); op_offset++; break; \ } \ } #define LITERALROW 0x00 #define LITERALSPAN 0x40 #define WHITE ((1<<2)-1) static int NeXTDecode(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s) { static const char module[] = "NeXTDecode"; unsigned char *bp, *op; tmsize_t cc; uint8* row; tmsize_t scanline, n; (void) s; /* * Each scanline is assumed to start off as all * white (we assume a PhotometricInterpretation * of ``min-is-black''). */ for (op = (unsigned char*) buf, cc = occ; cc-- > 0;) *op++ = 0xff; bp = (unsigned char *)tif->tif_rawcp; cc = tif->tif_rawcc; scanline = tif->tif_scanlinesize; if (occ % scanline) { TIFFErrorExt(tif->tif_clientdata, module, "Fractional scanlines cannot be read"); return (0); } for (row = buf; cc > 0 && occ > 0; occ -= scanline, row += scanline) { n = *bp++, cc--; switch (n) { case LITERALROW: /* * The entire scanline is given as literal values. */ if (cc < scanline) goto bad; _TIFFmemcpy(row, bp, scanline); bp += scanline; cc -= scanline; break; case LITERALSPAN: { tmsize_t off; /* * The scanline has a literal span that begins at some * offset. */ if( cc < 4 ) goto bad; off = (bp[0] * 256) + bp[1]; n = (bp[2] * 256) + bp[3]; if (cc < 4+n || off+n > scanline) goto bad; _TIFFmemcpy(row+off, bp+4, n); bp += 4+n; cc -= 4+n; break; } default: { uint32 npixels = 0, grey; uint32 imagewidth = tif->tif_dir.td_imagewidth; if( isTiled(tif) ) imagewidth = tif->tif_dir.td_tilewidth; tmsize_t op_offset = 0; /* * The scanline is composed of a sequence of constant * color ``runs''. We shift into ``run mode'' and * interpret bytes as codes of the form * <color><npixels> until we've filled the scanline. */ op = row; for (;;) { grey = (uint32)((n>>6) & 0x3); n &= 0x3f; /* * Ensure the run does not exceed the scanline * bounds, potentially resulting in a security * issue. */ while (n-- > 0 && npixels < imagewidth && op_offset < scanline) SETPIXEL(op, grey); if (npixels >= imagewidth) break; if (op_offset >= scanline ) { TIFFErrorExt(tif->tif_clientdata, module, "Invalid data for scanline %ld", (long) tif->tif_row); return (0); } if (cc == 0) goto bad; n = *bp++, cc--; } break; } } } tif->tif_rawcp = (uint8*) bp; tif->tif_rawcc = cc; return (1); bad: TIFFErrorExt(tif->tif_clientdata, module, "Not enough data for scanline %ld", (long) tif->tif_row); return (0); } static int NeXTPreDecode(TIFF* tif, uint16 s) { static const char module[] = "NeXTPreDecode"; TIFFDirectory *td = &tif->tif_dir; (void)s; if( td->td_bitspersample != 2 ) { TIFFErrorExt(tif->tif_clientdata, module, "Unsupported BitsPerSample = %d", td->td_bitspersample); return (0); } return (1); } int TIFFInitNeXT(TIFF* tif, int scheme) { (void) scheme; tif->tif_predecode = NeXTPreDecode; tif->tif_decoderow = NeXTDecode; tif->tif_decodestrip = NeXTDecode; tif->tif_decodetile = NeXTDecode; return (1); } #endif /* NEXT_SUPPORT */ /* vim: set ts=8 sts=8 sw=8 noet: */ /* * Local Variables: * mode: c * c-basic-offset: 8 * fill-column: 78 * End: */