chromium/third_party/pdfium/third_party/libtiff/tif_thunder.c

/*
 * 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"
#include <assert.h>
#ifdef THUNDER_SUPPORT
/*
 * TIFF Library.
 *
 * ThunderScan 4-bit Compression Algorithm Support
 */

/*
 * ThunderScan uses an encoding scheme designed for
 * 4-bit pixel values.  Data is encoded in bytes, with
 * each byte split into a 2-bit code word and a 6-bit
 * data value.  The encoding gives raw data, runs of
 * pixels, or pixel values encoded as a delta from the
 * previous pixel value.  For the latter, either 2-bit
 * or 3-bit delta values are used, with the deltas packed
 * into a single byte.
 */
#define THUNDER_DATA …
#define THUNDER_CODE …
/* code values */
#define THUNDER_RUN …
#define THUNDER_2BITDELTAS …
#define DELTA2_SKIP …
#define THUNDER_3BITDELTAS …
#define DELTA3_SKIP …
#define THUNDER_RAW …

static const int twobitdeltas[4] = …;
static const int threebitdeltas[8] = …;

#define SETPIXEL(op, v) …

static int ThunderSetupDecode(TIFF *tif)
{ … }

static int ThunderDecode(TIFF *tif, uint8_t *op, tmsize_t maxpixels)
{ … }

static int ThunderDecodeRow(TIFF *tif, uint8_t *buf, tmsize_t occ, uint16_t s)
{ … }

int TIFFInitThunderScan(TIFF *tif, int scheme)
{ … }
#endif /* THUNDER_SUPPORT */