root/3rdparty/libtiff/tif_predict.c

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DEFINITIONS

This source file includes following definitions.
  1. PredictorSetup
  2. PredictorSetupDecode
  3. PredictorSetupEncode
  4. horAcc8
  5. swabHorAcc16
  6. horAcc16
  7. swabHorAcc32
  8. horAcc32
  9. fpAcc
  10. PredictorDecodeRow
  11. PredictorDecodeTile
  12. horDiff8
  13. horDiff16
  14. horDiff32
  15. fpDiff
  16. PredictorEncodeRow
  17. PredictorEncodeTile
  18. PredictorVSetField
  19. PredictorVGetField
  20. PredictorPrintDir
  21. TIFFPredictorInit
  22. TIFFPredictorCleanup

/* $Id: tif_predict.c,v 1.32 2010-03-10 18:56:49 bfriesen 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.
 */

/*
 * TIFF Library.
 *
 * Predictor Tag Support (used by multiple codecs).
 */
#include "tiffiop.h"
#include "tif_predict.h"

#define PredictorState(tif)     ((TIFFPredictorState*) (tif)->tif_data)

static void horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc);
static void horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc);
static void horAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);
static void swabHorAcc16(TIFF* tif, uint8* cp0, tmsize_t cc);
static void swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc);
static void horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc);
static void horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc);
static void horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc);
static void fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc);
static void fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc);
static int PredictorDecodeRow(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s);
static int PredictorDecodeTile(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s);
static int PredictorEncodeRow(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s);
static int PredictorEncodeTile(TIFF* tif, uint8* bp0, tmsize_t cc0, uint16 s);

static int
PredictorSetup(TIFF* tif)
{
    static const char module[] = "PredictorSetup";

    TIFFPredictorState* sp = PredictorState(tif);
    TIFFDirectory* td = &tif->tif_dir;

    switch (sp->predictor)              /* no differencing */
    {
        case PREDICTOR_NONE:
            return 1;
        case PREDICTOR_HORIZONTAL:
            if (td->td_bitspersample != 8
                && td->td_bitspersample != 16
                && td->td_bitspersample != 32) {
                TIFFErrorExt(tif->tif_clientdata, module,
                    "Horizontal differencing \"Predictor\" not supported with %d-bit samples",
                    td->td_bitspersample);
                return 0;
            }
            break;
        case PREDICTOR_FLOATINGPOINT:
            if (td->td_sampleformat != SAMPLEFORMAT_IEEEFP) {
                TIFFErrorExt(tif->tif_clientdata, module,
                    "Floating point \"Predictor\" not supported with %d data format",
                    td->td_sampleformat);
                return 0;
            }
            break;
        default:
            TIFFErrorExt(tif->tif_clientdata, module,
                "\"Predictor\" value %d not supported",
                sp->predictor);
            return 0;
    }
    sp->stride = (td->td_planarconfig == PLANARCONFIG_CONTIG ?
        td->td_samplesperpixel : 1);
    /*
     * Calculate the scanline/tile-width size in bytes.
     */
    if (isTiled(tif))
        sp->rowsize = TIFFTileRowSize(tif);
    else
        sp->rowsize = TIFFScanlineSize(tif);
    if (sp->rowsize == 0)
        return 0;

    return 1;
}

static int
PredictorSetupDecode(TIFF* tif)
{
    TIFFPredictorState* sp = PredictorState(tif);
    TIFFDirectory* td = &tif->tif_dir;

    if (!(*sp->setupdecode)(tif) || !PredictorSetup(tif))
        return 0;

    if (sp->predictor == 2) {
        switch (td->td_bitspersample) {
            case 8:  sp->decodepfunc = horAcc8; break;
            case 16: sp->decodepfunc = horAcc16; break;
            case 32: sp->decodepfunc = horAcc32; break;
        }
        /*
         * Override default decoding method with one that does the
         * predictor stuff.
         */
                if( tif->tif_decoderow != PredictorDecodeRow )
                {
                    sp->decoderow = tif->tif_decoderow;
                    tif->tif_decoderow = PredictorDecodeRow;
                    sp->decodestrip = tif->tif_decodestrip;
                    tif->tif_decodestrip = PredictorDecodeTile;
                    sp->decodetile = tif->tif_decodetile;
                    tif->tif_decodetile = PredictorDecodeTile;
                }

        /*
         * If the data is horizontally differenced 16-bit data that
         * requires byte-swapping, then it must be byte swapped before
         * the accumulation step.  We do this with a special-purpose
         * routine and override the normal post decoding logic that
         * the library setup when the directory was read.
         */
        if (tif->tif_flags & TIFF_SWAB) {
            if (sp->decodepfunc == horAcc16) {
                sp->decodepfunc = swabHorAcc16;
                tif->tif_postdecode = _TIFFNoPostDecode;
            } else if (sp->decodepfunc == horAcc32) {
                sp->decodepfunc = swabHorAcc32;
                tif->tif_postdecode = _TIFFNoPostDecode;
            }
        }
    }

    else if (sp->predictor == 3) {
        sp->decodepfunc = fpAcc;
        /*
         * Override default decoding method with one that does the
         * predictor stuff.
         */
                if( tif->tif_decoderow != PredictorDecodeRow )
                {
                    sp->decoderow = tif->tif_decoderow;
                    tif->tif_decoderow = PredictorDecodeRow;
                    sp->decodestrip = tif->tif_decodestrip;
                    tif->tif_decodestrip = PredictorDecodeTile;
                    sp->decodetile = tif->tif_decodetile;
                    tif->tif_decodetile = PredictorDecodeTile;
                }
        /*
         * The data should not be swapped outside of the floating
         * point predictor, the accumulation routine should return
         * byres in the native order.
         */
        if (tif->tif_flags & TIFF_SWAB) {
            tif->tif_postdecode = _TIFFNoPostDecode;
        }
        /*
         * Allocate buffer to keep the decoded bytes before
         * rearranging in the ight order
         */
    }

    return 1;
}

static int
PredictorSetupEncode(TIFF* tif)
{
    TIFFPredictorState* sp = PredictorState(tif);
    TIFFDirectory* td = &tif->tif_dir;

    if (!(*sp->setupencode)(tif) || !PredictorSetup(tif))
        return 0;

    if (sp->predictor == 2) {
        switch (td->td_bitspersample) {
            case 8:  sp->encodepfunc = horDiff8; break;
            case 16: sp->encodepfunc = horDiff16; break;
            case 32: sp->encodepfunc = horDiff32; break;
        }
        /*
         * Override default encoding method with one that does the
         * predictor stuff.
         */
                if( tif->tif_encoderow != PredictorEncodeRow )
                {
                    sp->encoderow = tif->tif_encoderow;
                    tif->tif_encoderow = PredictorEncodeRow;
                    sp->encodestrip = tif->tif_encodestrip;
                    tif->tif_encodestrip = PredictorEncodeTile;
                    sp->encodetile = tif->tif_encodetile;
                    tif->tif_encodetile = PredictorEncodeTile;
                }
    }

    else if (sp->predictor == 3) {
        sp->encodepfunc = fpDiff;
        /*
         * Override default encoding method with one that does the
         * predictor stuff.
         */
                if( tif->tif_encoderow != PredictorEncodeRow )
                {
                    sp->encoderow = tif->tif_encoderow;
                    tif->tif_encoderow = PredictorEncodeRow;
                    sp->encodestrip = tif->tif_encodestrip;
                    tif->tif_encodestrip = PredictorEncodeTile;
                    sp->encodetile = tif->tif_encodetile;
                    tif->tif_encodetile = PredictorEncodeTile;
                }
    }

    return 1;
}

#define REPEAT4(n, op)          \
    switch (n) {                \
    default: { tmsize_t i; for (i = n-4; i > 0; i--) { op; } } \
    case 4:  op;                \
    case 3:  op;                \
    case 2:  op;                \
    case 1:  op;                \
    case 0:  ;                  \
    }

static void
horAcc8(TIFF* tif, uint8* cp0, tmsize_t cc)
{
    tmsize_t stride = PredictorState(tif)->stride;

    char* cp = (char*) cp0;
    assert((cc%stride)==0);
    if (cc > stride) {
        /*
         * Pipeline the most common cases.
         */
        if (stride == 3)  {
            unsigned int cr = cp[0];
            unsigned int cg = cp[1];
            unsigned int cb = cp[2];
            cc -= 3;
            cp += 3;
            while (cc>0) {
                cp[0] = (char) (cr += cp[0]);
                cp[1] = (char) (cg += cp[1]);
                cp[2] = (char) (cb += cp[2]);
                cc -= 3;
                cp += 3;
            }
        } else if (stride == 4)  {
            unsigned int cr = cp[0];
            unsigned int cg = cp[1];
            unsigned int cb = cp[2];
            unsigned int ca = cp[3];
            cc -= 4;
            cp += 4;
            while (cc>0) {
                cp[0] = (char) (cr += cp[0]);
                cp[1] = (char) (cg += cp[1]);
                cp[2] = (char) (cb += cp[2]);
                cp[3] = (char) (ca += cp[3]);
                cc -= 4;
                cp += 4;
            }
        } else  {
            cc -= stride;
            do {
                REPEAT4(stride, cp[stride] =
                    (char) (cp[stride] + *cp); cp++)
                cc -= stride;
            } while (cc>0);
        }
    }
}

static void
swabHorAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)
{
    tmsize_t stride = PredictorState(tif)->stride;
    uint16* wp = (uint16*) cp0;
    tmsize_t wc = cc / 2;

    assert((cc%(2*stride))==0);

    if (wc > stride) {
        TIFFSwabArrayOfShort(wp, wc);
        wc -= stride;
        do {
            REPEAT4(stride, wp[stride] += wp[0]; wp++)
            wc -= stride;
        } while (wc > 0);
    }
}

static void
horAcc16(TIFF* tif, uint8* cp0, tmsize_t cc)
{
    tmsize_t stride = PredictorState(tif)->stride;
    uint16* wp = (uint16*) cp0;
    tmsize_t wc = cc / 2;

    assert((cc%(2*stride))==0);

    if (wc > stride) {
        wc -= stride;
        do {
            REPEAT4(stride, wp[stride] += wp[0]; wp++)
            wc -= stride;
        } while (wc > 0);
    }
}

static void
swabHorAcc32(TIFF* tif, uint8* cp0, tmsize_t cc)
{
    tmsize_t stride = PredictorState(tif)->stride;
    uint32* wp = (uint32*) cp0;
    tmsize_t wc = cc / 4;

    assert((cc%(4*stride))==0);

    if (wc > stride) {
        TIFFSwabArrayOfLong(wp, wc);
        wc -= stride;
        do {
            REPEAT4(stride, wp[stride] += wp[0]; wp++)
            wc -= stride;
        } while (wc > 0);
    }
}

static void
horAcc32(TIFF* tif, uint8* cp0, tmsize_t cc)
{
    tmsize_t stride = PredictorState(tif)->stride;
    uint32* wp = (uint32*) cp0;
    tmsize_t wc = cc / 4;

    assert((cc%(4*stride))==0);

    if (wc > stride) {
        wc -= stride;
        do {
            REPEAT4(stride, wp[stride] += wp[0]; wp++)
            wc -= stride;
        } while (wc > 0);
    }
}

/*
 * Floating point predictor accumulation routine.
 */
static void
fpAcc(TIFF* tif, uint8* cp0, tmsize_t cc)
{
    tmsize_t stride = PredictorState(tif)->stride;
    uint32 bps = tif->tif_dir.td_bitspersample / 8;
    tmsize_t wc = cc / bps;
    tmsize_t count = cc;
    uint8 *cp = (uint8 *) cp0;
    uint8 *tmp = (uint8 *)_TIFFmalloc(cc);

    assert((cc%(bps*stride))==0);

    if (!tmp)
        return;

    while (count > stride) {
        REPEAT4(stride, cp[stride] += cp[0]; cp++)
        count -= stride;
    }

    _TIFFmemcpy(tmp, cp0, cc);
    cp = (uint8 *) cp0;
    for (count = 0; count < wc; count++) {
        uint32 byte;
        for (byte = 0; byte < bps; byte++) {
            #if WORDS_BIGENDIAN
            cp[bps * count + byte] = tmp[byte * wc + count];
            #else
            cp[bps * count + byte] =
                tmp[(bps - byte - 1) * wc + count];
            #endif
        }
    }
    _TIFFfree(tmp);
}

/*
 * Decode a scanline and apply the predictor routine.
 */
static int
PredictorDecodeRow(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
{
    TIFFPredictorState *sp = PredictorState(tif);

    assert(sp != NULL);
    assert(sp->decoderow != NULL);
    assert(sp->decodepfunc != NULL);

    if ((*sp->decoderow)(tif, op0, occ0, s)) {
        (*sp->decodepfunc)(tif, op0, occ0);
        return 1;
    } else
        return 0;
}

/*
 * Decode a tile/strip and apply the predictor routine.
 * Note that horizontal differencing must be done on a
 * row-by-row basis.  The width of a "row" has already
 * been calculated at pre-decode time according to the
 * strip/tile dimensions.
 */
static int
PredictorDecodeTile(TIFF* tif, uint8* op0, tmsize_t occ0, uint16 s)
{
    TIFFPredictorState *sp = PredictorState(tif);

    assert(sp != NULL);
    assert(sp->decodetile != NULL);

    if ((*sp->decodetile)(tif, op0, occ0, s)) {
        tmsize_t rowsize = sp->rowsize;
        assert(rowsize > 0);
        assert((occ0%rowsize)==0);
        assert(sp->decodepfunc != NULL);
        while (occ0 > 0) {
            (*sp->decodepfunc)(tif, op0, rowsize);
            occ0 -= rowsize;
            op0 += rowsize;
        }
        return 1;
    } else
        return 0;
}

static void
horDiff8(TIFF* tif, uint8* cp0, tmsize_t cc)
{
    TIFFPredictorState* sp = PredictorState(tif);
    tmsize_t stride = sp->stride;
    char* cp = (char*) cp0;

    assert((cc%stride)==0);

    if (cc > stride) {
        cc -= stride;
        /*
         * Pipeline the most common cases.
         */
        if (stride == 3) {
            int r1, g1, b1;
            int r2 = cp[0];
            int g2 = cp[1];
            int b2 = cp[2];
            do {
                r1 = cp[3]; cp[3] = r1-r2; r2 = r1;
                g1 = cp[4]; cp[4] = g1-g2; g2 = g1;
                b1 = cp[5]; cp[5] = b1-b2; b2 = b1;
                cp += 3;
            } while ((cc -= 3) > 0);
        } else if (stride == 4) {
            int r1, g1, b1, a1;
            int r2 = cp[0];
            int g2 = cp[1];
            int b2 = cp[2];
            int a2 = cp[3];
            do {
                r1 = cp[4]; cp[4] = r1-r2; r2 = r1;
                g1 = cp[5]; cp[5] = g1-g2; g2 = g1;
                b1 = cp[6]; cp[6] = b1-b2; b2 = b1;
                a1 = cp[7]; cp[7] = a1-a2; a2 = a1;
                cp += 4;
            } while ((cc -= 4) > 0);
        } else {
            cp += cc - 1;
            do {
                REPEAT4(stride, cp[stride] -= cp[0]; cp--)
            } while ((cc -= stride) > 0);
        }
    }
}

static void
horDiff16(TIFF* tif, uint8* cp0, tmsize_t cc)
{
    TIFFPredictorState* sp = PredictorState(tif);
    tmsize_t stride = sp->stride;
    int16 *wp = (int16*) cp0;
    tmsize_t wc = cc/2;

    assert((cc%(2*stride))==0);

    if (wc > stride) {
        wc -= stride;
        wp += wc - 1;
        do {
            REPEAT4(stride, wp[stride] -= wp[0]; wp--)
            wc -= stride;
        } while (wc > 0);
    }
}

static void
horDiff32(TIFF* tif, uint8* cp0, tmsize_t cc)
{
    TIFFPredictorState* sp = PredictorState(tif);
    tmsize_t stride = sp->stride;
    int32 *wp = (int32*) cp0;
    tmsize_t wc = cc/4;

    assert((cc%(4*stride))==0);

    if (wc > stride) {
        wc -= stride;
        wp += wc - 1;
        do {
            REPEAT4(stride, wp[stride] -= wp[0]; wp--)
            wc -= stride;
        } while (wc > 0);
    }
}

/*
 * Floating point predictor differencing routine.
 */
static void
fpDiff(TIFF* tif, uint8* cp0, tmsize_t cc)
{
    tmsize_t stride = PredictorState(tif)->stride;
    uint32 bps = tif->tif_dir.td_bitspersample / 8;
    tmsize_t wc = cc / bps;
    tmsize_t count;
    uint8 *cp = (uint8 *) cp0;
    uint8 *tmp = (uint8 *)_TIFFmalloc(cc);

    assert((cc%(bps*stride))==0);

    if (!tmp)
        return;

    _TIFFmemcpy(tmp, cp0, cc);
    for (count = 0; count < wc; count++) {
        uint32 byte;
        for (byte = 0; byte < bps; byte++) {
            #if WORDS_BIGENDIAN
            cp[byte * wc + count] = tmp[bps * count + byte];
            #else
            cp[(bps - byte - 1) * wc + count] =
                tmp[bps * count + byte];
            #endif
        }
    }
    _TIFFfree(tmp);

    cp = (uint8 *) cp0;
    cp += cc - stride - 1;
    for (count = cc; count > stride; count -= stride)
        REPEAT4(stride, cp[stride] -= cp[0]; cp--)
}

static int
PredictorEncodeRow(TIFF* tif, uint8* bp, tmsize_t cc, uint16 s)
{
    TIFFPredictorState *sp = PredictorState(tif);

    assert(sp != NULL);
    assert(sp->encodepfunc != NULL);
    assert(sp->encoderow != NULL);

    /* XXX horizontal differencing alters user's data XXX */
    (*sp->encodepfunc)(tif, bp, cc);
    return (*sp->encoderow)(tif, bp, cc, s);
}

static int
PredictorEncodeTile(TIFF* tif, uint8* bp0, tmsize_t cc0, uint16 s)
{
    static const char module[] = "PredictorEncodeTile";
    TIFFPredictorState *sp = PredictorState(tif);
        uint8 *working_copy;
    tmsize_t cc = cc0, rowsize;
    unsigned char* bp;
        int result_code;

    assert(sp != NULL);
    assert(sp->encodepfunc != NULL);
    assert(sp->encodetile != NULL);

        /*
         * Do predictor manipulation in a working buffer to avoid altering
         * the callers buffer. http://trac.osgeo.org/gdal/ticket/1965
         */
        working_copy = (uint8*) _TIFFmalloc(cc0);
        if( working_copy == NULL )
        {
            TIFFErrorExt(tif->tif_clientdata, module,
                         "Out of memory allocating " TIFF_SSIZE_FORMAT " byte temp buffer.",
                         cc0 );
            return 0;
        }
        memcpy( working_copy, bp0, cc0 );
        bp = working_copy;

    rowsize = sp->rowsize;
    assert(rowsize > 0);
    assert((cc0%rowsize)==0);
    while (cc > 0) {
        (*sp->encodepfunc)(tif, bp, rowsize);
        cc -= rowsize;
        bp += rowsize;
    }
    result_code = (*sp->encodetile)(tif, working_copy, cc0, s);

        _TIFFfree( working_copy );

        return result_code;
}

#define FIELD_PREDICTOR (FIELD_CODEC+0)         /* XXX */

static const TIFFField predictFields[] = {
    { TIFFTAG_PREDICTOR, 1, 1, TIFF_SHORT, 0, TIFF_SETGET_UINT16, TIFF_SETGET_UINT16, FIELD_PREDICTOR, FALSE, FALSE, "Predictor", NULL },
};

static int
PredictorVSetField(TIFF* tif, uint32 tag, va_list ap)
{
    TIFFPredictorState *sp = PredictorState(tif);

    assert(sp != NULL);
    assert(sp->vsetparent != NULL);

    switch (tag) {
    case TIFFTAG_PREDICTOR:
        sp->predictor = (uint16) va_arg(ap, uint16_vap);
        TIFFSetFieldBit(tif, FIELD_PREDICTOR);
        break;
    default:
        return (*sp->vsetparent)(tif, tag, ap);
    }
    tif->tif_flags |= TIFF_DIRTYDIRECT;
    return 1;
}

static int
PredictorVGetField(TIFF* tif, uint32 tag, va_list ap)
{
    TIFFPredictorState *sp = PredictorState(tif);

    assert(sp != NULL);
    assert(sp->vgetparent != NULL);

    switch (tag) {
    case TIFFTAG_PREDICTOR:
        *va_arg(ap, uint16*) = sp->predictor;
        break;
    default:
        return (*sp->vgetparent)(tif, tag, ap);
    }
    return 1;
}

static void
PredictorPrintDir(TIFF* tif, FILE* fd, long flags)
{
    TIFFPredictorState* sp = PredictorState(tif);

    (void) flags;
    if (TIFFFieldSet(tif,FIELD_PREDICTOR)) {
        fprintf(fd, "  Predictor: ");
        switch (sp->predictor) {
            case 1: fprintf(fd, "none "); break;
            case 2: fprintf(fd, "horizontal differencing "); break;
            case 3: fprintf(fd, "floating point predictor "); break;
        }
        fprintf(fd, "%u (0x%x)\n", sp->predictor, sp->predictor);
    }
    if (sp->printdir)
        (*sp->printdir)(tif, fd, flags);
}

int
TIFFPredictorInit(TIFF* tif)
{
    TIFFPredictorState* sp = PredictorState(tif);

    assert(sp != 0);

    /*
     * Merge codec-specific tag information.
     */
    if (!_TIFFMergeFields(tif, predictFields,
                  TIFFArrayCount(predictFields))) {
        TIFFErrorExt(tif->tif_clientdata, "TIFFPredictorInit",
            "Merging Predictor codec-specific tags failed");
        return 0;
    }

    /*
     * Override parent get/set field methods.
     */
    sp->vgetparent = tif->tif_tagmethods.vgetfield;
    tif->tif_tagmethods.vgetfield =
            PredictorVGetField;/* hook for predictor tag */
    sp->vsetparent = tif->tif_tagmethods.vsetfield;
    tif->tif_tagmethods.vsetfield =
        PredictorVSetField;/* hook for predictor tag */
    sp->printdir = tif->tif_tagmethods.printdir;
    tif->tif_tagmethods.printdir =
            PredictorPrintDir;  /* hook for predictor tag */

    sp->setupdecode = tif->tif_setupdecode;
    tif->tif_setupdecode = PredictorSetupDecode;
    sp->setupencode = tif->tif_setupencode;
    tif->tif_setupencode = PredictorSetupEncode;

    sp->predictor = 1;                  /* default value */
    sp->encodepfunc = NULL;                     /* no predictor routine */
    sp->decodepfunc = NULL;                     /* no predictor routine */
    return 1;
}

int
TIFFPredictorCleanup(TIFF* tif)
{
    TIFFPredictorState* sp = PredictorState(tif);

    assert(sp != 0);

    tif->tif_tagmethods.vgetfield = sp->vgetparent;
    tif->tif_tagmethods.vsetfield = sp->vsetparent;
    tif->tif_tagmethods.printdir = sp->printdir;
    tif->tif_setupdecode = sp->setupdecode;
    tif->tif_setupencode = sp->setupencode;

    return 1;
}

/* vim: set ts=8 sts=8 sw=8 noet: */
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 8
 * fill-column: 78
 * End:
 */

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