/* $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++) {
      #ifdef 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++) {
      #ifdef 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:
 */
