paparazzi/sw/ext/libexif/exif-utils.c

/* exif-utils.c
 *
 * Copyright (c) 2001 Lutz Mueller <lutz@users.sourceforge.net>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301  USA.
 */

#include <config.h>

#include <libexif/exif-utils.h>

void
exif_array_set_byte_order(ExifFormat f, unsigned char *b, unsigned int n,
                          ExifByteOrder o_orig, ExifByteOrder o_new)
{
  unsigned int j;
  unsigned int fs = exif_format_get_size(f);
  ExifShort s;
  ExifSShort ss;
  ExifLong l;
  ExifSLong sl;
  ExifRational r;
  ExifSRational sr;

  if (!b || !n || !fs) { return; }

  switch (f) {
    case EXIF_FORMAT_SHORT:
      for (j = 0; j < n; j++) {
        s = exif_get_short(b + j * fs, o_orig);
        exif_set_short(b + j * fs, o_new, s);
      }
      break;
    case EXIF_FORMAT_SSHORT:
      for (j = 0; j < n; j++) {
        ss = exif_get_sshort(b + j * fs, o_orig);
        exif_set_sshort(b + j * fs, o_new, ss);
      }
      break;
    case EXIF_FORMAT_LONG:
      for (j = 0; j < n; j++) {
        l = exif_get_long(b + j * fs, o_orig);
        exif_set_long(b + j * fs, o_new, l);
      }
      break;
    case EXIF_FORMAT_RATIONAL:
      for (j = 0; j < n; j++) {
        r = exif_get_rational(b + j * fs, o_orig);
        exif_set_rational(b + j * fs, o_new, r);
      }
      break;
    case EXIF_FORMAT_SLONG:
      for (j = 0; j < n; j++) {
        sl = exif_get_slong(b + j * fs, o_orig);
        exif_set_slong(b + j * fs, o_new, sl);
      }
      break;
    case EXIF_FORMAT_SRATIONAL:
      for (j = 0; j < n; j++) {
        sr = exif_get_srational(b + j * fs, o_orig);
        exif_set_srational(b + j * fs, o_new, sr);
      }
      break;
    case EXIF_FORMAT_UNDEFINED:
    case EXIF_FORMAT_BYTE:
    case EXIF_FORMAT_ASCII:
    default:
      /* Nothing here. */
      break;
  }
}

ExifSShort
exif_get_sshort(const unsigned char *buf, ExifByteOrder order)
{
  if (!buf) { return 0; }
  switch (order) {
    case EXIF_BYTE_ORDER_MOTOROLA:
      return ((buf[0] << 8) | buf[1]);
    case EXIF_BYTE_ORDER_INTEL:
      return ((buf[1] << 8) | buf[0]);
  }

  /* Won't be reached */
  return (0);
}

ExifShort
exif_get_short(const unsigned char *buf, ExifByteOrder order)
{
  return (exif_get_sshort(buf, order) & 0xffff);
}

void
exif_set_sshort(unsigned char *b, ExifByteOrder order, ExifSShort value)
{
  if (!b) { return; }
  switch (order) {
    case EXIF_BYTE_ORDER_MOTOROLA:
      b[0] = (unsigned char)(value >> 8);
      b[1] = (unsigned char) value;
      break;
    case EXIF_BYTE_ORDER_INTEL:
      b[0] = (unsigned char) value;
      b[1] = (unsigned char)(value >> 8);
      break;
  }
}

void
exif_set_short(unsigned char *b, ExifByteOrder order, ExifShort value)
{
  exif_set_sshort(b, order, value);
}

ExifSLong
exif_get_slong(const unsigned char *b, ExifByteOrder order)
{
  if (!b) { return 0; }
  switch (order) {
    case EXIF_BYTE_ORDER_MOTOROLA:
      return ((b[0] << 24) | (b[1] << 16) | (b[2] << 8) | b[3]);
    case EXIF_BYTE_ORDER_INTEL:
      return ((b[3] << 24) | (b[2] << 16) | (b[1] << 8) | b[0]);
  }

  /* Won't be reached */
  return (0);
}

void
exif_set_slong(unsigned char *b, ExifByteOrder order, ExifSLong value)
{
  if (!b) { return; }
  switch (order) {
    case EXIF_BYTE_ORDER_MOTOROLA:
      b[0] = (unsigned char)(value >> 24);
      b[1] = (unsigned char)(value >> 16);
      b[2] = (unsigned char)(value >> 8);
      b[3] = (unsigned char) value;
      break;
    case EXIF_BYTE_ORDER_INTEL:
      b[3] = (unsigned char)(value >> 24);
      b[2] = (unsigned char)(value >> 16);
      b[1] = (unsigned char)(value >> 8);
      b[0] = (unsigned char) value;
      break;
  }
}

ExifLong
exif_get_long(const unsigned char *buf, ExifByteOrder order)
{
  return (exif_get_slong(buf, order) & 0xffffffff);
}

void
exif_set_long(unsigned char *b, ExifByteOrder order, ExifLong value)
{
  exif_set_slong(b, order, value);
}

ExifSRational
exif_get_srational(const unsigned char *buf, ExifByteOrder order)
{
  ExifSRational r;

  r.numerator   = buf ? exif_get_slong(buf, order) : 0;
  r.denominator = buf ? exif_get_slong(buf + 4, order) : 0;

  return (r);
}

ExifRational
exif_get_rational(const unsigned char *buf, ExifByteOrder order)
{
  ExifRational r;

  r.numerator   = buf ? exif_get_long(buf, order) : 0;
  r.denominator = buf ? exif_get_long(buf + 4, order) : 0;

  return (r);
}

void
exif_set_rational(unsigned char *buf, ExifByteOrder order,
                  ExifRational value)
{
  if (!buf) { return; }
  exif_set_long(buf, order, value.numerator);
  exif_set_long(buf + 4, order, value.denominator);
}

void
exif_set_srational(unsigned char *buf, ExifByteOrder order,
                   ExifSRational value)
{
  if (!buf) { return; }
  exif_set_slong(buf, order, value.numerator);
  exif_set_slong(buf + 4, order, value.denominator);
}

/*! This function converts rather UCS-2LE than UTF-16 to UTF-8.
 * It should really be replaced by iconv().
 */
void
exif_convert_utf16_to_utf8(char *out, const unsigned short *in, int maxlen)
{
  if (maxlen <= 0) {
    return;
  }
  while (*in) {
    if (*in < 0x80) {
      if (maxlen > 1) {
        *out++ = (char) * in++;
        maxlen--;
      } else {
        break;
      }
    } else if (*in < 0x800) {
      if (maxlen > 2) {
        *out++ = ((*in >> 6) & 0x1F) | 0xC0;
        *out++ = (*in++ & 0x3F) | 0x80;
        maxlen -= 2;
      } else {
        break;
      }
    } else {
      if (maxlen > 3) {
        *out++ = ((*in >> 12) & 0x0F) | 0xE0;
        *out++ = ((*in >> 6) & 0x3F) | 0x80;
        *out++ = (*in++ & 0x3F) | 0x80;
        maxlen -= 3;
      } else {
        break;
      }
    }
  }
  *out = 0;
}