/src/libexif/libexif/exif-entry.c

Source
/* exif-entry.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.
 *
 * SPDX-License-Identifier: LGPL-2.0-or-later
 */

#include <config.h>

#include <libexif/exif-entry.h>
#include <libexif/exif-ifd.h>
#include <libexif/exif-utils.h>
#include <libexif/i18n.h>

#include <libexif/exif-gps-ifd.h>

#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <math.h>

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

struct _ExifEntryPrivate
{
  unsigned int ref_count;

  ExifMem *mem;
};

/* This function is hidden in exif-data.c */
ExifLog *exif_data_get_log (ExifData *);

#ifndef NO_VERBOSE_TAG_STRINGS
static void
exif_entry_log (ExifEntry *e, ExifLogCode code, const char *format, ...)
{
  va_list args;
  ExifLog *l = NULL;

  if (e && e->parent && e->parent->parent)
    l = exif_data_get_log (e->parent->parent);
  va_start (args, format);
  exif_logv (l, code, "ExifEntry", format, args);
  va_end (args);
}
#else
#if defined(__STDC_VERSION__) &&  __STDC_VERSION__ >= 199901L
#define exif_entry_log(...) do { } while (0)
#elif defined(__GNUC__)
#define exif_entry_log(x...) do { } while (0)
#else
#define exif_entry_log (void)
#endif
#endif

static void *
exif_entry_alloc (ExifEntry *e, unsigned int i)
{
  void *d;
  ExifLog *l = NULL;

  if (!e || !e->priv || !i) return NULL;

  d = exif_mem_alloc (e->priv->mem, i);
  if (d) return d;

  if (e->parent && e->parent->parent)
    l = exif_data_get_log (e->parent->parent);
  EXIF_LOG_NO_MEMORY (l, "ExifEntry", i);
  return NULL;
}

static void *
exif_entry_realloc (ExifEntry *e, void *d_orig, unsigned int i)
{
  void *d;
  ExifLog *l = NULL;

  if (!e || !e->priv) return NULL;

  if (!i) { exif_mem_free (e->priv->mem, d_orig); return NULL; }

  d = exif_mem_realloc (e->priv->mem, d_orig, i);
  if (d) return d;

  if (e->parent && e->parent->parent)
    l = exif_data_get_log (e->parent->parent);
  EXIF_LOG_NO_MEMORY (l, "ExifEntry", i);
  return NULL;
}

ExifEntry *
exif_entry_new (void)
{
  ExifMem *mem = exif_mem_new_default ();
  ExifEntry *e = exif_entry_new_mem (mem);

  exif_mem_unref (mem);

  return e;
}

ExifEntry *
exif_entry_new_mem (ExifMem *mem)
{
  ExifEntry *e = NULL;

  e = exif_mem_alloc (mem, sizeof (ExifEntry));
  if (!e) return NULL;
  e->priv = exif_mem_alloc (mem, sizeof (ExifEntryPrivate));
  if (!e->priv) { exif_mem_free (mem, e); return NULL; }
  e->priv->ref_count = 1;

  e->priv->mem = mem;
  exif_mem_ref (mem);

  return e;
}

void
exif_entry_ref (ExifEntry *e)
{
  if (!e) return;

  e->priv->ref_count++;
}

void
exif_entry_unref (ExifEntry *e)
{
  if (!e) return;

  e->priv->ref_count--;
  if (!e->priv->ref_count)
    exif_entry_free (e);
}

void
exif_entry_free (ExifEntry *e)
{
  if (!e) return;

  if (e->priv) {
    ExifMem *mem = e->priv->mem;
    if (e->data)
      exif_mem_free (mem, e->data);
    exif_mem_free (mem, e->priv);
    exif_mem_free (mem, e);
    exif_mem_unref (mem);
  }
}

static void
clear_entry (ExifEntry *e)
{
  e->components = 0;
  e->size = 0;
}

/*! Get a value and convert it to an ExifShort.
 * \bug Not all types are converted that could be converted and no indication
 *      is made when that occurs
 */
static inline ExifShort
exif_get_short_convert (const unsigned char *buf, ExifFormat format,
      ExifByteOrder order)
{
  switch (format) {
  case EXIF_FORMAT_LONG:
    return (ExifShort) exif_get_long (buf, order);
  case EXIF_FORMAT_SLONG:
    return (ExifShort) exif_get_slong (buf, order);
  case EXIF_FORMAT_SHORT:
    return (ExifShort) exif_get_short (buf, order);
  case EXIF_FORMAT_SSHORT:
    return (ExifShort) exif_get_sshort (buf, order);
  case EXIF_FORMAT_BYTE:
  case EXIF_FORMAT_SBYTE:
    return (ExifShort) buf[0];
  default:
    /* Unsupported type */
    return (ExifShort) 0;
  }
}

void
exif_entry_fix (ExifEntry *e)
{
  unsigned int i, newsize;
  unsigned char *newdata;
  ExifByteOrder o;
  ExifRational r;
  ExifSRational sr;

  if (!e || !e->priv) return;

  switch (e->tag) {
  
  /* These tags all need to be of format SHORT. */
  case EXIF_TAG_YCBCR_SUB_SAMPLING:
  case EXIF_TAG_SUBJECT_AREA:
  case EXIF_TAG_COLOR_SPACE:
  case EXIF_TAG_PLANAR_CONFIGURATION:
  case EXIF_TAG_SENSING_METHOD:
  case EXIF_TAG_ORIENTATION:
  case EXIF_TAG_YCBCR_POSITIONING:
  case EXIF_TAG_PHOTOMETRIC_INTERPRETATION:
  case EXIF_TAG_CUSTOM_RENDERED:
  case EXIF_TAG_EXPOSURE_MODE:
  case EXIF_TAG_WHITE_BALANCE:
  case EXIF_TAG_SCENE_CAPTURE_TYPE:
  case EXIF_TAG_GAIN_CONTROL:
  case EXIF_TAG_SATURATION:
  case EXIF_TAG_CONTRAST:
  case EXIF_TAG_SHARPNESS:
  case EXIF_TAG_ISO_SPEED_RATINGS:
    switch (e->format) {
    case EXIF_FORMAT_LONG:
    case EXIF_FORMAT_SLONG:
    case EXIF_FORMAT_BYTE:
    case EXIF_FORMAT_SBYTE:
    case EXIF_FORMAT_SSHORT:
      if (!e->parent || !e->parent->parent) break;
      exif_entry_log (e, EXIF_LOG_CODE_DEBUG,
        _("Tag '%s' was of format '%s' (which is "
        "against specification) and has been "
        "changed to format '%s'."),
        exif_tag_get_name_in_ifd(e->tag,
              exif_entry_get_ifd(e)),
        exif_format_get_name (e->format),
        exif_format_get_name (EXIF_FORMAT_SHORT));

      o = exif_data_get_byte_order (e->parent->parent);
      newsize = e->components * exif_format_get_size (EXIF_FORMAT_SHORT);
      newdata = exif_entry_alloc (e, newsize);
      if (!newdata) {
        exif_entry_log (e, EXIF_LOG_CODE_NO_MEMORY,
          "Could not allocate %lu byte(s).", (unsigned long)newsize);
        break;
      }

      for (i = 0; i < e->components; i++)
        exif_set_short (
          newdata + i *
          exif_format_get_size (
           EXIF_FORMAT_SHORT), o,
           exif_get_short_convert (
            e->data + i *
            exif_format_get_size (e->format),
            e->format, o));

      exif_mem_free (e->priv->mem, e->data);
      e->data = newdata;
      e->size = newsize;
      e->format = EXIF_FORMAT_SHORT;
      break;
    case EXIF_FORMAT_SHORT:
      /* No conversion necessary */
      break;
    default:
      exif_entry_log (e, EXIF_LOG_CODE_CORRUPT_DATA,
        _("Tag '%s' is of format '%s' (which is "
        "against specification) but cannot be changed "
        "to format '%s'."),
        exif_tag_get_name_in_ifd(e->tag,
              exif_entry_get_ifd(e)),
        exif_format_get_name (e->format),
        exif_format_get_name (EXIF_FORMAT_SHORT));
      break;
    }
    break;

  /* All these tags need to be of format 'Rational'. */
  case EXIF_TAG_FNUMBER:
  case EXIF_TAG_APERTURE_VALUE:
  case EXIF_TAG_EXPOSURE_TIME:
  case EXIF_TAG_FOCAL_LENGTH:
    switch (e->format) {
    case EXIF_FORMAT_SRATIONAL:
      if (!e->parent || !e->parent->parent) break;
      o = exif_data_get_byte_order (e->parent->parent);
      for (i = 0; i < e->components; i++) {
        sr = exif_get_srational (e->data + i * 
          exif_format_get_size (
            EXIF_FORMAT_SRATIONAL), o);
        r.numerator = (ExifLong) sr.numerator;
        r.denominator = (ExifLong) sr.denominator;
        exif_set_rational (e->data + i *
          exif_format_get_size (
            EXIF_FORMAT_RATIONAL), o, r);
      }
      e->format = EXIF_FORMAT_RATIONAL;
      exif_entry_log (e, EXIF_LOG_CODE_DEBUG,
        _("Tag '%s' was of format '%s' (which is "
        "against specification) and has been "
        "changed to format '%s'."),
        exif_tag_get_name_in_ifd(e->tag,
              exif_entry_get_ifd(e)),
        exif_format_get_name (EXIF_FORMAT_SRATIONAL),
        exif_format_get_name (EXIF_FORMAT_RATIONAL));
      break;
    default:
      break;
    }
    break;

  /* All these tags need to be of format 'SRational'. */
  case EXIF_TAG_EXPOSURE_BIAS_VALUE:
  case EXIF_TAG_BRIGHTNESS_VALUE:
  case EXIF_TAG_SHUTTER_SPEED_VALUE:
    switch (e->format) {
    case EXIF_FORMAT_RATIONAL:
      if (!e->parent || !e->parent->parent) break;
      o = exif_data_get_byte_order (e->parent->parent);
      for (i = 0; i < e->components; i++) {
        r = exif_get_rational (e->data + i * 
          exif_format_get_size (
            EXIF_FORMAT_RATIONAL), o);
        sr.numerator = (ExifLong) r.numerator;
        sr.denominator = (ExifLong) r.denominator;
        exif_set_srational (e->data + i *
          exif_format_get_size (
            EXIF_FORMAT_SRATIONAL), o, sr);
      }
      e->format = EXIF_FORMAT_SRATIONAL;
      exif_entry_log (e, EXIF_LOG_CODE_DEBUG,
        _("Tag '%s' was of format '%s' (which is "
        "against specification) and has been "
        "changed to format '%s'."),
        exif_tag_get_name_in_ifd(e->tag,
              exif_entry_get_ifd(e)),
        exif_format_get_name (EXIF_FORMAT_RATIONAL),
        exif_format_get_name (EXIF_FORMAT_SRATIONAL));
      break;
    default:
      break;
    }
    break;

  case EXIF_TAG_USER_COMMENT:

    /* Format needs to be UNDEFINED. */
    if (e->format != EXIF_FORMAT_UNDEFINED) {
      exif_entry_log (e, EXIF_LOG_CODE_DEBUG,
        _("Tag 'UserComment' had invalid format '%s'. "
        "Format has been set to 'undefined'."),
        exif_format_get_name (e->format));
      e->format = EXIF_FORMAT_UNDEFINED;
    }

    /* Some packages like Canon ZoomBrowser EX 4.5 store
       only one zero byte followed by 7 bytes of rubbish */
    if ((e->size >= 8) && (e->data[0] == 0)) {
      memcpy(e->data, "\0\0\0\0\0\0\0\0", 8);
    }

    /* There need to be at least 8 bytes. */
    if (e->size < 8) {
      e->data = exif_entry_realloc (e, e->data, 8 + e->size);
      if (!e->data) {
        clear_entry(e);
        return;
      }

      /* Assume ASCII */
      memmove (e->data + 8, e->data, e->size);
      memcpy (e->data, "ASCII\0\0\0", 8);
      e->size += 8;
      e->components += 8;
      exif_entry_log (e, EXIF_LOG_CODE_DEBUG,
        _("Tag 'UserComment' has been expanded to at "
        "least 8 bytes in order to follow the "
        "specification."));
      break;
    }

    /*
     * If the first 8 bytes are empty and real data starts
     * afterwards, let's assume ASCII and claim the 8 first
     * bytes for the format specifyer.
     */
    for (i = 0; (i < e->size) && !e->data[i]; i++);
    if (!i) for ( ; (i < e->size) && (e->data[i] == ' '); i++);
    if ((i >= 8) && (i < e->size)) {
      exif_entry_log (e, EXIF_LOG_CODE_DEBUG,
        _("Tag 'UserComment' is not empty but does not "
        "start with a format identifier. "
        "This has been fixed."));
      memcpy (e->data, "ASCII\0\0\0", 8);
      break;
    }

    /* 
     * First 8 bytes need to follow the specification. If they don't, 
     * assume ASCII.
     */
    if (memcmp (e->data, "ASCII\0\0\0"     , 8) &&
        memcmp (e->data, "UNICODE\0"       , 8) &&
        memcmp (e->data, "JIS\0\0\0\0\0"   , 8) &&
        memcmp (e->data, "\0\0\0\0\0\0\0\0", 8)) {
      e->data = exif_entry_realloc (e, e->data, 8 + e->size);
      if (!e->data) {
        clear_entry(e);
        break;
      }

      /* Assume ASCII */
      memmove (e->data + 8, e->data, e->size);
      memcpy (e->data, "ASCII\0\0\0", 8);
      e->size += 8;
      e->components += 8;
      exif_entry_log (e, EXIF_LOG_CODE_DEBUG,
        _("Tag 'UserComment' did not start with a "
        "format identifier. This has been fixed."));
      break;
    }

    break;
  default:
    break;
  }
}

/*! Format the value of an ExifEntry for human display in a generic way.
 * The output is localized. The formatting is independent of the tag number
 * and is based entirely on the data type.
 * \pre The ExifEntry is already a member of an ExifData.
 * \param[in] e EXIF entry
 * \param[out] val buffer in which to store value
 * \param[in] maxlen the length of the buffer val
 */
static void
exif_entry_format_value(ExifEntry *e, char *val, size_t maxlen)
{
  ExifByte v_byte;
  ExifShort v_short;
  ExifSShort v_sshort;
  ExifLong v_long;
  ExifRational v_rat;
  ExifSRational v_srat;
  ExifSLong v_slong;
  unsigned int i;
  size_t len;
  const ExifByteOrder o = exif_data_get_byte_order (e->parent->parent);

  if (!e->size || !maxlen)
    return;
  switch (e->format) {
  case EXIF_FORMAT_UNDEFINED:
    snprintf (val, maxlen, _("%i bytes undefined data"), e->size);
    break;
  case EXIF_FORMAT_BYTE:
  case EXIF_FORMAT_SBYTE:
    v_byte = e->data[0];
    snprintf (val, maxlen, "0x%02x", v_byte);
    len = strlen (val);
    for (i = 1; i < e->components; i++) {
      v_byte = e->data[i];
      snprintf (val+len, maxlen-len, ", 0x%02x", v_byte);
      len += strlen (val+len);
      if (len >= maxlen-1) break;
    }
    break;
  case EXIF_FORMAT_SHORT:
    v_short = exif_get_short (e->data, o);
    snprintf (val, maxlen, "%u", v_short);
    len = strlen (val);
    for (i = 1; i < e->components; i++) {
      v_short = exif_get_short (e->data +
        exif_format_get_size (e->format) * i, o);
      snprintf (val+len, maxlen-len, ", %u", v_short);
      len += strlen (val+len);
      if (len >= maxlen-1) break;
    }
    break;
  case EXIF_FORMAT_SSHORT:
    v_sshort = exif_get_sshort (e->data, o);
    snprintf (val, maxlen, "%i", v_sshort);
    len = strlen (val);
    for (i = 1; i < e->components; i++) {
      v_sshort = exif_get_short (e->data +
        exif_format_get_size (e->format) *
        i, o);
      snprintf (val+len, maxlen-len, ", %i", v_sshort);
      len += strlen (val+len);
      if (len >= maxlen-1) break;
    }
    break;
  case EXIF_FORMAT_LONG:
    v_long = exif_get_long (e->data, o);
    snprintf (val, maxlen, "%lu", (unsigned long) v_long);
    len = strlen (val);
    for (i = 1; i < e->components; i++) {
      v_long = exif_get_long (e->data +
        exif_format_get_size (e->format) *
        i, o);
      snprintf (val+len, maxlen-len, ", %lu", (unsigned long) v_long);
      len += strlen (val+len);
      if (len >= maxlen-1) break;
    }
    break;
  case EXIF_FORMAT_SLONG:
    v_slong = exif_get_slong (e->data, o);
    snprintf (val, maxlen, "%li", (long) v_slong);
    len = strlen (val);
    for (i = 1; i < e->components; i++) {
      v_slong = exif_get_slong (e->data +
        exif_format_get_size (e->format) * i, o);
      snprintf (val+len, maxlen-len, ", %li", (long) v_slong);
      len += strlen (val+len);
      if (len >= maxlen-1) break;
    }
    break;
  case EXIF_FORMAT_ASCII:
    strncpy (val, (char *) e->data, MIN (maxlen-1, e->size));
    val[MIN (maxlen-1, e->size)] = 0;
    break;
  case EXIF_FORMAT_RATIONAL:
    len = 0;
    for (i = 0; i < e->components; i++) {
      if (i > 0) {
        snprintf (val+len, maxlen-len, ", ");
        len += strlen (val+len);
      }
      v_rat = exif_get_rational (
        e->data + 8 * i, o);
      if (v_rat.denominator) {
        /*
         * Choose the number of significant digits to
         * display based on the size of the denominator.
         * It is scaled so that denominators within the
         * range 13..120 will show 2 decimal points.
         */
        int decimals = (int)(log10(v_rat.denominator)-0.08+1.0);
        snprintf (val+len, maxlen-len, "%2.*f",
            decimals,
            (double) v_rat.numerator /
            (double) v_rat.denominator);
      } else
        snprintf (val+len, maxlen-len, "%lu/%lu",
          (unsigned long) v_rat.numerator,
          (unsigned long) v_rat.denominator);
      len += strlen (val+len);
      if (len >= maxlen-1) break;
    }
    break;
  case EXIF_FORMAT_SRATIONAL:
    len = 0;
    for (i = 0; i < e->components; i++) {
      if (i > 0) {
        snprintf (val+len, maxlen-len, ", ");
        len += strlen (val+len);
      }
      v_srat = exif_get_srational (
        e->data + 8 * i, o);
      if (v_srat.denominator && v_srat.denominator > INT32_MIN) {
        int decimals = (int)(log10(abs(v_srat.denominator))-0.08+1.0);
        snprintf (val+len, maxlen-len, "%2.*f",
            decimals,
            (double) v_srat.numerator /
            (double) v_srat.denominator);
      } else
        snprintf (val+len, maxlen-len, "%li/%li",
          (long) v_srat.numerator,
          (long) v_srat.denominator);
      len += strlen (val+len);
      if (len >= maxlen-1) break;
    }
    break;
  case EXIF_FORMAT_DOUBLE:
  case EXIF_FORMAT_FLOAT:
  default:
    snprintf (val, maxlen, _("%i bytes unsupported data type"),
        e->size);
    break;
  }
}

void
exif_entry_dump (ExifEntry *e, unsigned int indent)
{
  char buf[1024];
  char value[1024];
  unsigned int l;

  if (!e)
    return;

  l = MIN(sizeof(buf)-1, 2*indent);
  memset(buf, ' ', l);
  buf[l] = '\0';

  printf ("%sTag: 0x%x ('%s')\n", buf, e->tag,
    exif_tag_get_name_in_ifd (e->tag, exif_entry_get_ifd(e)));
  printf ("%s  Format: %i ('%s')\n", buf, e->format,
    exif_format_get_name (e->format));
  printf ("%s  Components: %i\n", buf, (int) e->components);
  printf ("%s  Size: %i\n", buf, e->size);
  printf ("%s  Value: %s\n", buf, exif_entry_get_value (e, value, sizeof(value)));
}

/*! Check if a string consists entirely of a single, repeated character.
 * Up to first n bytes are checked.
 * 
 * \param[in] data pointer of string to check
 * \param[in] ch character to match
 * \param[in] n maximum number of characters to match
 *
 * \return 0 if the string matches or is of zero length, nonzero otherwise
 */
static int
match_repeated_char(const unsigned char *data, unsigned char ch, size_t n)
{
  int i;
  for (i=n; i; --i, ++data) {
    if (*data == 0) {
      i = 0;  /* all bytes before NUL matched */
      break;
    }
    if (*data != ch)
      break;
  }
  return i;
}

#define CF(entry,target,v,maxlen)         \
{                 \
  if (entry->format != target) {         \
    exif_entry_log (entry, EXIF_LOG_CODE_CORRUPT_DATA,  \
      _("The tag '%s' contains data of an invalid "  \
      "format ('%s', expected '%s')."),   \
      exif_tag_get_name (entry->tag),     \
      exif_format_get_name (entry->format),   \
      exif_format_get_name (target));     \
    break;              \
  }                \
}

#define CC(entry,target,v,maxlen)         \
{                 \
  if (entry->components != target) {       \
    exif_entry_log (entry, EXIF_LOG_CODE_CORRUPT_DATA,  \
      _("The tag '%s' contains an invalid number of "  \
        "components (%i, expected %i)."),   \
      exif_tag_get_name (entry->tag),   \
      (int) entry->components, (int) target);   \
    break;              \
  }                \
}

static const struct {
  ExifTag tag;
  const char *strings[10];
} list[] = {
#ifndef NO_VERBOSE_TAG_DATA
  { EXIF_TAG_PLANAR_CONFIGURATION,
    { N_("Chunky format"), N_("Planar format"), NULL}},
  { EXIF_TAG_SENSING_METHOD,
    { "", N_("Not defined"), N_("One-chip color area sensor"),
      N_("Two-chip color area sensor"), N_("Three-chip color area sensor"),
      N_("Color sequential area sensor"), "", N_("Trilinear sensor"),
      N_("Color sequential linear sensor"), NULL}},
  { EXIF_TAG_ORIENTATION,
    { "", N_("Top-left"), N_("Top-right"), N_("Bottom-right"),
      N_("Bottom-left"), N_("Left-top"), N_("Right-top"),
      N_("Right-bottom"), N_("Left-bottom"), NULL}},
  { EXIF_TAG_YCBCR_POSITIONING,
    { "", N_("Centered"), N_("Co-sited"), NULL}},
  { EXIF_TAG_PHOTOMETRIC_INTERPRETATION,
    { N_("Reversed mono"), N_("Normal mono"), N_("RGB"), N_("Palette"), "",
      N_("CMYK"), N_("YCbCr"), "", N_("CieLAB"), NULL}},
  { EXIF_TAG_CUSTOM_RENDERED,
    { N_("Normal process"), N_("Custom process"), NULL}},
  { EXIF_TAG_EXPOSURE_MODE,
    { N_("Auto exposure"), N_("Manual exposure"), N_("Auto bracket"), NULL}},
  { EXIF_TAG_WHITE_BALANCE,
    { N_("Auto white balance"), N_("Manual white balance"), NULL}},
  { EXIF_TAG_SCENE_CAPTURE_TYPE,
    { N_("Standard"), N_("Landscape"), N_("Portrait"),
      N_("Night scene"), NULL}},
  { EXIF_TAG_GAIN_CONTROL,
    { N_("Normal"), N_("Low gain up"), N_("High gain up"),
      N_("Low gain down"), N_("High gain down"), NULL}},
  { EXIF_TAG_SATURATION,
    { N_("Normal"), N_("Low saturation"), N_("High saturation"), NULL}},
  { EXIF_TAG_CONTRAST , {N_("Normal"), N_("Soft"), N_("Hard"), NULL}},
  { EXIF_TAG_SHARPNESS, {N_("Normal"), N_("Soft"), N_("Hard"), NULL}},
#endif
  { 0, {NULL}}
};

static const struct {
  ExifTag tag;
  struct {
    ExifShort index;
    const char *values[4]; /*!< list of progressively shorter string
          descriptions; the longest one that fits will be
          selected */
  } elem[25];
} list2[] = {
#ifndef NO_VERBOSE_TAG_DATA
  { EXIF_TAG_METERING_MODE,
    { {  0, {N_("Unknown"), NULL}},
      {  1, {N_("Average"), N_("Avg"), NULL}},
      {  2, {N_("Center-weighted average"), N_("Center-weight"), NULL}},
      {  3, {N_("Spot"), NULL}},
      {  4, {N_("Multi spot"), NULL}},
      {  5, {N_("Pattern"), NULL}},
      {  6, {N_("Partial"), NULL}},
      {255, {N_("Other"), NULL}},
      {  0, {NULL}}}},
  { EXIF_TAG_COMPRESSION,
    { {1, {N_("Uncompressed"), NULL}},
      {5, {N_("LZW compression"), NULL}},
      {6, {N_("JPEG compression"), NULL}},
      {7, {N_("JPEG compression"), NULL}},
      {8, {N_("Deflate/ZIP compression"), NULL}},
      {32773, {N_("PackBits compression"), NULL}},
      {0, {NULL}}}},
  { EXIF_TAG_LIGHT_SOURCE,
    { {  0, {N_("Unknown"), NULL}},
      {  1, {N_("Daylight"), NULL}},
      {  2, {N_("Fluorescent"), NULL}},
      {  3, {N_("Tungsten incandescent light"), N_("Tungsten"), NULL}},
      {  4, {N_("Flash"), NULL}},
      {  9, {N_("Fine weather"), NULL}},
      { 10, {N_("Cloudy weather"), N_("Cloudy"), NULL}},
      { 11, {N_("Shade"), NULL}},
      { 12, {N_("Daylight fluorescent"), NULL}},
      { 13, {N_("Day white fluorescent"), NULL}},
      { 14, {N_("Cool white fluorescent"), NULL}},
      { 15, {N_("White fluorescent"), NULL}},
      { 17, {N_("Standard light A"), NULL}},
      { 18, {N_("Standard light B"), NULL}},
      { 19, {N_("Standard light C"), NULL}},
      { 20, {N_("D55"), NULL}},
      { 21, {N_("D65"), NULL}},
      { 22, {N_("D75"), NULL}},
      { 24, {N_("ISO studio tungsten"),NULL}},
      {255, {N_("Other"), NULL}},
      {  0, {NULL}}}},
  { EXIF_TAG_FOCAL_PLANE_RESOLUTION_UNIT,
    { {2, {N_("Inch"), N_("in"), NULL}},
      {3, {N_("Centimeter"), N_("cm"), NULL}},
      {0, {NULL}}}},
  { EXIF_TAG_RESOLUTION_UNIT,
    { {2, {N_("Inch"), N_("in"), NULL}},
      {3, {N_("Centimeter"), N_("cm"), NULL}}, 
      {0, {NULL}}}},
  { EXIF_TAG_EXPOSURE_PROGRAM,
    { {0, {N_("Not defined"), NULL}},
      {1, {N_("Manual"), NULL}},
      {2, {N_("Normal program"), N_("Normal"), NULL}},
      {3, {N_("Aperture priority"), N_("Aperture"), NULL}},
      {4, {N_("Shutter priority"),N_("Shutter"), NULL}},
      {5, {N_("Creative program (biased toward depth of field)"),
     N_("Creative"), NULL}},
      {6, {N_("Creative program (biased toward fast shutter speed)"),
     N_("Action"), NULL}},
      {7, {N_("Portrait mode (for closeup photos with the background out "
        "of focus)"), N_("Portrait"), NULL}},
      {8, {N_("Landscape mode (for landscape photos with the background "
        "in focus)"), N_("Landscape"), NULL}},
      {0, {NULL}}}},
  { EXIF_TAG_SENSITIVITY_TYPE,
    { {0, {N_("Unknown"), NULL}},
      {1, {N_("Standard output sensitivity (SOS)"), NULL}},
      {2, {N_("Recommended exposure index (REI)"), NULL}},
      {3, {N_("ISO speed"), NULL}},
      {4, {N_("Standard output sensitivity (SOS) and recommended exposure index (REI)"), NULL}},
      {5, {N_("Standard output sensitivity (SOS) and ISO speed"), NULL}},
      {6, {N_("Recommended exposure index (REI) and ISO speed"), NULL}},
      {7, {N_("Standard output sensitivity (SOS) and recommended exposure index (REI) and ISO speed"), NULL}},
      {0, {NULL}}}},
  { EXIF_TAG_FLASH,
    { {0x0000, {N_("Flash did not fire"), N_("No flash"), NULL}},
      {0x0001, {N_("Flash fired"), N_("Flash"), N_("Yes"), NULL}},
      {0x0005, {N_("Strobe return light not detected"), N_("Without strobe"),
    NULL}},
      {0x0007, {N_("Strobe return light detected"), N_("With strobe"), NULL}},
      {0x0008, {N_("Flash did not fire"), NULL}}, /* Olympus E-330 */
      {0x0009, {N_("Flash fired, compulsory flash mode"), NULL}},
      {0x000d, {N_("Flash fired, compulsory flash mode, return light "
       "not detected"), NULL}},
      {0x000f, {N_("Flash fired, compulsory flash mode, return light "
       "detected"), NULL}},
      {0x0010, {N_("Flash did not fire, compulsory flash mode"), NULL}},
      {0x0018, {N_("Flash did not fire, auto mode"), NULL}},
      {0x0019, {N_("Flash fired, auto mode"), NULL}},
      {0x001d, {N_("Flash fired, auto mode, return light not detected"),
    NULL}},
      {0x001f, {N_("Flash fired, auto mode, return light detected"), NULL}},
      {0x0020, {N_("No flash function"),NULL}},
      {0x0041, {N_("Flash fired, red-eye reduction mode"), NULL}},
      {0x0045, {N_("Flash fired, red-eye reduction mode, return light "
       "not detected"), NULL}},
      {0x0047, {N_("Flash fired, red-eye reduction mode, return light "
       "detected"), NULL}},
      {0x0049, {N_("Flash fired, compulsory flash mode, red-eye reduction "
       "mode"), NULL}},
      {0x004d, {N_("Flash fired, compulsory flash mode, red-eye reduction "
      "mode, return light not detected"), NULL}},
      {0x004f, {N_("Flash fired, compulsory flash mode, red-eye reduction mode, "
       "return light detected"), NULL}},
      {0x0058, {N_("Flash did not fire, auto mode, red-eye reduction mode"), NULL}},
      {0x0059, {N_("Flash fired, auto mode, red-eye reduction mode"), NULL}},
      {0x005d, {N_("Flash fired, auto mode, return light not detected, "
       "red-eye reduction mode"), NULL}},
      {0x005f, {N_("Flash fired, auto mode, return light detected, "
       "red-eye reduction mode"), NULL}},
      {0x0000, {NULL}}}},
  { EXIF_TAG_SUBJECT_DISTANCE_RANGE, 
    { {0, {N_("Unknown"), N_("?"), NULL}},
      {1, {N_("Macro"), NULL}},
      {2, {N_("Close view"), N_("Close"), NULL}},
      {3, {N_("Distant view"), N_("Distant"), NULL}},
      {0, {NULL}}}},
  { EXIF_TAG_COLOR_SPACE,
    { {1, {N_("sRGB"), NULL}},
      {2, {N_("Adobe RGB"), NULL}},
      {0xffff, {N_("Uncalibrated"), NULL}},
      {0x0000, {NULL}}}},
  { EXIF_TAG_COMPOSITE_IMAGE,
    { {0, {N_("Unknown"), NULL}},
      {1, {N_("Not a composite image"), NULL}},
      {2, {N_("General composite image"), NULL}},
      {3, {N_("Composite image captured while shooting"), NULL}},
      {0, {NULL}}}},
#endif
  {0, { { 0, {NULL}}} }
};

const char *
exif_entry_get_value (ExifEntry *e, char *val, unsigned int maxlen)
{
  unsigned int i, j, k;
  ExifShort v_short, v_short2, v_short3, v_short4;
  ExifByte v_byte;
  ExifRational v_rat;
  ExifSRational v_srat;
  char b[64];
  const char *c;
  ExifByteOrder o;
  double d;
  ExifEntry *entry;
  static const struct {
    char label[5];
    char major, minor;
  } versions[] = {
    {"0110", 1,  1},
    {"0120", 1,  2},
    {"0200", 2,  0},
    {"0210", 2,  1},
    {"0220", 2,  2},
    {"0221", 2, 21},
    {"0230", 2,  3},
    {"0231", 2, 31},
    {"0232", 2, 32},
    {""    , 0,  0}
  };

  (void) bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR);

  if (!e || !e->parent || !e->parent->parent || !maxlen || !val)
    return val;

  /* make sure the returned string is zero terminated */
  /* FIXME: this is inefficient in the case of long buffers and should
   * instead be taken care of on each write instead. */
  memset (val, 0, maxlen);

  /* We need the byte order */
  o = exif_data_get_byte_order (e->parent->parent);

  /* Sanity check */
  if (e->size != e->components * exif_format_get_size (e->format)) {
    snprintf (val, maxlen, _("Invalid size of entry (%i, "
      "expected %li x %i)."), e->size, e->components,
        exif_format_get_size (e->format));
    return val;
  }

  switch (e->tag) {
  case EXIF_TAG_USER_COMMENT:

    /*
     * The specification says UNDEFINED, but some
     * manufacturers don't care and use ASCII. If this is the
     * case here, only refuse to read it if there is no chance
     * of finding readable data.
     */
    if ((e->format != EXIF_FORMAT_ASCII) || 
        (e->size <= 8) ||
        ( memcmp (e->data, "ASCII\0\0\0"  , 8) &&
          memcmp (e->data, "UNICODE\0"    , 8) &&
          memcmp (e->data, "JIS\0\0\0\0\0", 8) &&
          memcmp (e->data, "\0\0\0\0\0\0\0\0", 8)))
      CF (e, EXIF_FORMAT_UNDEFINED, val, maxlen)

    /*
     * Note that, according to the specification (V2.1, p 40),
     * the user comment field does not have to be 
     * NULL terminated.
     */
    if ((e->size >= 8) && !memcmp (e->data, "ASCII\0\0\0", 8)) {
      strncpy (val, (char *) e->data + 8, MIN (e->size - 8, maxlen-1));
      break;
    }
    if ((e->size >= 8) && !memcmp (e->data, "UNICODE\0", 8)) {
      strncpy (val, _("Unsupported UNICODE string"), maxlen-1);
    /* FIXME: use iconv to convert into the locale encoding.
     * EXIF 2.2 implies (but does not say) that this encoding is
     * UCS-2.
     */
      break;
    }
    if ((e->size >= 8) && !memcmp (e->data, "JIS\0\0\0\0\0", 8)) {
      strncpy (val, _("Unsupported JIS string"), maxlen-1);
    /* FIXME: use iconv to convert into the locale encoding */
      break;
    }

    /* Check if there is really some information in the tag. */
    for (i = 0; (i < e->size) &&
          (!e->data[i] || (e->data[i] == ' ')); i++);
    if (i == e->size) break;

    /*
     * If we reach this point, the tag does not
     * comply with the standard but seems to contain data.
     * Print as much as possible.
     * Note: make sure we do not overwrite the final \0 at maxlen-1
     */
    exif_entry_log (e, EXIF_LOG_CODE_DEBUG,
      _("Tag UserComment contains data but is "
        "against specification."));
    for (j = 0; (i < e->size) && (j < maxlen-1); i++, j++) {
      exif_entry_log (e, EXIF_LOG_CODE_DEBUG,
        _("Byte at position %i: 0x%02x"), i, e->data[i]);
      val[j] = isprint (e->data[i]) ? e->data[i] : '.';
    }
    break;

  case EXIF_TAG_EXIF_VERSION:
    CF (e, EXIF_FORMAT_UNDEFINED, val, maxlen)
    CC (e, 4, val, maxlen)
    strncpy (val, _("Unknown Exif Version"), maxlen-1);
    for (i = 0; *versions[i].label; i++) {
      if (!memcmp (e->data, versions[i].label, 4)) {
            snprintf (val, maxlen,
          _("Exif Version %d.%d"),
          versions[i].major,
          versions[i].minor);
            break;
      }
    }
    break;
  case EXIF_TAG_FLASH_PIX_VERSION:
    CF (e, EXIF_FORMAT_UNDEFINED, val, maxlen)
    CC (e, 4, val, maxlen)
    if (!memcmp (e->data, "0100", 4))
      strncpy (val, _("FlashPix Version 1.0"), maxlen-1);
    else if (!memcmp (e->data, "0101", 4))
      strncpy (val, _("FlashPix Version 1.01"), maxlen-1);
    else
      strncpy (val, _("Unknown FlashPix Version"), maxlen-1);
    break;
  case EXIF_TAG_COPYRIGHT:
    CF (e, EXIF_FORMAT_ASCII, val, maxlen)

    /*
     * First part: Photographer.
     * Some cameras store a string like "   " here. Ignore it.
     * Remember that a corrupted tag might not be NUL-terminated
     */
    if (e->size && e->data && match_repeated_char(e->data, ' ', e->size))
      strncpy (val, (char *) e->data, MIN (maxlen-1, e->size));
    else
      strncpy (val, _("[None]"), maxlen-1);
    strncat (val, " ", maxlen-1 - strlen (val));
    strncat (val, _("(Photographer)"), maxlen-1 - strlen (val));

    /* Second part: Editor. */
    strncat (val, " - ", maxlen-1 - strlen (val));
    k = 0;
    if (e->size && e->data) {
      const unsigned char *tagdata = memchr(e->data, 0, e->size);
      if (tagdata++) {
        unsigned int editor_ofs = tagdata - e->data;
        unsigned int remaining = e->size - editor_ofs;
        if (match_repeated_char(tagdata, ' ', remaining)) {
          strncat (val, (const char*)tagdata, MIN (maxlen-1 - strlen (val), remaining));
          ++k;
        }
      }
    }
    if (!k)
      strncat (val, _("[None]"), maxlen-1 - strlen (val));
    strncat (val, " ", maxlen-1 - strlen (val));
    strncat (val, _("(Editor)"), maxlen-1 - strlen (val));

    break;
  case EXIF_TAG_FNUMBER:
    CF (e, EXIF_FORMAT_RATIONAL, val, maxlen)
    CC (e, 1, val, maxlen)
    v_rat = exif_get_rational (e->data, o);
    if (!v_rat.denominator) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }
    d = (double) v_rat.numerator / (double) v_rat.denominator;
    snprintf (val, maxlen, "f/%.01f", d);
    break;
  case EXIF_TAG_APERTURE_VALUE:
  case EXIF_TAG_MAX_APERTURE_VALUE:
    CF (e, EXIF_FORMAT_RATIONAL, val, maxlen)
    CC (e, 1, val, maxlen)
    v_rat = exif_get_rational (e->data, o);
    if (!v_rat.denominator || (0x80000000 == v_rat.numerator)) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }
    d = (double) v_rat.numerator / (double) v_rat.denominator;
    snprintf (val, maxlen, _("%.02f EV"), d);
    snprintf (b, sizeof (b), _(" (f/%.01f)"), pow (2, d / 2.));
    strncat (val, b, maxlen-1 - strlen (val));
    break;
  case EXIF_TAG_FOCAL_LENGTH:
    CF (e, EXIF_FORMAT_RATIONAL, val, maxlen)
    CC (e, 1, val, maxlen)
    v_rat = exif_get_rational (e->data, o);
    if (!v_rat.denominator) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }

    /*
     * For calculation of the 35mm equivalent,
     * Minolta cameras need a multiplier that depends on the
     * camera model.
     */
    d = 0.;
    entry = exif_content_get_entry (
      e->parent->parent->ifd[EXIF_IFD_0], EXIF_TAG_MAKE);
    if (entry && entry->data && entry->size >= 7 &&
        !strncmp ((char *)entry->data, "Minolta", 7)) {
      entry = exif_content_get_entry (
          e->parent->parent->ifd[EXIF_IFD_0],
          EXIF_TAG_MODEL);
      if (entry && entry->data && entry->size >= 8) {
        if (!strncmp ((char *)entry->data, "DiMAGE 7", 8))
          d = 3.9;
        else if (!strncmp ((char *)entry->data, "DiMAGE 5", 8))
          d = 4.9;
      }
    }
    if (d)
      snprintf (b, sizeof (b), _(" (35 equivalent: %.0f mm)"),
          (d * (double) v_rat.numerator /
               (double) v_rat.denominator));
    else
      b[0] = 0;

    d = (double) v_rat.numerator / (double) v_rat.denominator;
    snprintf (val, maxlen, "%.1f mm", d);
    strncat (val, b, maxlen-1 - strlen (val));
    break;
  case EXIF_TAG_SUBJECT_DISTANCE:
    CF (e, EXIF_FORMAT_RATIONAL, val, maxlen)
    CC (e, 1, val, maxlen)
    v_rat = exif_get_rational (e->data, o);
    if (!v_rat.denominator) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }
    d = (double) v_rat.numerator / (double) v_rat.denominator;
    snprintf (val, maxlen, "%.1f m", d);
    break;
  case EXIF_TAG_EXPOSURE_TIME:
    CF (e, EXIF_FORMAT_RATIONAL, val, maxlen)
    CC (e, 1, val, maxlen)
    v_rat = exif_get_rational (e->data, o);
    if (!v_rat.denominator) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }
    d = (double) v_rat.numerator / (double) v_rat.denominator;
    if (d < 1 && d)
      snprintf (val, maxlen, _("1/%.0f"), 1. / d);
    else
      snprintf (val, maxlen, "%.0f", d);
    strncat (val, _(" sec."), maxlen-1 - strlen (val));
    break;
  case EXIF_TAG_SHUTTER_SPEED_VALUE:
    CF (e, EXIF_FORMAT_SRATIONAL, val, maxlen)
    CC (e, 1, val, maxlen)
    v_srat = exif_get_srational (e->data, o);
    if (!v_srat.denominator) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }
    d = (double) v_srat.numerator / (double) v_srat.denominator;
    snprintf (val, maxlen, _("%.02f EV"), d);
    if (pow (2, d))
      d = 1. / pow (2, d);
    if (d < 1 && d)
      snprintf (b, sizeof (b), _(" (1/%.0f sec.)"), 1. / d);
    else
      snprintf (b, sizeof (b), _(" (%.0f sec.)"), d);
    strncat (val, b, maxlen-1 - strlen (val));
    break;
  case EXIF_TAG_BRIGHTNESS_VALUE:
    CF (e, EXIF_FORMAT_SRATIONAL, val, maxlen)
    CC (e, 1, val, maxlen)
    v_srat = exif_get_srational (e->data, o);
    if (!v_srat.denominator) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }
    d = (double) v_srat.numerator / (double) v_srat.denominator;
    snprintf (val, maxlen, _("%.02f EV"), d);
    snprintf (b, sizeof (b), _(" (%.02f cd/m^2)"),
      1. / (M_PI * 0.3048 * 0.3048) * pow (2, d));
    strncat (val, b, maxlen-1 - strlen (val));
    break;
  case EXIF_TAG_FILE_SOURCE:
    CF (e, EXIF_FORMAT_UNDEFINED, val, maxlen)
    CC (e, 1, val, maxlen)
    v_byte = e->data[0];
    if (v_byte == 3)
      strncpy (val, _("DSC"), maxlen-1);
    else
      snprintf (val, maxlen, _("Internal error (unknown "
          "value %i)"), v_byte);
    break;
  case EXIF_TAG_COMPONENTS_CONFIGURATION:
    CF (e, EXIF_FORMAT_UNDEFINED, val, maxlen)
    CC (e, 4, val, maxlen)
    for (i = 0; i < 4; i++) {
      switch (e->data[i]) {
      case 0: c = _("-"); break;
      case 1: c = _("Y"); break;
      case 2: c = _("Cb"); break;
      case 3: c = _("Cr"); break;
      case 4: c = _("R"); break;
      case 5: c = _("G"); break;
      case 6: c = _("B"); break;
      default: c = _("Reserved"); break;
      }
      strncat (val, c, maxlen-1 - strlen (val));
      if (i < 3)
        strncat (val, " ", maxlen-1 - strlen (val));
    }
    break;
  case EXIF_TAG_EXPOSURE_BIAS_VALUE:
    CF (e, EXIF_FORMAT_SRATIONAL, val, maxlen)
    CC (e, 1, val, maxlen)
    v_srat = exif_get_srational (e->data, o);
    if (!v_srat.denominator) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }
    d = (double) v_srat.numerator / (double) v_srat.denominator;
    snprintf (val, maxlen, _("%.02f EV"), d);
    break;
  case EXIF_TAG_SCENE_TYPE:
    CF (e, EXIF_FORMAT_UNDEFINED, val, maxlen)
    CC (e, 1, val, maxlen)
    v_byte = e->data[0];
    if (v_byte == 1)
      strncpy (val, _("Directly photographed"), maxlen-1);
    else
      snprintf (val, maxlen, _("Internal error (unknown "
          "value %i)"), v_byte);
    break;
  case EXIF_TAG_YCBCR_SUB_SAMPLING:
    CF (e, EXIF_FORMAT_SHORT, val, maxlen)
    CC (e, 2, val, maxlen)
    v_short  = exif_get_short (e->data, o);
    v_short2 = exif_get_short (
      e->data + exif_format_get_size (e->format),
      o);
    if ((v_short == 2) && (v_short2 == 1))
      strncpy (val, _("YCbCr4:2:2"), maxlen-1);
    else if ((v_short == 2) && (v_short2 == 2))
      strncpy (val, _("YCbCr4:2:0"), maxlen-1);
    else
      snprintf (val, maxlen, "%u, %u", v_short, v_short2);
    break;
  case EXIF_TAG_SUBJECT_AREA:
    CF (e, EXIF_FORMAT_SHORT, val, maxlen)
    switch (e->components) {
    case 2:
      v_short  = exif_get_short (e->data, o);
      v_short2 = exif_get_short (e->data + 2, o);
      snprintf (val, maxlen, "(x,y) = (%i,%i)",
          v_short, v_short2);
      break;
    case 3:
      v_short  = exif_get_short (e->data, o);
      v_short2 = exif_get_short (e->data + 2, o);
      v_short3 = exif_get_short (e->data + 4, o);
      snprintf (val, maxlen, _("Within distance %i of "
        "(x,y) = (%i,%i)"), v_short3, v_short,
        v_short2);
      break;
    case 4:
      v_short  = exif_get_short (e->data, o);
      v_short2 = exif_get_short (e->data + 2, o);
      v_short3 = exif_get_short (e->data + 4, o);
      v_short4 = exif_get_short (e->data + 6, o);
      snprintf (val, maxlen, _("Within rectangle "
        "(width %i, height %i) around "
        "(x,y) = (%i,%i)"), v_short3, v_short4,
        v_short, v_short2);
      break;
    default:
      snprintf (val, maxlen, _("Unexpected number "
        "of components (%li, expected 2, 3, or 4)."),
        e->components); 
    }
    break;
  case EXIF_TAG_GPS_VERSION_ID:
    /* This is only valid in the GPS IFD */
    CF (e, EXIF_FORMAT_BYTE, val, maxlen)
    CC (e, 4, val, maxlen)
    v_byte = e->data[0];
    snprintf (val, maxlen, "%u", v_byte);
    for (i = 1; i < e->components; i++) {
      v_byte = e->data[i];
      snprintf (b, sizeof (b), ".%u", v_byte);
      strncat (val, b, maxlen-1 - strlen (val));
    }
    break;
  case EXIF_TAG_INTEROPERABILITY_VERSION:
  /* a.k.a. case EXIF_TAG_GPS_LATITUDE: */
    /* This tag occurs in EXIF_IFD_INTEROPERABILITY */
    if (e->format == EXIF_FORMAT_UNDEFINED) {
      strncpy (val, (char *) e->data, MIN (maxlen-1, e->size));
      break;
    }
    /* EXIF_TAG_GPS_LATITUDE is the same numerically as
     * EXIF_TAG_INTEROPERABILITY_VERSION but in EXIF_IFD_GPS
     */
    exif_entry_format_value(e, val, maxlen);
    break;
  case EXIF_TAG_GPS_ALTITUDE_REF:
    /* This is only valid in the GPS IFD */
    CF (e, EXIF_FORMAT_BYTE, val, maxlen)
    CC (e, 1, val, maxlen)
    v_byte = e->data[0];
    if (v_byte == 0)
      strncpy (val, _("Sea level"), maxlen-1);
    else if (v_byte == 1)
      strncpy (val, _("Sea level reference"), maxlen-1);
    else
      snprintf (val, maxlen, _("Internal error (unknown "
          "value %i)"), v_byte);
    break;
  case EXIF_TAG_GPS_TIME_STAMP:
    /* This is only valid in the GPS IFD */
    CF (e, EXIF_FORMAT_RATIONAL, val, maxlen)
    CC (e, 3, val, maxlen)

    v_rat  = exif_get_rational (e->data, o);
    if (!v_rat.denominator) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }
    i = v_rat.numerator / v_rat.denominator;

    v_rat = exif_get_rational (e->data +
               exif_format_get_size (e->format),
             o);
    if (!v_rat.denominator) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }
    j = v_rat.numerator / v_rat.denominator;

    v_rat = exif_get_rational (e->data +
               2*exif_format_get_size (e->format),
               o);
    if (!v_rat.denominator) {
      exif_entry_format_value(e, val, maxlen);
      break;
    }
    d = (double) v_rat.numerator / (double) v_rat.denominator;
    snprintf (val, maxlen, "%02u:%02u:%05.2f", i, j, d);
    break;

  case EXIF_TAG_METERING_MODE:
  case EXIF_TAG_COMPRESSION:
  case EXIF_TAG_LIGHT_SOURCE:
  case EXIF_TAG_FOCAL_PLANE_RESOLUTION_UNIT:
  case EXIF_TAG_RESOLUTION_UNIT:
  case EXIF_TAG_EXPOSURE_PROGRAM:
  case EXIF_TAG_SENSITIVITY_TYPE:
  case EXIF_TAG_FLASH:
  case EXIF_TAG_SUBJECT_DISTANCE_RANGE:
  case EXIF_TAG_COLOR_SPACE:
  case EXIF_TAG_COMPOSITE_IMAGE:
    CF (e,EXIF_FORMAT_SHORT, val, maxlen)
    CC (e, 1, val, maxlen)
    v_short = exif_get_short (e->data, o);

    /* Search the tag */
    for (i = 0; list2[i].tag && (list2[i].tag != e->tag); i++);
    if (!list2[i].tag) {
      snprintf (val, maxlen, _("Internal error (unknown "
          "value %i)"), v_short);
      break;
    }

    /* Find the value */
    for (j = 0; list2[i].elem[j].values[0] &&
          (list2[i].elem[j].index < v_short); j++);
    if (list2[i].elem[j].index != v_short) {
      snprintf (val, maxlen, _("Internal error (unknown "
          "value %i)"), v_short);
      break;
    }

    /* Find a short enough value */
    memset (val, 0, maxlen);
    for (k = 0; list2[i].elem[j].values[k]; k++) {
      size_t l = strlen (_(list2[i].elem[j].values[k]));
      if ((maxlen > l) && (strlen (val) < l))
        strncpy (val, _(list2[i].elem[j].values[k]), maxlen-1);
    }
    if (!val[0]) snprintf (val, maxlen, "%i", v_short);

    break;

  case EXIF_TAG_PLANAR_CONFIGURATION:
  case EXIF_TAG_SENSING_METHOD:
  case EXIF_TAG_ORIENTATION:
  case EXIF_TAG_YCBCR_POSITIONING:
  case EXIF_TAG_PHOTOMETRIC_INTERPRETATION:
  case EXIF_TAG_CUSTOM_RENDERED:
  case EXIF_TAG_EXPOSURE_MODE:
  case EXIF_TAG_WHITE_BALANCE:
  case EXIF_TAG_SCENE_CAPTURE_TYPE:
  case EXIF_TAG_GAIN_CONTROL:
  case EXIF_TAG_SATURATION:
  case EXIF_TAG_CONTRAST:
  case EXIF_TAG_SHARPNESS:
    CF (e, EXIF_FORMAT_SHORT, val, maxlen)
    CC (e, 1, val, maxlen)
    v_short = exif_get_short (e->data, o);

    /* Search the tag */
    for (i = 0; list[i].tag && (list[i].tag != e->tag); i++);
    if (!list[i].tag) {
      snprintf (val, maxlen, _("Internal error (unknown "
          "value %i)"), v_short);
      break;
    }

    /* Find the value */
    for (j = 0; list[i].strings[j] && (j < v_short); j++);
    if (!list[i].strings[j])
      snprintf (val, maxlen, "%i", v_short);
    else if (!*list[i].strings[j])
      snprintf (val, maxlen, _("Unknown value %i"), v_short);
    else
      strncpy (val, _(list[i].strings[j]), maxlen-1);
    break;

  case EXIF_TAG_XP_TITLE:
  case EXIF_TAG_XP_COMMENT:
  case EXIF_TAG_XP_AUTHOR:
  case EXIF_TAG_XP_KEYWORDS:
  case EXIF_TAG_XP_SUBJECT:
  {
    unsigned char *utf16;

    /* Sanity check the size to prevent overflow. Note EXIF files are 64kb at most. */
    if (e->size >= 65536 - sizeof(uint16_t)*2) break;

    /* The tag may not be U+0000-terminated , so make a local
       U+0000-terminated copy before converting it */
    utf16 = exif_mem_alloc (e->priv->mem, e->size+sizeof(uint16_t)+1);
    if (!utf16) break;
    memcpy(utf16, e->data, e->size);

    /* NUL terminate the string. If the size is odd (which isn't possible
     * for a valid UTF16 string), then this will overwrite the high byte of
     * the final half word, plus add a full zero NUL word at the end.
     */
    utf16[e->size] = 0;
    utf16[e->size+1] = 0;
    utf16[e->size+2] = 0;

    /* Warning! The texts are converted from UTF16 to UTF8 */
    /* FIXME: use iconv to convert into the locale encoding */
    exif_convert_utf16_to_utf8(val, utf16, maxlen);
    exif_mem_free(e->priv->mem, utf16);
    break;
  }

  default:
    /* Use a generic value formatting */
    exif_entry_format_value(e, val, maxlen);
  }

  return val;
}

static
void exif_entry_initialize_gps(ExifEntry *e, ExifTag tag) {
  const ExifGPSIfdTagInfo* info = exif_get_gps_tag_info(tag);

  if(!info) {
    e->components = 0;
    e->format = EXIF_FORMAT_UNDEFINED;
    e->size = 0;
    e->data = NULL;
    return;
  }

  e->format = info->format;
  e->components = info->components;

  if(info->components == 0) {
    /* No pre-allocation */
    e->size = 0;
    e->data = NULL;
  } else {
    int hasDefault = (info->default_size && info->default_value);
    int allocSize = hasDefault ? info->default_size : (exif_format_get_size (e->format) * e->components);
    e->size = allocSize;
    e->data = exif_entry_alloc (e, e->size);
    if(!e->data) {
      clear_entry(e);
      return;
    }
    if(hasDefault) {
      memcpy(e->data, info->default_value, info->default_size);
    }
  }
}

/*!
 * \bug Log and report failed exif_mem_malloc() calls.
 */
void
exif_entry_initialize (ExifEntry *e, ExifTag tag)
{
  ExifRational r;
  ExifByteOrder o;

  if (!e || !e->parent || e->data || !e->parent->parent)
    return;
  /* We need the byte order */
  o = exif_data_get_byte_order (e->parent->parent);

  e->tag = tag;

  if(exif_entry_get_ifd(e) == EXIF_IFD_GPS) {
    exif_entry_initialize_gps(e, tag);
      return;
  }

  switch (tag) {

  /* LONG, 1 component, no default */
  case EXIF_TAG_PIXEL_X_DIMENSION:
  case EXIF_TAG_PIXEL_Y_DIMENSION:
  case EXIF_TAG_EXIF_IFD_POINTER:
  case EXIF_TAG_GPS_INFO_IFD_POINTER:
  case EXIF_TAG_INTEROPERABILITY_IFD_POINTER:
  case EXIF_TAG_JPEG_INTERCHANGE_FORMAT_LENGTH:
  case EXIF_TAG_JPEG_INTERCHANGE_FORMAT:
  case EXIF_TAG_STANDARD_OUTPUT_SENSITIVITY:
  case EXIF_TAG_RECOMMENDED_EXPOSURE_INDEX:
  case EXIF_TAG_ISO_SPEED:
  case EXIF_TAG_ISO_SPEEDLatitudeYYY:
  case EXIF_TAG_ISO_SPEEDLatitudeZZZ:
    e->components = 1;
    e->format = EXIF_FORMAT_LONG;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    break;

  /* SHORT, 1 component, no default */
  case EXIF_TAG_SUBJECT_LOCATION:
  case EXIF_TAG_SENSING_METHOD:
  case EXIF_TAG_PHOTOMETRIC_INTERPRETATION:
  case EXIF_TAG_COMPRESSION:
  case EXIF_TAG_EXPOSURE_MODE:
  case EXIF_TAG_WHITE_BALANCE:
  case EXIF_TAG_FOCAL_LENGTH_IN_35MM_FILM:
  case EXIF_TAG_GAIN_CONTROL:
  case EXIF_TAG_SUBJECT_DISTANCE_RANGE:
  case EXIF_TAG_FLASH:
  case EXIF_TAG_ISO_SPEED_RATINGS:
  case EXIF_TAG_SENSITIVITY_TYPE:
  case EXIF_TAG_COMPOSITE_IMAGE:

  /* SHORT, 1 component, default 0 */
  case EXIF_TAG_IMAGE_WIDTH:
  case EXIF_TAG_IMAGE_LENGTH:
  case EXIF_TAG_EXPOSURE_PROGRAM:
  case EXIF_TAG_LIGHT_SOURCE:
  case EXIF_TAG_METERING_MODE:
  case EXIF_TAG_CUSTOM_RENDERED:
  case EXIF_TAG_SCENE_CAPTURE_TYPE:
  case EXIF_TAG_CONTRAST:
  case EXIF_TAG_SATURATION:
  case EXIF_TAG_SHARPNESS:
    e->components = 1;
    e->format = EXIF_FORMAT_SHORT;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    exif_set_short (e->data, o, 0);
    break;

  /* SHORT, 1 component, default 1 */
  case EXIF_TAG_ORIENTATION:
  case EXIF_TAG_PLANAR_CONFIGURATION:
  case EXIF_TAG_YCBCR_POSITIONING:
    e->components = 1;
    e->format = EXIF_FORMAT_SHORT;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    exif_set_short (e->data, o, 1);
    break;

  /* SHORT, 1 component, default 2 */
  case EXIF_TAG_RESOLUTION_UNIT:
  case EXIF_TAG_FOCAL_PLANE_RESOLUTION_UNIT:
    e->components = 1;
    e->format = EXIF_FORMAT_SHORT;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    exif_set_short (e->data, o, 2);
    break;

  /* SHORT, 1 component, default 3 */
  case EXIF_TAG_SAMPLES_PER_PIXEL:
    e->components = 1;
    e->format = EXIF_FORMAT_SHORT;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    exif_set_short (e->data, o, 3);
    break;

  /* SHORT, 1 component, default 0xffff */
  case EXIF_TAG_COLOR_SPACE:
    e->components = 1;
    e->format = EXIF_FORMAT_SHORT;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    exif_set_short (e->data, o, 0xffff);
    break;

  /* SHORT, 3 components, default 8 8 8 */
  case EXIF_TAG_BITS_PER_SAMPLE:
    e->components = 3;
    e->format = EXIF_FORMAT_SHORT;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    exif_set_short (e->data, o, 8);
    exif_set_short (
      e->data + exif_format_get_size (e->format),
      o, 8);
    exif_set_short (
      e->data + 2 * exif_format_get_size (e->format),
      o, 8);
    break;

  /* SHORT, 2 components, default 0 0 */
  case EXIF_TAG_SOURCE_IMAGE_NUMBER_OF_COMPOSITE_IMAGE:
    e->components = 2;
    e->format = EXIF_FORMAT_SHORT;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    exif_set_short (e->data, o, 0);
    exif_set_short (
      e->data + exif_format_get_size (e->format),
      o, 0);
    break;

  /* SHORT, 2 components, default 2 1 */
  case EXIF_TAG_YCBCR_SUB_SAMPLING:
    e->components = 2;
    e->format = EXIF_FORMAT_SHORT;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    exif_set_short (e->data, o, 2);
    exif_set_short (
      e->data + exif_format_get_size (e->format),
      o, 1);
    break;

  /* SRATIONAL, 1 component, no default */
  case EXIF_TAG_EXPOSURE_BIAS_VALUE:
  case EXIF_TAG_BRIGHTNESS_VALUE:
  case EXIF_TAG_SHUTTER_SPEED_VALUE:
    e->components = 1;
    e->format = EXIF_FORMAT_SRATIONAL;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    break;

  /* RATIONAL, 1 component, no default */
  case EXIF_TAG_EXPOSURE_TIME:
  case EXIF_TAG_FOCAL_PLANE_X_RESOLUTION:
  case EXIF_TAG_FOCAL_PLANE_Y_RESOLUTION:
  case EXIF_TAG_EXPOSURE_INDEX:
  case EXIF_TAG_FLASH_ENERGY:
  case EXIF_TAG_FNUMBER:
  case EXIF_TAG_FOCAL_LENGTH:
  case EXIF_TAG_SUBJECT_DISTANCE:
  case EXIF_TAG_MAX_APERTURE_VALUE:
  case EXIF_TAG_APERTURE_VALUE:
  case EXIF_TAG_COMPRESSED_BITS_PER_PIXEL:
  case EXIF_TAG_PRIMARY_CHROMATICITIES:
  case EXIF_TAG_DIGITAL_ZOOM_RATIO:
  case EXIF_TAG_GAMMA:
    e->components = 1;
    e->format = EXIF_FORMAT_RATIONAL;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    break;

  /* RATIONAL, 1 component, default 72/1 */
  case EXIF_TAG_X_RESOLUTION:
  case EXIF_TAG_Y_RESOLUTION:
    e->components = 1;
    e->format = EXIF_FORMAT_RATIONAL;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    r.numerator = 72;
    r.denominator = 1;
    exif_set_rational (e->data, o, r);
    break;

  /* RATIONAL, 2 components, no default */
  case EXIF_TAG_WHITE_POINT:
    e->components = 2;
    e->format = EXIF_FORMAT_RATIONAL;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    break;

  /* RATIONAL, 4 components, no default */
  case EXIF_TAG_LENS_SPECIFICATION:
    e->components = 4;
    e->format = EXIF_FORMAT_RATIONAL;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    break;

  /* RATIONAL, 6 components */
  case EXIF_TAG_REFERENCE_BLACK_WHITE:
    e->components = 6;
    e->format = EXIF_FORMAT_RATIONAL;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    r.denominator = 1;
    r.numerator = 0;
    exif_set_rational (e->data, o, r);
    r.numerator = 255;
    exif_set_rational (
      e->data + exif_format_get_size (e->format), o, r);
    r.numerator = 0;
    exif_set_rational (
      e->data + 2 * exif_format_get_size (e->format), o, r);
    r.numerator = 255;
    exif_set_rational (
      e->data + 3 * exif_format_get_size (e->format), o, r);
    r.numerator = 0;
    exif_set_rational (
      e->data + 4 * exif_format_get_size (e->format), o, r);
    r.numerator = 255;
    exif_set_rational (
      e->data + 5 * exif_format_get_size (e->format), o, r);
    break;

  /* ASCII, 20 components */
  case EXIF_TAG_DATE_TIME:
  case EXIF_TAG_DATE_TIME_ORIGINAL:
  case EXIF_TAG_DATE_TIME_DIGITIZED:
  {
    time_t t;
#if defined(HAVE_LOCALTIME_R) || defined(HAVE_LOCALTIME_S)
    struct tm tms;
#endif
    struct tm *tm;

    t = time (NULL);
#if defined(HAVE_LOCALTIME_S)
    localtime_s (&tms, &t);
    tm = &tms;
#elif defined(HAVE_LOCALTIME_R)
    tm = localtime_r (&t, &tms);
#else
    tm = localtime (&t);
#endif
    e->components = 20;
    e->format = EXIF_FORMAT_ASCII;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    snprintf ((char *) e->data, e->size,
        "%04i:%02i:%02i %02i:%02i:%02i",
        tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
        tm->tm_hour, tm->tm_min, tm->tm_sec);
    break;
  }

  /* ASCII, no default */
  case EXIF_TAG_SUB_SEC_TIME:
  case EXIF_TAG_SUB_SEC_TIME_ORIGINAL:
  case EXIF_TAG_SUB_SEC_TIME_DIGITIZED:
  case EXIF_TAG_OFFSET_TIME:
  case EXIF_TAG_OFFSET_TIME_ORIGINAL:
  case EXIF_TAG_OFFSET_TIME_DIGITIZED:
    e->components = 0;
    e->format = EXIF_FORMAT_ASCII;
    e->size = 0;
    e->data = NULL;
    break;

  /* ASCII, default "[None]" */
  case EXIF_TAG_IMAGE_DESCRIPTION:
  case EXIF_TAG_MAKE:
  case EXIF_TAG_MODEL:
  case EXIF_TAG_SOFTWARE:
  case EXIF_TAG_ARTIST:
  case EXIF_TAG_CAMERA_OWNER_NAME:
  case EXIF_TAG_BODY_SERIAL_NUMBER:
  case EXIF_TAG_LENS_MAKE:
  case EXIF_TAG_LENS_MODEL:
  case EXIF_TAG_LENS_SERIAL_NUMBER:
    e->components = strlen (_("[None]")) + 1;
    e->format = EXIF_FORMAT_ASCII;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    strncpy ((char *)e->data, _("[None]"), e->size);
    break;
  /* ASCII, default "[None]\0[None]\0" */
  case EXIF_TAG_COPYRIGHT:
    e->components = (strlen (_("[None]")) + 1) * 2;
    e->format = EXIF_FORMAT_ASCII;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    strcpy (((char *)e->data) + 0, _("[None]"));
    strcpy (((char *)e->data) + strlen (_("[None]")) + 1, _("[None]"));
    break;

  /* UNDEFINED, 1 component, default 1 */
  case EXIF_TAG_SCENE_TYPE:
    e->components = 1;
    e->format = EXIF_FORMAT_UNDEFINED;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    e->data[0] = 0x01;
    break;

  /* UNDEFINED, 1 component, default 3 */
  case EXIF_TAG_FILE_SOURCE:
    e->components = 1;
    e->format = EXIF_FORMAT_UNDEFINED;
    e->size = exif_format_get_size (e->format) * e->components;
    e->data = exif_entry_alloc (e, e->size);
    if (!e->data) { clear_entry(e); break; }
    e->data[0] = 0x03;
    break;

  /* UNDEFINED, 4 components, default 48 49 48 48 */
        case EXIF_TAG_FLASH_PIX_VERSION:
                e->components = 4;
                e->format = EXIF_FORMAT_UNDEFINED;
                e->size = exif_format_get_size (e->format) * e->components;
                e->data = exif_entry_alloc (e, e->size);
                if (!e->data) { clear_entry(e); break; }
                memcpy (e->data, "0100", 4);
                break;

        /* UNDEFINED, 4 components, default 48 50 49 48 */
        case EXIF_TAG_EXIF_VERSION:
                e->components = 4;
                e->format = EXIF_FORMAT_UNDEFINED;
                e->size = exif_format_get_size (e->format) * e->components;
                e->data = exif_entry_alloc (e, e->size);
                if (!e->data) { clear_entry(e); break; }
                memcpy (e->data, "0210", 4);
                break;

        /* UNDEFINED, 4 components, default 1 2 3 0 */
        case EXIF_TAG_COMPONENTS_CONFIGURATION:
                e->components = 4;
                e->format = EXIF_FORMAT_UNDEFINED;
                e->size = exif_format_get_size (e->format) * e->components;
                e->data = exif_entry_alloc (e, e->size);
                if (!e->data) { clear_entry(e); break; }
    e->data[0] = 1;
    e->data[1] = 2;
    e->data[2] = 3;
    e->data[3] = 0;
                break;

  /* UNDEFINED, no components, no default */
  /* Use this if the tag is otherwise unsupported */
  case EXIF_TAG_MAKER_NOTE:
  case EXIF_TAG_USER_COMMENT:
  default:
    e->components = 0;
    e->format = EXIF_FORMAT_UNDEFINED;
    e->size = 0;
    e->data = NULL;
    break;
  }
}

Coverage Report

Created: 2025-12-01 06:39