gstreamer/ext/metadata/metadataexif.c

/*
 * GStreamer
 * Copyright 2007 Edgard Lima <edgard.lima@indt.org.br>
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Alternatively, the contents of this file may be used under the
 * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
 * which case the following provisions apply instead of the ones
 * mentioned above:
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * SECTION: metadataexif
 * @short_description: This module provides functions to extract tags from
 * EXIF metadata chunks and create EXIF chunks from metadata tags.
 * @see_also: #metadatatags.[c/h]
 *
 * If libexif isn't available at compilation time, only the whole chunk
 * (#METADATA_TAG_MAP_WHOLECHUNK) tags is created. It means that individual
 * tags aren't mapped.
 *
 * Last reviewed on 2008-01-24 (0.10.15)
 */

/*
 * includes
 */

#include "metadataexif.h"
#include "metadataparseutil.h"
#include "metadatatags.h"

/*
 * defines
 */

GST_DEBUG_CATEGORY (gst_metadata_exif_debug);
#define GST_CAT_DEFAULT gst_metadata_exif_debug

/*
 * Implementation when libexif isn't available at compilation time
 */

#ifndef HAVE_EXIF

/*
 * extern functions implementations
 */


void
metadataparse_exif_tag_list_add (GstTagList * taglist, GstTagMergeMode mode,
    GstAdapter * adapter, MetadataTagMapping mapping)
{

  if (mapping & METADATA_TAG_MAP_WHOLECHUNK) {
    GST_LOG ("EXIF not defined, sending just one tag as whole chunk");
    metadataparse_util_tag_list_add_chunk (taglist, mode, GST_TAG_EXIF,
        adapter);
  }

}

void
metadatamux_exif_create_chunk_from_tag_list (guint8 ** buf, guint32 * size,
    const GstTagList * taglist)
{
  /* do nothing */
}

#else /* ifndef HAVE_EXIF */

/*
 * Implementation when libexif is available at compilation time
 */

/*
 * includes
 */

#include <libexif/exif-data.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

/*
 * enum and types
 */

typedef struct _tag_MEUserData
{
  GstTagList *taglist;
  GstTagMergeMode mode;
  ExifShort resolution_unit;    /* 2- inches (default), 3- cm */
} MEUserData;

typedef struct _tag_MapIntStr
{
  ExifTag exif;
  ExifIfd ifd;
  const gchar *str;
} MapIntStr;

/*
 * defines and static global vars
 */

/* *INDENT-OFF* */
static MapIntStr mappedTags[] = {
  {EXIF_TAG_MAKE,               /*ASCII,*/     EXIF_IFD_0,
   GST_TAG_DEVICE_MAKE,              /*STRING*/},
  {EXIF_TAG_MODEL,              /*ASCII,*/     EXIF_IFD_0,
   GST_TAG_DEVICE_MODEL,             /*STRING*/},
  {EXIF_TAG_SOFTWARE,           /*ASCII,*/     EXIF_IFD_0,
   GST_TAG_CREATOR_TOOL,             /*STRING*/},
  {EXIF_TAG_X_RESOLUTION,       /*RATIONAL,*/  EXIF_IFD_0,
   GST_TAG_IMAGE_XRESOLUTION,        /*FRACTION*/},   /* inches */
  {EXIF_TAG_Y_RESOLUTION,       /*RATIONAL,*/  EXIF_IFD_0,
   GST_TAG_IMAGE_YRESOLUTION,        /*FRACTION*/},   /* inches */
  {EXIF_TAG_EXPOSURE_TIME,      /*RATIONAL,*/  EXIF_IFD_EXIF,
   GST_TAG_CAPTURE_EXPOSURE_TIME,    /*FRACTION*/},
  {EXIF_TAG_FNUMBER,            /*RATIONAL,*/  EXIF_IFD_EXIF,
   GST_TAG_CAPTURE_FNUMBER,          /*FRACTION*/},
  {EXIF_TAG_EXPOSURE_PROGRAM,   /*SHORT,*/     EXIF_IFD_EXIF,
   GST_TAG_CAPTURE_EXPOSURE_PROGRAM, /*UINT*/},
  {EXIF_TAG_BRIGHTNESS_VALUE,   /*SRATIONAL,*/ EXIF_IFD_0,
   GST_TAG_CAPTURE_BRIGHTNESS,       /*FRACTION*/},
  {EXIF_TAG_WHITE_BALANCE,      /*SHORT,*/     EXIF_IFD_0,
   GST_TAG_CAPTURE_WHITE_BALANCE,    /*UINT*/},
  {EXIF_TAG_DIGITAL_ZOOM_RATIO, /*RATIONAL,*/  EXIF_IFD_0,
   GST_TAG_CAPTURE_DIGITAL_ZOOM,     /*FRACTION*/},
  {EXIF_TAG_GAIN_CONTROL,       /*SHORT,*/     EXIF_IFD_0,
   GST_TAG_CAPTURE_GAIN,             /*UINT*/},
  {EXIF_TAG_CONTRAST,           /*SHORT,*/     EXIF_IFD_0,
   GST_TAG_CAPTURE_CONTRAST,         /*INT*/},
  {EXIF_TAG_SATURATION,         /*SHORT,*/     EXIF_IFD_0,
   GST_TAG_CAPTURE_SATURATION,       /*INT*/},
  {0, EXIF_IFD_COUNT, NULL}
};
/* *INDENT-ON* */

/*
 * static helper functions declaration
 */

static const gchar *metadataparse_exif_get_tag_from_exif (ExifTag exif,
    GType * type);

static ExifTag
metadatamux_exif_get_exif_from_tag (const gchar * tag, GType * type,
    ExifIfd * ifd);

static void
metadataparse_exif_data_foreach_content_func (ExifContent * content,
    void *callback_data);

static void
metadataparse_exif_content_foreach_entry_func (ExifEntry * entry,
    void *user_data);

static void
metadatamux_exif_for_each_tag_in_list (const GstTagList * list,
    const gchar * tag, gpointer user_data);

/*
 * extern functions implementations
 */

/*
 * metadataparse_exif_tag_list_add:
 * @taglist: tag list in which extracted tags will be added
 * @mode: tag list merge mode
 * @adapter: contains the EXIF metadata chunk
 * @mapping: if is to extract individual tags and/or the whole chunk.
 * 
 * This function gets a EXIF chunk (@adapter) and extract tags from it 
 * and the add to @taglist.
 * Note: The EXIF chunk (@adapetr) must NOT be wrapped by any bytes specific
 * to any file format
 *
 * Returns: nothing
 */

void
metadataparse_exif_tag_list_add (GstTagList * taglist, GstTagMergeMode mode,
    GstAdapter * adapter, MetadataTagMapping mapping)
{
  const guint8 *buf;
  guint32 size;
  ExifData *exif = NULL;
  MEUserData user_data = { taglist, mode, 2 };

  if (adapter == NULL || (size = gst_adapter_available (adapter)) == 0) {
    goto done;
  }

  /* add chunk tag */
  if (mapping & METADATA_TAG_MAP_WHOLECHUNK)
    metadataparse_util_tag_list_add_chunk (taglist, mode, GST_TAG_EXIF,
        adapter);

  if (!(mapping & METADATA_TAG_MAP_INDIVIDUALS))
    goto done;

  buf = gst_adapter_peek (adapter, size);

  exif = exif_data_new_from_data (buf, size);
  if (exif == NULL) {
    goto done;
  }

  exif_data_foreach_content (exif,
      metadataparse_exif_data_foreach_content_func, (void *) &user_data);

done:

  if (exif)
    exif_data_unref (exif);

  return;

}

/*
 * metadatamux_exif_create_chunk_from_tag_list:
 * @buf: buffer that will have the created EXIF chunk
 * @size: size of the buffer that will be created
 * @taglist: list of tags to be added to EXIF chunk
 *
 * Get tags from @taglist, create a EXIF chunk based on it and save to @buf.
 * Note: The EXIF chunk is NOT wrapped by any bytes specific to any file format
 *
 * Returns: nothing
 */

void
metadatamux_exif_create_chunk_from_tag_list (guint8 ** buf, guint32 * size,
    const GstTagList * taglist)
{
  ExifData *ed = NULL;
  GstBuffer *exif_chunk = NULL;
  const GValue *val = NULL;

  if (!(buf && size))
    goto done;
  if (*buf) {
    g_free (*buf);
    *buf = NULL;
  }
  *size = 0;

  val = gst_tag_list_get_value_index (taglist, GST_TAG_EXIF, 0);
  if (val) {
    exif_chunk = gst_value_get_buffer (val);
    if (exif_chunk) {
      ed = exif_data_new_from_data (GST_BUFFER_DATA (exif_chunk),
          GST_BUFFER_SIZE (exif_chunk));
    }
  }

  if (!ed) {
    ed = exif_data_new ();
    exif_data_set_data_type (ed, EXIF_DATA_TYPE_COMPRESSED);
    exif_data_fix (ed);
  }

  gst_tag_list_foreach (taglist, metadatamux_exif_for_each_tag_in_list, ed);

  exif_data_save_data (ed, buf, size);


done:

  if (ed)
    exif_data_unref (ed);

  return;
}


/*
 * static helper functions implementation
 */

/*
 * metadataparse_exif_get_tag_from_exif:
 * @exif: EXIF tag to look for
 * @type: the type of the GStreamer tag mapped to @exif
 *
 * This returns the GStreamer tag mapped to an EXIF tag.
 *
 * Returns:
 * <itemizedlist>
 * <listitem><para>The GStreamer tag mapped to the @exif
 * </para></listitem>
 * <listitem><para>%NULL if there is no mapped GST tag for @exif
 * </para></listitem>
 * </itemizedlist>
 */

static const gchar *
metadataparse_exif_get_tag_from_exif (ExifTag exif, GType * type)
{
  int i = 0;

  while (mappedTags[i].exif) {
    if (exif == mappedTags[i].exif) {
      *type = gst_tag_get_type (mappedTags[i].str);
      break;
    }
    ++i;
  }

  return mappedTags[i].str;

}

/*
 * metadatamux_exif_get_exif_from_tag:
 * @tag: GST tag to look for
 * @type: the type of the GStreamer @tag
 * @ifd: the place into EXIF chunk @exif belongs to.
 *
 * This returns thet EXIF tag mapped to an GStreamer @tag.
 *
 * Returns:
 * <itemizedlist>
 * <listitem><para>The EXIF tag mapped to the GST @tag
 * </para></listitem>
 * <listitem><para>0 if there is no mapped EXIF tag for GST @tag
 * </para></listitem>
 * </itemizedlist>
 */

static ExifTag
metadatamux_exif_get_exif_from_tag (const gchar * tag, GType * type,
    ExifIfd * ifd)
{
  int i = 0;

  while (mappedTags[i].exif) {
    if (0 == strcmp (mappedTags[i].str, tag)) {
      *type = gst_tag_get_type (tag);
      *ifd = mappedTags[i].ifd;
      break;
    }
    ++i;
  }

  return mappedTags[i].exif;

}

/*
 * metadataparse_exif_data_foreach_content_func:
 * @content: EXIF structure from libexif containg a IFD
 * @user_data: pointer to #MEUserData
 *
 * This function designed to be called for each EXIF IFD in a EXIF chunk. This
 * function gets calls another function for each tag into @content. Then all
 * tags into a EXIF chunk can be extracted to a tag list in @user_data.
 * @see_also: #metadataparse_exif_tag_list_add
 * #metadataparse_exif_content_foreach_entry_func
 *
 * Returns: nothing
 */

static void
metadataparse_exif_data_foreach_content_func (ExifContent * content,
    void *user_data)
{
  ExifIfd ifd = exif_content_get_ifd (content);

  GST_LOG ("\n  Content %p: %s (ifd=%d)", content, exif_ifd_get_name (ifd),
      ifd);
  exif_content_foreach_entry (content,
      metadataparse_exif_content_foreach_entry_func, user_data);
}

/*
 * metadataparse_exif_content_foreach_entry_func:
 * @entry: EXIF structure from libexif having a EXIF tag
 * @user_data: pointer to #MEUserData
 *
 * This function designed to be called for each EXIF tag in a EXIF IFD. This
 * function gets the EXIF tag from @entry and then add to the tag list
 * in @user_data by using a merge mode also specified in @user_data
 * @see_also: #metadataparse_exif_data_foreach_content_func
 *
 * Returns: nothing
 */

static void
metadataparse_exif_content_foreach_entry_func (ExifEntry * entry,
    void *user_data)
{
  char buf[2048];
  MEUserData *meudata = (MEUserData *) user_data;
  GType type;
  ExifByteOrder byte_order;
  const gchar *tag = metadataparse_exif_get_tag_from_exif (entry->tag, &type);

  /* We need the byte order */
  if (!entry || !entry->parent || !entry->parent->parent)
    return;
  byte_order = exif_data_get_byte_order (entry->parent->parent);

  if (entry->tag == EXIF_TAG_RESOLUTION_UNIT) {
    meudata->resolution_unit = exif_get_short (entry->data, byte_order);
    if (meudata->resolution_unit == 3) {
      /* if [xy]resolution has alredy been add in cm, replace it in inches */
      gfloat value;

      if (gst_tag_list_get_float (meudata->taglist, GST_TAG_IMAGE_XRESOLUTION,
              &value))
        gst_tag_list_add (meudata->taglist, GST_TAG_MERGE_REPLACE,
            GST_TAG_IMAGE_XRESOLUTION, value * 0.4f, NULL);
      if (gst_tag_list_get_float (meudata->taglist, GST_TAG_IMAGE_YRESOLUTION,
              &value))
        gst_tag_list_add (meudata->taglist, GST_TAG_MERGE_REPLACE,
            GST_TAG_IMAGE_YRESOLUTION, value * 0.4f, NULL);
    }
    goto done;
  }

  if (!tag)
    goto done;

  if (type == GST_TYPE_FRACTION) {
    gint numerator = 0;
    gint denominator = 1;

    switch (entry->format) {
      case EXIF_FORMAT_SRATIONAL:
      {
        ExifSRational v_srat;

        v_srat = exif_get_srational (entry->data, byte_order);
        if (v_srat.denominator) {
          numerator = (gint) v_srat.numerator;
          denominator = (gint) v_srat.denominator;
        }
      }
        break;
      case EXIF_FORMAT_RATIONAL:
      {
        ExifRational v_rat;

        v_rat = exif_get_rational (entry->data, byte_order);
        if (v_rat.denominator) {
          numerator = (gint) v_rat.numerator;
          denominator = (gint) v_rat.denominator;
        }
        if (meudata->resolution_unit == 3) {
          /* converts from cm to inches */
          if (entry->tag == EXIF_TAG_X_RESOLUTION
              || entry->tag == EXIF_TAG_Y_RESOLUTION) {
            numerator *= 2;
            denominator *= 5;
          }
        }
      }
        break;
      default:
        GST_ERROR ("Unexpected Tag Type");
        goto done;
        break;
    }
    gst_tag_list_add (meudata->taglist, meudata->mode, tag, numerator,
        denominator, NULL);

  } else {

    switch (type) {
      case G_TYPE_STRING:
        gst_tag_list_add (meudata->taglist, meudata->mode, tag,
            exif_entry_get_value (entry, buf, sizeof (buf)), NULL);
        break;
      case G_TYPE_INT:
        /* fall through */
      case G_TYPE_UINT:
      {
        gint value;

        switch (entry->format) {
          case EXIF_FORMAT_SHORT:
            value = exif_get_short (entry->data, byte_order);
            break;
          default:
            GST_ERROR ("Unexpected Exif Tag Type (%s - %s)",
                tag, exif_format_get_name (entry->format));
            goto done;
            break;
        }
        if (entry->tag == EXIF_TAG_CONTRAST ||
            entry->tag == EXIF_TAG_SATURATION) {
          switch (value) {
            case 0:
              break;
            case 1:
              value = -67;      /* -100-34 /2 */
              break;
            case 2:
              value = 67;       /* 100+34 /2 */
              break;
            default:
              GST_ERROR ("Unexpected value");
              break;
          }
        }
        gst_tag_list_add (meudata->taglist, meudata->mode, tag, value, NULL);
      }
        break;
      default:
        break;
    }

  }


done:

  GST_LOG ("\n    Entry %p: %s (%s)\n"
      "      Size, Comps: %d, %d\n"
      "      Value: %s\n"
      "      Title: %s\n"
      "      Description: %s\n",
      entry,
      exif_tag_get_name (entry->tag),
      exif_format_get_name (entry->format),
      entry->size,
      (int) (entry->components),
      exif_entry_get_value (entry, buf, sizeof (buf)),
      exif_tag_get_title (entry->tag), exif_tag_get_description (entry->tag));

  return;

}

/*
 * metadatamux_exif_for_each_tag_in_list:
 * @list: GStreamer tag list from which @tag belongs to
 * @tag: GStreamer tag to be added to the EXIF chunk
 * @user_data: pointer to #ExifData in which the tag will be added
 *
 * This function designed to be called for each tag in GST tag list. This
 * function adds get the tag value from tag @list and then add it to the EXIF
 * chunk by using #ExifData and related functions from libexif
 * @see_also: #metadatamux_exif_create_chunk_from_tag_list
 *
 * Returns: nothing
 */

static void
metadatamux_exif_for_each_tag_in_list (const GstTagList * list,
    const gchar * tag, gpointer user_data)
{
  ExifData *ed = (ExifData *) user_data;
  ExifTag exif_tag;
  GType type;
  ExifEntry *entry = NULL;
  ExifIfd ifd;
  const ExifByteOrder byte_order = exif_data_get_byte_order (ed);

  exif_tag = metadatamux_exif_get_exif_from_tag (tag, &type, &ifd);

  if (!exif_tag)
    goto done;

  entry = exif_data_get_entry (ed, exif_tag);

  if (entry)
    exif_entry_ref (entry);
  else {
    entry = exif_entry_new ();
    exif_content_add_entry (ed->ifd[ifd], entry);
    exif_entry_initialize (entry, exif_tag);
  }

  if (type == GST_TYPE_FRACTION) {
    const GValue *gvalue = gst_tag_list_get_value_index (list, tag, 0);
    gint numerator = gst_value_get_fraction_numerator (gvalue);
    gint denominator = gst_value_get_fraction_denominator (gvalue);

    switch (entry->format) {
      case EXIF_FORMAT_SRATIONAL:
      {
        ExifSRational sr = { numerator, denominator };

        exif_set_srational (entry->data, byte_order, sr);
      }
        break;
      case EXIF_FORMAT_RATIONAL:
      {
        ExifRational r = { numerator, denominator };

        exif_set_rational (entry->data, byte_order, r);
        if (entry->tag == EXIF_TAG_X_RESOLUTION ||
            entry->tag == EXIF_TAG_Y_RESOLUTION) {
          ExifEntry *unit_entry = NULL;

          unit_entry = exif_data_get_entry (ed, EXIF_TAG_RESOLUTION_UNIT);

          if (unit_entry) {
            ExifShort vsh = exif_get_short (unit_entry->data, byte_order);

            if (vsh != 2)       /* inches */
              exif_set_short (unit_entry->data, byte_order, 2);
          }
        }
      }
        break;
      default:
        break;
    }
  } else {

    switch (type) {
      case G_TYPE_STRING:
      {
        gchar *value = NULL;

        if (gst_tag_list_get_string (list, tag, &value)) {
          entry->components = strlen (value) + 1;
          entry->size =
              exif_format_get_size (entry->format) * entry->components;
          entry->data = value;
        }
      }
        break;
      case G_TYPE_UINT:
      case G_TYPE_INT:
      {
        gint value;
        ExifShort v_short;

        if (G_TYPE_UINT == type) {
          gst_tag_list_get_uint (list, tag, &value);
        } else {
          gst_tag_list_get_int (list, tag, &value);
        }
        if (entry->tag == EXIF_TAG_CONTRAST
            || entry->tag == EXIF_TAG_SATURATION) {
          if (value < -33)
            value = 1;          /* low */
          else if (value < 34)
            value = 0;          /* normal */
          else
            value = 2;          /* high */
        }
        v_short = value;
        exif_set_short (entry->data, byte_order, v_short);
      }
        break;
      default:
        break;
    }
  }

done:

  if (entry)
    exif_entry_unref (entry);

}


#endif /* else (ifndef HAVE_EXIF) */