--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gst_plugins_base/gst-libs/gst/tag/tags.c	Thu Dec 17 08:53:32 2009 +0200
@@ -0,0 +1,348 @@
+/* GStreamer non-core tag registration and tag utility functions
+ * Copyright (C) 2005 Ross Burton <ross@burtonini.com>
+ * Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifndef __SYMBIAN32__
+#include <gst/gst-i18n-plugin.h>
+#else
+#include "gst/gst-i18n-plugin.h"
+#endif
+#include <gst/gst.h>
+#include "tag.h"
+
+#include <string.h>
+
+/**
+ * SECTION:gsttag
+ * @short_description: additional tag definitions for plugins and applications
+ * @see_also: #GstTagList
+ * 
+ * <refsect2>
+ * <para>
+ * Contains additional standardized GStreamer tag definitions for plugins
+ * and applications, and functions to register them with the GStreamer
+ * tag system.
+ * </para>
+ * </refsect2>
+ */
+
+
+static gpointer
+gst_tag_register_tags_internal (gpointer unused)
+{
+#ifdef ENABLE_NLS
+  GST_DEBUG ("binding text domain %s to locale dir %s", GETTEXT_PACKAGE,
+      LOCALEDIR);
+  bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR);
+#endif
+
+  /* musicbrainz tags */
+  gst_tag_register (GST_TAG_MUSICBRAINZ_TRACKID, GST_TAG_FLAG_META,
+      G_TYPE_STRING, _("track ID"), _("MusicBrainz track ID"), NULL);
+  gst_tag_register (GST_TAG_MUSICBRAINZ_ARTISTID, GST_TAG_FLAG_META,
+      G_TYPE_STRING, _("artist ID"), _("MusicBrainz artist ID"), NULL);
+  gst_tag_register (GST_TAG_MUSICBRAINZ_ALBUMID, GST_TAG_FLAG_META,
+      G_TYPE_STRING, _("album ID"), _("MusicBrainz album ID"), NULL);
+  gst_tag_register (GST_TAG_MUSICBRAINZ_ALBUMARTISTID, GST_TAG_FLAG_META,
+      G_TYPE_STRING,
+      _("album artist ID"), _("MusicBrainz album artist ID"), NULL);
+  gst_tag_register (GST_TAG_MUSICBRAINZ_TRMID, GST_TAG_FLAG_META,
+      G_TYPE_STRING, _("track TRM ID"), _("MusicBrainz TRM ID"), NULL);
+
+  /* CDDA tags */
+  gst_tag_register (GST_TAG_CDDA_CDDB_DISCID, GST_TAG_FLAG_META,
+      G_TYPE_STRING, "discid", "CDDB discid for metadata retrieval",
+      gst_tag_merge_use_first);
+
+  gst_tag_register (GST_TAG_CDDA_CDDB_DISCID_FULL, GST_TAG_FLAG_META,
+      G_TYPE_STRING, "discid full",
+      "CDDB discid for metadata retrieval (full)", gst_tag_merge_use_first);
+
+  gst_tag_register (GST_TAG_CDDA_MUSICBRAINZ_DISCID, GST_TAG_FLAG_META,
+      G_TYPE_STRING, "musicbrainz-discid",
+      "Musicbrainz discid for metadata retrieval", gst_tag_merge_use_first);
+
+  gst_tag_register (GST_TAG_CDDA_MUSICBRAINZ_DISCID_FULL, GST_TAG_FLAG_META,
+      G_TYPE_STRING, "musicbrainz-discid-full",
+      "Musicbrainz discid for metadata retrieval (full)",
+      gst_tag_merge_use_first);
+
+  return NULL;
+}
+
+/* FIXME 0.11: rename this to gst_tag_init() or gst_tag_register_tags() */
+/**
+ * gst_tag_register_musicbrainz_tags
+ *
+ * Registers additional musicbrainz-specific tags with the GStreamer tag
+ * system. Plugins and applications that use these tags should call this
+ * function before using them. Can be called multiple times.
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+void
+gst_tag_register_musicbrainz_tags (void)
+{
+  static GOnce mb_once = G_ONCE_INIT;
+
+  g_once (&mb_once, gst_tag_register_tags_internal, NULL);
+}
+
+static void
+register_tag_image_type_enum (GType * id)
+{
+  static const GEnumValue image_types[] = {
+    {GST_TAG_IMAGE_TYPE_UNDEFINED, "GST_TAG_IMAGE_TYPE_UNDEFINED", "undefined"},
+    {GST_TAG_IMAGE_TYPE_FRONT_COVER, "GST_TAG_IMAGE_TYPE_FRONT_COVER",
+        "front-cover"},
+    {GST_TAG_IMAGE_TYPE_BACK_COVER, "GST_TAG_IMAGE_TYPE_BACK_COVER",
+        "back-cover"},
+    {GST_TAG_IMAGE_TYPE_LEAFLET_PAGE, "GST_TAG_IMAGE_TYPE_LEAFLET_PAGE",
+        "leaflet-page"},
+    {GST_TAG_IMAGE_TYPE_MEDIUM, "GST_TAG_IMAGE_TYPE_MEDIUM", "medium"},
+    {GST_TAG_IMAGE_TYPE_LEAD_ARTIST, "GST_TAG_IMAGE_TYPE_LEAD_ARTIST",
+        "lead-artist"},
+    {GST_TAG_IMAGE_TYPE_ARTIST, "GST_TAG_IMAGE_TYPE_ARTIST", "artist"},
+    {GST_TAG_IMAGE_TYPE_CONDUCTOR, "GST_TAG_IMAGE_TYPE_CONDUCTOR", "conductor"},
+    {GST_TAG_IMAGE_TYPE_BAND_ORCHESTRA, "GST_TAG_IMAGE_TYPE_BAND_ORCHESTRA",
+        "band-orchestra"},
+    {GST_TAG_IMAGE_TYPE_COMPOSER, "GST_TAG_IMAGE_TYPE_COMPOSER", "composer"},
+    {GST_TAG_IMAGE_TYPE_LYRICIST, "GST_TAG_IMAGE_TYPE_LYRICIST", "lyricist"},
+    {GST_TAG_IMAGE_TYPE_RECORDING_LOCATION,
+          "GST_TAG_IMAGE_TYPE_RECORDING_LOCATION",
+        "recording-location"},
+    {GST_TAG_IMAGE_TYPE_DURING_RECORDING, "GST_TAG_IMAGE_TYPE_DURING_RECORDING",
+        "during-recording"},
+    {GST_TAG_IMAGE_TYPE_DURING_PERFORMANCE,
+          "GST_TAG_IMAGE_TYPE_DURING_PERFORMANCE",
+        "during-performance"},
+    {GST_TAG_IMAGE_TYPE_VIDEO_CAPTURE, "GST_TAG_IMAGE_TYPE_VIDEO_CAPTURE",
+        "video-capture"},
+    {GST_TAG_IMAGE_TYPE_FISH, "GST_TAG_IMAGE_TYPE_FISH", "fish"},
+    {GST_TAG_IMAGE_TYPE_ILLUSTRATION, "GST_TAG_IMAGE_TYPE_ILLUSTRATION",
+        "illustration"},
+    {GST_TAG_IMAGE_TYPE_BAND_ARTIST_LOGO, "GST_TAG_IMAGE_TYPE_BAND_ARTIST_LOGO",
+        "artist-logo"},
+    {GST_TAG_IMAGE_TYPE_PUBLISHER_STUDIO_LOGO,
+          "GST_TAG_IMAGE_TYPE_PUBLISHER_STUDIO_LOGO",
+        "publisher-studio-logo"},
+    {0, NULL, NULL}
+  };
+
+  *id = g_enum_register_static ("GstTagImageType", image_types);
+}
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+
+GType
+gst_tag_image_type_get_type (void)
+{
+  static GType id;
+  static GOnce once = G_ONCE_INIT;
+
+  g_once (&once, (GThreadFunc) register_tag_image_type_enum, &id);
+  return id;
+}
+
+/**
+ * gst_tag_parse_extended_comment:
+ * @ext_comment: an extended comment string, see #GST_TAG_EXTENDED_COMMENT
+ * @key: return location for the comment description key, or NULL
+ * @lang: return location for the comment ISO-639 language code, or NULL
+ * @value: return location for the actual comment string, or NULL
+ * @fail_if_no_key: whether to fail if strings are not in key=value form
+ *
+ * Convenience function to parse a GST_TAG_EXTENDED_COMMENT string and
+ * separate it into its components.
+ *
+ * If successful, @key, @lang and/or @value will be set to newly allocated
+ * strings that you need to free with g_free() when done. @key and @lang
+ * may also be set to NULL by this function if there is no key or no language
+ * code in the extended comment string.
+ *
+ * Returns: TRUE if the string could be parsed, otherwise FALSE
+ *
+ * Since: 0.10.10
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gboolean
+gst_tag_parse_extended_comment (const gchar * ext_comment, gchar ** key,
+    gchar ** lang, gchar ** value, gboolean fail_if_no_key)
+{
+  const gchar *div, *bop, *bcl;
+
+  g_return_val_if_fail (ext_comment != NULL, FALSE);
+  g_return_val_if_fail (g_utf8_validate (ext_comment, -1, NULL), FALSE);
+
+  if (key)
+    *key = NULL;
+  if (lang)
+    *lang = NULL;
+
+  div = strchr (ext_comment, '=');
+  bop = strchr (ext_comment, '[');
+  bcl = strchr (ext_comment, ']');
+
+  if (div == NULL) {
+    if (fail_if_no_key)
+      return FALSE;
+    if (value)
+      *value = g_strdup (ext_comment);
+    return TRUE;
+  }
+
+  if (bop != NULL && bop < div) {
+    if (bcl < bop || bcl > div)
+      return FALSE;
+    if (key)
+      *key = g_strndup (ext_comment, bop - ext_comment);
+    if (lang)
+      *lang = g_strndup (bop + 1, bcl - bop - 1);
+  } else {
+    if (key)
+      *key = g_strndup (ext_comment, div - ext_comment);
+  }
+
+  if (value)
+    *value = g_strdup (div + 1);
+
+  return TRUE;
+}
+
+/**
+ * gst_tag_freeform_string_to_utf8:
+ * @data: string data
+ * @size: length of string data, or -1 if the string is NUL-terminated
+ * @env_vars: a NULL-terminated string array of environment variable names,
+ *            or NULL
+ *
+ * Convenience function to read a string with unknown character encoding. If
+ * the string is already in UTF-8 encoding, it will be returned right away.
+ * Otherwise, the environment will be searched for a number of environment
+ * variables (whose names are specified in the NULL-terminated string array
+ * @env_vars) containing a list of character encodings to try/use. If none
+ * are specified, the current locale will be tried. If that also doesn't work,
+ * ISO-8859-1 is assumed (which will almost always succeed).
+ *
+ * Returns: a newly-allocated string in UTF-8 encoding, or NULL
+ *
+ * Since: 0.10.13
+ */
+#ifdef __SYMBIAN32__
+EXPORT_C
+#endif
+
+gchar *
+gst_tag_freeform_string_to_utf8 (const gchar * data, gint size,
+    const gchar ** env_vars)
+{
+  const gchar *cur_loc = NULL;
+  gsize bytes_read;
+  gchar *utf8 = NULL;
+
+  g_return_val_if_fail (data != NULL, NULL);
+
+  if (size < 0)
+    size = strlen (data);
+
+  /* chop off trailing string terminators to make sure utf8_validate doesn't
+   * get to see them (since that would make the utf8 check fail) */
+  while (size > 0 && data[size - 1] == '\0')
+    --size;
+
+  /* Should we try the charsets specified
+   * via environment variables FIRST ? */
+  if (g_utf8_validate (data, size, NULL)) {
+    utf8 = g_strndup (data, size);
+    GST_LOG ("String '%s' is valid UTF-8 already", utf8);
+    goto beach;
+  }
+
+  while (env_vars && *env_vars != NULL) {
+    const gchar *env = NULL;
+
+    /* Try charsets specified via the environment */
+    env = g_getenv (*env_vars);
+    if (env != NULL && *env != '\0') {
+      gchar **c, **csets;
+
+      csets = g_strsplit (env, G_SEARCHPATH_SEPARATOR_S, -1);
+
+      for (c = csets; c && *c; ++c) {
+        GST_LOG ("Trying to convert freeform string to UTF-8 from '%s'", *c);
+        if ((utf8 =
+                g_convert (data, size, "UTF-8", *c, &bytes_read, NULL, NULL))) {
+          if (bytes_read == size) {
+            g_strfreev (csets);
+            goto beach;
+          }
+          g_free (utf8);
+          utf8 = NULL;
+        }
+      }
+
+      g_strfreev (csets);
+    }
+    ++env_vars;
+  }
+
+  /* Try current locale (if not UTF-8) */
+  if (!g_get_charset (&cur_loc)) {
+    GST_LOG ("Trying to convert freeform string using locale ('%s')", cur_loc);
+    if ((utf8 = g_locale_to_utf8 (data, size, &bytes_read, NULL, NULL))) {
+      if (bytes_read == size) {
+        goto beach;
+      }
+      g_free (utf8);
+      utf8 = NULL;
+    }
+  }
+
+  /* Try ISO-8859-1 */
+  GST_LOG ("Trying to convert freeform string using ISO-8859-1 fallback");
+  utf8 = g_convert (data, size, "UTF-8", "ISO-8859-1", &bytes_read, NULL, NULL);
+  if (utf8 != NULL && bytes_read == size) {
+    goto beach;
+  }
+
+  g_free (utf8);
+  return NULL;
+
+beach:
+
+  g_strchomp (utf8);
+  if (utf8 && utf8[0] != '\0') {
+    GST_LOG ("Returning '%s'", utf8);
+    return utf8;
+  }
+
+  g_free (utf8);
+  return NULL;
+}