1 /* GStreamer non-core tag registration and tag utility functions
2 * Copyright (C) 2005 Ross Burton <ross@burtonini.com>
3 * Copyright (C) 2006-2008 Tim-Philipp Müller <tim centricular net>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
25 #include <gst/gst-i18n-plugin.h>
26 #include <gst/base/gsttypefindhelper.h>
34 * @short_description: additional tag definitions for plugins and applications
35 * @see_also: #GstTagList
39 * Contains additional standardized GStreamer tag definitions for plugins
40 * and applications, and functions to register them with the GStreamer
46 #define GST_CAT_DEFAULT gst_tag_ensure_debug_category()
48 static GstDebugCategory *
49 gst_tag_ensure_debug_category (void)
51 static gsize cat_gonce = 0;
53 if (g_once_init_enter (&cat_gonce)) {
54 GstDebugCategory *cat = NULL;
56 GST_DEBUG_CATEGORY_INIT (cat, "tag-tags", 0, "GstTag helper functions");
58 g_once_init_leave (&cat_gonce, (gsize) cat);
61 return (GstDebugCategory *) cat_gonce;
65 gst_tag_register_tags_internal (gpointer unused)
68 GST_DEBUG ("binding text domain %s to locale dir %s", GETTEXT_PACKAGE,
70 bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR);
71 bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
74 /* musicbrainz tags */
75 gst_tag_register (GST_TAG_MUSICBRAINZ_TRACKID, GST_TAG_FLAG_META,
76 G_TYPE_STRING, _("track ID"), _("MusicBrainz track ID"), NULL);
77 gst_tag_register (GST_TAG_MUSICBRAINZ_ARTISTID, GST_TAG_FLAG_META,
78 G_TYPE_STRING, _("artist ID"), _("MusicBrainz artist ID"), NULL);
79 gst_tag_register (GST_TAG_MUSICBRAINZ_ALBUMID, GST_TAG_FLAG_META,
80 G_TYPE_STRING, _("album ID"), _("MusicBrainz album ID"), NULL);
81 gst_tag_register (GST_TAG_MUSICBRAINZ_ALBUMARTISTID, GST_TAG_FLAG_META,
83 _("album artist ID"), _("MusicBrainz album artist ID"), NULL);
84 gst_tag_register (GST_TAG_MUSICBRAINZ_TRMID, GST_TAG_FLAG_META,
85 G_TYPE_STRING, _("track TRM ID"), _("MusicBrainz TRM ID"), NULL);
88 gst_tag_register (GST_TAG_CDDA_CDDB_DISCID, GST_TAG_FLAG_META,
89 G_TYPE_STRING, "discid", "CDDB discid for metadata retrieval",
90 gst_tag_merge_use_first);
92 gst_tag_register (GST_TAG_CDDA_CDDB_DISCID_FULL, GST_TAG_FLAG_META,
93 G_TYPE_STRING, "discid full",
94 "CDDB discid for metadata retrieval (full)", gst_tag_merge_use_first);
96 gst_tag_register (GST_TAG_CDDA_MUSICBRAINZ_DISCID, GST_TAG_FLAG_META,
97 G_TYPE_STRING, "musicbrainz-discid",
98 "Musicbrainz discid for metadata retrieval", gst_tag_merge_use_first);
100 gst_tag_register (GST_TAG_CDDA_MUSICBRAINZ_DISCID_FULL, GST_TAG_FLAG_META,
101 G_TYPE_STRING, "musicbrainz-discid-full",
102 "Musicbrainz discid for metadata retrieval (full)",
103 gst_tag_merge_use_first);
105 /* photography tags */
106 gst_tag_register (GST_TAG_CAPTURING_SHUTTER_SPEED, GST_TAG_FLAG_META,
107 GST_TYPE_FRACTION, _("capturing shutter speed"),
108 _("Shutter speed used when capturing an image, in seconds"), NULL);
110 gst_tag_register (GST_TAG_CAPTURING_FOCAL_RATIO, GST_TAG_FLAG_META,
111 G_TYPE_DOUBLE, _("capturing focal ratio"),
112 _("Focal ratio (f-number) used when capturing the image"), NULL);
114 gst_tag_register (GST_TAG_CAPTURING_FOCAL_LENGTH, GST_TAG_FLAG_META,
115 G_TYPE_DOUBLE, _("capturing focal length"),
116 _("Focal length of the lens used capturing the image, in mm"), NULL);
118 gst_tag_register (GST_TAG_CAPTURING_DIGITAL_ZOOM_RATIO, GST_TAG_FLAG_META,
119 G_TYPE_DOUBLE, _("capturing digital zoom ratio"),
120 _("Digital zoom ratio used when capturing an image"), NULL);
122 gst_tag_register (GST_TAG_CAPTURING_ISO_SPEED, GST_TAG_FLAG_META,
123 G_TYPE_INT, _("capturing iso speed"),
124 _("The ISO speed used when capturing an image"), NULL);
126 gst_tag_register (GST_TAG_CAPTURING_EXPOSURE_PROGRAM, GST_TAG_FLAG_META,
127 G_TYPE_STRING, _("capturing exposure program"),
128 _("The exposure program used when capturing an image"), NULL);
130 gst_tag_register (GST_TAG_CAPTURING_EXPOSURE_MODE, GST_TAG_FLAG_META,
131 G_TYPE_STRING, _("capturing exposure mode"),
132 _("The exposure mode used when capturing an image"), NULL);
134 gst_tag_register (GST_TAG_CAPTURING_SCENE_CAPTURE_TYPE, GST_TAG_FLAG_META,
135 G_TYPE_STRING, _("capturing scene capture type"),
136 _("The scene capture mode used when capturing an image"), NULL);
138 gst_tag_register (GST_TAG_CAPTURING_GAIN_ADJUSTMENT, GST_TAG_FLAG_META,
139 G_TYPE_STRING, _("capturing gain adjustment"),
140 _("The overall gain adjustment applied on an image"), NULL);
142 gst_tag_register (GST_TAG_CAPTURING_WHITE_BALANCE, GST_TAG_FLAG_META,
143 G_TYPE_STRING, _("capturing white balance"),
144 _("The white balance mode set when capturing an image"), NULL);
146 gst_tag_register (GST_TAG_CAPTURING_CONTRAST, GST_TAG_FLAG_META,
147 G_TYPE_STRING, _("capturing contrast"),
148 _("The direction of contrast processing applied "
149 "when capturing an image"), NULL);
151 gst_tag_register (GST_TAG_CAPTURING_SATURATION, GST_TAG_FLAG_META,
152 G_TYPE_STRING, _("capturing saturation"),
153 _("The direction of saturation processing applied when "
154 "capturing an image"), NULL);
156 gst_tag_register (GST_TAG_CAPTURING_FLASH_FIRED, GST_TAG_FLAG_META,
157 G_TYPE_BOOLEAN, _("capturing flash fired"),
158 _("If the flash fired while capturing and image"), NULL);
160 gst_tag_register (GST_TAG_CAPTURING_FLASH_MODE, GST_TAG_FLAG_META,
161 G_TYPE_STRING, _("capturing flash mode"),
162 _("The selected flash mode while capturing and image"), NULL);
164 gst_tag_register (GST_TAG_IMAGE_HORIZONTAL_PPI, GST_TAG_FLAG_META,
165 G_TYPE_DOUBLE, _("image horizontal ppi"),
166 _("Media (image/video) intended horizontal pixel density in ppi"), NULL);
168 gst_tag_register (GST_TAG_IMAGE_VERTICAL_PPI, GST_TAG_FLAG_META,
169 G_TYPE_DOUBLE, _("image vertical ppi"),
170 _("Media (image/video) intended vertical pixel density in ppi"), NULL);
175 /* FIXME 0.11: rename this to gst_tag_init() or gst_tag_register_tags() */
177 * gst_tag_register_musicbrainz_tags
179 * Registers additional musicbrainz-specific tags with the GStreamer tag
180 * system. Plugins and applications that use these tags should call this
181 * function before using them. Can be called multiple times.
184 gst_tag_register_musicbrainz_tags (void)
186 static GOnce mb_once = G_ONCE_INIT;
188 g_once (&mb_once, gst_tag_register_tags_internal, NULL);
192 register_tag_image_type_enum (GType * id)
194 static const GEnumValue image_types[] = {
195 {GST_TAG_IMAGE_TYPE_NONE, "GST_TAG_IMAGE_TYPE_NONE", "none"},
196 {GST_TAG_IMAGE_TYPE_UNDEFINED, "GST_TAG_IMAGE_TYPE_UNDEFINED", "undefined"},
197 {GST_TAG_IMAGE_TYPE_FRONT_COVER, "GST_TAG_IMAGE_TYPE_FRONT_COVER",
199 {GST_TAG_IMAGE_TYPE_BACK_COVER, "GST_TAG_IMAGE_TYPE_BACK_COVER",
201 {GST_TAG_IMAGE_TYPE_LEAFLET_PAGE, "GST_TAG_IMAGE_TYPE_LEAFLET_PAGE",
203 {GST_TAG_IMAGE_TYPE_MEDIUM, "GST_TAG_IMAGE_TYPE_MEDIUM", "medium"},
204 {GST_TAG_IMAGE_TYPE_LEAD_ARTIST, "GST_TAG_IMAGE_TYPE_LEAD_ARTIST",
206 {GST_TAG_IMAGE_TYPE_ARTIST, "GST_TAG_IMAGE_TYPE_ARTIST", "artist"},
207 {GST_TAG_IMAGE_TYPE_CONDUCTOR, "GST_TAG_IMAGE_TYPE_CONDUCTOR", "conductor"},
208 {GST_TAG_IMAGE_TYPE_BAND_ORCHESTRA, "GST_TAG_IMAGE_TYPE_BAND_ORCHESTRA",
210 {GST_TAG_IMAGE_TYPE_COMPOSER, "GST_TAG_IMAGE_TYPE_COMPOSER", "composer"},
211 {GST_TAG_IMAGE_TYPE_LYRICIST, "GST_TAG_IMAGE_TYPE_LYRICIST", "lyricist"},
212 {GST_TAG_IMAGE_TYPE_RECORDING_LOCATION,
213 "GST_TAG_IMAGE_TYPE_RECORDING_LOCATION",
214 "recording-location"},
215 {GST_TAG_IMAGE_TYPE_DURING_RECORDING, "GST_TAG_IMAGE_TYPE_DURING_RECORDING",
217 {GST_TAG_IMAGE_TYPE_DURING_PERFORMANCE,
218 "GST_TAG_IMAGE_TYPE_DURING_PERFORMANCE",
219 "during-performance"},
220 {GST_TAG_IMAGE_TYPE_VIDEO_CAPTURE, "GST_TAG_IMAGE_TYPE_VIDEO_CAPTURE",
222 {GST_TAG_IMAGE_TYPE_FISH, "GST_TAG_IMAGE_TYPE_FISH", "fish"},
223 {GST_TAG_IMAGE_TYPE_ILLUSTRATION, "GST_TAG_IMAGE_TYPE_ILLUSTRATION",
225 {GST_TAG_IMAGE_TYPE_BAND_ARTIST_LOGO, "GST_TAG_IMAGE_TYPE_BAND_ARTIST_LOGO",
227 {GST_TAG_IMAGE_TYPE_PUBLISHER_STUDIO_LOGO,
228 "GST_TAG_IMAGE_TYPE_PUBLISHER_STUDIO_LOGO",
229 "publisher-studio-logo"},
233 *id = g_enum_register_static ("GstTagImageType", image_types);
235 /* work around thread-safety issue with class creation in GLib */
236 g_type_class_ref (*id);
240 gst_tag_image_type_get_type (void)
244 static GOnce once = G_ONCE_INIT;
246 g_once (&once, (GThreadFunc) register_tag_image_type_enum, &id);
250 static inline gboolean
251 gst_tag_image_type_is_valid (GstTagImageType type)
257 klass = g_type_class_ref (gst_tag_image_type_get_type ());
258 res = (g_enum_get_value (klass, type) != NULL);
259 g_type_class_unref (klass);
265 * gst_tag_parse_extended_comment:
266 * @ext_comment: an extended comment string, see #GST_TAG_EXTENDED_COMMENT
267 * @key: return location for the comment description key, or NULL
268 * @lang: return location for the comment ISO-639 language code, or NULL
269 * @value: return location for the actual comment string, or NULL
270 * @fail_if_no_key: whether to fail if strings are not in key=value form
272 * Convenience function to parse a GST_TAG_EXTENDED_COMMENT string and
273 * separate it into its components.
275 * If successful, @key, @lang and/or @value will be set to newly allocated
276 * strings that you need to free with g_free() when done. @key and @lang
277 * may also be set to NULL by this function if there is no key or no language
278 * code in the extended comment string.
280 * Returns: TRUE if the string could be parsed, otherwise FALSE
285 gst_tag_parse_extended_comment (const gchar * ext_comment, gchar ** key,
286 gchar ** lang, gchar ** value, gboolean fail_if_no_key)
288 const gchar *div, *bop, *bcl;
290 g_return_val_if_fail (ext_comment != NULL, FALSE);
291 g_return_val_if_fail (g_utf8_validate (ext_comment, -1, NULL), FALSE);
298 div = strchr (ext_comment, '=');
299 bop = strchr (ext_comment, '[');
300 bcl = strchr (ext_comment, ']');
306 *value = g_strdup (ext_comment);
310 if (bop != NULL && bop < div) {
311 if (bcl < bop || bcl > div)
314 *key = g_strndup (ext_comment, bop - ext_comment);
316 *lang = g_strndup (bop + 1, bcl - bop - 1);
319 *key = g_strndup (ext_comment, div - ext_comment);
323 *value = g_strdup (div + 1);
329 * gst_tag_freeform_string_to_utf8:
331 * @size: length of string data, or -1 if the string is NUL-terminated
332 * @env_vars: a NULL-terminated string array of environment variable names,
335 * Convenience function to read a string with unknown character encoding. If
336 * the string is already in UTF-8 encoding, it will be returned right away.
337 * If not it tries to detect byte-order-mark for UTF-16/32 cases and use that.
338 * Otherwise, the environment will be searched for a number of environment
339 * variables (whose names are specified in the NULL-terminated string array
340 * @env_vars) containing a list of character encodings to try/use. If none
341 * are specified, the current locale will be tried. If that also doesn't work,
342 * WINDOWS-1252/ISO-8859-1 is assumed (which will almost always succeed).
344 * Returns: a newly-allocated string in UTF-8 encoding, or NULL
349 gst_tag_freeform_string_to_utf8 (const gchar * data, gint size,
350 const gchar ** env_vars)
352 const gchar *cur_loc = NULL;
358 g_return_val_if_fail (data != NULL, NULL);
361 size = strlen (data);
363 /* chop off trailing string terminators to make sure utf8_validate doesn't
364 * get to see them (since that would make the utf8 check fail) */
365 while (size > 0 && data[size - 1] == '\0')
368 /* Should we try the charsets specified
369 * via environment variables FIRST ? */
370 if (g_utf8_validate (data, size, NULL)) {
371 utf8 = g_strndup (data, size);
372 GST_LOG ("String '%s' is valid UTF-8 already", utf8);
376 /* check for and use byte-order-mark for UTF-16/32 cases */
378 const gchar *c = NULL;
383 ssize = GST_ROUND_DOWN_4 (size - 4);
384 switch (GST_READ_UINT32_BE (data)) {
397 ssize = GST_ROUND_DOWN_2 (size - 2);
398 switch (GST_READ_UINT16_BE (data)) {
410 GST_LOG ("Trying to convert freeform string to UTF-8 from '%s'", c);
412 g_convert (data + prefix, ssize, "UTF-8", c, &bytes_read, NULL,
414 if (bytes_read == ssize)
422 while (env_vars && *env_vars != NULL) {
423 const gchar *env = NULL;
425 /* Try charsets specified via the environment */
426 env = g_getenv (*env_vars);
427 if (env != NULL && *env != '\0') {
430 csets = g_strsplit (env, G_SEARCHPATH_SEPARATOR_S, -1);
432 for (c = csets; c && *c; ++c) {
433 GST_LOG ("Trying to convert freeform string to UTF-8 from '%s'", *c);
435 g_convert (data, size, "UTF-8", *c, &bytes_read, NULL, NULL))) {
436 if (bytes_read == size) {
450 /* Try current locale (if not UTF-8) */
451 if (!g_get_charset (&cur_loc)) {
452 GST_LOG ("Trying to convert freeform string using locale ('%s')", cur_loc);
453 if ((utf8 = g_locale_to_utf8 (data, size, &bytes_read, NULL, NULL))) {
454 if (bytes_read == size) {
462 /* Try Windows-1252 (which is a superset of ISO 8859-1 that uses a control
463 * character range in ISO 8859-1 for more printable characters) */
467 GST_LOG ("Trying to convert freeform string using Windows-1252/ISO-8859-1 "
469 utf8 = g_convert (data, size, "UTF-8", "WINDOWS-1252", &bytes_read, NULL,
472 /* fallback in case iconv implementation doesn't support windows-1252
474 if (err->code == G_CONVERT_ERROR_NO_CONVERSION) {
475 utf8 = g_convert (data, size, "UTF-8", "ISO-8859-1", &bytes_read,
481 if (utf8 != NULL && bytes_read == size)
491 if (utf8 && utf8[0] != '\0') {
492 GST_LOG ("Returning '%s'", utf8);
501 * gst_tag_image_data_to_image_buffer:
502 * @image_data: the (encoded) image
503 * @image_data_len: the length of the encoded image data at @image_data
504 * @image_type: type of the image, or #GST_TAG_IMAGE_TYPE_UNDEFINED. Pass
505 * #GST_TAG_IMAGE_TYPE_NONE if no image type should be set at all (e.g.
506 * for preview images)
508 * Helper function for tag-reading plugins to create a #GstBuffer suitable to
509 * add to a #GstTagList as an image tag (such as #GST_TAG_IMAGE or
510 * #GST_TAG_PREVIEW_IMAGE) from the encoded image data and an (optional) image
513 * Background: cover art and other images in tags are usually stored as a
514 * blob of binary image data, often accompanied by a MIME type or some other
515 * content type string (e.g. 'png', 'jpeg', 'jpg'). Sometimes there is also an
516 * 'image type' to indicate what kind of image this is (e.g. front cover,
517 * back cover, artist, etc.). The image data may also be an URI to the image
518 * rather than the image itself.
520 * In GStreamer, image tags are #GstBuffer<!-- -->s containing the raw image
521 * data, with the buffer caps describing the content type of the image
522 * (e.g. image/jpeg, image/png, text/uri-list). The buffer caps may contain
523 * an additional 'image-type' field of #GST_TYPE_TAG_IMAGE_TYPE to describe
524 * the type of image (front cover, back cover etc.). #GST_TAG_PREVIEW_IMAGE
525 * tags should not carry an image type, their type is already indicated via
526 * the special tag name.
528 * This function will do various checks and typefind the encoded image
529 * data (we can't trust the declared mime type).
531 * Returns: a newly-allocated image buffer for use in tag lists, or NULL
536 gst_tag_image_data_to_image_buffer (const guint8 * image_data,
537 guint image_data_len, GstTagImageType image_type)
545 g_return_val_if_fail (image_data != NULL, NULL);
546 g_return_val_if_fail (image_data_len > 0, NULL);
547 g_return_val_if_fail (gst_tag_image_type_is_valid (image_type), NULL);
549 GST_DEBUG ("image data len: %u bytes", image_data_len);
551 /* allocate space for a NUL terminator for an uri too */
552 image = gst_buffer_try_new_and_alloc (image_data_len + 1);
554 GST_WARNING ("failed to allocate buffer of %d for image", image_data_len);
558 memcpy (GST_BUFFER_DATA (image), image_data, image_data_len);
559 GST_BUFFER_DATA (image)[image_data_len] = '\0';
561 /* Find GStreamer media type, can't trust declared type */
562 caps = gst_type_find_helper_for_buffer (NULL, image, NULL);
567 GST_DEBUG ("Found GStreamer media type: %" GST_PTR_FORMAT, caps);
569 /* sanity check: make sure typefound/declared caps are either URI or image */
570 name = gst_structure_get_name (gst_caps_get_structure (caps, 0));
572 if (!g_str_has_prefix (name, "image/") &&
573 !g_str_has_prefix (name, "video/") &&
574 !g_str_equal (name, "text/uri-list")) {
575 GST_DEBUG ("Unexpected image type '%s', ignoring image frame", name);
579 /* Decrease size by 1 if we don't have an URI list
580 * to keep the original size of the image
582 if (!g_str_equal (name, "text/uri-list"))
583 GST_BUFFER_SIZE (image) = image_data_len;
585 if (image_type != GST_TAG_IMAGE_TYPE_NONE) {
586 GST_LOG ("Setting image type: %d", image_type);
587 caps = gst_caps_make_writable (caps);
588 gst_caps_set_simple (caps, "image-type", GST_TYPE_TAG_IMAGE_TYPE,
592 gst_buffer_set_caps (image, caps);
593 gst_caps_unref (caps);
599 GST_DEBUG ("Could not determine GStreamer media type, ignoring image");
605 gst_buffer_unref (image);
607 gst_caps_unref (caps);