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 #ifndef GST_DISABLE_GST_DEBUG
47 #define GST_CAT_DEFAULT gst_tag_ensure_debug_category()
49 static GstDebugCategory *
50 gst_tag_ensure_debug_category (void)
52 static gsize cat_gonce = 0;
54 if (g_once_init_enter (&cat_gonce)) {
55 GstDebugCategory *cat = NULL;
57 GST_DEBUG_CATEGORY_INIT (cat, "tag-tags", 0, "GstTag helper functions");
59 g_once_init_leave (&cat_gonce, (gsize) cat);
62 return (GstDebugCategory *) cat_gonce;
64 #endif /* GST_DISABLE_GST_DEBUG */
67 gst_tag_register_tags_internal (gpointer unused)
70 GST_DEBUG ("binding text domain %s to locale dir %s", GETTEXT_PACKAGE,
72 bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR);
73 bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8");
76 /* musicbrainz tags */
77 gst_tag_register (GST_TAG_MUSICBRAINZ_TRACKID, GST_TAG_FLAG_META,
78 G_TYPE_STRING, _("track ID"), _("MusicBrainz track ID"), NULL);
79 gst_tag_register (GST_TAG_MUSICBRAINZ_ARTISTID, GST_TAG_FLAG_META,
80 G_TYPE_STRING, _("artist ID"), _("MusicBrainz artist ID"), NULL);
81 gst_tag_register (GST_TAG_MUSICBRAINZ_ALBUMID, GST_TAG_FLAG_META,
82 G_TYPE_STRING, _("album ID"), _("MusicBrainz album ID"), NULL);
83 gst_tag_register (GST_TAG_MUSICBRAINZ_ALBUMARTISTID, GST_TAG_FLAG_META,
85 _("album artist ID"), _("MusicBrainz album artist ID"), NULL);
86 gst_tag_register (GST_TAG_MUSICBRAINZ_TRMID, GST_TAG_FLAG_META,
87 G_TYPE_STRING, _("track TRM ID"), _("MusicBrainz TRM ID"), NULL);
90 gst_tag_register (GST_TAG_CDDA_CDDB_DISCID, GST_TAG_FLAG_META,
91 G_TYPE_STRING, "discid", "CDDB discid for metadata retrieval",
92 gst_tag_merge_use_first);
94 gst_tag_register (GST_TAG_CDDA_CDDB_DISCID_FULL, GST_TAG_FLAG_META,
95 G_TYPE_STRING, "discid full",
96 "CDDB discid for metadata retrieval (full)", gst_tag_merge_use_first);
98 gst_tag_register (GST_TAG_CDDA_MUSICBRAINZ_DISCID, GST_TAG_FLAG_META,
99 G_TYPE_STRING, "musicbrainz-discid",
100 "Musicbrainz discid for metadata retrieval", gst_tag_merge_use_first);
102 gst_tag_register (GST_TAG_CDDA_MUSICBRAINZ_DISCID_FULL, GST_TAG_FLAG_META,
103 G_TYPE_STRING, "musicbrainz-discid-full",
104 "Musicbrainz discid for metadata retrieval (full)",
105 gst_tag_merge_use_first);
107 /* photography tags */
108 gst_tag_register (GST_TAG_CAPTURING_SHUTTER_SPEED, GST_TAG_FLAG_META,
109 GST_TYPE_FRACTION, _("capturing shutter speed"),
110 _("Shutter speed used when capturing an image, in seconds"), NULL);
112 gst_tag_register (GST_TAG_CAPTURING_FOCAL_RATIO, GST_TAG_FLAG_META,
113 G_TYPE_DOUBLE, _("capturing focal ratio"),
114 _("Focal ratio (f-number) used when capturing the image"), NULL);
116 gst_tag_register (GST_TAG_CAPTURING_FOCAL_LENGTH, GST_TAG_FLAG_META,
117 G_TYPE_DOUBLE, _("capturing focal length"),
118 _("Focal length of the lens used capturing the image, in mm"), NULL);
120 gst_tag_register (GST_TAG_CAPTURING_DIGITAL_ZOOM_RATIO, GST_TAG_FLAG_META,
121 G_TYPE_DOUBLE, _("capturing digital zoom ratio"),
122 _("Digital zoom ratio used when capturing an image"), NULL);
124 gst_tag_register (GST_TAG_CAPTURING_ISO_SPEED, GST_TAG_FLAG_META,
125 G_TYPE_INT, _("capturing iso speed"),
126 _("The ISO speed used when capturing an image"), NULL);
128 gst_tag_register (GST_TAG_CAPTURING_EXPOSURE_PROGRAM, GST_TAG_FLAG_META,
129 G_TYPE_STRING, _("capturing exposure program"),
130 _("The exposure program used when capturing an image"), NULL);
132 gst_tag_register (GST_TAG_CAPTURING_EXPOSURE_MODE, GST_TAG_FLAG_META,
133 G_TYPE_STRING, _("capturing exposure mode"),
134 _("The exposure mode used when capturing an image"), NULL);
136 gst_tag_register (GST_TAG_CAPTURING_SCENE_CAPTURE_TYPE, GST_TAG_FLAG_META,
137 G_TYPE_STRING, _("capturing scene capture type"),
138 _("The scene capture mode used when capturing an image"), NULL);
140 gst_tag_register (GST_TAG_CAPTURING_GAIN_ADJUSTMENT, GST_TAG_FLAG_META,
141 G_TYPE_STRING, _("capturing gain adjustment"),
142 _("The overall gain adjustment applied on an image"), NULL);
144 gst_tag_register (GST_TAG_CAPTURING_WHITE_BALANCE, GST_TAG_FLAG_META,
145 G_TYPE_STRING, _("capturing white balance"),
146 _("The white balance mode set when capturing an image"), NULL);
148 gst_tag_register (GST_TAG_CAPTURING_CONTRAST, GST_TAG_FLAG_META,
149 G_TYPE_STRING, _("capturing contrast"),
150 _("The direction of contrast processing applied "
151 "when capturing an image"), NULL);
153 gst_tag_register (GST_TAG_CAPTURING_SATURATION, GST_TAG_FLAG_META,
154 G_TYPE_STRING, _("capturing saturation"),
155 _("The direction of saturation processing applied when "
156 "capturing an image"), NULL);
158 gst_tag_register (GST_TAG_CAPTURING_FLASH_FIRED, GST_TAG_FLAG_META,
159 G_TYPE_BOOLEAN, _("capturing flash fired"),
160 _("If the flash fired while capturing and image"), NULL);
162 gst_tag_register (GST_TAG_CAPTURING_FLASH_MODE, GST_TAG_FLAG_META,
163 G_TYPE_STRING, _("capturing flash mode"),
164 _("The selected flash mode while capturing and image"), NULL);
166 gst_tag_register (GST_TAG_IMAGE_HORIZONTAL_PPI, GST_TAG_FLAG_META,
167 G_TYPE_DOUBLE, _("image horizontal ppi"),
168 _("Media (image/video) intended horizontal pixel density in ppi"), NULL);
170 gst_tag_register (GST_TAG_IMAGE_VERTICAL_PPI, GST_TAG_FLAG_META,
171 G_TYPE_DOUBLE, _("image vertical ppi"),
172 _("Media (image/video) intended vertical pixel density in ppi"), NULL);
177 /* FIXME 0.11: rename this to gst_tag_init() or gst_tag_register_tags() */
179 * gst_tag_register_musicbrainz_tags
181 * Registers additional musicbrainz-specific tags with the GStreamer tag
182 * system. Plugins and applications that use these tags should call this
183 * function before using them. Can be called multiple times.
186 gst_tag_register_musicbrainz_tags (void)
188 static GOnce mb_once = G_ONCE_INIT;
190 g_once (&mb_once, gst_tag_register_tags_internal, NULL);
194 register_tag_image_type_enum (GType * id)
196 static const GEnumValue image_types[] = {
197 {GST_TAG_IMAGE_TYPE_NONE, "GST_TAG_IMAGE_TYPE_NONE", "none"},
198 {GST_TAG_IMAGE_TYPE_UNDEFINED, "GST_TAG_IMAGE_TYPE_UNDEFINED", "undefined"},
199 {GST_TAG_IMAGE_TYPE_FRONT_COVER, "GST_TAG_IMAGE_TYPE_FRONT_COVER",
201 {GST_TAG_IMAGE_TYPE_BACK_COVER, "GST_TAG_IMAGE_TYPE_BACK_COVER",
203 {GST_TAG_IMAGE_TYPE_LEAFLET_PAGE, "GST_TAG_IMAGE_TYPE_LEAFLET_PAGE",
205 {GST_TAG_IMAGE_TYPE_MEDIUM, "GST_TAG_IMAGE_TYPE_MEDIUM", "medium"},
206 {GST_TAG_IMAGE_TYPE_LEAD_ARTIST, "GST_TAG_IMAGE_TYPE_LEAD_ARTIST",
208 {GST_TAG_IMAGE_TYPE_ARTIST, "GST_TAG_IMAGE_TYPE_ARTIST", "artist"},
209 {GST_TAG_IMAGE_TYPE_CONDUCTOR, "GST_TAG_IMAGE_TYPE_CONDUCTOR", "conductor"},
210 {GST_TAG_IMAGE_TYPE_BAND_ORCHESTRA, "GST_TAG_IMAGE_TYPE_BAND_ORCHESTRA",
212 {GST_TAG_IMAGE_TYPE_COMPOSER, "GST_TAG_IMAGE_TYPE_COMPOSER", "composer"},
213 {GST_TAG_IMAGE_TYPE_LYRICIST, "GST_TAG_IMAGE_TYPE_LYRICIST", "lyricist"},
214 {GST_TAG_IMAGE_TYPE_RECORDING_LOCATION,
215 "GST_TAG_IMAGE_TYPE_RECORDING_LOCATION",
216 "recording-location"},
217 {GST_TAG_IMAGE_TYPE_DURING_RECORDING, "GST_TAG_IMAGE_TYPE_DURING_RECORDING",
219 {GST_TAG_IMAGE_TYPE_DURING_PERFORMANCE,
220 "GST_TAG_IMAGE_TYPE_DURING_PERFORMANCE",
221 "during-performance"},
222 {GST_TAG_IMAGE_TYPE_VIDEO_CAPTURE, "GST_TAG_IMAGE_TYPE_VIDEO_CAPTURE",
224 {GST_TAG_IMAGE_TYPE_FISH, "GST_TAG_IMAGE_TYPE_FISH", "fish"},
225 {GST_TAG_IMAGE_TYPE_ILLUSTRATION, "GST_TAG_IMAGE_TYPE_ILLUSTRATION",
227 {GST_TAG_IMAGE_TYPE_BAND_ARTIST_LOGO, "GST_TAG_IMAGE_TYPE_BAND_ARTIST_LOGO",
229 {GST_TAG_IMAGE_TYPE_PUBLISHER_STUDIO_LOGO,
230 "GST_TAG_IMAGE_TYPE_PUBLISHER_STUDIO_LOGO",
231 "publisher-studio-logo"},
235 *id = g_enum_register_static ("GstTagImageType", image_types);
237 /* work around thread-safety issue with class creation in GLib */
238 g_type_class_ref (*id);
242 gst_tag_image_type_get_type (void)
246 static GOnce once = G_ONCE_INIT;
248 g_once (&once, (GThreadFunc) register_tag_image_type_enum, &id);
252 static inline gboolean
253 gst_tag_image_type_is_valid (GstTagImageType type)
259 klass = g_type_class_ref (gst_tag_image_type_get_type ());
260 res = (g_enum_get_value (klass, type) != NULL);
261 g_type_class_unref (klass);
267 * gst_tag_parse_extended_comment:
268 * @ext_comment: an extended comment string, see #GST_TAG_EXTENDED_COMMENT
269 * @key: return location for the comment description key, or NULL
270 * @lang: return location for the comment ISO-639 language code, or NULL
271 * @value: return location for the actual comment string, or NULL
272 * @fail_if_no_key: whether to fail if strings are not in key=value form
274 * Convenience function to parse a GST_TAG_EXTENDED_COMMENT string and
275 * separate it into its components.
277 * If successful, @key, @lang and/or @value will be set to newly allocated
278 * strings that you need to free with g_free() when done. @key and @lang
279 * may also be set to NULL by this function if there is no key or no language
280 * code in the extended comment string.
282 * Returns: TRUE if the string could be parsed, otherwise FALSE
287 gst_tag_parse_extended_comment (const gchar * ext_comment, gchar ** key,
288 gchar ** lang, gchar ** value, gboolean fail_if_no_key)
290 const gchar *div, *bop, *bcl;
292 g_return_val_if_fail (ext_comment != NULL, FALSE);
293 g_return_val_if_fail (g_utf8_validate (ext_comment, -1, NULL), FALSE);
300 div = strchr (ext_comment, '=');
301 bop = strchr (ext_comment, '[');
302 bcl = strchr (ext_comment, ']');
308 *value = g_strdup (ext_comment);
312 if (bop != NULL && bop < div) {
313 if (bcl < bop || bcl > div)
316 *key = g_strndup (ext_comment, bop - ext_comment);
318 *lang = g_strndup (bop + 1, bcl - bop - 1);
321 *key = g_strndup (ext_comment, div - ext_comment);
325 *value = g_strdup (div + 1);
331 * gst_tag_freeform_string_to_utf8:
333 * @size: length of string data, or -1 if the string is NUL-terminated
334 * @env_vars: a NULL-terminated string array of environment variable names,
337 * Convenience function to read a string with unknown character encoding. If
338 * the string is already in UTF-8 encoding, it will be returned right away.
339 * If not it tries to detect byte-order-mark for UTF-16/32 cases and use that.
340 * Otherwise, the environment will be searched for a number of environment
341 * variables (whose names are specified in the NULL-terminated string array
342 * @env_vars) containing a list of character encodings to try/use. If none
343 * are specified, the current locale will be tried. If that also doesn't work,
344 * WINDOWS-1252/ISO-8859-1 is assumed (which will almost always succeed).
346 * Returns: a newly-allocated string in UTF-8 encoding, or NULL
351 gst_tag_freeform_string_to_utf8 (const gchar * data, gint size,
352 const gchar ** env_vars)
354 const gchar *cur_loc = NULL;
360 g_return_val_if_fail (data != NULL, NULL);
363 size = strlen (data);
365 /* chop off trailing string terminators to make sure utf8_validate doesn't
366 * get to see them (since that would make the utf8 check fail) */
367 while (size > 0 && data[size - 1] == '\0')
370 /* Should we try the charsets specified
371 * via environment variables FIRST ? */
372 if (g_utf8_validate (data, size, NULL)) {
373 utf8 = g_strndup (data, size);
374 GST_LOG ("String '%s' is valid UTF-8 already", utf8);
378 /* check for and use byte-order-mark for UTF-16/32 cases */
380 const gchar *c = NULL;
385 ssize = GST_ROUND_DOWN_4 (size - 4);
386 switch (GST_READ_UINT32_BE (data)) {
399 ssize = GST_ROUND_DOWN_2 (size - 2);
400 switch (GST_READ_UINT16_BE (data)) {
412 GST_LOG ("Trying to convert freeform string to UTF-8 from '%s'", c);
414 g_convert (data + prefix, ssize, "UTF-8", c, &bytes_read, NULL,
416 if (bytes_read == ssize)
424 while (env_vars && *env_vars != NULL) {
425 const gchar *env = NULL;
427 /* Try charsets specified via the environment */
428 env = g_getenv (*env_vars);
429 if (env != NULL && *env != '\0') {
432 csets = g_strsplit (env, G_SEARCHPATH_SEPARATOR_S, -1);
434 for (c = csets; c && *c; ++c) {
435 GST_LOG ("Trying to convert freeform string to UTF-8 from '%s'", *c);
437 g_convert (data, size, "UTF-8", *c, &bytes_read, NULL, NULL))) {
438 if (bytes_read == size) {
452 /* Try current locale (if not UTF-8) */
453 if (!g_get_charset (&cur_loc)) {
454 GST_LOG ("Trying to convert freeform string using locale ('%s')", cur_loc);
455 if ((utf8 = g_locale_to_utf8 (data, size, &bytes_read, NULL, NULL))) {
456 if (bytes_read == size) {
464 /* Try Windows-1252 (which is a superset of ISO 8859-1 that uses a control
465 * character range in ISO 8859-1 for more printable characters) */
469 GST_LOG ("Trying to convert freeform string using Windows-1252/ISO-8859-1 "
471 utf8 = g_convert (data, size, "UTF-8", "WINDOWS-1252", &bytes_read, NULL,
474 /* fallback in case iconv implementation doesn't support windows-1252
476 if (err->code == G_CONVERT_ERROR_NO_CONVERSION) {
477 utf8 = g_convert (data, size, "UTF-8", "ISO-8859-1", &bytes_read,
483 if (utf8 != NULL && bytes_read == size)
493 if (utf8 && utf8[0] != '\0') {
494 GST_LOG ("Returning '%s'", utf8);
503 * gst_tag_image_data_to_image_buffer:
504 * @image_data: the (encoded) image
505 * @image_data_len: the length of the encoded image data at @image_data
506 * @image_type: type of the image, or #GST_TAG_IMAGE_TYPE_UNDEFINED. Pass
507 * #GST_TAG_IMAGE_TYPE_NONE if no image type should be set at all (e.g.
508 * for preview images)
510 * Helper function for tag-reading plugins to create a #GstBuffer suitable to
511 * add to a #GstTagList as an image tag (such as #GST_TAG_IMAGE or
512 * #GST_TAG_PREVIEW_IMAGE) from the encoded image data and an (optional) image
515 * Background: cover art and other images in tags are usually stored as a
516 * blob of binary image data, often accompanied by a MIME type or some other
517 * content type string (e.g. 'png', 'jpeg', 'jpg'). Sometimes there is also an
518 * 'image type' to indicate what kind of image this is (e.g. front cover,
519 * back cover, artist, etc.). The image data may also be an URI to the image
520 * rather than the image itself.
522 * In GStreamer, image tags are #GstBuffer<!-- -->s containing the raw image
523 * data, with the buffer caps describing the content type of the image
524 * (e.g. image/jpeg, image/png, text/uri-list). The buffer caps may contain
525 * an additional 'image-type' field of #GST_TYPE_TAG_IMAGE_TYPE to describe
526 * the type of image (front cover, back cover etc.). #GST_TAG_PREVIEW_IMAGE
527 * tags should not carry an image type, their type is already indicated via
528 * the special tag name.
530 * This function will do various checks and typefind the encoded image
531 * data (we can't trust the declared mime type).
533 * Returns: a newly-allocated image buffer for use in tag lists, or NULL
538 gst_tag_image_data_to_image_buffer (const guint8 * image_data,
539 guint image_data_len, GstTagImageType image_type)
547 g_return_val_if_fail (image_data != NULL, NULL);
548 g_return_val_if_fail (image_data_len > 0, NULL);
549 g_return_val_if_fail (gst_tag_image_type_is_valid (image_type), NULL);
551 GST_DEBUG ("image data len: %u bytes", image_data_len);
553 /* allocate space for a NUL terminator for an uri too */
554 image = gst_buffer_try_new_and_alloc (image_data_len + 1);
556 GST_WARNING ("failed to allocate buffer of %d for image", image_data_len);
560 memcpy (GST_BUFFER_DATA (image), image_data, image_data_len);
561 GST_BUFFER_DATA (image)[image_data_len] = '\0';
563 /* Find GStreamer media type, can't trust declared type */
564 caps = gst_type_find_helper_for_buffer (NULL, image, NULL);
569 GST_DEBUG ("Found GStreamer media type: %" GST_PTR_FORMAT, caps);
571 /* sanity check: make sure typefound/declared caps are either URI or image */
572 name = gst_structure_get_name (gst_caps_get_structure (caps, 0));
574 if (!g_str_has_prefix (name, "image/") &&
575 !g_str_has_prefix (name, "video/") &&
576 !g_str_equal (name, "text/uri-list")) {
577 GST_DEBUG ("Unexpected image type '%s', ignoring image frame", name);
581 /* Decrease size by 1 if we don't have an URI list
582 * to keep the original size of the image
584 if (!g_str_equal (name, "text/uri-list"))
585 GST_BUFFER_SIZE (image) = image_data_len;
587 if (image_type != GST_TAG_IMAGE_TYPE_NONE) {
588 GST_LOG ("Setting image type: %d", image_type);
589 caps = gst_caps_make_writable (caps);
590 gst_caps_set_simple (caps, "image-type", GST_TYPE_TAG_IMAGE_TYPE,
594 gst_buffer_set_caps (image, caps);
595 gst_caps_unref (caps);
601 GST_DEBUG ("Could not determine GStreamer media type, ignoring image");
607 gst_buffer_unref (image);
609 gst_caps_unref (caps);