Direction of contrast processing applied when capturing an image. (string) The allowed values are: "normal" "soft" "hard" Digital zoom ratio used when capturing an image. (double) Exposure compensation using when capturing an image in EV. (double) Exposure mode used when capturing an image. (string) The allowed values are: "auto-exposure" "manual-exposure" "auto-bracket" Type of exposure control used when capturing an image. (string) The allowed values are: "undefined" "manual" "normal" - automatically controlled "aperture-priority" - user selects aperture value "shutter-priority" - user selects shutter speed "creative" - biased towards depth of field "action" - biased towards fast shutter speed "portrait" - closeup, leaving background out of focus "landscape" - landscape photos, background in focus If flash was fired during the capture of an image. (boolean) Note that if this tag isn't present, it should not be assumed that the flash did not fire. It should be treated as unknown. The flash mode selected during the capture of an image. (string) The allowed values are: "auto" "always" "never" Focal length used when capturing an image, in mm. (double) 35 mm equivalent focal length used when capturing an image, in mm. (double) Focal ratio (f-number) used when capturing an image. (double) The value stored is the denominator of the focal ratio (f-number). For example, if this tag value is 2, the focal ratio is f/2. Gain adjustment applied to an image. (string) The allowed values are: "none" "low-gain-up" "high-gain-up" "low-gain-down" "high-gain-down" ISO speed used when capturing an image. (integer) Defines the way a camera determines the exposure. (string) The allowed values are: "unknown" "average" "center-weighted-average" "spot" "multi-spot" "pattern" "partial" "other" Direction of saturation processing applied when capturing an image. (string) The allowed values are: "normal" "low-saturation" "high-saturation" Scene mode used when capturing an image. (string) The allowed values are: "standard" "landscape" "portrait" "night-scene" Direction of sharpness processing applied when capturing an image. (string) The allowed values are: "normal" "soft" "hard" Shutter speed used when capturing an image, in seconds. (fraction) Indicates the source of capture. The device/medium used to do the capture. (string) Allowed values are: "dsc" (= digital still camera) "transparent-scanner" "reflex-scanner" "other" White balance mode used when capturing an image. (string) The allowed values are: "auto" "manual" "daylight" "cloudy" "tungsten" "fluorescent" "fluorescent h" (newer daylight-calibrated fluorescents) "flash" CDDB disc id in its short form (e.g. 'aa063d0f') CDDB disc id including all details Musicbrainz disc id (e.g. 'ahg7JUcfR3vCYBphSDIogOOWrr0-') Musicbrainz disc id details Annodex CMML clip element tag Annodex CMML head element tag Annodex CMML stream element tag ID3V2 header size considered minimum input for some functions such as gst_tag_list_from_id3v2_tag() and gst_tag_get_id3v2_tag_size() for example. Media (image/video) intended horizontal pixel density in ppi. (double) Media (image/video) intended vertical pixel density in ppi. (double) Musical key in which the sound starts. It is represented as a string with a maximum length of three characters. The ground keys are represented with "A","B","C","D","E", "F" and "G" and halfkeys represented with "b" and "#". Minor is represented as "m" (e.g. "Dbm"). Off key is represented with an "o" only. This notation might be extended in the future to support non-minor/major keys. MusicBrainz album artist ID MusicBrainz album ID MusicBrainz artist ID MusicBrainz track ID MusicBrainz track TRM ID Provides a base class for demuxing tags at the beginning or end of a stream and handles things like typefinding, querying, seeking, and different modes of operation (chain-based, pull_range-based, and providing downstream elements with random access if upstream supports that). The tag is stripped from the output, and all offsets are adjusted for the tag sizes, so that to the downstream element the stream will appear as if there was no tag at all. Also, once the tag has been parsed, GstTagDemux will try to determine the media type of the resulting stream and add a source pad with the appropriate caps in order to facilitate auto-plugging. ## Deriving from GstTagDemux Subclasses have to do four things: * In their base init function, they must add a pad template for the sink pad to the element class, describing the media type they can parse in the caps of the pad template. * In their class init function, they must override GST_TAG_DEMUX_CLASS(demux_klass)->identify_tag with their own identify function. * In their class init function, they must override GST_TAG_DEMUX_CLASS(demux_klass)->parse_tag with their own parse function. * In their class init function, they must also set GST_TAG_DEMUX_CLASS(demux_klass)->min_start_size and/or GST_TAG_DEMUX_CLASS(demux_klass)->min_end_size to the minimum size required for the identify function to decide whether the stream has a supported tag or not. A class parsing ID3v1 tags, for example, would set min_end_size to 128 bytes. parent element The #GstTagDemuxClass structure. See documentation at beginning of section for details about what subclasses need to override and do. the parent class. minimum size required to identify a tag at the start and determine its total size. Set to 0 if not interested in start tags. Subclasses should set this in their class_init function. minimum size required to identify a tag at the end and determine its total size. Set to 0 if not interested in end tags. Subclasses should set this in their class_init function. Result values from the parse_tag virtual function. cannot parse tag, just skip it call again with less or more data parsed tag successfully Type of image contained in an image tag (specified as "image-type" field in the info structure in the image's #GstSample) No image type. Can be used to tell functions such as gst_tag_image_data_to_image_sample() that no image type should be set. Undefined/other image type Cover (front) Cover (back) Leaflet page Medium (e.g. label side of CD) Lead artist/lead performer/soloist Artist/performer Conductor Band/orchestra Composer Lyricist/text writer Recording location During recording During performance Movie/video screen capture A fish as funny as the ID3v2 spec Illustration Band/artist logotype Publisher/studio logotype See http://creativecommons.org/ns for more information. making multiple copies is allowed distribution, public display and public performance are allowed distribution of derivative works is allowed commercial derivatives are allowed, but only non-commercial distribution is allowed copyright and license notices must be kept intact credit must be given to copyright holder and/or author derivative works must be licensed under the same terms or compatible terms as the original work source code (the preferred form for making modifications) must be provided when exercising some rights granted by the license derivative and combined works must be licensed under specified terms, similar to those of the original work derivative works must be licensed under specified terms, with at least the same conditions as the original work; combinations with the work may be licensed under different terms exercising rights for commercial purposes is prohibited use in a non-developing country is prohibited this license was created by the Creative Commons project this license was created by the Free Software Foundation (FSF) Provides a base class for adding tags at the beginning or end of a stream. ## Deriving from GstTagMux Subclasses have to do the following things: * In their base init function, they must add pad templates for the sink pad and the source pad to the element class, describing the media type they accept and output in the caps of the pad template. * In their class init function, they must override the GST_TAG_MUX_CLASS(mux_klass)->render_start_tag and/or GST_TAG_MUX_CLASS(mux_klass)->render_end_tag vfuncs and set up a render function. parent element The #GstTagMuxClass structure. Subclasses need to override at least one of the two render vfuncs. the parent class. This interface is implemented by elements that are able to do XMP serialization. Examples for such elements are #jifmux and #qtmux. Applications can use this interface to configure which XMP schemas should be used when serializing tags into XMP. Schemas are represented by their names, a full list of the supported schemas can be obtained from gst_tag_xmp_list_schemas(). By default, all schemas are used. Adds all available XMP schemas to the configuration. Meaning that all will be used. a #GstTagXmpWriter Adds @schema to the list schemas a #GstTagXmpWriter the schema to be added Checks if @schema is going to be used %TRUE if it is going to be used a #GstTagXmpWriter the schema to test Removes all schemas from the list of schemas to use. Meaning that no XMP will be generated. a #GstTagXmpWriter Removes a schema from the list of schemas to use. Nothing is done if the schema wasn't in the list a #GstTagXmpWriter the schema to remove Check if a given string contains a known ISO 639 language code. This is useful in situations where it's not clear whether a given string is a language code (which should be put into a #GST_TAG_LANGUAGE_CODE tag) or a free-form language name descriptor (which should be put into a #GST_TAG_LANGUAGE_NAME tag instead). TRUE if the two- or three-letter language code in @lang_code is a valid ISO-639 language code. ISO-639 language code (e.g. "deu" or "ger" or "de") 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. If not it tries to detect byte-order-mark for UTF-16/32 cases and use that. 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, WINDOWS-1252/ISO-8859-1 is assumed (which will almost always succeed). a newly-allocated string in UTF-8 encoding, or NULL string data length of string data, or -1 if the string is NUL-terminated a NULL-terminated string array of environment variable names, or NULL Looks up the GStreamer tag for a ID3v2 tag. The corresponding GStreamer tag or NULL if none exists. ID3v2 tag to convert to GStreamer tag Looks up the GStreamer tag for an ID3v2 user tag (e.g. description in TXXX frame or owner in UFID frame). The corresponding GStreamer tag or NULL if none exists. the type of ID3v2 user tag (e.g. "TXXX" or "UDIF") ID3v2 user tag to convert to GStreamer tag Looks up the GStreamer tag for a vorbiscomment tag. The corresponding GStreamer tag or NULL if none exists. vorbiscomment tag to convert to GStreamer tag Determines size of an ID3v2 tag on buffer containing at least ID3v2 header, i.e. at least #GST_TAG_ID3V2_HEADER_SIZE (10) bytes; Size of tag, or 0 if header is invalid or too small. buffer holding ID3v2 tag (or at least the start of one) Returns two-letter ISO-639-1 language code given a three-letter ISO-639-2 language code or two-letter ISO-639-1 language code (both are accepted for convenience). Language codes are case-sensitive and expected to be lower case. two-letter ISO-639-1 language code string that maps to @lang_code, or NULL if no mapping is known. The returned string must not be modified or freed. ISO-639 language code (e.g. "deu" or "ger" or "de") Returns three-letter ISO-639-2 "bibliographic" language code given a two-letter ISO-639-1 language code or a three-letter ISO-639-2 language code (both are accepted for convenience). The "bibliographic" code is derived from the English name of the language (e.g. "ger" for German instead of "de" or "deu"). In most scenarios, the "terminological" codes are prefered. Language codes are case-sensitive and expected to be lower case. three-letter ISO-639-2 language code string that maps to @lang_code, or NULL if no mapping is known. The returned string must not be modified or freed. ISO-639 language code (e.g. "deu" or "ger" or "de") Returns three-letter ISO-639-2 "terminological" language code given a two-letter ISO-639-1 language code or a three-letter ISO-639-2 language code (both are accepted for convenience). The "terminological" code is derived from the local name of the language (e.g. "deu" for German instead of "ger"). In most scenarios, the "terminological" codes are prefered over the "bibliographic" ones. Language codes are case-sensitive and expected to be lower case. three-letter ISO-639-2 language code string that maps to @lang_code, or NULL if no mapping is known. The returned string must not be modified or freed. ISO-639 language code (e.g. "deu" or "ger" or "de") Returns a list of known language codes (in form of two-letter ISO-639-1 codes). This is useful for UIs to build a list of available languages for tagging purposes (e.g. to tag an audio track appropriately in a video or audio editor). NULL-terminated string array with two-letter language codes. Free with g_strfreev() when no longer needed. Returns the name of the language given an ISO-639 language code as found in a GST_TAG_LANGUAGE_CODE tag. The name will be translated according to the current locale (if the library was built against the iso-codes package, otherwise the English name will be returned). Language codes are case-sensitive and expected to be lower case. language name in UTF-8 format, or NULL if @language_code could not be mapped to a language name. The returned string must not be modified and does not need to freed; it will stay valid until the application is terminated. two or three-letter ISO-639 language code Get the description of a license, which is a translated description of the license's main features. the description of the license, or NULL if the license is unknown or a description is not available. a license reference string in form of a URI, e.g. "http://creativecommons.org/licenses/by-nc-nd/2.0/" Get the flags of a license, which describe most of the features of a license in their most general form. the flags of the license, or 0 if the license is unknown a license reference string in form of a URI, e.g. "http://creativecommons.org/licenses/by-nc-nd/2.0/" Get the jurisdiction code of a license. This is usually a two-letter ISO 3166-1 alpha-2 code, but there is also the special case of Scotland, for which no code exists and which is thus represented as "scotland". Known jurisdictions: ar, at, au, be, bg, br, ca, ch, cl, cn, co, de, dk, es, fi, fr, hr, hu, il, in, it, jp, kr, mk, mt, mx, my, nl, pe, pl, pt, scotland, se, si, tw, uk, us, za. the jurisdiction code of the license, or NULL if the license is unknown or is not specific to a particular jurisdiction. a license reference string in form of a URI, e.g. "http://creativecommons.org/licenses/by-nc-nd/2.0/" Get the nick name of a license, which is a short (untranslated) string such as e.g. "CC BY-NC-ND 2.0 UK". the nick name of the license, or NULL if the license is unknown a license reference string in form of a URI, e.g. "http://creativecommons.org/licenses/by-nc-nd/2.0/" Get the title of a license, which is a short translated description of the license's features (generally not very pretty though). the title of the license, or NULL if the license is unknown or no title is available. a license reference string in form of a URI, e.g. "http://creativecommons.org/licenses/by-nc-nd/2.0/" Get the version of a license. the version of the license, or NULL if the license is not known or has no version a license reference string in form of a URI, e.g. "http://creativecommons.org/licenses/by-nc-nd/2.0/" Returns a list of known license references (in form of URIs). This is useful for UIs to build a list of available licenses for tagging purposes (e.g. to tag an audio track appropriately in a video or audio editor, or an image in a camera application). NULL-terminated array of license strings. Free with g_strfreev() when no longer needed. Gets the number of ID3v1 genres that can be identified. Winamp genres are included. the number of ID3v1 genres that can be identified Gets the ID3v1 genre name for a given ID. the genre or NULL if no genre is associated with that ID. ID of genre to query Helper function for tag-reading plugins to create a #GstSample suitable to add to a #GstTagList as an image tag (such as #GST_TAG_IMAGE or #GST_TAG_PREVIEW_IMAGE) from the encoded image data and an (optional) image type. Background: cover art and other images in tags are usually stored as a blob of binary image data, often accompanied by a MIME type or some other content type string (e.g. 'png', 'jpeg', 'jpg'). Sometimes there is also an 'image type' to indicate what kind of image this is (e.g. front cover, back cover, artist, etc.). The image data may also be an URI to the image rather than the image itself. In GStreamer, image tags are #GstSample<!-- -->s containing the raw image data, with the sample caps describing the content type of the image (e.g. image/jpeg, image/png, text/uri-list). The sample info may contain an additional 'image-type' field of #GST_TYPE_TAG_IMAGE_TYPE to describe the type of image (front cover, back cover etc.). #GST_TAG_PREVIEW_IMAGE tags should not carry an image type, their type is already indicated via the special tag name. This function will do various checks and typefind the encoded image data (we can't trust the declared mime type). a newly-allocated image sample for use in tag lists, or NULL the (encoded) image the length of the encoded image data at @image_data type of the image, or #GST_TAG_IMAGE_TYPE_UNDEFINED. Pass #GST_TAG_IMAGE_TYPE_NONE if no image type should be set at all (e.g. for preview images) Adds an image from an ID3 APIC frame (or similar, such as used in FLAC) to the given tag list. Also see gst_tag_image_data_to_image_sample() for more information on image tags in GStreamer. %TRUE if the image was processed, otherwise %FALSE a tag list the (encoded) image the length of the encoded image data at @image_data picture type as per the ID3 (v2.4.0) specification for the APIC frame (0 = unknown/other) Parses the IFD and IFD tags data contained in the buffer and puts it on a taglist. The base_offset is used to subtract from the offset in the tag entries and be able to get the offset relative to the buffer start The parsed taglist The exif buffer byte order of the data Offset from the tiff header to this buffer Parses the exif tags starting with a tiff header structure. The taglist The exif buffer Creates a new tag list that contains the information parsed out of a ID3 tag. A new #GstTagList with all tags that could be extracted from the given vorbiscomment buffer or NULL on error. buffer to convert Creates a new tag list that contains the information parsed out of a vorbiscomment packet. A new #GstTagList with all tags that could be extracted from the given vorbiscomment buffer or NULL on error. data to convert size of @data identification data at start of stream length of identification data pointer to a string that should take the vendor string of this vorbis comment or NULL if you don't need it. Creates a new tag list that contains the information parsed out of a vorbiscomment packet. A new #GstTagList with all tags that could be extracted from the given vorbiscomment buffer or NULL on error. buffer to convert identification data at start of stream length of identification data pointer to a string that should take the vendor string of this vorbis comment or NULL if you don't need it. Parse a xmp packet into a taglist. new taglist or %NULL, free the list when done buffer Parses the data containing an ID3v1 tag and returns a #GstTagList from the parsed data. A new tag list or NULL if the data was not an ID3v1 tag. 128 bytes of data containing the ID3v1 tag Formats the tags in taglist on exif format. The resulting buffer contains the tags IFD and is followed by the data pointed by the tag entries. A GstBuffer containing the tag entries followed by the tag data The taglist byte order used in writing (G_LITTLE_ENDIAN or G_BIG_ENDIAN) Offset from the tiff header first byte Formats the tags in taglist into exif structure, a tiff header is put in the beginning of the buffer. A GstBuffer containing the data The taglist Creates a new vorbiscomment buffer from a tag list. A new #GstBuffer containing a vorbiscomment buffer with all tags that could be converted from the given tag list. tag list to convert identification data at start of stream length of identification data, may be 0 if @id_data is NULL string that describes the vendor string or NULL Formats a taglist as a xmp packet using only the selected schemas. An empty list (%NULL) means that all schemas should be used new buffer or %NULL, unref the buffer when done tags does the container forbid inplace editing %NULL terminated array of schemas to be used on serialization 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. TRUE if the string could be parsed, otherwise FALSE an extended comment string, see #GST_TAG_EXTENDED_COMMENT return location for the comment description key, or NULL return location for the comment ISO-639 language code, or NULL return location for the actual comment string, or NULL whether to fail if strings are not in key=value form 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. Looks up the ID3v2 tag for a GStreamer tag. The corresponding ID3v2 tag or NULL if none exists. GStreamer tag to convert to vorbiscomment tag Creates a new tag list that contains the information parsed out of a vorbiscomment packet. A #GList of newly-allocated key=value strings. Free with g_list_foreach (list, (GFunc) g_free, NULL) plus g_list_free (list) a #GstTagList a GStreamer tag identifier, such as #GST_TAG_ARTIST Looks up the vorbiscomment tag for a GStreamer tag. The corresponding vorbiscomment tag or NULL if none exists. GStreamer tag to convert to vorbiscomment tag Gets the list of supported schemas in the xmp lib a %NULL terminated array of strings with the schema names Convenience function using gst_tag_from_vorbis_tag(), parsing a vorbis comment string into the right type and adding it to the given taglist @list. Unknown vorbiscomment tags will be added to the tag list in form of a #GST_TAG_EXTENDED_COMMENT. a #GstTagList a vorbiscomment tag string (key in key=value), must be valid UTF-8 a vorbiscomment value string (value in key=value), must be valid UTF-8