gst.types

A function that will be called from [gst.buffer.Buffer.foreachMeta]. The meta field will point to a the reference of the meta.

buffer should not be modified from this callback.

When this function returns true, the next meta will be returned. When false is returned, [gst.buffer.Buffer.foreachMeta] will return.

When meta is set to null, the item will be removed from the buffer.

A function that will be called from [gst.buffer_list.BufferList.foreach_]. The buffer field will point to a the reference of the buffer at idx.

When this function returns true, the next buffer will be returned. When false is returned, [gst.buffer_list.BufferList.foreach_] will return.

When buffer is set to null, the item will be removed from the bufferlist. When buffer has been made writable, the new buffer reference can be assigned to buffer. This function is responsible for unreffing the old buffer when removing or modifying.

Specifies the type of function passed to [gst.bus.Bus.addWatch] or [gst.bus.Bus.addWatchFull], which is called from the mainloop when a message is available on the bus.

The message passed to the function will be unreffed after execution of this function so it should not be freed in the function.

Note that this function is used as a #GSourceFunc which means that returning false will remove the #GSource from the mainloop.

Handler will be invoked synchronously, when a new message has been injected into the bus. This function is mostly used internally. Only one sync handler can be attached to a given bus.

If the handler returns [gst.types.BusSyncReply.Drop], it should unref the message, else the message should not be unreffed by the sync handler.

A function that will be called in [gst.caps.Caps.filterAndMapInPlace]. The function may modify features and structure, and both will be removed from the caps if false is returned.

A function that will be called in [gst.caps.Caps.foreach_]. The function may not modify features or structure.

A function that will be called in [gst.caps.Caps.mapInPlace]. The function may modify features and structure.

The function prototype of the callback.

FIXME(2.0): remove, this is unused

Function for returning a value for a given timestamp.

Function for returning an array of values starting at a given timestamp.

Function called for each meta in buffer as a result of performing a transformation that yields transbuf. Additional type specific transform data is passed to the function as data.

Implementations should check the type of the transform and parse additional type specific fields in data that should be used to update the metadata on transbuf.

we define this to avoid a compiler warning regarding a cast from a function pointer to a void pointer (see https://bugzilla.gnome.org/show_bug.cgi?id=309253)

Callback prototype used in #gst_element_call_async

Function called for each pad when using [gst.element.Element.foreachSinkPad], [gst.element.Element.foreachSrcPad], or [gst.element.Element.foreachPad].

This function will be called when creating a copy of it and should create a copy of all custom iterator fields or increase their reference counts.

A function to be passed to [gst.iterator.Iterator.fold].

A function that is called by [gst.iterator.Iterator.foreach_] for every element.

This function will be called when the iterator is freed.

Implementors of a #GstIterator should implement this function and pass it to the constructor of the custom iterator. The function will be called with the iterator lock held.

The function that will be called after the next item of the iterator has been retrieved. This function can be used to skip items or stop the iterator.

The function will be called with the iterator lock held.

The function that will be called when the next element of the iterator should be retrieved.

Implementors of a #GstIterator should implement this function and pass it to the constructor of the custom iterator. The function will be called with the iterator lock held.

This function will be called whenever a concurrent update happened to the iterated datastructure. The implementor of the iterator should restart the iterator from the beginning and clean up any state it might have.

Implementors of a #GstIterator should implement this function and pass it to the constructor of the custom iterator. The function will be called with the iterator lock held.

Function prototype for a logging function that can be registered with [gst.global.debugAddLogFunction]. Use G_GNUC_NO_INSTRUMENT on that function.

Copy size bytes from mem starting at offset and return them wrapped in a new GstMemory object. If size is set to -1, all bytes starting at offset are copied.

Check if mem1 and mem2 occupy contiguous memory and return the offset of mem1 in the parent buffer in offset.

Get the memory of mem that can be accessed according to the mode specified in info's flags. The function should return a pointer that contains at least maxsize bytes.

Get the memory of mem that can be accessed according to the mode specified in flags. The function should return a pointer that contains at least maxsize bytes.

Share size bytes from mem starting at offset and return them wrapped in a new GstMemory object. If size is set to -1, all bytes starting at offset are shared. This function does not make a copy of the bytes in mem.

Release the pointer previously retrieved with [gst.memory.Memory.map] with info.

Release the pointer previously retrieved with [gst.memory.Memory.map].

Clears the content of the meta. This will be called by the GstBufferPool when a pooled buffer is returned.

Recreate a #GstMeta from serialized data returned by #GstMetaSerializeFunction and add it to buffer.

Function called when meta is freed in buffer.

Function called when meta is initialized in buffer.

Function called for each meta in buffer as a result of performing a transformation on transbuf. Additional type specific transform data is passed to the function as data.

Implementations should check the type of the transform and parse additional type specific fields in data that should be used to update the metadata on transbuf.

Function prototype for methods to create copies of instances.

Function prototype for when a miniobject has lost its last refcount. Implementation of the mini object are allowed to revive the passed object by doing a [gst.mini_object.MiniObject.ref_]. If the object is not revived after the dispose function, the function should return true and the memory associated with the object is freed.

Virtual function prototype for methods to free resources used by mini-objects.

A #GstMiniObjectNotify function can be added to a mini object as a callback that gets triggered when [gst.mini_object.MiniObject.unref] drops the last ref and obj is about to be freed.

This function is called when the pad is activated during the element READY to PAUSED state change. By default this function will call the activate function that puts the pad in push mode but elements can override this function to activate the pad in pull mode if they wish.

The prototype of the push and pull activate functions.

A function that will be called on sinkpads when chaining buffers. The function typically processes the data contained in the buffer and either consumes the data or passes it on to the internally linked pad(s).

The implementer of this function receives a refcount to buffer and should gst_buffer_unref() when the buffer is no longer needed.

When a chain function detects an error in the data stream, it must post an error on the bus and return an appropriate #GstFlowReturn value.

A function that will be called on sinkpads when chaining buffer lists. The function typically processes the data contained in the buffer list and either consumes the data or passes it on to the internally linked pad(s).

The implementer of this function receives a refcount to list and should gst_buffer_list_unref() when the list is no longer needed.

When a chainlist function detects an error in the data stream, it must post an error on the bus and return an appropriate #GstFlowReturn value.

Function signature to handle an event for the pad.

This variant is for specific elements that will take into account the last downstream flow return (from a pad push), in which case they can return it.

Function signature to handle an event for the pad.

A forward function is called for all internally linked pads, see [gst.pad.Pad.forward].

This function will be called on source pads when a peer element request a buffer at the specified offset and length. If this function returns #GST_FLOW_OK, the result buffer will be stored in buffer. The contents of buffer is invalid for any other return value.

This function is installed on a source pad with gst_pad_set_getrange_function() and can only be called on source pads after they are successfully activated with [gst.pad.Pad.activateMode] with the #GST_PAD_MODE_PULL.

offset and length are always given in byte units. offset must normally be a value between 0 and the length in bytes of the data available on pad. The length (duration in bytes) can be retrieved with a #GST_QUERY_DURATION or with a #GST_QUERY_SEEKING.

Any offset larger or equal than the length will make the function return #GST_FLOW_EOS, which corresponds to EOS. In this case buffer does not contain a valid buffer.

The buffer size of buffer will only be smaller than length when offset is near the end of the stream. In all other cases, the size of buffer must be exactly the requested size.

It is allowed to call this function with a 0 length and valid offset, in which case buffer will contain a 0-sized buffer and the function returns #GST_FLOW_OK.

When this function is called with a -1 offset, the sequentially next buffer of length length in the stream is returned.

When this function is called with a -1 length, a buffer with a default optimal length is returned in buffer. The length might depend on the value of offset.

The signature of the internal pad link iterator function.

Function signature to handle a new link on the pad.

Callback used by [gst.pad.Pad.addProbe]. Gets called to notify about the current blocking type.

The callback is allowed to modify the data pointer in info.

The signature of the query function.

Callback used by [gst.pad.Pad.stickyEventsForeach].

When this function returns true, the next event will be returned. When false is returned, [gst.pad.Pad.stickyEventsForeach] will return.

When event is set to null, the item will be removed from the list of sticky events. event can be replaced by assigning a new reference to it. This function is responsible for unreffing the old event when removing or modifying.

Function signature to handle a unlinking the pad prom its peer.

The pad's lock is already held when the unlink function is called, so most pad functions cannot be called from within the callback.

A function that can be used with e.g. [gst.registry.Registry.featureFilter] to get a list of pluginfeature that match certain criteria.

A function that can be used with e.g. [gst.registry.Registry.pluginFilter] to get a list of plugins that match certain criteria.

A plugin should provide a pointer to a function of either #GstPluginInitFunc or this type in the plugin_desc struct. The function will be called by the loader at startup. One would then register each #GstPluginFeature. This version allows user data to be passed to init function (useful for bindings).

A plugin should provide a pointer to a function of this type in the plugin_desc struct. This function will be called by the loader at startup. One would then register each #GstPluginFeature.

A function that will be called in [gst.structure.Structure.filterAndMapInPlace]. The function may modify value, and the value will be removed from the structure if false is returned.

A function that will be called in [gst.structure.Structure.foreach_]. The function may not modify value.

A function that will be called in [gst.structure.Structure.mapInPlace]. The function may modify value.

A function that will be called in [gst.tag_list.TagList.foreach_]. The function may not modify the tag list.

A function for merging multiple values of a tag used when registering tags.

A function that will repeatedly be called in the thread created by a #GstTask.

Task function, see [gst.task_pool.TaskPool.push].

Custom GstTask thread callback functions that can be installed.

A function that will be called by typefinding.

Used together with [gst.global.valueCompare] to compare #GValue items.

Used by [gst.global.valueDeserialize] to parse a non-binary form into the #GValue.

Used by [gst.global.valueDeserializeWithPspec] to parse a non-binary form into the #GValue.

Used by [gst.global.valueSerialize] to obtain a non-binary form of the #GValue.

Free-function: g_free

The allocator name for the default system memory allocator

Combination of all possible fields that can be copied with [gst.buffer.Buffer.copyInto].

Combination of all possible metadata fields that can be copied with [gst.buffer.Buffer.copyInto].

Constant for no-offset return results.

Constant to define an undefined clock time.

Elements interacting with hardware devices should specify this classifier in their metadata. You may need to put the element in "READY" state to test if the hardware is present in the system.

Elements of any of the defined GST_ELEMENT_FACTORY_LIST types

All sinks handling audio, video or image media types

All encoders handling audio media types

All elements used to 'decode' streams (decoders, demuxers, parsers, depayloaders)

Elements matching any of the defined GST_ELEMENT_FACTORY_TYPE_MEDIA types

Timestamp correcting elements

All encoders handling video or image media types

Name and contact details of the author(s). Use \n to separate multiple author details. E.g: "Joe Bloggs <joe.blogs at foo.com>"

Sentence describing the purpose of the element. E.g: "Write stream to a file"

Set uri pointing to user documentation. Applications can use this to show help for e.g. effects to users.

Elements that bridge to certain other products can include an icon of that used product. Application can show the icon in menus/selectors to help identifying specific elements.

String describing the type of element, as an unordered list separated with slashes ('/'). See draft-klass.txt of the design docs for more details and common types. E.g: "Sink/File"

The long English name of the element. E.g. "File Sink"

Builds a string using errno describing the previously failed system call. To be used as the debug argument in #GST_ELEMENT_ERROR.

The same thing as #GST_EVENT_TYPE_UPSTREAM | #GST_EVENT_TYPE_DOWNSTREAM.

A mask value with all bits set, for use as a GstFlagSet mask where all flag bits must match exactly

The PERCENT format is between 0 and this value

The value used to scale down the reported PERCENT format value to its real value.

Can be used together with #GST_FOURCC_ARGS to properly output a #guint32 fourcc value in a printf\()-style text message.

printf ("fourcc: %" GST_FOURCC_FORMAT "\n", GST_FOURCC_ARGS (fcc));

A value which is guaranteed to never be returned by [gst.global.utilGroupIdNext].

Can be used as a default value in variables used to store group_id.

To be used in GST_PLUGIN_DEFINE if unsure about the licence.

GstLockFlags value alias for GST_LOCK_FLAG_READ | GST_LOCK_FLAG_WRITE

GstMapFlags value alias for GST_MAP_READ | GST_MAP_WRITE

This metadata stays relevant until a deep copy is made.

This metadata stays relevant as long as memory layout is unchanged. In hindsight, this tag should have been called "memory-layout".

Constant that defines one GStreamer millisecond.

Constant that defines one GStreamer nanosecond

Use this flag on GObject properties of GstObject to indicate that they might not be available depending on environment such as OS, device, etc, so such properties will be installed conditionally only if the GstObject is able to support it.

Use this flag on GObject properties to signal they can make sense to be. controlled over time. This hint is used by the GstController.

Use this flag on GObject properties of GstObject to indicate that during gst-inspect and friends, the default value should be used as default instead of the current value.

Use this flag on GObject properties of GstElements to indicate that they can be changed when the element is in the PAUSED or lower state. This flag implies GST_PARAM_MUTABLE_READY.

Use this flag on GObject properties of GstElements to indicate that they can be changed when the element is in the PLAYING or lower state. This flag implies GST_PARAM_MUTABLE_PAUSED.

Use this flag on GObject properties of GstElements to indicate that they can be changed when the element is in the READY or lower state.

Bits based on GST_PARAM_USER_SHIFT can be used by 3rd party applications.

The field name in a GstCaps that is used to signal the UUID of the protection system.

The protection system value of the unspecified UUID. In some cases the system protection ID is not present in the contents or in their metadata, as encrypted WebM. This define is used to set the value of the "system_id" field in GstProtectionEvent, with this value, the application will use an external information to choose which protection system to use.

Example: The matroskademux uses this value in the case of encrypted WebM, the application will choose the appropriate protection system based on the information received through EME API.

printf format type used to debug GStreamer types. You can use this in combination with GStreamer's debug logging system as well as the functions [gst.global.infoVasprintf], [gst.global.infoStrdupVprintf] and [gst.global.infoStrdupPrintf] to pretty-print the following types: #GstCaps, #GstStructure, #GstCapsFeatures, #GstTagList, #GstDateTime, #GstBuffer, #GstBufferList, #GstMessage, #GstEvent, #GstQuery, #GstContext, #GstPad, #GstObject. All #GObject types will be printed as typename plus pointer, and everything else will simply be printed as pointer address.

This can only be used on types whose size is >= sizeof(gpointer).

The same thing as #GST_QUERY_TYPE_UPSTREAM | #GST_QUERY_TYPE_DOWNSTREAM.

Constant that defines one GStreamer second.

printf format type used to debug GStreamer segments. You can use this in combination with GStreamer's debug logging system as well as the functions [gst.global.infoVasprintf], [gst.global.infoStrdupVprintf] and [gst.global.infoStrdupPrintf] to pretty-print #GstSegment structures. This can only be used on pointers to GstSegment structures.

A value which is guaranteed to never be returned by [gst.global.utilSeqnumNext].

Can be used as a default value in variables used to store seqnum.

printf format type used to debug GStreamer signed time value pointers. You can use this in combination with GStreamer's debug logging system as well as the functions [gst.global.infoVasprintf], [gst.global.infoStrdupVprintf] and [gst.global.infoStrdupPrintf] to pretty-print signed time (pointers to #GstClockTimeDiff or #gint64).

A string that can be used in printf-like format strings to display a signed #GstClockTimeDiff or #gint64 value in h:m:s format. Use GST_TIME_ARGS() to construct the matching arguments.

Example:

`` C printf("%" GST_STIME_FORMAT "\n", GST_STIME_ARGS(ts)); ``

album containing this data (string)

The album name as it should be displayed, e.g. 'The Jazz Guitar'

The artist of the entire album, as it should be displayed.

The artist of the entire album, as it should be sorted.

album gain in db (double)

peak of the album (double)

album containing this data, as used for sorting (string)

The album name as it should be sorted, e.g. 'Jazz Guitar, The'

count of discs inside collection this disc belongs to (unsigned integer)

disc number inside a collection (unsigned integer)

Arbitrary application data (sample)

Some formats allow applications to add their own arbitrary data into files. This data is application dependent.

Name of the application used to create the media (string)

person(s) responsible for the recording (string)

The artist name as it should be displayed, e.g. 'Jimi Hendrix' or 'The Guitar Heroes'

person(s) responsible for the recording, as used for sorting (string)

The artist name as it should be sorted, e.g. 'Hendrix, Jimi' or 'Guitar Heroes, The'

generic file attachment (sample) (sample taglist should specify the content type and if possible set "filename" to the file name of the attachment)

codec the audio data is stored in (string)

number of beats per minute in audio (double)

exact or average bitrate in bits/s (unsigned integer)

codec the data is stored in (string)

free text commenting the data (string)

person(s) who composed the recording (string)

The composer's name, used for sorting (string)

conductor/performer refinement (string)

contact information (string)

container format the data is stored in (string)

Unique identifier for the audio, video or text track this tag is associated with. The mappings for several container formats are defined in the Sourcing In-band Media Resource Tracks from Media Containers into HTML specification.

copyright notice of the data (string)

URI to location where copyright details can be found (string)

date the data was created (#GDate structure)

date and time the data was created (#GstDateTime structure)

short text describing the content of the data (string)

Manufacturer of the device used to create the media (string)

Model of the device used to create the media (string)

length in GStreamer time units (nanoseconds) (unsigned 64-bit integer)

name of the person or organisation that encoded the file. May contain a copyright message if the person or organisation also holds the copyright (string)

encoder used to encode this stream (string)

version of the encoder used to encode this stream (unsigned integer)

key/value text commenting the data (string)

Must be in the form of 'key=comment' or 'key[lc]=comment' where 'lc' is an ISO-639 language code.

This tag is used for unknown Vorbis comment tags, unknown APE tags and certain ID3v2 comment fields.

genre this data belongs to (string)

Indicates the direction the device is pointing to when capturing a media. It is represented as degrees in floating point representation, 0 means the geographic north, and increases clockwise (double from 0 to 360)

See also #GST_TAG_GEO_LOCATION_MOVEMENT_DIRECTION

The city (english name) where the media has been produced (string).

The country (english name) where the media has been produced (string).

geo elevation of where the media has been recorded or produced in meters according to WGS84 (zero is average sea level) (double).

Represents the expected error on the horizontal positioning in meters (double).

geo latitude location of where the media has been recorded or produced in degrees according to WGS84 (zero at the equator, negative values for southern latitudes) (double).

geo longitude location of where the media has been recorded or produced in degrees according to WGS84 (zero at the prime meridian in Greenwich/UK, negative values for western longitudes). (double).

Indicates the movement direction of the device performing the capture of a media. It is represented as degrees in floating point representation, 0 means the geographic north, and increases clockwise (double from 0 to 360)

See also #GST_TAG_GEO_LOCATION_CAPTURE_DIRECTION

Speed of the capturing device when performing the capture. Represented in m/s. (double)

See also #GST_TAG_GEO_LOCATION_MOVEMENT_DIRECTION

human readable descriptive location of where the media has been recorded or produced. (string).

A location 'smaller' than GST_TAG_GEO_LOCATION_CITY that specifies better where the media has been produced. (e.g. the neighborhood) (string).

This tag has been added as this is how it is handled/named in XMP's Iptc4xmpcore schema.

Groups together media that are related and spans multiple tracks. An example are multiple pieces of a concerto. (string)

Homepage for this media (i.e. artist or movie homepage) (string)

image (sample) (sample taglist should specify the content type and preferably also set "image-type" field as [gsttag.types.TagImageType])

Represents the 'Orientation' tag from EXIF. Defines how the image should be rotated and mirrored for display. (string)

This tag has a predefined set of allowed values: "rotate-0" "rotate-90" "rotate-180" "rotate-270" "flip-rotate-0" "flip-rotate-90" "flip-rotate-180" "flip-rotate-270"

The naming is adopted according to a possible transformation to perform on the image to fix its orientation, obviously equivalent operations will yield the same result.

Rotations indicated by the values are in clockwise direction and 'flip' means an horizontal mirroring.

Information about the people behind a remix and similar interpretations of another existing piece (string)

International Standard Recording Code - see http://www.ifpi.org/isrc/ (string)

comma separated keywords describing the content (string).

ISO-639-2 or ISO-639-1 code for the language the content is in (string)

There is utility API in libgsttag in gst-plugins-base to obtain a translated language name from the language code: [gsttag.global.tagGetLanguageName]

Name of the language the content is in (string)

Free-form name of the language the content is in, if a language code is not available. This tag should not be set in addition to a language code. It is undefined what language or locale the language name is in.

license of data (string)

URI to location where license details can be found (string)

Origin of media as a URI (location, where the original of the file or stream is hosted) (string)

The lyrics of the media (string)

maximum bitrate in bits/s (unsigned integer)

of the audio track. This is useful for sample instruments and in particular for multi-samples.

minimum bitrate in bits/s (unsigned integer)

nominal bitrate in bits/s (unsigned integer). The actual bitrate might be different from this target bitrate.

organization (string)

person(s) performing (string)

image that is meant for preview purposes, e.g. small icon-sized version (sample) (sample taglist should specify the content type)

Any private data that may be contained in tags (sample).

It is represented by #GstSample in which #GstBuffer contains the binary data and the sample's info #GstStructure may contain any extra information that identifies the origin or meaning of the data.

Private frames in ID3v2 tags ('PRIV' frames) will be represented using this tag, in which case the GstStructure will be named "ID3PrivateFrame" and contain a field named "owner" of type string which contains the owner-identification string from the tag.

Name of the label or publisher (string)

reference level of track and album gain values (double)

serial number of track (unsigned integer)

Number of the episode within a season/show (unsigned integer)

Name of the show, used for displaying (string)

Number of the season of a show/series (unsigned integer)

Name of the show, used for sorting (string)

codec/format the subtitle data is stored in (string)

commonly used title (string)

The title as it should be displayed, e.g. 'The Doll House'

commonly used title, as used for sorting (string)

The title as it should be sorted, e.g. 'Doll House, The'

count of tracks inside collection this track belongs to (unsigned integer)

track gain in db (double)

track number inside a collection (unsigned integer)

peak of the track (double)

Rating attributed by a person (likely the application user). The higher the value, the more the user likes this media (unsigned int from 0 to 100)

version of this data (string)

codec the video data is stored in (string)

printf format type used to debug GStreamer ClockTime pointers. You can use this in combination with GStreamer's debug logging system as well as the functions [gst.global.infoVasprintf], [gst.global.infoStrdupVprintf] and [gst.global.infoStrdupPrintf] to pretty-print #GstClockTime pointers. This can only be used on pointers to GstClockTime values.

A string that can be used in printf-like format strings to display a #GstClockTime value in h:m:s format. Use GST_TIME_ARGS() to construct the matching arguments.

Example:

`` C printf("%" GST_TIME_FORMAT "\n", GST_TIME_ARGS(ts)); ``

Special value for the repeat_count set in [gst.toc_entry.TocEntry.setLoop] or returned by [gst.toc_entry.TocEntry.setLoop] to indicate infinite looping.

Value for #GstUri<!-- -->.port to indicate no port number.

Constant that defines one GStreamer microsecond.

Indicates that the first value provided to a comparison function ([gst.global.valueCompare]) is equal to the second one.

Indicates that the first value provided to a comparison function ([gst.global.valueCompare]) is greater than the second one.

Indicates that the first value provided to a comparison function ([gst.global.valueCompare]) is lesser than the second one.

Indicates that the comparison function ([gst.global.valueCompare]) can not determine a order for the two provided values.

The major version of GStreamer at compile time:

The micro version of GStreamer at compile time:

The minor version of GStreamer at compile time:

The nano version of GStreamer at compile time: Actual releases have 0, GIT versions have 1, prerelease versions have 2-...