GstTagsetter

Element interface that allows setting of media metadata.

Elements that support changing a stream's metadata will implement this interface. Examples of such elements are 'vorbisenc', 'theoraenc' and 'id3v2mux'.

If you just want to retrieve metadata in your application then all you need to do is watch for tag messages on your pipeline's bus. This interface is only for setting metadata, not for extracting it. To set tags from the application, find tagsetter elements and set tags using e.g. gst_tag_setter_merge_tags or gst_tag_setter_add_tags. Also consider setting the GstTagMergeMode that is used for tag events that arrive at the tagsetter element (default mode is to keep existing tags). The application should do that before the element goes to GST_STATE_PAUSED.

Elements implementing the GstTagSetter interface often have to merge any tags received from upstream and the tags set by the application via the interface. This can be done like this:

 GstTagMergeMode merge_mode;
 const GstTagList *application_tags;
 const GstTagList *event_tags;
 GstTagSetter *tagsetter;
 GstTagList *result;

 tagsetter = GST_TAG_SETTER (element);

 merge_mode = gst_tag_setter_get_tag_merge_mode (tagsetter);
 application_tags = gst_tag_setter_get_tag_list (tagsetter);
 event_tags = (const GstTagList *) element->event_tags;

 GST_LOG_OBJECT (tagsetter, "merging tags, merge mode = %d", merge_mode);
 GST_LOG_OBJECT (tagsetter, "event tags: %" GST_PTR_FORMAT, event_tags);
 GST_LOG_OBJECT (tagsetter, "set   tags: %" GST_PTR_FORMAT, application_tags);

 result = gst_tag_list_merge (application_tags, event_tags, merge_mode);

 GST_LOG_OBJECT (tagsetter, "final tags: %" GST_PTR_FORMAT, result);

GstTagSetter

Opaque GstTagSetter data structure.


Gst.TagSetter

Opaque Gst.TagSetter data structure.


Gst.TagSetter

Opaque Gst.TagSetter data structure.


Methods

gst_tag_setter_add_tag_valist

gst_tag_setter_add_tag_valist (GstTagSetter * setter,
                               GstTagMergeMode mode,
                               const gchar * tag,
                               va_list var_args)

Adds the given tag / value pairs on the setter using the given merge mode. The list must be terminated with NULL.

Parameters:

setter

a GstTagSetter

mode

the mode to use

tag

tag to set

var_args

tag / value pairs to set


gst_tag_setter_add_tag_valist_values

gst_tag_setter_add_tag_valist_values (GstTagSetter * setter,
                                      GstTagMergeMode mode,
                                      const gchar * tag,
                                      va_list var_args)

Adds the given tag / GValue pairs on the setter using the given merge mode. The list must be terminated with NULL.

Parameters:

setter

a GstTagSetter

mode

the mode to use

tag

tag to set

var_args

tag / GValue pairs to set


gst_tag_setter_add_tag_value

gst_tag_setter_add_tag_value (GstTagSetter * setter,
                              GstTagMergeMode mode,
                              const gchar * tag,
                              const GValue * value)

Adds the given tag / GValue pair on the setter using the given merge mode.

Parameters:

setter

a GstTagSetter

mode

the mode to use

tag

tag to set

value

GValue to set for the tag


Gst.TagSetter.add_tag_value

def Gst.TagSetter.add_tag_value (self, mode, tag, value):
    #python wrapper for 'gst_tag_setter_add_tag_value'

Adds the given tag / GValue pair on the setter using the given merge mode.

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter

mode ( Gst.TagMergeMode ) –

the mode to use

tag ( str ) –

tag to set

value ( GObject.Value ) –

GValue to set for the tag


Gst.TagSetter.prototype.add_tag_value

function Gst.TagSetter.prototype.add_tag_value(mode: Gst.TagMergeMode, tag: String, value: GObject.Value): {
    // javascript wrapper for 'gst_tag_setter_add_tag_value'
}

Adds the given tag / GValue pair on the setter using the given merge mode.

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter

mode ( Gst.TagMergeMode ) –

the mode to use

tag ( String ) –

tag to set

value ( GObject.Value ) –

GValue to set for the tag


gst_tag_setter_add_tag_values

gst_tag_setter_add_tag_values (GstTagSetter * setter,
                               GstTagMergeMode mode,
                               const gchar * tag,
                               ... ...)

Adds the given tag / GValue pairs on the setter using the given merge mode. The list must be terminated with NULL.

Parameters:

setter

a GstTagSetter

mode

the mode to use

tag

tag to set

...

more tag / GValue pairs to set


gst_tag_setter_add_tags

gst_tag_setter_add_tags (GstTagSetter * setter,
                         GstTagMergeMode mode,
                         const gchar * tag,
                         ... ...)

Adds the given tag / value pairs on the setter using the given merge mode. The list must be terminated with NULL.

Parameters:

setter

a GstTagSetter

mode

the mode to use

tag

tag to set

...

more tag / value pairs to set


gst_tag_setter_get_tag_list

const GstTagList *
gst_tag_setter_get_tag_list (GstTagSetter * setter)

Returns the current list of tags the setter uses. The list should not be modified or freed.

This function is not thread-safe.

Parameters:

setter

a GstTagSetter

Returns ( [transfer: none] [nullable] ) –

a current snapshot of the taglist used in the setter or NULL if none is used.


Gst.TagSetter.get_tag_list

def Gst.TagSetter.get_tag_list (self):
    #python wrapper for 'gst_tag_setter_get_tag_list'

Returns the current list of tags the setter uses. The list should not be modified or freed.

This function is not thread-safe.

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter

Returns ( Gst.TagList ) –

a current snapshot of the taglist used in the setter or None if none is used.


Gst.TagSetter.prototype.get_tag_list

function Gst.TagSetter.prototype.get_tag_list(): {
    // javascript wrapper for 'gst_tag_setter_get_tag_list'
}

Returns the current list of tags the setter uses. The list should not be modified or freed.

This function is not thread-safe.

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter

Returns ( Gst.TagList ) –

a current snapshot of the taglist used in the setter or null if none is used.


gst_tag_setter_get_tag_merge_mode

GstTagMergeMode
gst_tag_setter_get_tag_merge_mode (GstTagSetter * setter)

Queries the mode by which tags inside the setter are overwritten by tags from events

Parameters:

setter

a GstTagSetter

Returns

the merge mode used inside the element.


Gst.TagSetter.get_tag_merge_mode

def Gst.TagSetter.get_tag_merge_mode (self):
    #python wrapper for 'gst_tag_setter_get_tag_merge_mode'

Queries the mode by which tags inside the setter are overwritten by tags from events

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter

Returns ( Gst.TagMergeMode ) –

the merge mode used inside the element.


Gst.TagSetter.prototype.get_tag_merge_mode

function Gst.TagSetter.prototype.get_tag_merge_mode(): {
    // javascript wrapper for 'gst_tag_setter_get_tag_merge_mode'
}

Queries the mode by which tags inside the setter are overwritten by tags from events

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter

Returns ( Gst.TagMergeMode ) –

the merge mode used inside the element.


gst_tag_setter_merge_tags

gst_tag_setter_merge_tags (GstTagSetter * setter,
                           const GstTagList * list,
                           GstTagMergeMode mode)

Merges the given list into the setter's list using the given mode.

Parameters:

setter

a GstTagSetter

list

a tag list to merge from

mode

the mode to merge with


Gst.TagSetter.merge_tags

def Gst.TagSetter.merge_tags (self, list, mode):
    #python wrapper for 'gst_tag_setter_merge_tags'

Merges the given list into the setter's list using the given mode.

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter

list ( Gst.TagList ) –

a tag list to merge from

mode ( Gst.TagMergeMode ) –

the mode to merge with


Gst.TagSetter.prototype.merge_tags

function Gst.TagSetter.prototype.merge_tags(list: Gst.TagList, mode: Gst.TagMergeMode): {
    // javascript wrapper for 'gst_tag_setter_merge_tags'
}

Merges the given list into the setter's list using the given mode.

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter

list ( Gst.TagList ) –

a tag list to merge from

mode ( Gst.TagMergeMode ) –

the mode to merge with


gst_tag_setter_reset_tags

gst_tag_setter_reset_tags (GstTagSetter * setter)

Reset the internal taglist. Elements should call this from within the state-change handler.

Parameters:

setter

a GstTagSetter


Gst.TagSetter.reset_tags

def Gst.TagSetter.reset_tags (self):
    #python wrapper for 'gst_tag_setter_reset_tags'

Reset the internal taglist. Elements should call this from within the state-change handler.

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter


Gst.TagSetter.prototype.reset_tags

function Gst.TagSetter.prototype.reset_tags(): {
    // javascript wrapper for 'gst_tag_setter_reset_tags'
}

Reset the internal taglist. Elements should call this from within the state-change handler.

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter


gst_tag_setter_set_tag_merge_mode

gst_tag_setter_set_tag_merge_mode (GstTagSetter * setter,
                                   GstTagMergeMode mode)

Sets the given merge mode that is used for adding tags from events to tags specified by this interface. The default is GST_TAG_MERGE_KEEP, which keeps the tags set with this interface and discards tags from events.

Parameters:

setter

a GstTagSetter

mode

The mode with which tags are added


Gst.TagSetter.set_tag_merge_mode

def Gst.TagSetter.set_tag_merge_mode (self, mode):
    #python wrapper for 'gst_tag_setter_set_tag_merge_mode'

Sets the given merge mode that is used for adding tags from events to tags specified by this interface. The default is Gst.TagMergeMode.KEEP, which keeps the tags set with this interface and discards tags from events.

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter

mode ( Gst.TagMergeMode ) –

The mode with which tags are added


Gst.TagSetter.prototype.set_tag_merge_mode

function Gst.TagSetter.prototype.set_tag_merge_mode(mode: Gst.TagMergeMode): {
    // javascript wrapper for 'gst_tag_setter_set_tag_merge_mode'
}

Sets the given merge mode that is used for adding tags from events to tags specified by this interface. The default is Gst.TagMergeMode.KEEP, which keeps the tags set with this interface and discards tags from events.

Parameters:

setter ( Gst.TagSetter ) –

a Gst.TagSetter

mode ( Gst.TagMergeMode ) –

The mode with which tags are added


Function Macros

GST_TAG_SETTER_GET_INTERFACE

#define GST_TAG_SETTER_GET_INTERFACE(obj)       (G_TYPE_INSTANCE_GET_INTERFACE ((obj), GST_TYPE_TAG_SETTER, GstTagSetterInterface))

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