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GStreamer 0.10 Core Reference Manual | |
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#include <gst/gst.h>
GstTagSetter;
GstTagSetterIFace;
void gst_tag_setter_reset_tags (GstTagSetter *setter);
void gst_tag_setter_merge_tags (GstTagSetter *setter,
const GstTagList *list,
GstTagMergeMode mode);
void gst_tag_setter_add_tags (GstTagSetter *setter,
GstTagMergeMode mode,
const gchar *tag,
...);
void gst_tag_setter_add_tag_value (GstTagSetter *setter,
GstTagMergeMode mode,
const gchar *tag,
const GValue *value);
void gst_tag_setter_add_tag_values (GstTagSetter *setter,
GstTagMergeMode mode,
const gchar *tag,
...);
void gst_tag_setter_add_tag_valist (GstTagSetter *setter,
GstTagMergeMode mode,
const gchar *tag,
va_list var_args);
void gst_tag_setter_add_tag_valist_values
(GstTagSetter *setter,
GstTagMergeMode mode,
const gchar *tag,
va_list var_args);
const GstTagList* gst_tag_setter_get_tag_list (GstTagSetter *setter);
void gst_tag_setter_set_tag_merge_mode (GstTagSetter *setter,
GstTagMergeMode mode);
GstTagMergeMode gst_tag_setter_get_tag_merge_mode (GstTagSetter *setter);
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);
Last reviewed on 2006-05-18 (0.10.6)
typedef struct {
GTypeInterface g_iface;
/* signals */
/* virtual table */
} GstTagSetterIFace;
GstTagSetterIFace interface.
GTypeInterface g_iface; |
parent interface type. |
void gst_tag_setter_reset_tags (GstTagSetter *setter);
Reset the internal taglist. Elements should call this from within the state-change handler.
setter : |
a GstTagSetter |
Since 0.10.22
void 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.
setter : |
a GstTagSetter |
list : |
a tag list to merge from |
mode : |
the mode to merge with |
void 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.
setter : |
a GstTagSetter |
mode : |
the mode to use |
tag : |
tag to set |
... : |
more tag / value pairs to set |
void 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.
setter : |
a GstTagSetter |
mode : |
the mode to use |
tag : |
tag to set |
value : |
GValue to set for the tag |
Since 0.10.24
void 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.
setter : |
a GstTagSetter |
mode : |
the mode to use |
tag : |
tag to set |
... : |
more tag / GValue pairs to set |
void 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.
setter : |
a GstTagSetter |
mode : |
the mode to use |
tag : |
tag to set |
var_args : |
tag / value pairs to set |
void 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.
setter : |
a GstTagSetter |
mode : |
the mode to use |
tag : |
tag to set |
var_args : |
tag / GValue pairs to set |
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.
setter : |
a GstTagSetter |
| Returns : | a current snapshot of the taglist used in the setter or NULL if none is used. |
void 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.
setter : |
a GstTagSetter |
mode : |
The mode with which tags are added |
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
setter : |
a GstTagSetter |
| Returns : | the merge mode used inside the element. |