Gst.TagSetter

const Gst = imports.gi.Gst;

let tag_setter = new Gst.TagSetter();
  

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.merge_tags or Gst.add_tags. Also consider setting the Gst.TagMergeMode 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 Gst.TagSetter 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)