a #GstTagList
a GStreamer codec tag such as #GST_TAG_AUDIO_CODEC, #GST_TAG_VIDEO_CODEC or #GST_TAG_CODEC. If none is specified, the function will attempt to detect the appropriate category.
the (fixed) #GstCaps for which a codec tag should be added.
TRUE if a codec tag was added, FALSE otherwise.
Adds a codec tag describing the format specified by caps to taglist.