Meta

The #GstMeta structure should be included as the first member of a #GstBuffer metadata structure. The structure defines the API of the metadata and should be accessible to all elements using the metadata.

A metadata API is registered with gst_meta_api_type_register() which takes a name for the metadata API and some tags associated with the metadata. With gst_meta_api_type_has_tag() one can check if a certain metadata API contains a given tag.

Multiple implementations of a metadata API can be registered. To implement a metadata API, gst_meta_register() should be used. This function takes all parameters needed to create, free and transform metadata along with the size of the metadata. The function returns a #GstMetaInfo structure that contains the information for the implementation of the API.

A specific implementation can be retrieved by name with gst_meta_get_info().

See #GstBuffer for how the metadata can be added, retrieved and removed from buffers.

final

class Meta {

GstMeta* getMetaStruct(bool transferOwnership);

void* getStruct();

this(GstMeta* gstMeta, bool ownedRef);

~this();

GstMetaFlags flags [@property getter];

GstMetaFlags flags [@property setter];

GstMetaInfo* info [@property getter];

GstMetaInfo* info [@property setter];

int compareSeqnum(Meta meta2);

ulong getSeqnum();

static string[] apiTypeGetTags(GType api);

static bool apiTypeHasTag(GType api, GQuark tag);

static GType apiTypeRegister(string api, string[] tags);

static GstMetaInfo* getInfo(string impl);

static GstMetaInfo* register(GType api, string impl, size_t size, GstMetaInitFunction initFunc, GstMetaFreeFunction freeFunc, GstMetaTransformFunction transformFunc);

}

Constructors

this this(GstMeta* gstMeta, bool ownedRef): Sets our main struct and passes it to the parent class.

Destructor

~this ~this(): Undocumented in source.

Members

Functions

compareSeqnum int compareSeqnum(Meta meta2): Meta sequence number compare function. Can be used as #GCompareFunc or a #GCompareDataFunc.
getMetaStruct GstMeta* getMetaStruct(bool transferOwnership): Get the main Gtk struct
getSeqnum ulong getSeqnum(): Gets seqnum for this meta.
getStruct void* getStruct(): the main Gtk struct as a void*

Properties

flags GstMetaFlags flags [@property getter]
GstMetaFlags flags [@property setter]: extra flags for the metadata
info GstMetaInfo* info [@property getter]
GstMetaInfo* info [@property setter]: pointer to the #GstMetaInfo

Static functions

apiTypeGetTags string[] apiTypeGetTags(GType api)
apiTypeHasTag bool apiTypeHasTag(GType api, GQuark tag): Check if @api was registered with @tag.
apiTypeRegister GType apiTypeRegister(string api, string[] tags): Register and return a GType for the @api and associate it with @tags.
getInfo GstMetaInfo* getInfo(string impl): Lookup a previously registered meta info structure by its implementation name @impl.
register GstMetaInfo* register(GType api, string impl, size_t size, GstMetaInitFunction initFunc, GstMetaFreeFunction freeFunc, GstMetaTransformFunction transformFunc): Register a new #GstMeta implementation.

Variables

gstMeta GstMeta* gstMeta;: the main Gtk struct
ownedRef bool ownedRef;: Undocumented in source.