GI.Gst.Structs.Meta

The 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.

Exported types

newtype Meta

Constructors

Meta (ForeignPtr Meta)

Instances

((~) * info (ResolveMetaMethod t Meta), MethodInfo * info Meta p) => IsLabel t (Meta -> p)

Methods

fromLabel :: Proxy# Symbol t -> Meta -> p

((~) * info (ResolveMetaMethod t Meta), MethodInfo * info Meta p) => IsLabelProxy t (Meta -> p)

Methods

fromLabelProxy :: Proxy Symbol t -> Meta -> p

newZeroMeta :: MonadIO m => m Meta

Construct a Meta struct initialized to zero.

noMeta :: Maybe Meta

Methods

metaApiTypeGetTags

metaApiTypeGetTags :: MonadIO m => GType -> m [Text]

metaApiTypeHasTag

metaApiTypeHasTag :: MonadIO m => GType -> Word32 -> m Bool

metaApiTypeRegister

metaApiTypeRegister :: MonadIO m => Text -> Text -> m GType

metaGetInfo

metaGetInfo :: MonadIO m => Text -> m MetaInfo

metaRegister

metaRegister :: MonadIO m => GType -> Text -> Word64 -> MetaInitFunction -> MetaFreeFunction -> MetaTransformFunction -> m MetaInfo

Properties

Flags

metaReadFlags :: Meta -> IO [MetaFlags]

Info

metaReadInfo :: Meta -> IO MetaInfo