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 (ManagedPtr Meta)

Instances

WrappedPtr Meta

Methods

wrappedPtrCalloc :: IO (Ptr Meta)

wrappedPtrCopy :: Ptr Meta -> IO (Ptr Meta)

wrappedPtrFree :: Maybe (FunPtr (Ptr Meta -> IO ()))

(~) AttrOpTag tag AttrSet => Constructible Meta tag

Methods

new :: MonadIO m => (ManagedPtr Meta -> Meta) -> [AttrOp Meta tag] -> m Meta

((~) * 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

HasAttributeList * Meta

type AttributeList Meta

type AttributeList Meta

newZeroMeta :: MonadIO m => m Meta

Construct a Meta struct initialized to zero.

noMeta :: Maybe Meta

Methods

apiTypeGetTags

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

apiTypeHasTag

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

apiTypeRegister

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

getInfo

metaGetInfo :: MonadIO m => Text -> m (Maybe MetaInfo)

register

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

Properties

flags

getMetaFlags :: MonadIO m => Meta -> m [MetaFlags]

meta_flags :: AttrLabelProxy "flags"

setMetaFlags :: MonadIO m => Meta -> [MetaFlags] -> m ()

info

clearMetaInfo :: MonadIO m => Meta -> m ()

getMetaInfo :: MonadIO m => Meta -> m (Maybe MetaInfo)

meta_info :: AttrLabelProxy "info"

setMetaInfo :: MonadIO m => Meta -> Ptr MetaInfo -> m ()