GI.GstBase.Objects.Aggregator

Manages a set of pads with the purpose of aggregating their buffers. Control is given to the subclass when all pads have data.

• Base class for mixers and muxers. Subclasses should at least implement the AggregatorClass.aggregate() virtual method.
• Installs a PadChainFunction, a PadEventFullFunction and a PadQueryFunction to queue all serialized data packets per sink pad. Subclasses should not overwrite those, but instead implement AggregatorClass.sink_event() and AggregatorClass.sink_query() as needed.
• When data is queued on all pads, the aggregate vmethod is called.
• One can peek at the data on any given GstAggregatorPad with the gst_aggregator_pad_peek_buffer () method, and remove it from the pad with the gst_aggregator_pad_pop_buffer () method. When a buffer has been taken with pop_buffer (), a new buffer can be queued on that pad.
• If the subclass wishes to push a buffer downstream in its aggregate implementation, it should do so through the gst_aggregator_finish_buffer () method. This method will take care of sending and ordering mandatory events such as stream start, caps and segment.
• Same goes for EOS events, which should not be pushed directly by the subclass, it should instead return GST_FLOW_EOS in its aggregate implementation.
• Note that the aggregator logic regarding gap event handling is to turn these into gap buffers with matching PTS and duration. It will also flag these buffers with GST_BUFFER_FLAG_GAP and GST_BUFFER_FLAG_DROPPABLE to ease their identification and subsequent processing.
• Subclasses must use (a subclass of) AggregatorPad for both their sink and source pads. See elementClassAddStaticPadTemplateWithGtype.

This class used to live in gst-plugins-bad and was moved to core.

Since: 1.14

Exported types

newtype Aggregator

Memory-managed wrapper type.

Constructors

Aggregator (ManagedPtr Aggregator)

Instances

Eq Aggregator

Defined in GI.GstBase.Objects.Aggregator

Methods

(==) :: Aggregator -> Aggregator -> Bool

(/=) :: Aggregator -> Aggregator -> Bool

GObject Aggregator

Defined in GI.GstBase.Objects.Aggregator

Methods

gobjectType :: IO GType

IsGValue Aggregator

Convert Aggregator to and from GValue with toGValue and fromGValue.

Defined in GI.GstBase.Objects.Aggregator

Methods

toGValue :: Aggregator -> IO GValue

fromGValue :: GValue -> IO Aggregator

HasParentTypes Aggregator

Defined in GI.GstBase.Objects.Aggregator

type ParentTypes Aggregator

Defined in GI.GstBase.Objects.Aggregator

type ParentTypes Aggregator = '[Element, Object, Object]

class (GObject o, IsDescendantOf Aggregator o) => IsAggregator o

Type class for types which can be safely cast to Aggregator, for instance with toAggregator.

Instances

(GObject o, IsDescendantOf Aggregator o) => IsAggregator o

Defined in GI.GstBase.Objects.Aggregator

toAggregator :: (MonadIO m, IsAggregator o) => o -> m Aggregator

Cast to Aggregator, for types for which this is known to be safe. For general casts, use castTo.

noAggregator :: Maybe Aggregator

A convenience alias for Nothing :: Maybe Aggregator.

Methods

Overloaded methods

finishBuffer

aggregatorFinishBuffer

Arguments

:: (HasCallStack, MonadIO m, IsAggregator a)

=> a

aggregator: The Aggregator

-> Buffer

buffer: the Buffer to push.

-> m FlowReturn

This method will push the provided output buffer downstream. If needed, mandatory events such as stream-start, caps, and segment events will be sent before pushing the buffer.

getAllocator

aggregatorGetAllocator

Arguments

:: (HasCallStack, MonadIO m, IsAggregator a)

=> a

self: a Aggregator

-> m (Allocator, AllocationParams)

Lets Aggregator sub-classes get the memory allocator acquired by the base class and its params.

Unref the allocator after use it.

getBufferPool

aggregatorGetBufferPool

Arguments

:: (HasCallStack, MonadIO m, IsAggregator a)

=> a

self: a Aggregator

-> m BufferPool

Returns: the instance of the BufferPool used by trans; free it after use it

No description available in the introspection data.

getLatency

aggregatorGetLatency

Arguments

:: (HasCallStack, MonadIO m, IsAggregator a)

=> a

self: a Aggregator

-> m Word64

Returns: The latency or CLOCK_TIME_NONE if the element does not sync

Retrieves the latency values reported by self in response to the latency query, or CLOCK_TIME_NONE if there is not live source connected and the element will not wait for the clock.

Typically only called by subclasses.

setLatency

aggregatorSetLatency

Arguments

:: (HasCallStack, MonadIO m, IsAggregator a)

=> a

self: a Aggregator

-> Word64

minLatency: minimum latency

-> Word64

maxLatency: maximum latency

-> m ()

Lets Aggregator sub-classes tell the baseclass what their internal latency is. Will also post a LATENCY message on the bus so the pipeline can reconfigure its global latency.

setSrcCaps

aggregatorSetSrcCaps

Arguments

:: (HasCallStack, MonadIO m, IsAggregator a)

=> a

self: The Aggregator

-> Caps

caps: The Caps to set on the src pad.

-> m ()

Sets the caps to be used on the src pad.

simpleGetNextTime

aggregatorSimpleGetNextTime

Arguments

:: (HasCallStack, MonadIO m, IsAggregator a)

=> a

self: A Aggregator

-> m Word64

Returns: The running time based on the position

This is a simple Aggregator::get_next_time implementation that just looks at the Segment on the srcpad of the aggregator and bases the next time on the running time there.

This is the desired behaviour in most cases where you have a live source and you have a dead line based aggregator subclass.

Since: 1.16

Properties

latency

No description available in the introspection data.

constructAggregatorLatency :: IsAggregator o => Word64 -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “latency” property. This is rarely needed directly, but it is used by new.

getAggregatorLatency :: (MonadIO m, IsAggregator o) => o -> m Word64

Get the value of the “latency” property. When overloading is enabled, this is equivalent to

get aggregator #latency

setAggregatorLatency :: (MonadIO m, IsAggregator o) => o -> Word64 -> m ()

Set the value of the “latency” property. When overloading is enabled, this is equivalent to

set aggregator [ #latency := value ]

minUpstreamLatency

Force minimum upstream latency (in nanoseconds). When sources with a higher latency are expected to be plugged in dynamically after the aggregator has started playing, this allows overriding the minimum latency reported by the initial source(s). This is only taken into account when larger than the actually reported minimum latency.

Since: 1.16

constructAggregatorMinUpstreamLatency :: IsAggregator o => Word64 -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “min-upstream-latency” property. This is rarely needed directly, but it is used by new.

getAggregatorMinUpstreamLatency :: (MonadIO m, IsAggregator o) => o -> m Word64

Get the value of the “min-upstream-latency” property. When overloading is enabled, this is equivalent to

get aggregator #minUpstreamLatency

setAggregatorMinUpstreamLatency :: (MonadIO m, IsAggregator o) => o -> Word64 -> m ()

Set the value of the “min-upstream-latency” property. When overloading is enabled, this is equivalent to

set aggregator [ #minUpstreamLatency := value ]

startTime

No description available in the introspection data.

constructAggregatorStartTime :: IsAggregator o => Word64 -> IO (GValueConstruct o)

Construct a GValueConstruct with valid value for the “start-time” property. This is rarely needed directly, but it is used by new.

getAggregatorStartTime :: (MonadIO m, IsAggregator o) => o -> m Word64

Get the value of the “start-time” property. When overloading is enabled, this is equivalent to

get aggregator #startTime

setAggregatorStartTime :: (MonadIO m, IsAggregator o) => o -> Word64 -> m ()

Set the value of the “start-time” property. When overloading is enabled, this is equivalent to

set aggregator [ #startTime := value ]