View Source Membrane.Element.WithOutputPads behaviour (Membrane Core v1.1.0)

Module defining behaviour for source and filter elements.

When used declares behaviour implementation, provides default callback definitions and imports macros.

For more information on implementing elements, see Membrane.Element.Base.

Summary

Callbacks

Callback called when buffers should be emitted by a source, filter or endpoint.

Functions

Macro that defines output pad for the element.

Callbacks

Link to this callback

handle_demand(pad, size, unit, context, state)

View Source (optional)

Callback called when buffers should be emitted by a source, filter or endpoint.

It is called only for output pads in the :manual flow control mode, as in their case demand is triggered by the input pad of the subsequent element.

In sources and endpoint, appropriate amount of data should be sent here.

In filters, this callback should usually return :demand action with size sufficient for supplying incoming demand. This will result in calling c:Membrane.WithInputPads.handle_buffer/4, which is to supply the demand.

If a source or an endpoint is unable to produce enough buffers, or a filter underestimated returned demand, the :redemand action should be used (see Membrane.Element.Action.redemand/0).

Context passed to this callback contains additional field :incoming_demand.

Functions

Link to this macro

def_output_pad(name, spec)

View Source (macro)

Macro that defines output pad for the element.

It automatically generates documentation from the given definition and adds compile-time stream format specs validation.

The type Membrane.Pad.element_spec/0 describes how the definition of pads should look.