Membrane.Filter behaviour (Membrane Core v0.7.0) View Source

Module defining behaviour for filters - elements processing data.

Behaviours for filters are specified, besides this place, in modules Membrane.Element.Base, Membrane.Element.WithOutputPads, and Membrane.Element.WithInputPads.

Filters can have both input and output pads. Job of a usual filter is to receive some data on a input pad, process the data and send it through the output pad. If these pads work in pull mode, which is the most common case, then filter is also responsible for receiving demands on the output pad and requesting them on the input pad (for more details, see Membrane.Element.WithOutputPads.handle_demand/5 callback). Filters, like all elements, can of course have multiple pads if needed to provide more complex solutions.

Link to this section Summary

Functions

__using__(options)

Brings all the stuff necessary to implement a filter element.

Callbacks

handle_process(pad, buffer, context, state)

Callback that is to process buffers. In contrast to handle_process_list/4, it is passed only a single buffer.

handle_process_list(pad, buffers, context, state)

Callback that is to process buffers.

Link to this section Functions

using(options)

(macro)

Brings all the stuff necessary to implement a filter element.

Options:

:bring_pad? - if true (default) requires and aliases Membrane.Pad

Link to this section Callbacks

handle_process(pad, buffer, context, state)

Specs

handle_process(
  pad :: Membrane.Pad.ref_t(),
  buffer :: Membrane.Buffer.t(),
  context :: Membrane.Element.CallbackContext.Process.t(),
  state :: Membrane.Element.state_t()
) :: Membrane.Element.Base.callback_return_t()

Callback that is to process buffers. In contrast to handle_process_list/4, it is passed only a single buffer.

Called by default implementation of handle_process_list/4.

handle_process_list(pad, buffers, context, state)

Specs

handle_process_list(
  pad :: Membrane.Pad.ref_t(),
  buffers :: [Membrane.Buffer.t()],
  context :: Membrane.Element.CallbackContext.Process.t(),
  state :: Membrane.Element.state_t()
) :: Membrane.Element.Base.callback_return_t()

Callback that is to process buffers.

By default calls handle_process/4 for each buffer.

For pads in pull mode it is called when buffers have been demanded (by returning :demand action from any callback).

For pads in push mode it is invoked when buffers arrive.