View Source Membrane.Testing.DynamicSource (Membrane Core v1.1.0)

Testing Element for supplying data based on generator function or payloads passed through options. It is very similar to Membrane.Testing.Source but is has dynamic pad instead of static.

Example usage

As mentioned earlier you can use this element in one of two ways, providing either a generator function or an Enumerable.t.

If you provide an Enumerable.t with payloads, then each of those payloads will be wrapped in a Membrane.Buffer and sent through :output pad.

%Source{output: [0xA1, 0xB2, 0xC3, 0xD4]}

In order to specify Membrane.Testing.Source with generator function you need to provide initial state and function that matches generator/0 type. This function should take state and demand size as its arguments and return a tuple consisting of actions that element will return during the Membrane.Element.WithOutputPads.handle_demand/5 callback and new state.

generator_function = fn state, pad, size ->
  #generate some buffers
  {actions, state + 1}

%Source{output: {1, generator_function}}

Element options

Passed via struct Membrane.Testing.DynamicSource.t/0

  • output

    {initial_state :: any(), generator()} | Enum.t()

    Default value: {0, &Membrane.Testing.DynamicSource.default_buf_gen/3}
    If output is an enumerable with Membrane.Payload.t/0 then buffer containing those payloads will be sent through the :output pad and followed by Membrane.Element.Action.end_of_stream/0.

    If output is a {initial_state, function} tuple then the the function will be invoked each time handle_demand is called. It is an action generator that takes two arguments. The first argument is the state that is initially set to initial_state. The second one defines the pad on which the demand has been requested. The third one defines the size of the demand. Such function should return {actions, next_state} where actions is a list of actions that will be returned from handle_demand/4 and next_state is the value that will be used for the next call.

  • stream_format


    Default value: %Membrane.RemoteStream{content_format: nil, type: :bytestream}
    Stream format to be sent before the output.



Accepted formats:

Flow control::manual
Demand unit:nil




Struct containing options for Membrane.Testing.DynamicSource


Returns description of options available for this module


@type generator() ::
  (state :: any(), pad :: Membrane.Pad.ref(), buffers_cnt :: pos_integer() ->
     {[Membrane.Element.Action.t()], state :: any()})
@type t() :: %Membrane.Testing.DynamicSource{
  output: {initial_state :: any(), generator()} | Enum.t(),
  stream_format: struct()

Struct containing options for Membrane.Testing.DynamicSource


Link to this function

default_buf_gen(generator_state, pad, size)

View Source
@spec default_buf_gen(integer(), Membrane.Pad.ref(), integer()) ::
  {[Membrane.Element.Action.t()], integer()}
@spec options() :: keyword()

Returns description of options available for this module