Module that allows to specify valid caps and verify that they match specification.

Caps specifications (specs) should be in one of the formats:

• simply module name of the desired caps (e.g. Membrane.Caps.Audio.Raw or Raw with proper alias)
• tuple with module name and keyword list of specs for specific caps fields (e.g. {Raw, format: :s24le})
• list of the formats described above

Field values can be specified in following ways:

• By a raw value for the field (e.g. :s24le)
• Using range/2 for values comparable with Kernel.<=/2 and Kernel.>=/2 (e.g. Matcher.range(0, 255))
• With one_of/1 and a list of valid values (e.g Matcher.one_of([:u8, :s16le, :s32le])) Checks on the values from list are performed recursively i.e. it can contain another range/2, for example Matcher.one_of([0, Matcher.range(2, 4), Matcher.range(10, 20)])

If the specs are defined inside of Membrane.Element.WithInputPads.def_input_pad/2 and Membrane.Element.WithOutputPads.def_output_pad/2 module name can be omitted from range/2 and one_of/1 calls.

Example

Below is a pad definition with an example of specs for caps matcher:

alias Membrane.Caps.Video.Raw

def_input_pad :input,
  demand_unit: :buffers,
  caps: {Raw, format: one_of([:I420, :I422]), aligned: true}