@type t() :: %ExMP4.Box.Dops{
  channel_mapping_family: non_neg_integer(),
  channel_mapping_table:
    %{
      stream_count: non_neg_integer(),
      coupled_count: non_neg_integer(),
      channel_mapping: non_neg_integer()
    }
    | nil,
  input_sample_rate: non_neg_integer(),
  output_channel_count: non_neg_integer(),
  output_gain: integer(),
  pre_skip: non_neg_integer(),
  version: 0
}