FFprobe.format

You're seeing just the function format, go back to FFprobe module for more information.

format(file_path)

format(binary()) ::
  {:ok, format_map()} | {:error, :invalid_file} | {:error, :no_such_file}

Get the "format" map, containing general info for the specified file, such as number of streams, duration, file size, and more.

If the file does not exist, returns {:error, :no_such_file}. If the file is a non media file, returns {:error, :invalid_file}.