def convert_short_channel_id_to_channel_id(blockheight, transaction, output):
    """
    Converts short channel id (blockheight:transaction:output) to a long integer channel id.

    :param blockheight:
    :param transaction: Number of transaction in the block.
    :param output: Number of output in the transaction.
    :return: channel id: Encoded integer number representing the channel,
     can be decoded by :func:`lib.conversion.extract_short_channel_id_from_string`.
    """
    return blockheight << 40 | transaction << 16 | output
