What is the appropriate standard for determining whether a patent claim is directed to a patent-ineligible concept when determining whether an invention is eligible for patenting under 35 U.S.C. § 101?

QUESTION PRESENTED ENCO owns and practices a patent for a system and method for automatically converting human speech carried in an audio-visual signal into the text captions that appear on one’s TV screen. The Federal Circuit ruled that the invention was not eligible for patent protection under 35 U.S.C. § 101 because it was allegedly directed to an abstract idea. The single question presented is: What is the appropriate standard for determining whether a patent claim is directed to a patent-ineligible concept when determining whether an invention is eligible for patenting under 35 U.S.C. § 101?