 While AVC uses the integer DCT with 4x4 and 8x8 block sizes, HEVC uses integer DCT and DST transforms with varied block sizes between 4x4 and 32x32.HEVC is heavily patented, with the majority of patents belonging to Samsung Electronics, GE, NTT and JVC Kenwood.It is currently being challenged by the aiming-to-be-freely-licensed AV1 format.