THE AV1 CONSTRAINED DIRECTIONAL ENHANCEMENT FILTER (CDEF) Steinar Midtskogen Jean-Marc Valin Cisco Systems Inc. Mozilla Corporation Lysaker, Norway Mountain View, CA, USA
[email protected] [email protected] 0 1 2 3 4 5 6 7 0 0 1 1 2 2 3 3 0 0 0 0 0 0 0 0 3 3 2 2 1 1 0 0 ABSTRACT 1 2 3 4 5 6 7 8 1 1 2 2 3 3 4 4 1 1 1 1 1 1 1 1 4 4 3 3 2 2 1 1 2 3 4 5 6 7 8 9 2 2 3 3 4 4 5 5 2 2 2 2 2 2 2 2 5 5 4 4 3 3 2 2 This paper presents the constrained directional enhancement filter 3 4 5 6 7 8 9 10 3 3 4 4 5 5 6 6 3 3 3 3 3 3 3 3 6 6 5 5 4 4 3 3 4 5 6 7 8 9 10 11 4 4 5 5 6 6 7 7 4 4 4 4 4 4 4 4 7 7 6 6 5 5 4 4 designed for the AV1 royalty-free video codec. The in-loop filter 5 6 7 8 9 10 11 12 5 5 6 6 7 7 8 8 5 5 5 5 5 5 5 5 8 8 7 7 6 6 5 5 is based on a non-linear low-pass filter and is designed for vector- 6 7 8 9 10 11 12 13 6 6 7 7 8 8 9 9 6 6 6 6 6 6 6 6 9 9 8 8 7 7 6 6 7 8 9 10 11 12 13 14 7 7 8 8 9 9 10 10 7 7 7 7 7 7 7 7 10 10 9 9 8 8 7 7 ization efficiency.