On May 19, 2022, all of the original claims of EP 3 471 416 and EP 3 487 179, owned by GE Video Compression LLC (GEVC), were found unpatentable based on two separate challenges filed by Unified. Only after several failed attempts to amend the claims was GEVC able to gain allowance by adding significant narrowing limitations to the claims. The two EP patents were related to U.S. patents that are designated essential to the Access Advance (previously HEVC Advance) patent pool and Sisvel's AV1 and VP9 pools.
Only after several failed attempts to amend was GEVC able to gain allowance of significantly narrowed claims. These amendments affect the essentiality for both sets of claims. For example, the claims of both patents now require for a "transform coefficient block,” context adaptive entropy decoding that uses contexts “selected…depending on a number of positions at which according to the previously extracted and associated first-type syntax elements significant transform coefficients are situated in a predetermined neighborhood” where "the predetermined neighborhood” is “inside” (for EP’416) or “within” (for EP’179) "the transform coefficient block." But the H.265 standard considers only whether another neighborhood has a significant coefficient (not the significant coefficients within the same transform coefficient block) and provides that information via a single sub-block flag (not a specific number). See Section 9.3.4.2.5. Moreover, although the H.264 standard used a technique of keeping track of the number of previously decoded syntax elements, the claims explicitly recite that “the transform coefficient block is larger than 8x8,” and H.264 only handles blocks up to 8x8.
Unified was represented by Dr. Andrew McGettrick and Dr. Susan Keston of HGF Law LLP, and by in-house counsel, Jessica L.A. Marks and Roshan Mansinghani.