Two Chinese ETRI video codec patents held invalid

The Beijing Intellectual Property Court found all claims of two Chinese patents, CN103384333B and CN104219523B, invalid after the patent owner, Electronics and Telecommunications Research Institute (ETRI), filed an appeal. The CN’333 and CN’523 patents are related to patents that are designated essential to the Access Advance (formerly known as HEVC Advance) patent pool as well as SISVEL’s AV1 and VP9 patent pools.

Unified is represented by Tao Chen, Yu Yan, and Peter Zhang at Wei Chixue Law Firm, and the case is managed by in-house counsel, Jessica L.A. Marks and Roshan Mansinghani.

GEVC patent in SISVEL AV1 pool appears not essential

As part of an ongoing series examining the patent holders and pools erroneously designating patents as essential, we highlight U.S. Patent 10,460,344 titled “Region merging and coding parameter reuse via merging.” This patent is owned by GE Video Compression (GEVC). GEVC has designated the ’344 patent as essential to the AV1 standard as a part of SISVEL’s AV1 Patent Pool. See AV1 Patent List, AV1 Family AV1-040, available at https://www.sisvel.com/images/documents/Video-Coding-Platform/PatentList_AV1.pdf.

GEVC’s U.S. Patent 10,460,344 should not be considered to be essential to the AV1 standard. The ’344 patent is directed to a decoder that uses a merging or grouping of simply connected regions using a reduced amount of data. ’344 patent, Abstract. Namely, a merge indicator indicates whether a region currently being decoded should be reconstructed based on a motion coding parameter. If the indicator indicates copying, the appropriate vector is copied. If the indicator indicates compute, the appropriate motion vector is computed.  Id., claims 1, 9, 17, 26. 

The concept of a merge indicator is an evolved form of motion vector competition. See, e.g., Joel Jung and Guillaume Laroche, “Competition-Based Scheme for Motion Vector Selection and Coding,” VCEG Contribution VCEG-AC06r1, Klagenfurt, Austria, July 2006. In contrast to the ’344 patent and prior motion vector competition literature, the AV1 standard does not employ a merge indicator; rather, the concepts of merging and computing a motion vector is spread over multiple values, not merely an indicator to either copy the ap or compute the motion vector.  See, e.g., AV1 §§ 5.11.26 (assign_mv syntax code used to limit the maximum size of motion vectors); 5.11.23 (syntax); 6.10.22 (semantics describing new_mv, zero_mv, and ref_mv);. 

Thus, the ’344 patent does not appear to be essential to the AV1 standard despite being declared as essential. The public would benefit from appropriate scrutiny of patent pools that allegedly cover critical technical standards, particularly open-source standards such as AV1.

Another InterDigital patent in SISVEL AV1 pool appears not essential

As part of an ongoing series examining the patent holders and pools erroneously designating patents as essential, we highlight U.S. Patent 9,674,556 titled “Methods and apparatus for in-loop de-artifact filtering.” This patent is owned by InterDigital VC Holdings, Inc. InterDigital has designated the ’556 patent as essential to the AV1 standard as a part of SISVEL’s AV1 Patent Pool. See AV1 Patent List, AV1 Family AV1-056, available at https://www.sisvel.com/images/documents/Video-Coding-Platform/PatentList_AV1.pdf.

InterDigital’s ’556 patent should not be considered to be essential to the AV1 standard. The ’556 patent is directed to in-loop artifact filtering, and in particular, two filters for successively performing in-loop filtering. The claims of the ’556 patent require (1) “a deblocking filter for performing a first pass to reduce blocking artifacts” and (2) “an adaptive sparse de-noising filter for performing a second pass to reduce noise.” ’556 patent, claim 1.

The AV1 standard uses a de-ringing filter called CDEF as its second filter, not the ’556 patent’s claimed “de-noising filter.” In detail, the AV1 standard employs a distinct process known as the CDEF (constrained directional enhancement filter) process. According to the AV1 standard, the “purpose of the CDEF is to perform deringing….” See AV1, § 7.15 (emphasis added). Contemporaneous research confirms the CDEF works to reduce ringing artifacts. See Midtskogen et al., “The AV1 Constrained Directional Enhancement Filter (CDEF),” arXiv:1602.05975 [cs.MM], Feb. 18, 2016, p. 1, available at https://doi.org/10.48550/arXiv.1602.05975.

Although InterDigital cites the CDEF provisions of the AV1 standard as part of its claims for essentiality, the applicant expressly disclaimed de-ringing filters from the scope of its claims. The ’556 Patent explicitly distinguishes between de-ringing filters (e.g., CDEF) and its claimed “de-noising” filters, listing them as separate filtering options: “At least one of the filters includes, for example, a deblocking filter, a de-ringing filter, a de-noising filter…” ’556 patent, 10:13–16. The difference was confirmed by the applicant during prosecution of the ’556 patent’s parent application, U.S. Patent Application No. 12/312,386, in which the applicant stated that an applied reference’s “deringing filtering does not disclose or suggest a sparse de-noising filter for performing a second pass to reduce noise,” which is similarly included in the ’556 Patent’s claims. See Prosecution History of U.S. Patent Application 12/312,386, Response to Office Action filed June 3, 2014, p. 10 (italics in original).

Moreover, AV1 standard’s use of (1) a deblocking filter followed by (2) de-ringing filter was already well known in the art prior to the ’556 Patent. For example, U.S. Patent 7,738,563 to Pelc, filed over two years prior to the ’556 Patent’s earliest priority date, disclosed a “filter 430 [that] applied [1] deblocking filtering operations and then [2] de-ringing filtering operations.” Pelc ‘563, 5:49-52. Similarly, U.S. Patent 8,537,903 to Lim, filed over a year prior to the ’556 Patent’s earliest priority date, disclosed a decoding system with “[1] a de-blocking system configured to receive decoded video data and decoding information and remove blocking artifacts from the decoded video data, and [2] a de-ringing system configured to remove ringing artifacts from the de-blocked video data.” Lim ‘903, Abstract. Again, this is similar to the operations described in the AV1 standard and distinct from a second-stage “adaptive sparse de-noising filter” in the ’556 Patent.

Thus, the ’556 Patent does not appear to be essential to the AV1 standard even though it has been declared essential and actively licensed as being so. The public would benefit from appropriate scrutiny of patent pools that allegedly cover critical technical standards.

The ’556 Patent is related to U.S. Patent 9,277,243, which InterDigital has also declared essential, but whose non-essentiality is reviewed in this post, https://www.unifiedpatents.com/insights/2023/6/15/interdigital-sisvels-av1-pool-us-9227243.

InterDigital patent in SISVEL AV1 pool appears not essential

As part of an ongoing series examining the patent holders and pools erroneously designating patents as essential, we highlight U.S. Patent 9,277,243 titled “Methods and apparatus for in-loop de-artifact filtering.” This patent is owned by InterDigital VC Holdings, Inc. InterDigital has designated the ’243 patent as essential to the AV1 standard as a part of SISVEL’s AV1 Patent Pool. See AV1 Patent List, AV1 Family AV1-056, available at https://www.sisvel.com/images/documents/Video-Coding-Platform/PatentList_AV1.pdf.

InterDigital’s ’243 Patent should not be considered to be essential to the AV1 standard. The ’243 Patent contains a single claim directed to in-loop artifact filtering, and in particular, two filters for successively performing in-loop filtering:  (1) “a deblocking filter for performing a first pass to reduce blocking artifacts” and (2) “an adaptive sparse de-noising filter for performing a second pass to reduce noise.” ’243 Patent, claim 1.

The AV1 standard uses a de-ringing filter called CDEF as its second filter, not the ’243 Patent’s claimed “de-noising filter.” In detail, the AV1 standard employs a distinct process known as the CDEF (constrained directional enhancement filter) process. According to the AV1 standard, the “purpose of the CDEF is to perform deringing….” See AV1, § 7.15 (emphasis added). Contemporaneous research confirms the CDEF works to reduce ringing artifacts. See Midtskogen et al., “The AV1 Constrained Directional Enhancement Filter (CDEF),” arXiv:1602.05975 [cs.MM], Feb. 18, 2016, p. 1, available at https://doi.org/10.48550/arXiv.1602.05975.

Although InterDigital cites the CDEF provisions of the AV1 standard as part of its claims for essentiality, the applicant expressly disclaimed de-ringing filters from the scope of its claims. The ’243 Patent explicitly distinguishes between de-ringing filters (e.g., CDEF) and its claimed “de-noising” filters, listing them as separate filtering options: “At least one of the filters includes, for example, a deblocking filter, a de-ringing filter, a de-noising filter…” ’243 Patent, 10:2-5. The difference was confirmed by the applicant during prosecution of the ’243 Patent’s application, U.S. Patent Application No. 12/312,386, in which the applicant stated that an applied reference’s “deringing filtering does not disclose or suggest a sparse de-noising filter for performing a second pass to reduce noise,” which is similarly included in the ’243 Patent’s claims. See Prosecution History of U.S. Patent Application 12/312,386, Response to Office Action filed June 3, 2014, p. 10 (italics in original).

Moreover, AV1 standard’s use of (1) a deblocking filter followed by (2) de-ringing filter was already well known in the art prior to the ’243 Patent. For example, U.S. Patent 7,738,563 to Pelc, filed over two years prior to the ’243 Patent’s earliest priority date, disclosed a “filter 430 [that] applied [1] deblocking filtering operations and then [2] de-ringing filtering operations.” Pelc ‘563, 5:49-52. Similarly, U.S. Patent 8,537,903 to Lim, filed over a year prior to the ’243 Patent’s earliest priority date, disclosed a decoding system with “[1] a de-blocking system configured to receive decoded video data and decoding information and remove blocking artifacts from the decoded video data, and [2] a de-ringing system configured to remove ringing artifacts from the de-blocked video data.” Lim ‘903, Abstract. Again, this is similar to the operations described in the AV1 standard and distinct from a second-stage “adaptive sparse de-noising filter” in the ’243 Patent.

Thus, the ’243 Patent does not appear to be essential to the AV1 standard even though it has been declared essential and actively licensed as being so. The public would benefit from appropriate scrutiny of patent pools that allegedly cover critical technical standards.