Netflix, Inc. v. DivX, LLC

I'll research this case across the PTAB docket, parallel district court litigation, and press coverage.

Case Overview and Background

Parties. The IPR at hand, Netflix, Inc. v. DivX, LLC, IPR2020-00558, is the PTAB flank of a parallel district court action, DivX, LLC v. Netflix, Inc., No. 2:19-cv-01602 (C.D. Cal.) (originally assigned to Judge Philip S. Gutierrez as 2:19-cv-01602-PSG-DFM, later reassigned to Judge George H. Wu as 2:19-cv-1602-GW-AGRx). Netflix, Inc. is the operating-company defendant — the global streaming service, a Delaware corporation headquartered in Los Gatos with an approximately 800-employee Los Angeles office; Netflix's petition in IPR2020-00558 was filed jointly with Hulu, LLC as co-petitioner (see Petitioner's Updated Exhibit List, IPR2020-00558, captioned "Netflix, Inc. and Hulu, LLC"). DivX, LLC is a Delaware LLC with its principal place of business in San Diego that describes itself as owning "patents covering foundational internet video streaming technologies." Netflix's characterization in the district court is far blunter: per its motion-in-limine briefing (Dkt. 797-1, filed Jan. 29, 2026), the plaintiff entity is not the historic DivX codec company but "DivX CF Holdings LLC," created by Fortress Investment Group in December 2017 to buy patent assets from NeuLion's subsidiary Sonic IP, Inc., renamed "DivX, LLC" in February 2018 — with no engineering department, one engineer, an attorney at the helm, and litigation/licensing as its primary business, operating as a Fortress-controlled pass-through (97% owned by DivX CF Investors LLC). That NPE/PAE framing is a litigating position in Netflix's brief, not a court finding, and DivX contested it; treat the corporate-history details as well documented but the normative label as contested.

Accused technology and patents. DivX's operative pleading (First Amended Complaint, Dkt. 60) targeted Netflix's end-to-end streaming pipeline — content ingest and encoding (including H.265/HEVC), packaging into MP4 with ISO Common Encryption/Microsoft PIFF sample-encryption boxes, adaptive bitrate streaming, index/manifest generation, and DRM — plus indirect infringement based on subscriber playback on licensed devices (complaint ¶¶ 145–152; venue allegations at ¶¶ 14–20). The original FASC asserted eight patents; four reached the jury. Technical sketches: U.S. Pat. No. 7,295,673 — securing compressed video by partially encrypting selected frame portions and synchronizing frame decryption information with the encrypted content (claims 29, 32 tried); U.S. Pat. No. 8,139,651 — a block-boundary deblocking-filter method (claim 2 tried); U.S. Pat. No. 8,472,792 ("Multimedia Distribution System") — a dual-index file structure with an abridged index alongside the full index for faster seek/trick-play (claim 16 tried); U.S. Pat. No. 9,270,720 and U.S. Pat. No. 9,998,515 — generating device-specific top-level index files based on playback-device capabilities (both held invalid under § 101 by the court, Dkt. 774); U.S. Pat. No. 10,212,486 — a playback device for adaptive streaming of partially encrypted frames keyed with a common key set (claims 1, 4, 15 tried); U.S. Pat. No. 10,225,588 (Kiefer et al.; inventors Michael George Kiefer, Eric William Grab, and Jason Braness) — the IPR patent, claiming adaptive bitrate playback of protected content using a top-level index file, byte-range requests, and "locating encryption information that identifies encrypted portions of frames of video within the requested portions of the selected stream of protected video" (claim 1, limitation [l]); and U.S. Pat. No. 9,184,920, which DivX withdrew after the PTAB invalidated all challenged claims on remand.

Posture, venue, and why it matters. DivX filed in C.D. Cal. on March 5, 2019, pleading venue under 28 U.S.C. §§ 1391, 1400(b) on the strength of Netflix's Los Angeles office and engineering staff — a deliberate forum choice away from Netflix's N.D. Cal. home and from DivX's own San Diego base. DivX simultaneously sued Hulu, LLC (No. 2:19-cv-01606, dismissed Aug. 25, 2022) and pursued foreign counterparts in Brazil, Germany, and the Netherlands, as reflected in Netflix's motions in limine. Critically, the district case was stayed for roughly four years while Netflix and Hulu filed IPRs covering nearly every asserted patent (e.g., IPR2020-00052 on the '651, -00614 on the '673, -00646 on the '792, -00647 on the '720, -00648 on the '515, and -00558 on the '588). The stay was lifted in May 2024; trial ran March 13–25, 2026; the jury returned a unanimous defense verdict on March 25, 2026 (Dkt. 1152), and final judgment entered May 7, 2026 (Dkt. 1197), holding no infringement of the '673, '651, '792, and '486 patents and invalidating the '720 and '515 claims under § 101 — against a damages demand reported at over $400 million (WilmerHale client release, Apr. 8, 2026). Post-trial JMOL/new-trial motions were filed June 4, 2026 (Dkts. 1206–1207), briefed through August 2026 (Dkts. 1210–1218); I could not source the outcome of those motions. The IPR itself is the case here: Netflix (with Hulu) petitioned on Feb. 18, 2020 on all claims over Chen, Lindahl, and Hurst; the Board instituted Aug. 26, 2020; the first final written decision rejected Netflix's challenge; the Federal Circuit vacated and remanded (No. 22-1083, Mar. 1, 2023); on remand a PTAB majority adopted DivX's narrow construction of limitation [l] and upheld the claims over APJ Turner's 37-page dissent (Paper 66, Feb. 22, 2024, 2024 WL 734765); and in a precedential Feb. 13, 2026 decision the Federal Circuit reversed that construction — holding "within the requested portions of the selected stream" modifies "encrypted portions of frames of video," not "encryption information" — held limitation [l] taught by the asserted prior art, and vacated and remanded with costs to Netflix (No. 24-1541). That is why IPR2020-00558 remains "on remand." The case is notable on several axes: (1) as precedent on modifier-attachment/claim-drafting grammar (with practical lessons for both prosecutors and IPR petitioners); (2) as a textbook illustration of IPR linkage — serial PTAB and Federal Circuit rounds, a multi-year stay, and one construction issue flipping patentability; (3) as a market-context story, pitting adaptive-bitrate/HTTP-streaming and DRM patents against the largest streamer, and a Fortress-backed licensing entity against an operating company, with a rare PTAB dissent and a complete defense verdict against a nine-figure demand.

Sourcing caveats. The DivX corporate-history and NPE characterization comes from Netflix's briefing (Dkt. 797-1) rather than an adjudicated finding; DivX's own description of its business comes from its complaint. I found no authoritative source confirming DivX's current ultimate parent or whether IPR2020-00558 has issued a post-2026-remand decision, and the disposition of the pending JMOL/new-trial motions is not yet documented in the sources reviewed. Per the case metadata, DivX's post-appeal covenant not to sue on the '588 patent (reported by WilmerHale) mooted the district court dispute over that patent but did not terminate the IPR.

I'll research this case and the parallel litigation. Let me start with several searches.

I have the core outline. Let me dig into the district court docket and the PTAB proceedings in parallel.

Scope note

IPR2020-00558 is not an infringement action. It is a PTAB inter partes review that Netflix (joined by Hulu) filed against DivX's U.S. Patent No. 10,225,588. The infringement litigation you're asking about is the parallel district court case that gave rise to it:

• DivX, LLC v. Netflix, Inc., No. 2:19-cv-01602 (C.D. Cal.) (originally 2:19-cv-1602-PSG-DFMx; later 2:19-cv-1602-GW-AGRx)
• Companion case: DivX, LLC v. Hulu, LLC, No. 2:19-cv-01606 (C.D. Cal.)

The '588 patent is the bridge between the two. Both tracks are covered below in chronological order. Where sources conflict (notably the sequencing of the '588 covenant/dismissal versus the February 2026 Federal Circuit decision), I flag it rather than guess.

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1. Filing and initial pleadings (2019)

Caveat: I could not verify the dispositions of the May 31, 2019 or September 4, 2019 motions to dismiss from the sources retrieved. The fact that DivX amended once as of right and Netflix then answered the FAC and pleaded counterclaims indicates the operative complaint survived in material part, but the specific ruling text is not in the record I could access.

Damages exposure: DivX's demand grew from ~$424 million (as reported at trial) to more than $500 million at the time the stay was lifted in 2024 (WilmerHale, 2026-04-08).

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2. Parallel PTAB proceedings (2019–2024) — the driver of the stay

Netflix (with Hulu in several proceedings) began filing IPR petitions in October 2019, with the bulk filed February–March 2020. The § 315(b) one-year bar ran in mid-March 2020 (per the court's 2020-05-11 stay order, Dkt. 106). Eight asserted patents; IPRs were filed on all but the '486.

IPR2020-00558 (the '588 patent) — core proceeding

Other IPRs on the asserted patents (effect on the litigation)

From the parties' joint status reports (esp. Dkt. 158 and Dkt. 164), the net PTAB outcomes were:

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3. Pre-trial motions of substance and the stay (2020–2024)

• 2020-01-29 / 2020-02-20 — Case schedule entered: trial 2021-04-27, final pretrial conference 2021-04-12, non-expert discovery cutoff 2020-09-24, claim construction hearing 2020-08-31. DivX served its list of ≤30 asserted claims on 2020-04-16 (Dkt. 106).
• 2020-03-13 — Netflix moves to stay pending IPR (Dkt. 94); Hulu files a parallel motion (No. 2:19-cv-01606). DivX opposes (Dkt. 102, 2020-04-27); Netflix replies (Dkt. 104, 2020-05-04).
• 2020-04-10 / 2020-04-16 / 2020-04-23 — Protective order, mediator appointment, and ESI order entered by stipulation — the last discovery infrastructure completed before the stay.
• 2020-05-11 — Court grants the stay (Dkt. 106). Applying the Ethicon/Landis three-factor test, the court found the cases "in their early stages" (claim construction barely begun; limited discovery) and that the IPRs would simplify the issues. This order is the single most consequential pre-trial ruling in the case — it froze the litigation for four years.
• 2022-01-08 — DivX moves to lift the stay after final written decisions in all IPRs.
• 2022-03-29 — Court denies the motion to lift the stay (Dkt. 130), and orders the parties to file joint status reports within 10 days of each Federal Circuit resolution.
• 2023-04-17 — Joint status report confirming the '588 and '651 appeals were complete, four more appeals fully briefed and argued, and one patent ('486) never in an IPR.
• 2023-12-29 — DivX files a second motion to lift the stay (Dkt. 146-1), hearing set 2024-01-26. Netflix opposes (Dkt. 153), arguing further simplification from the pending remands.
• 2024-02 — Court continues the stay (Dkt. 158), reasoning that the remand proceedings were of "a relatively short, finite duration."
• 2024-04 — Joint status report (Dkt. 164): Netflix confirms it will appeal the '588 remand FWD; DivX argues the stay should end because "claims that have been tested and withstood Netflix's challenges in the PTAB and the Federal Circuit."
• 2024-05-01 — Court lifts the stay (Dkt. 165), reopens the case, and sets a scheduling conference for 2024-05-09. WilmerHale was retained shortly before this point. By then DivX was asserting seven patents and seeking >$500M.

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4. Claim construction (Markman)

• The only district court claim construction event on the calendar was the 2020-08-31 Markman hearing, which was superseded by the 2020-05-11 stay before it occurred; the parties had exchanged claim-construction disclosures only as of 2020-05-07.
• I found no public record of a post-2024 Markman hearing or claim construction order in the C.D. Cal. case. The operative claim-construction rulings that shaped this dispute were made by the PTAB and the Federal Circuit in IPR2020-00558 — specifically the construction of claim 1 limitation [l] of the '588 patent (narrow, DivX-favoring construction adopted by the Board majority on 2024-02-22; rejected by the Federal Circuit on 2026-02-13).
• DivX's own 2023-12-29 brief notes that the "simplification the Court intended to achieve through stays, in particular in terms of the Federal Circuit guidance for claim construction, has been achieved."

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5. Discovery milestones with strategic significance

• 2020-04-16 — DivX serves its narrowed list of ≤30 asserted claims (pre-stay).
• 2024-07-09 — Netflix serves First Supplemental Invalidity Contentions, first raising an ensnarement defense against DivX's doctrine-of-equivalents theories.
• 2025-02-24 — Scheduling conference; order at ECF 317 (no deadline to amend pleadings). Trial originally set for 2025-12-02.
• 2025-03-05 — Netflix serves Third Supplemental Invalidity Contentions (ensnarement).
• 2025-05-19 — Netflix supplements interrogatory responses on ensnarement.
• 2025-06-13 — Close of fact discovery. At 6:00 p.m. Pacific on the final day, DivX produced additional license agreements (a 2012 Rovi–Vizio license and a 2010 Rovi–Comcast license) that Netflix contends support patent exhaustion defenses (Dkt. 356).
• 2025-06-17 / 2025-06-23 — Netflix circulates a draft amended answer and meets and confers; DivX signals it will oppose as untimely.
• 2025 (mid) — Netflix moves for leave to amend its answer (Dkt. 356) to add patent exhaustion and ensnarement defenses. Netflix argues no prejudice because both defenses were disclosed 11+ months before the close of fact discovery and ~17 months before trial.

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6. Summary judgment and trial (2025–2026)

• 2025-12-11 — Hearing; 2025-12-28 — Court issues final rulings on the parties' summary judgment motions (Dkt. 774):
  • Netflix wins § 101 invalidity of claims 1–2, 4, 5 of the '720 patent and claim 1 of the '515 patent (two asserted patents knocked out).
  • DivX wins partial summary judgment on Netflix's "PS3 invalidity" theory, but "only with respect to the server-side code" — a limit that spawned a pretrial dispute over whether any non-server-side code existed (Dkt. 780).
• 2026-01-08 — Status conference (Dkt. 766); dispute over trial scope; DivX asserted 13 claims across 5 patents at that point.
• 2026-01-29 — Motions in limine filed, including Netflix's MIL to exclude references to other litigations and foreign proceedings (Dkt. 793, 797) and DivX MILs aimed at Netflix's Fortress/patent-assertion-entity narrative.
• 2026-02-03 — Order granting a joint stipulation dismissing all claims and counterclaims on the '588 patent without prejudice (Dkt. 840).
• 2026-02-13 — Federal Circuit's precedential "grammar" decision in No. 24-1541 reversing the PTAB on the '588 claim construction (see § 2).
• 2026-03-02 to 2026-03-05 — Pretrial conference before Judge George H. Wu; MILs argued and taken under submission, with supplemental briefing ordered (Dkt. entries ~1000–1020).
• 2026-03-13 — Jury trial commences (seven trial days).
• 2026-03-25 — Jury verdict (Dkt. 1152): Netflix did not infringe any asserted claim — '673 claims 29, 32; '651 claim 2; '792 claim 16; '486 claims 1, 4, 15. Because the jury answered "no" on every infringement question, it did not reach invalidity or damages. Verdict after roughly one full day of deliberations.
• 2026-05-07 — Final Judgment (Dkt. 1197):
  • Declaratory judgment of non-infringement on all four tried patents.
  • Claims 1–2, 4, 5 of the '720 patent and claim 1 of the '515 patent invalid under § 101.
  • Judgment for Netflix on Counts I–III and V–VII of the FAC and Counts I, III, V, X, XII–XIII of Netflix's counterclaims.
  • Count IV of the FAC dismissed with prejudice; the '588 counts (FAC Count VIII and counterclaim Counts XV–XVI) dismissed without prejudice per Dkt. 840; several counterclaim counts dismissed without prejudice.
  • "Plaintiff takes nothing from and against Netflix."
  • Netflix declared the prevailing party and awarded costs under FRCP 54(d)(1), Local Rule 54, and 28 U.S.C. § 1920; Netflix directed to file a bill of costs.
  • All Rule 50(a) motions made at trial denied as moot, "without prejudice to, and subject to, such motions being renewed as post-trial motions."

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7. Post-trial motions, settlement, and present posture

• Rule 50(a)/50(b), new trial, and fees: The Final Judgment expressly preserved the right to renew Rule 50(a) motions post-trial, but I found no public record of a Rule 50(b) JMOL motion, a new-trial motion, or an attorney-fees motion as of 2026-09-30. Netflix's only documented post-judgment step is the costs application contemplated by ¶ 12.
• Settlement / covenant: WilmerHale's 2026-04-08 release states that "[e]arlier this month, the US Court of Appeals for the Federal Circuit reversed the PTAB's decision upholding a third patent, and DivX granted Netflix a covenant not to sue on that patent." That is consistent with the '588 patent (the Fed. Cir. reversed the PTAB's upholding of it), but the public docket places the '588 dismissal order on 2026-02-03 (Dkt. 840) — ten days before the 2026-02-13 opinion. The exact date of any covenant not to sue and its interplay with Dkt. 840 is therefore not fully documented in the sources I could verify; treat the covenant's date as uncertain.
• Appeal: DivX can appeal the final judgment to the Federal Circuit (non-infringement verdict and the § 101 rulings); the deadline would run from the 2026-05-07 judgment. No notice of appeal was located.
• District court case status: Closed (JS-6, "Case Terminated," Dkt. 1197). The live "on remand" element is the PTAB proceeding IPR2020-00558, back before the Board after the 2026-02-13 Federal Circuit decision.

Global parallel proceedings (context, not part of the U.S. case)

Per IP Fray's post-verdict report: DivX extended its campaign to Brazil (State Court of Rio de Janeiro, October 2020; first-ever Brazilian permanent injunction granted January 2024 and upheld), the Mannheim Regional Court (April 2022), and the UPC's Munich Local Division (May 2025), with a Munich hearing scheduled for 2026-07-21. Netflix countered with invalidity proceedings in the U.S., Germany, the Netherlands, and Brazil; the parties disputed at the 2026 C.D. Cal. trial whether any foreign or collateral proceedings should be admissible (Netflix MIL, Dkt. 793).

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Bottom line

The litigation was a 2019 portfolio suit that was consumed for four years by the parallel IPR track — stayed 2020-05-11, stay lifted 2024-05-01, then tried in March 2026. The PTAB track produced mixed results for Netflix (invalidating the '920 and much of the '792, and later seeing the '720 and '515 fall on § 101), but it also produced the two Federal Circuit decisions on the '588 patent — the 2023-03-01 vacatur and the 2026-02-13 precedential "rule of last antecedent" ruling — the latter being the most legally significant development in the case and the reason IPR2020-00558 is still "on remand." At the district court level, the case ended in a complete defense verdict on 2026-03-25 across four patents (seven claims) and a final judgment on 2026-05-07 awarding Netflix declaratory non-infringement relief, § 101 invalidation of two more patents, and prevailing-party costs.

I'll research this now. Note upfront: this is a PTAB inter partes review, so the "plaintiff" is the petitioner, Netflix, Inc. Let me find counsel of record from the docket and related district court litigation.

Good start. Now let me confirm current counsel on the remanded IPR and the Federal Circuit appeal, plus check for any substitution of counsel.

Let me pin down the counsel block on the Feb. 2026 Federal Circuit opinion and any 2026 remand filings in the IPR.

Threshold clarification

IPR2020-00558 is not a district-court infringement action — it is a PTAB inter partes review. There is no "plaintiff" in the technical sense. The party on the plaintiff side of the caption is the petitioner, Netflix, Inc. (originally Netflix and Hulu, LLC), and the defendant-side party is the patent owner, DivX, LLC. If by "plaintiff(s)" you mean the party that filed and is prosecuting this case, that is Netflix. I've answered on that basis, and then added the co-pending C.D. Cal. litigation where DivX actually is the plaintiff (roles reversed), since that is likely relevant to your question.

Caveat up front: PTAB papers I could retrieve are the petition/power-of-attorney (Feb. 2020), the 2021 scheduling orders and hearing transcript, the 2023 remand briefing, and the 2023 Hulu termination motion. I could not retrieve a 2026-updated mandatory notice or appearance for the current remand, so the roster below is verified as of the last available filings; there is no indication of substitution.

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1. Netflix, Inc. (petitioner / "plaintiff-side") — PTAB counsel of record

Sheppard, Mullin, Richter & Hampton LLP — Silicon Valley office (379 Lytton Avenue, Palo Alto, CA 94301, as listed on the power of attorney; later filings use 1540 El Camino Real, Suite 120, Menlo Park, CA 94025).

Service/customer: filings were made under Sheppard Mullin Customer Number 166,219, with service to LegalTM-Net-DivX-IPR@sheppardmullin.com / LegalTm-DivX-IPR@sheppardmullin.com.

Note on Hulu, LLC: Hulu was a named co-petitioner for most of the proceeding (the power of attorney and early Board papers are captioned "Netflix, Inc. and Hulu, LLC"). Hulu and DivX jointly moved to terminate as to Hulu on May 11, 2023 after settlement, asking the Board to change the caption to remove Hulu (Paper — "Joint Motion to Terminate Pursuant to 35 U.S.C. § 317"). So Hulu should not be treated as a current party. (motion)

WilmerHale also appears in Netflix's appellate representation in the companion Federal Circuit appeal: the Apr. 18, 2023 nonprecedential opinion lists "HARPER BATTS, Sheppard Mullin Richter & Hampton LLP, Menlo Park, CA, argued for appellee. Also represented by JEFFREY LIANG, CHRISTOPHER SCOTT PONDER; MARK CHRISTOPHER FLEMING, Wilmer Cutler Pickering Hale and Dorr LLP, Boston, MA." (opinion PDF) I could not independently verify who signed the briefs in the current appeal, Netflix, Inc. v. DivX, LLC, No. 24-1541 (Fed. Cir. Feb. 13, 2026) (Moore, C.J.; Dyk, Taranto, JJ.) — the opinion text I retrieved does not include the counsel block. Given the parallel district-court team (below), it is plausible that WilmerHale and Sheppard Mullin are both on it, but I'm flagging that as unverified rather than asserting it.

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2. DivX, LLC (patent owner) — PTAB counsel of record

Lowenstein & Weatherwax LLP — 1016 Pico Boulevard, Santa Monica, CA 90405.

• Kenneth J. Weatherwax — lead counsel; argued for DivX at the May 25, 2021 hearing.
• Back-up/appearing: Nathan Lowenstein, Bridget Smith, Flavio Rose, Edward Hsieh, Parham Hendifar, Patrick Maloney, Jason C. Linger (all Lowenstein & Weatherwax), service address DivX_IPRs@lowensteinweatherwax.com. (2021 scheduling order; 2021 exhibit-list service)

Lowenstein & Weatherwax (Weatherwax and Hendifar) is a well-known patent-owner-side PTAB boutique; it is DivX's PTAB counsel across the parallel DivX/Netflix IPR family (e.g., IPR2020-00511 on the '920 patent).

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3. Related district-court action — DivX, LLC v. Netflix, Inc., No. 2:19-cv-01602 (C.D. Cal.)

This is the actual patent infringement case, where DivX is the plaintiff. It was filed Mar. 5, 2019 before Judge Philip S. Gutierrez (later reassigned; case number appears as 2:19-cv-01602-PSG-DFMx and later 2:19-cv-01602-GW-AGRx). The case was stayed from May 2020 pending the IPRs and went to a jury trial in spring 2026, where the jury returned a defense verdict for Netflix. (stay order; WilmerHale trial announcement, Apr. 8, 2026)

DivX's counsel over time (plaintiff):

• Tensegrity Law Group LLP (Redwood Shores, CA and McLean, VA) — Matthew D. Powers, Paul Ehrlich, William P. Nelson, Natasha M. Saputo, Jerome Ma, Azra M. Hadzimehmedovic, Aaron M. Nathan, Samantha A. Jameson — primary plaintiff team in the 2020–2023 stay period. (Joint Status Report, Apr. 17, 2023)
• Brown Rudnick LLP (Irvine, CA) — David M. Stein — co-counsel; Stein appears in later filings with an olsonstein.com address, indicating a move to Olson Stein LLP.
• Irell & Manella LLP (Los Angeles, CA) — Jason G. Sheasby, Lisa Sharrock Glasser, David C. McPhie — trial team.
• Robins Kaplan LLP (Minneapolis, MN) — Aaron R. Fahrenkrog, Emily J. Tremblay, Kia Schmeckpeper (pro hac vice) — trial team. (service list, Jan. 29, 2026)

Netflix's counsel in the district court (defendant): Wilmer Cutler Pickering Hale and Dorr LLP — Mary (Mindy) V. Sooter (Denver, lead trial counsel), James M. Dowd, Christopher T. Casamassima, Jason Choy (Los Angeles), Joseph Taylor Gooch (San Francisco), Dominic E. Massa (Boston). WilmerHale states it was retained shortly before the stay was lifted in May 2024 and led the defense verdict; the same team (Sooter) is a plausible candidate for Netflix's 24-1541 appellate team, but I have not verified that.

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Reliability notes

• Names, registration numbers, roles, addresses, and the Batts/Liang hearing appearances are taken directly from filed PTAB papers (Power of Attorney, Feb. 2020; scheduling order, Feb. 2021; hearing transcript, May 25, 2021; 2023 remand filings) via Docket Alarm / PTAB records — solidly grounded.
• I found no evidence of a substitution of Netflix's PTAB counsel after the Feb. 13, 2026 Federal Circuit remand, and no new 2026 mandatory notice; the most recent Netflix-side PTAB filings I could retrieve still show Sheppard Mullin. Treat the current post-remand roster as "last confirmed = Sheppard Mullin," not as newly confirmed for 2026.
• I could not confirm the counsel block on the 24-1541 opinion (Feb. 13, 2026) or the docket entries in IPR2020-00558 after remand issued — do not attribute those to anyone without pulling the opinion's cover page or the PTAB docket.

I'll research counsel of record for DivX, LLC in this matter. Let me start with several targeted searches.

I have good initial data. Let me dig deeper into DivX's specific counsel of record, including the power of attorney and current counsel on remand.

Let me confirm the current counsel of record on remand and get firm/attorney background details.

Counsel of Record for the Defendant / Patent Owner — DivX, LLC

Threshold clarification: IPR2020-00558 is an inter partes review at the PTAB, not a district-court infringement action. In this proceeding Netflix is the Petitioner and DivX, LLC is the Patent Owner / respondent (the "defendant" side). DivX's team is drawn entirely from its outside PTAB boutique, Lowenstein & Weatherwax LLP (Los Angeles / Santa Monica, CA). The names below are drawn from the Board's oral-hearing transcript, the Patent Owner's powers of attorney, and the Federal Circuit briefing record; I could not pull the live PTAB docket directly (no PACER access), so treat the roster as accurate as of the last confirmed filings (2024–2025 pro hac vice papers) rather than as a same-day docket confirmation.

Confirmed DivX PTAB counsel (IPR2020-00558)

1. Kenneth J. Weatherwax — Lead counsel (registered practitioner, Reg. No. 54,528)

• Firm / office: Lowenstein & Weatherwax LLP, 1880 Century Park East, Suite 815, Los Angeles, CA 90067 (later also listed at 1016 Pico Blvd., Santa Monica, CA 90405).
• Role: Named lead counsel throughout the IPR; signed the substantive Patent Owner filings (e.g., the pro hac vice motions as recently as 2024–2025). Firm co-founder and namesake.
• Experience note: One of the highest-volume patent-owner-side PTAB practitioners in the country; the firm markets ~250 IPR/CBM matters and an appellate practice with ~40 Federal Circuit/9th Circuit/Supreme Court matters. Weatherwax argued for DivX in the closely related Netflix IPRs and has handled the parallel appellate work. (Source: hearing transcript; L&W firm news pages; PTAB pro hac vice filings.)

2. Nathan Lowenstein — Co-counsel / back-up counsel (admitted pro hac vice)

• Firm / office: Lowenstein & Weatherwax LLP, Los Angeles / Santa Monica.
• Role: Firm co-founder; appeared and argued for DivX at the May 25, 2021 oral hearing in this IPR ("It's Nathan Lowenstein for DivX. I'm joined by lead counsel, Kenneth Weatherwax, Parham Hendifar and Colette Woo"). Formally admitted pro hac vice via the Patent Owner's motions (declaration record spanning 2020–2025).
• Experience note: Reportedly ranked as the nation's top-performing patent-owner-side IPR attorney (2020–2025) per L&W's own announcement; extensive pro hac vice admissions across Netflix/Hulu v. DivX and other DivX IPRs (IPR2020-00558, -00614, -00646). (Source: hearing transcript; PTAB PHV declarations; L&W news.)

3. Parham Hendifar — Back-up counsel

• Firm / office: Lowenstein & Weatherwax LLP, Los Angeles / Santa Monica.
• Role: Listed in the appearances of counsel for the Patent Owner; co-tried this and related DivX IPRs.
• Experience note: Co-tried the Aug. 23, 2021 complete IPR trial win for DivX (L&W press release identifies "Parham Hendifar and Nathan Lowenstein" as co-trial counsel). Now a partner at L&W. (Source: hearing transcript; L&W news.)

4. Colette Woo — Back-up counsel

• Firm / office: Lowenstein & Weatherwax LLP, Los Angeles / Santa Monica.
• Role: Listed in the Patent Owner's appearances of counsel at the 2021 oral hearing.
• Experience note: PTAB patent-owner-side litigator; later a partner at L&W. (Source: hearing transcript; L&W firm listings.)

Additional / in-house

• Noel Egnatios — Vice President & General Counsel, DivX, LLC (in-house). Signed the Patent Owner's power of attorney (executed Nov. 2, 2021), i.e., the corporate officer authorizing L&W to act in these IPRs. DivX's address of record: 4350 La Jolla Village Drive, Suite 950, San Diego, CA 92122. (Source: DivX Patent Owner Updated Power of Attorney, Docket Alarm.)

Notes, caveats, and one likely source of confusion

• Firm address changes: Early filings used 1880 Century Park East (LA); by 2023 filings some DivX PTAB papers used 1016 Pico Blvd., Santa Monica, CA 90405. Both are L&W addresses.
• Possible additional names: L&W's press release on the related IPR2020-00511 (U.S. Pat. 9,184,920) win also credits Bridget Smith of L&W as DivX counsel. I have not confirmed Smith personally appeared in IPR2020-00558 itself, so treat her as related-case counsel unless a -558 filing confirms otherwise.
• Don't confuse with the parallel district-court case. Netflix's IPRs are companion to DivX, LLC v. Netflix, Inc., No. 2:19-cv-01602-PSG-(DFMx) (C.D. Cal.). There, roles reverse — DivX is the plaintiff (represented at various times by Irell & Manella, Robins Kaplan, Tensegrity Law Group, and Brown Rudnick) and Netflix is the defendant (WilmerHale, then Quinn Emanuel). Those firms are not DivX's PTAB counsel in IPR2020-00558. Because your prompt frames this as an "infringement case," be careful which docket you pull counsel from.
• Petitioner side (for contrast): Netflix's IPR counsel is Sheppard, Mullin, Richter & Hampton LLP — lead counsel Harper Batts (Reg. No. 56,160), with Jeffrey Liang and Chris Ponder — which is the mirror image of the "defendant" roster you asked about.
• Sourcing limits: Face-of-docket confirmation of any 2026 substitution of counsel (post-remand) was not obtainable within my search budget; the last authoritative counsel listing I could verify is the 2024–2025 pro hac vice record and the Patent Owner power of attorney. If counsel changed after the Feb. 13, 2026 Federal Circuit remand, I could not confirm it — and I will not guess at names.