IP Law Daily, PATENT—Fed. Cir.: Invalidity of DivX’s streaming patent affirmed on appeal, (Jun 25, 2025)

By Carolin Dennis, B.Sc., LL.B., LL.M.

The PTAB correctly determined that all claims of DivX’s streaming patent were unpatentable as obvious over a combination of Biderman and Gigliotti, and reasonably rejected DivX’s arguments of non-obviousness.

In a non-precedential disposition, the U.S. Court of Appeals for the Federal Circuit affirmed the Patent Trial and Appeal Board’s (PTAB) ruling that challenged claims in DivX’s ’987 patent were unpatentable under 35 U.S.C. § 103. The Federal Circuit refused to revive two independent claims in the ’987 patent and determined that the PTAB’s finding was supported by substantial evidence (DivX, LLC v. Unified Patents, LLC, No. 23-1699 (Fed. Cir. Jun. 24, 2025)).

The appellant DivX, LLC (DivX) owned U.S. Patent No. 10,326,987 (’987 patent) related to adaptive bitrate streaming of media in playback devices. The ’987 patent acknowledged that the prior art already taught playback devices capable of adaptive bitrate streaming. Unified Patents, LLC (Unified) petitioned for inter partes review. The PTAB concluded that claims 1 and 10 were unpatentable as obvious over a combination of Biderman and Gigliotti. The PTAB found that a skilled artisan would have been motivated to combine Gigliotti with Biderman because Gigliotti, which teaches a skilled artisan to consider the state of a buffer as part of its adaptive bitrate switching scheme, can help mitigate some shortcomings in Biderman’s adaptive bitrate streaming method. DivX appealed the final written decision of the PTAB, which concluded that the two independent claims in the ’987 patent were unpatentable under 35 U.S.C. § 103.

On appeal, DivX did not challenge the PTAB’s finding that a skilled artisan would be motivated to combine the teachings of Gigliotti with Biderman. Instead, DivX argued that such a reference combination would only teach a playback device that incorporates Gigliotti’s teachings—consideration of the state of Biderman’s buffer—for the entire playback process, whereas the claim required consideration of the state of the buffer only after the initial startup period of playback. The Federal Circuit noted that DivX did not challenge the PTAB’s finding that a skilled artisan would leverage Gigliotti’s teachings to improve Biderman’s method or dispute that adding Gigliotti’s adaptive bitrate scheme during Biderman’s playback process necessarily would improve Biderman for that part of the process. The PTAB’s conclusion that a skilled artisan would adopt Gigliotti’s teachings for only a portion of the playback, according to DivX, still leaves “Biderman’s flawed methodology” in the picture for some parts of the playback. But the Federal Circuit determined that it is not necessary to show that a combination is the best option, only that it be a suitable option.

Additionally, DivX contended that Unified did not show that the very idea of using two different stream selection methods during playback existed in the prior art. The Federal Circuit found that DivX’s argument contradicted the record because Gigliotti itself teaches a playback device that embodies two different stream selection methods. The PTAB had found that Gigliotti’s playback device, at the beginning of playback, may stream media at a first bit rate to fill an initial buffer residing on the client and subsequently outputs this stream to the user. During this initial playback period, the device might select a relatively low bit rate value to ensure uninterrupted streaming of media. But as playback continues, Gigliotti’s playback device then begins to fill a separate buffer and transitions to an adaptive bitrate scheme.

Thus, the PTAB’s finding was supported by substantial evidence.

The Case is No. 23-1699.

Judge: Chen, R.

Attorneys: Parham Hendifar (Lowenstein & Weatherwax LLP) for DivX, LLC. Angela M. Oliver (Haynes and Boone, LLP) for Unified Patents, LLC.

Companies: DivX, LLC; Unified Patents, LLC

Cases: Patent FedCirNews USPTO