Cisco Open Sources H.264 for WebRTC
In blog post that Cisco shared with us yesterday, Cisco announced that it has open-sourced its H.264 codec, and will provide it as a downloadable binary module at no charge. Here’s the key bit: “Cisco will not pass on our MPEG LA licensing costs for this module, and based on the current licensing environment this will effectively make H.264 free for use in WebRTC.”
The last few words (“free for use in WebRTC”) seemed, at first, to indicate that free H.264 usage will be limited to the encode/decode tasks essential to WebRTC (described in the following section). However, our communications with Cisco and Mozilla indicate that the license will extend to HTML5 playback, so browsers that haven’t yet licensed H.264, most notably Firefox and Opera, can use the Cisco module to playback H.264-encoded video.
That said, most HTML5 video encoded with H.264 uses the AAC codec for audio. While Cisco has open-sourced and will fund the royalty obligations for H.264, its largesse doesn’t extend to AAC, which is also patent encumbered and has its own royalty obligation. While AAC is essential to HTML5 playback, it’s not required for WebRTC playback, which instead uses the Opus and several other codecs.
So, while the Cisco announcement could be a game-changer for WebRTC, its impact on browser-based HTML5 playback is uncertain. As Mozilla states in its blog post on the subject, “Provided we can get AAC audio decoders to match, using Cisco’s OpenH264 binary modules allows us to extend support to other platforms and uses of H.264.”
After the announcement, I asked Mozilla, “Does Mozilla plan to separately obtain AAC decode or are you waiting for someone else to fund that royalty obligation?” The company responded, “We're investigating a number of possibilities with respect to AAC playback for HTML5, but have nothing to announce at this time.” Until Mozilla does so, H.264 decode has limited utility for HTML5-related playback.
Let’s start our analysis with a look at the WebRTC market, where Cisco’s announcement will have a significant impact.
About WebRTC
By way of background, WebRTC (Web Real-Time Communication) is an application programming interface (API) enabling inter-application communications with voice, video chat, and P2P file sharing. In essence, WebRTC would enable Skype-like communications between a range of compliant applications without plug-ins, much the same way that HTML5 enables video playback without Flash or other plug-ins. While the initial implementations will likely appear in browsers like Chrome and Firefox, the communications aspects could extend to any application that supports the spec.
Like all web standards, there are multiple groups and standards bodies involved in WebRTC’s formulation and standardization, including the World Wide Web Consortium (W3C), the Web Hypertext Application Technology Working Group (WHATWG) and the Internet Engineering Task Force (IETF). In particular, the IETF is charged with choosing the mandatory-to-implement (MTI) video codec, with a final decision scheduled to be reached at an IETF meeting scheduled for Monday, November 4. As mentioned above, the audio codec issue has already been settled, with Opus and several other codecs mandatory to implement, but not AAC.
Note that the MTI codec isn’t the only codec that will be included in WebRTC; but it is the baseline codec that ensures inter-application communications. Other codecs can be included in WebRTC applications, but the MTI codec is required for compliance with the standard.
Victor Pascual presents a great overview of the video codec battle in his blog post entitled WebRTC mandatory video codec discussion: the final duel. Pascual notes that there are two proposals on the table for MTI video codecs; one advocating H.264, the other VP8, the Google-owned and open sourced codec included in WebM. Pascual reports that, “the VP8 proposal is only backed by Google, the H.264 proposal is backed by Ericsson, Nokia (or shall I say Microsoft?), BlackBerry, Qualcomm, Orange, Cisco, Microsoft and Apple -- note that codecs is the only WebRTC-related subject where Apple has participated and expressed their opinion.”
Pascual’s article and the IETF discussion thread make it clear that there was much debate about the comparative quality of VP8 and H.264, but that the “core issue” relates to H.264’s royalty obligation, or the Intellectual Property Rights (IPR) issue. In a comment posted on Wednesday, October 23, committee member Harald Alvestrand argued, “Both codecs are capable of high quality video encoding, and performance numbers are comparable. The real core question is the IPR issue. The tradition of the IETF says that allowing only business models that can sustain royalty agreements and royalty payments is bad for the Internet.”
By funding all royalties, of course, Cisco is taking the royalty issue off the table. The big question is why?
What Cisco Gets
I spoke with Cullen Jennings, a Cisco distinguished engineer and co-chair of the IETF about the new arrangement. First I clarified the breadth of the arrangement. Specifically, I asked about the decision to “make H.264 free for use in WebRTC” in the Cisco blog post, and Jennings stated that the new licensing arrangement will apply to general-purpose HTML5 playback as well as WebRTC. Jennings also verified that the arrangement relates to H.264 only, not AAC.
Regarding Cisco’s motivation, Jennings explained that unified communications (UC) systems are a big business for Cisco, incorporating a range of products including telephones, videophones, and telepresence systems, and they all use H.264 for video. The WebRTC standard, which Cisco supports, will allow all computers and mobile phones to serve as endpoints for Cisco UC systems, assuming that H.264 is the common codec. The substantial payments Cisco will make to the H.264 patent group organized by MPEG LA will help boost the utility and ultimately the sales of its UC systems.
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