AV1终于问世，但知识产权问题依然存在

After three years 和 multiple delays, the Alliance for Open Media froze its AV1 编码比特流, thus setting up a cacophony of HEVC/AV1 face-offs in booths 和 meeting rooms at the upcoming NAB Show. 这些比较将在很大程度上决定哪种编解码器将取代H.264作为“it”编解码器，用于流式传输到桌面, 移动设备, 智能电视, 和OTT设备, 尽管知识产权(IP)的前景仍不明朗.

顺便说一下背景, the Alliance for Open Media is a Joint Development Foundation Project formed in 2015 in response to the uncertain royalty situation surrounding HEVC. AOM发布的软件以不可撤销的方式提供, 非排他的, 和 royalty-free basis so long as the licensee is in conformance with the terms of the 开放媒体专利许可联盟.0. 如图所示图1, 成员包括编解码器开发中的主要参与者, 视频编码, 交付, 回放生态系统, ensuring the fastest possible technology adoption in all major submarkets.

图1. AOM成员和初始部署人员. (按此放大)

比特流冻结

3月29日，AOM宣布公开发布AOM视频1.AV1规范，即位流冻结. 他们还发布了一个“未优化”, experimental software decoder 和 encoder to create 和 consume the bitstream, 用于产品验证的参考流, 和 binding specifications to allow content creation 和 streaming tools for user-generated 和 commercial video."

根据AOM代表的说法, at NAB several members will show 30-40% better quality for UHD 4K videos than VP9/HEVC. 编码时间目前大约比VP9慢100倍, 他们认为到今年年底会降至5倍. 为解码, AOM目前比x86平台上的VP9慢5倍, 到2018年底，哪个应该降至2X.\

图2. AV1的开发时间表

图2 显示预期的部署时间表. 根据我们的谈话, AOM expects AV1 decode in several browsers 和 some content from member companies over the next few months. This will be followed by hardware implementations in about 12 months that can be integrated into devices that will ship in early to mid-2020.

鉴于AOM的成员资格, AV1在流媒体市场的成功几乎是板上钉钉的事, particularly given that HEVC has made little progress to date in markets other than streaming to 智能电视. 然而，自从它宣布以来, AV1 has been plagued by concerns regarding its intellectual property status.

不断变化的知识产权格局

具体地说, multiple sources have questioned AOM's ability to ship a codec that doesn't infringe upon existing IP that might be used in the H.264和HEVC编解码器. 例如，a 常见问题解答 HEVC专利集团Velos Media的网站上写道, “我们知道VP9采用了专利技术, 包括Velos Media为HEVC授权的一些专利. 和, 而AV1尚未公开发布, 它也可能结合来自多方的专利技术."

在我们与发行相关的对话中, AOM execs elaborated on their development approach 和 their efforts to ensure that AV1 didn't infringe upon existing IP. This started with a recital of the companies in the Alliance 和 the IP 和 codec development histories that they brought to the table. 例如，谷歌带来了所有On2、谷歌和摩托罗拉的知识产权收购了 in 2011. Microsoft brought all the IP from the Windows Media development effort, 而思科则带来了自己与thor相关的开发成果, 加上它的收购对象科学亚特兰大公司和泰德. 英特尔带来了自己的技术加上从职业 2012年，BBC、IBM和苹果都带来了自己的技术. Mozilla brought its Daala-related 和 other IP, plus years of codec development experience.

All technology was vetted in a rigorous patent review process before being integrated into the final spec. AOM的资料在设计编解码器时强调了这一点, if they couldn't work around a specific technique protected by a patent, 他们邀请专利所有人加入联盟, 即使他们是现有专利池的成员. In this regard, note that Apple, Cisco, Google 和 Microsoft are all licensors in the MPEG LA H.264专利池，并可能为AOM提供相同的知识产权.

除了, AOM created a legal defense fund so if one of the smaller member companies or an AV1 licensee is sued, 会有足够的资金进行辩护. That said, AOM will not indemnify licensees if AV1 is found infringing on any third-party technology.

我问律师大卫. 长，主人专利博客，有关AOM的知识产权公告. After the normal cautions that all parties should check with their own patent counsel for specific advice, Long confirmed that each patent owner is free to license its technology to multiple groups or pools as they wish, 包括对一些团体收费, 对其他人来说是免版税的. Long felt that the legal defense fund was a creative solution for protecting potential AV1 licensees, though he again cautioned that he had not researched this specific issue 和 there might be some unknown restrictions or limitations.

鉴于Velos的声明, I asked Long what steps potential AV1 licensees should take to protect their IP interests. 而 he felt that Velos' statements probably fell short of a true notice of infringements, he also suggested that potential licensees should do their own diligence to obtain a "reasonable good faith belief that there won't be an infringement. 例如, they can't simply rely on AOM's bare statements alone regarding the AOM patent review process, but should seek to underst和 the underlying facts 和 reasoning behind AOM's conclusion.

就ip相关的恐惧而言, 不确定性, 以及对AV1编解码器的质疑, 值得注意的是，谷歌的VP8和VP9也面临着类似的市场噪音. 而诺基亚确实起诉了谷歌声称VP8侵犯了它的H.264-related IP, Nokia ultimately lost the suit, 和 no other claims have emerged.

It's also worth noting that none of the HEVC pools guarantee that other claims from third parties won't arise; they simply provide a convenient mechanism for licensing the IP actually in their pool. 换句话说，当涉及到IP时，几乎没有任何保证. 即使有安慰，也无济于事，但这就是现实.

就AV1的性能而言，NAB之后我们会了解更多. 不幸的是，解决知识产权问题需要更长的时间.

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