一个人工智能，为所有人提供流媒体视频

By 2022, videos will make up more than 82 percent of all consumer internet traffic, 15 times higher than it was in 2017, according to a survey at Cisco. People watch videos on home Wi-Fi, on their cellphones, on a train, in cities, in mountains, after dinner when the whole family is using the internet, and at 3 AM when the kids are asleep. The variety of network conditions poses unprecedented challenges in online video streaming.

根据思科的一项调查，到2022年，视频将占所有消费者互联网流量的82%以上，比2017年高15倍。人们在家里的Wi-Fi上、在手机上、在火车上、在城市里、在山区、在晚饭后全家人都在使用互联网的时候、在凌晨3点孩子们睡着的时候观看视频。各种各样的网络条件给在线视频流带来了前所未有的挑战。

As of December 31, 2020, the Vimeo video player was powering ~100 billion views a month, with 297,000 new videos uploaded to our platform each day. High-resolution, seamless playback experiences are critical to the success of our creators. Among our numerous efforts to optimize the viewing experience, from the assignment of storage tiers and CDN selection and delivery to improving the efficiency of the algorithms that constitute our super-lightweight player, designing a good streaming algorithm is one of the most important.

截至2020年12月31日，Vimeo视频播放器每月提供约1000亿次浏览，每天有29.7万个新视频上传到我们的平台。高分辨率、无缝播放体验对我们的创作者的成功至关重要。在我们优化观看体验的众多努力中，从存储层的分配和CDN的选择和交付到提高构成我们超轻量级播放器的算法的效率，设计一个好的流媒体算法是最重要的之一。

Adaptive bitrate streaming, or ABR, is the modern epitome of seamless viewing. In old progressive streaming, the CDN delivers the entire video in one package and one transcode to the viewer. In an adaptive streaming session, a video is divided into short segments, which for most commercial players is either 3 or 6 seconds long. Each segment has different quality transcodes to select from, including 360p, 720p, 1080p, and so on. For each segment, an ABR algorithm selects the most suitable quality by gauging the current bandwidth and throughput (see Figure 1).

自适应比特率流，或ABR，是现代无缝观看的缩影。在旧的渐进式流媒体中，CDN以一个包和一个转码向观众提供整个视频。在一个自适应流媒体会话中，视频被分成很短的片段，对于大多数商业播放器来说，这些片段的长度为3或6秒。每个片段都有不同质量的转码可供选择，包括360p、720p、1080p，等等。对于每个片段，ABR算法通过衡量当前的带宽和吞吐量选择最合适的质量（见图1）。

Figure 1: Adaptive bitrate st...