2017年2月14日
By 克里斯·麦克 Wowza媒体系统的公关和通信总监
专题文章

虚拟现实:行业走向VR绿洲

所以你想进入虚拟现实? It’s a great time to do so, because VR is here to stay—awkward headgear or not.

不像其他过时的科技潮流已经落在了路边, VR的实用性已经超越了那些花哨的娱乐技巧. Games and immersive experiences are pulling us deeper into virtual entertainment, 比如欧内斯特·克莱恩的《百家乐软件》一号玩家准备就绪. Only now instead of the virtual revolution starting with a gaming console or dedicated VR system, 从你的智能手机开始.

考虑口袋妖怪去，手机增强现实游戏超过7.500万次下载. The game turns your phone into a conduit that uses cameras and GPS to let you engage in a virtual world within real-life surroundings. 这就是所谓的增强现实, 或基于“增大化现实”技术, 你把虚拟内容叠加在现实世界的视图上. 然而，增强现实只是迈向完全沉浸式虚拟现实的第一步.

VR has always been about immersion into completely artificial worlds and interaction with manufactured people, 字符, 和环境. 就在短短几年前，人们嘲笑这个想法 VR可以改变世界. Many people expected a Max Headroom type of display where things looked so incredibly fake and distorted that it was hard to imagine real experiences that embraced virtual interactions. But anyone who’s worn an Oculus Rift can tell you that the immersion can be a visually breathtaking experience that delivers 4K, ,很快, 8 k的视频.

New applications like 口袋妖怪去 will act like a gateway drug—building our appetite for not only more engaging content, 还有新的硬件. 不知不觉中, 购买像Oculus Rift这样的虚拟现实头盔, PlayStation虚拟现实, 或HTC VIVE, or investing in computers to power them won’t seem so far-fetched for the average consumer.

为了让VR在游戏和娱乐以外的领域腾飞, 高质量的内容和有效的传播方式需要得到解决. 从安全开始, 零售, 建设, 旅游业将从这项技术中受益, 让成千上万的人——如果不是几百万的话——都能接触到. Yet these immersive experiences demand pristine content delivery that can affordably scale with audience growth. 像这样, 视频质量(分辨率), 无缝播放, 低延迟将决定VR的成败.

打破质量和交付障碍，促进采用

VR提供高价值的体验, 然而，这确实需要一些深思熟虑的准备——尤其是对于现场活动. The recent rise of 360-degree video allows for viewers to be virtually transported to a live event such as a sporting event, 音乐会, 或者政治集会. 但要让你感觉你在那里，你需要尽可能高的质量. 图像质量越高, 比特率越大(视频点播资产的最终文件大小), 这反过来又需要更大的带宽. 目前, 大多数360度视频往往是用低分辨率相机拍摄的, 但更多的4K甚至8K相机正在崛起.

对于普通消费者, 来自NBA的360度视频, 潜望镜, Facebook可以吃掉数据套餐, 导致高昂的电话费, while also contributing to significant network congestion with a high volume of viewers. The congestion means that the user’s experience can be dramatically hindered, 当网络阻塞发送脂肪数据到移动设备. 因此, 网络运营商, 内容提供商, 消费者对VR的高效传输有着浓厚的兴趣.

360-degree VR streaming also introduces another challenge—latency—which affects two unique aspects of the viewing experience: head-motion and scaling 质量. If you’re moving your head (or eyes) and there’s lag between your movement and video refresh, 你会注意到运动到光子的延迟. 理想情况下，您希望桌面在90Hz下的刷新率低于11ms, 移动设备在60Hz下为16ms. 如果超过这个量，你可能会感到恶心.

The other latency issue arises when you try to reduce bandwidth requirements through adaptive streaming. 举个例子, one approach is dynamically adapting the stream to deliver high 质量 video only where the viewer is looking—so within their field of view (FOV)—and lower resolution everywhere else. As soon as the sensors in the headset detect that the user has moved their FOV, 他们现在关注的领域迅速成为焦点, 并且需要在几百毫秒内完成. 这种延迟是关键的, 它将要求流传输延迟小于200毫秒. Some providers are implementing this technology into what they call Field-of-View Adaptive Streaming or View-Optimized Streaming.

One of the final challenges is implementing high-efficiency encoding that reduces the bandwidth needed to deliver video streams. Both the VP9 and HEVC codecs are supported by most HTML5 players and mobile devices, 并以更低的比特率实现相同质量的视频, 减轻成本, 质量, 以及交付问题. However, they also require a bit more horsepower on the playback device to decode the stream.

虚拟现实的现实:制定游戏计划

User experience is going to be the driving force behind many of the technology decisions when you develop a VR engagement. 最后一件事是消费者, 网络运营商, or 内容提供商 want is for their VR content to choke the network and deliver a poor user experience, 这会分散沉浸式内容的注意力.

在一般情况下, companies should consider these best practices to ensure they lay the groundwork for building high-质量 VR:

考虑传输最高质量流所需的比特率, and provide adaptive bitrate streams that enable the flexibility required for VR content.
Use 360-degree adaptive streaming technology to minimize the data footprint and deliver an dynamically-adjusted viewing experience.
Determine how important low latency is for the live experience and tune your streaming workflow accordingly.
采用高效的编解码器，如VP9、HEVC.

虚拟现实的价值

VR has the ability to create technology-enabled experiences, ushering in the Internet of Experiences. 看看今年的消费电子展, far too many consumer electronics manufacturers would have you believe that the virtual experience, 比如坐在虚拟现实汽车里, 几乎和真品一样好吗. 它的潜力远远超出了游戏和娱乐. When you take the ability to place a viewer in an immersive environment that they can explore on their own and add data enhancements on top of their video feed, 您可以开始想象应用于企业培训的用例, 工业监控, 教育, 医学研究, 电子商务, 或者大量其他非娱乐应用程序.

Businesses must stop looking at VR as the next generation of cool entertainment media, 而是将其视为具有特定利基用途的信息工具. By taking steps now to plan an infrastructure that supports the 质量 and distribution aspects of VR, businesses will be better equipped to drive adoption of VR across industries and use cases.

虚拟现实的发展速度将超出我们大多数人的想象. 我们就越能继续增强我们的现实, the more we’ll find ourselves bouncing back and forth between mixed reality experiences. 在现实中, 我们已经迷失在Facebook和社交媒体的兔子洞里了, and it’s easy to see ourselves going through the looking glass into virtual worlds.

绿洲就在不远处.

克里斯·迈克尔斯(克里斯·麦克)是 Wowza媒体系统. 这是一篇由供应商提供的文章. 流媒体 accepts 文章 contributed by vendors based solely on the value of insight and 信息 they offer to our readers.