视频外带

After years of waiting for the technology and audience to develop, video to the desktop has finally arrived in a big, 大. Formats have been whittled down, delivery technologies have been improved, and broadband speeds have continued their steady march upwards.

最后, 内容所有者开始意识到将视频传送到桌面的可行商业模式. But the desktop was only the beginning. 现在, eyes are rapidly turning to what might be the most numerous, and undoubtedly smallest, screens out there: the ones in consumers’ pockets.

Mobile video is hot, and no one wants to be left behind as this space begins to mature; when audience interest starts reaching critical mass; and when the technologies that enable it are created, 增强, 和扩展. But like the early days of internet video to the desktop, 对于希望利用这些新平台的内容所有者来说，移动领域充满了复杂性和不确定性. 如果有什么区别的话, 与桌面视频相比，移动领域的挑战更加严峻，未来更加未知.

相互竞争的标准和交付技术各自承诺了一个丰富的移动媒体体验蓬勃发展的世界, 但在这一点上，几乎不可能假设谁会胜出，甚至是否有人会成为主宰.

移动设备市场为消费者提供了无限的特性和功能选择, 但这也意味着内容所有者必须准备好在各种形式因素和设备的存储和处理能力方面提供内容.

这是一个令人兴奋、充满活力、充满潜力、充满不确定性的领域. 如此之多，以至于任何声称知道事情走向的人，即使在六个月后，也可能不会发现历史是一个仁慈的情妇. But even in this uncertainty, 内容所有者必须尽最大努力跟上快速发展的市场, 特别是当供应商为他们提供新的解决方案来建立移动身份时.

所以，与其试图从一个明显模糊的水晶球里去猜测一切的走向, 本文将回顾并介绍五家试图在新兴的移动视频市场中扬名立万的公司, each one addressing a different part of the mobile video challenge.

Ortiva Wireless—The Mobile CDN
实现任何移动体验的关键是将视频传输到移动设备. 真正的, 移动流媒体可以像流媒体到桌面一样简单, but is that really the optimal way to deliver mobile video? Not according to Ortiva Wireless.

“传统的cdn旨在使内容尽可能接近边缘，并提供多个副本以允许弹性," says DeWayne Nelon, CEO of Ortiva Wireless. “但无论你使用的是什么设备，传统的CDN都无法为你提供任何服务. 最后一个长度是在试图传递移动视频时造成困难的原因."

Ortiva打算通过开发其所谓的业界首个移动CDN来解决这一挑战, though that’s admittedly something of a misnomer. "Delivery is not what we’re about; it’s that last little bit of the network. 事实上，我们经常在运输方面与其他交付网络合作，”Nelon说.

By leveraging its mobile CDN, Ortiva声称，它可以减少所需的下行和回程传输的数量和容量, increase the reach of the video signal to a broader geographic area, and ultimately enable a better overall mobile experience.

It accomplishes these feats through the use of three tools. First is the point of content ingestion, 它会查看进入的视频资产并评估如何调整它们以在受限的网络条件下工作. Second is their network resource monitoring, which looks at feedback from handsets to determine network conditions. And third is the streamer, which takes the network conditions, looks at the options available to adjust the content, 并动态地组装一个流，该流是为请求流时的网络条件定制的.

“每一个其他的解决方案都需要编码的内容，并将其流式传输. It may draw bitrate down, 但在几乎所有的情况下，流媒体将传输编码器编码的内容,Nelon说. “我们传输的不是编码器编码的内容，而是你的网络和设备能够承受的内容."

Ortiva不断测量网络状况，并在飞行中进行调整. "We’ll change the ratio of I-Frames to P-Frames, or we may change the quantization levels, or the audio-visual bandwidth mix. 我们将把它们结合起来，创造一种不同的体验。. 例如, in unsteady conditions, 他们可能会发送比p帧更多的i帧，以创建一个更有弹性的会话, 但在良好的条件下，它们会发送更多的p帧，以获得更高质量的图像.

重要的是，这些调整每隔几秒钟就会在实时流媒体会话中进行. "You can’t make these decisions in advance. 通过我们, 您不必为相同的内容创建多个版本来适应这些不同的网络条件,Nelon说.

The system comes set up with some default biases—for example, 在高分辨率视频上强调更少的停站和档位，但客户可以调整这些以适应他们的内容需求. 例如, default settings prioritize video over audio delivery, but if you’re sending music videos the audio may be more important.

Ortiva’s Stream Shaper handles on-demand delivery, while TV Shaper covers live video, which they claim to deliver with as little as 15 seconds of latency, compared to the multi-minute latency of its competitors.

Also available is Web Shaper, 将类似的原则应用于向移动设备交付丰富的网站. "With Web Shaper you don’t have to dumb down sites for mobile devices. 而不是, 你可以创建像你想要的一样丰富的网站，然后标记每个框架或项目对你来说有多重要,Nelon说. "So say you want a site to load in 35 seconds. As the page is requested, 再过两到三秒我们就能测量这个网络并确定我们能从管道里得到多少. 然后, in the remaining seconds, based on the priority you gave us, 我们将把该页面的最佳渲染效果发送到移动设备."

In addition to working with content owners, Ortiva与主要运营商达成了一系列协议，因为他们提供内容的能力将对网络的影响降到最低，这引起了运营商的兴趣.