网络直播解决方案买家指南

Many of you who are browsing the articles and advertisements in this issue have been in the online video business for a long time. 也许你们大多数人都是从上个世纪开始的. 让自己回到90年代, and you may remember the postage stamp-sized video with that cool little spinning pinwheel, 让你知道发生了缓冲, 但你最终还是会看到一些东西的. Viewers coming over to the online world from a lifetime of viewing television had no idea what buffering was, 他们并不在意, because most of them wouldn't wait for the video as they were trying to surf the net.

他们为什么要等那个视频? There was more compelling content and a much higher quality viewing experience from the couch. 这些管子太小了, 编码太复杂, the tool sets too hard to use-and there wasn't much in the way of monetization to compel anyone to take the leap into online video. 我不确定上个世纪是否还存在"M"这个词. The idea of attempting a live online video event was just crazy talk among a bunch of misguided geeks with too much time on their hands-and we owe them more than we could have ever imagined.

There is a television station in Norway named TV 2 that is producing 6Mbps live streams over broadband for its viewers. 美国国家橄榄球联盟和美国全国广播公司将周日晚间橄榄球加时赛放在一起, in HD, 有五个视图可选择的相机选择, 画中画, 和全DVR控制. 我在这篇文章中谈论的大部分内容最好简单地描述为“生活”." All live, all the time, and with the technologies to make it a compelling viewing experience. And there are a growing number of companies providing the software and hardware ecosystems to make it happen. Digital Rapids, Sonic Foundry, 进口技术, Adobe, Microsoft, Go-Live, Telestream, Livestream, Ustream, and a myriad of others have robust solutions that can get you live online if you are a big three-letter news and entertainment network targeting multiple screens or a small college or high school showing this week's home game. So let's look at some of the hardware and software solutions that will give you a feel for what's out there and that might just make your live streaming a bit easier.

我在和约翰·毕晓普谈话, co-founder and senior vice president of products and business development at 进口技术, 关于基于硬件的生活. Inlet had a vision that video could look better than postage-stamp size and could achieve broadcastlike quality over broadband. 许多人都熟悉Inlet的Spinnaker直播设备. Its products have been adopted by large news and entertainment networks; it's also one of the technologies behind NBC's coverage of the last Olympic Winter Games, 美国职业棒球大联盟, 以及2010年高尔夫大师赛的实时3D在线报道. It's interesting that Inlet's Spinnaker appliance does not use any proprietary hardware because, 正如毕晓普解释的那样, “Spinnaker是一款‘软件驱动’的硬件设备. We still see the rate of change in the broadband and mobile video space as phenomenally fast, and we want to have a software approach that allows us to respond to the ever changing market demands." And those market demands are growing as everyone is streaming to multiple screens as the next iPhone, Android device, 或者iPad上市.

自适应直播解决方案

The distinction between hardware and software solutions appears to be blurring; very often, the state-of-the-art software from so-called traditional software companies is incorporated into hardware appliances. This is evidenced by the fact that Adobe HTTP Dynamic Streaming and Microsoft Smooth Streaming are both integral pieces of delivery from hardware appliances. It is these adaptive bitrate technologies from Adobe and Microsoft that have made a tremendous positive impact on streaming in the past few years.

虽然自适应比特率的技术解释可以从许多来源获得, Bishop noted, “客户需要知道，自适应比特率并不是一种沙盒技术. 它被部署在世界上一些最大的数据中心. 如果客户使用的是2005年左右的流媒体解决方案, 他们远远落后于时代潮流，几乎是在使用劣质产品."

Adobe has done some of the largest live events ever delivered on the web using Flash, 包括奥巴马总统的就职典礼, 迈克尔·杰克逊的葬礼, 和ESPN的世界杯足球赛. In order to sustain growth and to make sure that the internet continues to be a place where people can build business models around streaming, Adobe投资于HTTP交付. As Kevin Towes, Adobe的高级产品经理, states, 使用HTTP传递, customers can leverage the benefits it offers such as ability to reach through a CDN with much greater capacity and the ultimate promise of lower cost of delivery."

Adaptive bitrate technology is also becoming a key component of live multicast delivery. Succinctly, while traditional streaming is a one-to-one relationship between the server and the client player, 组播客户端订阅相同的组播IP并接收相同的流. This clearly results in bandwidth savings but has always presented hurdles in network configuration and infrastructure expense.

Towes added that one of the key challenges has been to deliver a high-quality video experience within the enterprise without potentially disrupting core network services such as email and voice, while at the same time reducing the network infrastructure required to deliver that experience. Adobe addressed the issue by fusing together IP multicast and application-level multicast that it uses with the peer-to-peer functionality and multicast capabilities introduced in Flash Player 10.1. This effectively permits enterprise users who have the ability to consume multicast to help those who aren't able to consume a multicast stream experience the same view while realizing the bandwidth savings.