HTML5, the iPad, and the iPhone: What You Need to Know

对HTML5视频有问题吗? 你并不孤单. StreamingMedia.Com最近举办了一个网络研讨会杰夫·沃科特主持的话题, senior vice president of global marketing at Brightcove (the event was sponsored by Brightcove), 将近1,000人参加了会议. 整个事件被存档在这里 (registration is free), but if you want something you can skim, 在这里 are the highlights.

网络研讨会的标题是 HTML5准备, and sought to fill in the gaps for professionals who had heard the buzz on HTML5 video, 但还是有很多疑问. Whatcott解释了什么是HTML5视频, 展示了一些公司是如何使用它的, and gave recommendations for creating an HTML5 strategy.

HTML5, Whatcott解释, is the successor to the current HTML standard, one that started as a renegade project by a group that included Apple, Mozilla, 谷歌, 歌剧, 和其他人. The central idea was to allow video and audio to play on websites without plug-ins.

We're currently at the beginning of the HTML5 cycle, and only 38 percent of browsers support it. That means no content creator can afford to serve only HTML5 video, but needs to create a mixed format delivery system w在这里 users get the video in Flash or Silverlight if their browser isn't HTML5-compatible.

While HTML5's video tag is enjoying all the attention, the standard also includes audio and canvas tags, for delivering audio and dynamic images without plug-ins.

One of the standard's shortcomings is that it doesn't specify one format to use with it. That means t在这里 are a variety of choices, two of which enjoy major support. 提供者可以为H服务.264 video created with the MPEG4 codec, WebM video made with the VP8 codec, or Ogg Theora video. H.264 and WebM offer better video quality, Whatcott said, and WebM is open source.

The area has gotten complicated, since Apple backs the H.264 format and 谷歌 backs WebM in its Chrome browser (which soon won't support H.264 video). Whatcott sees the formats being used as weapons in a format battle, and doesn't want customers to become casualties.

That fragmentation means that content providers can't choose just one format when delivering HTML5 video, 但需要流两种格式. The real beneficiary of this Adobe's Flash video format, Whatcott says. 如果HTML5看起来太复杂, people will throw up their hands and just go with a system that works.

While that's true of serving desktop viewers, HTML5 is most relevant now for reaching mobile devices. Providers who want to reach the influential iOS demographic need to stream H.264 video. Android设备支持H.264 video, but not in all builds.

For those looking for more help with HTML5 video, Whatcott recommended this 链接集合, which he put together and continues to maintain.

提问时间到了, 网络研讨会 attendees showed that they were concerned about the limits of HTML5 video. They asked about adaptive bitrate streaming (HTML5 video doesn't offer it; the most it can do is one bandwidth check just before playback), analytics (tools aren't as rich as with Flash video), and live streaming (it's not supported in HTML5 video). They also asked about DRM and closed captioning, neither of which are available in HTML5 video.

For a more in-depth look at HTML5 video, check out the entire hour-long 网络研讨会为自己. It's a great introduction if you're starting to think about an HTML5 delivery strategy.