案例研究：马萨诸塞州处理流访问性

这些天, 我们大多数人都认为观看网络视频是理所当然的——找一个网站, 点击一两下, 我们开始吧. 多亏了Flash，这一切变得非常简单. 对于一些观众来说, though, it’s not quite so simple; accessing web videos can be a difficult—if not impossible—experience for those who have vision or hearing impairments. While current web technology mostly relies on commercial screen readers to synthesize web text into speech, many readers or self-talking browsers are not particularly reliable in enabling impaired users to access a website’s video player or helping them watch a particular video. This problem can be especially acute with videos that begin playing as soon as a page is loaded. 相应的, many webmasters and video content managers who are concerned with accessibility usually just post a transcript of the video and call it a day.

Having been involved in web video production for more than 3 years, the Massachusetts Department of Revenue (DOR) has always tried to make its videos more accessible to those with disabilities. 它敏锐地意识到, 作为一个国家机构, of the need for government sites to make a positive effort to comply with current federal accessibility law—in particular the requirements set forth in the 1998 amendment to the Federal Rehabilitation Act, 通常被称为第508条, and the web content accessibility guidelines developed by the World Wide Web Consortium (W3C). These guidelines were created to eliminate barriers in 信息 technology, 为残障人士提供新的机会, and encourage the development of technologies that help achieve these goals.

记住这些指导方针, the DOR created a specific goal for its video program: reach as many of its customers as possible by finding a solution that gives the vision- and hearing-impaired a better level of usability and control over the multimedia content on the department’s website. The DOR had other goals as well: improve the ability of its non-English-speaking customers to watch videos; provide a way for its video content to be shared on social networking sites such as Facebook, Digg, and MySpace; and find a media content management system better able to handle the time-consuming front-end video importing, 隐藏式字幕, 投寄程序.

After investigating a number of online video publishing solutions such as Brightcove, Vidego, 和YouTube, the DOR learned that these video management systems did not possess the accessibility features it was looking for. Moreover, some of these firms were largely video platforms looking to build a marketing base for non-entry-level streaming clients. 因为这些私营部门的解决方案都没有达到其目标, the DOR decided to take the initiative and build a content management system (CMS) and accessible video player itself (图1).

图1. The video player is located on the Massachusetts Department of Revenue’s homepage.

After obtaining support from revenue commissioner Navjeet Bal and senior deputy commissioner Jim Reynolds, a small working group was formed within the DOR’s publishing and media services group. 工作组成员包括Peter Olejnik, creative director; Alan Sweeney, interactive media developer; and William Grand, 交互式开发人员. Olejnik took the lead role in developing the media content management system and player while also managing the day-to-day particulars of the project.

经过几个月的编程, 设计配置, 和试验, 该集团推出了一款满足其最初目标的产品. 虽然对结果很满意, there are a number of other functionalities—such as "email to a friend,“观众投票功能, and improved reporting and metrics—that will be added in the next iteration.

解释了这个项目的起源, 下面是对CMS和视频播放器的更深入的了解.

媒体内容管理系统
简而言之, 媒体内容管理系统（MCMS）, 建立在Adobe的Air平台上, was designed to significantly simplify the front-end video importing, 隐藏式字幕, 投寄程序, 以及维护播放器的视频菜单. 作为网页内容管理员, it is important that the DOR be able to quickly perform these tasks and push videos out to its content delivery network (CDN), 尤其是后期的匆忙制作. 为了满足这些需求, MCMS允许DOR, 通过它自己设计的仪表盘菜单应用程序, 快速复制和粘贴视频脚本到媒体系统(图2和3). 粘贴后，DOR可以执行以下操作：
—Import, rearrange, or remove videos from the menu using a drag-and-drop methodology
-编辑视频标题和摘要
-改变其语音应答系统的文本转语音内容
-管理RSS源
-使用帧定时工作流快速格式化字幕
—Automatically create multilingual closed captions using Google’s open source translation application

Figure 2. Dashboard-DOR的媒体内容管理系统接口

图3. 一个媒体内容管理系统窗口

The management system and Dashboard are working well and have saved numerous hours of manual captioning and file preparation prior to posting on the DOR’s CDN.

总体设计
玩家的界面被设计成用户友好的, 像大多数当代富互联网应用程序一样. 这很重要, as a number of users felt that the DOR’s previous player design was a bit confusing. The old player utilized a scrolling menu that only showed five video thumbnails at a time; other video thumbnails were off-screen and were only visible by scrolling. The DOR’s usage metrics consistently showed that these off-screen videos streamed to far fewer viewers because they were not visible. 为了解决这个问题, the new player categorizes videos by topic buttons and toggles through one enlarged video thumbnail at a time (图4). This design is also crucial to the functionality of another player feature: the on-demand voice response system.

图4. 视频播放器的设计组件