Zencoder
Zencoder is the creator of an open-source HTML5 video player, Video.js, built with Javascript, HTML, and CSS. Video.js plays video via native playback in all HTML5 browsers and devices, or through Adobe Flash when HTML5 playback is not available.
Comparison of HTML5 and Flash
Both Flash and HTML text can be read by screen readers. However, special care must be taken to ensure Flash movies are read correctly. For example, if a Flash movie is set to repeat indefinitely, this can cause a screen reader to repeat the content endlessly. Selecting the "Make object accessible" check box in Adobe Flash Professional will create a text-only version of the object for screen readers. It will also hide any motion from the screen reader. Since Flash content is usually placed on a single webpage, it appears as a single entry in search engine result pages, unless techniques like deep linking are used with libraries like SWFAddress to provide multiple links within Flash websites and web applications. User interface widgets in Flash objects don't always behave like their host native counterparts. Keyboard, mouse and other accessibility shortcuts may not work unless the webpage developer explicitly adds support for it.