HTML5 video is an element introduced in the HTML5 draft specification for the purpose of playing videos or movies, partially replacing the object element. Adobe Flash Player is widely used to embed video content on websites such as YouTube.
The Flash Player is available as a plugin for recent versions of most web browsers (such as Mozilla Firefox, SeaMonkey, Opera and Safari), with exceptions such as the browsers on the Apple iPhone and iPad, Windows Phone 7 and on Android 2.1 or less). The plugin is not required for Google Chrome anymore since Google integrated the player into the browser.
HTML5 video is intended by its creators to become the new standard way to show video online, but has been hampered by lack of agreement as to which video formats should be supported in the video tag.
Even with only one choice, such hints may be necessary to a hypothetical browser for querying its multimedia framework for third party codecs. Due to lack of a common video format, multiple sources is an important feature to avoid the need for browser sniffing, which is error prone: given that any web developer’s knowledge of browsers will inevitably be incomplete, the browser in question knows best.
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