YouTube is giving developers a preview of some new embed code which will display a Flash or HTML5 player depending on your viewing environment.
If you use the new embed code style, your viewers will be able to view your embedded video in one of our Flash or HTML5 players, depending on their viewing environment and preferences. Environments that support the HTML5 video player are listed here on our HTML5 settings page. In instances where HTML5 isn't supported (e.g. our HTML5 player can't play videos with ads), we use Flash.
Eventually this new embed style will allow inline video to work on mobile devices which typically use a built-in player instead of Flash or HTML5.
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If you use the new embed code style, your viewers will be able to view your embedded video in one of our Flash or HTML5 players, depending on their viewing environment and preferences. Environments that support the HTML5 video player are listed here on our HTML5 settings page. In instances where HTML5 isn't supported (e.g. our HTML5 player can't play videos with ads), we use Flash.
Eventually this new embed style will allow inline video to work on mobile devices which typically use a built-in player instead of Flash or HTML5.
Read More