The S3 video plugin uses the free flash version of flowplayer.
Some considerations and tips when using Flowplayer are as follows:
-Playlists will always play in flowplayer regardless of what player is selected in the plugin settings.
-Flowplayer requires flash to work making it unsuitable for devices that do not have flash installed.
-If you are using .flv videos, it is recommended you use Flowplayer.
-The object embed code, is provided for use on pages external to Wordpress and as such must use Flowplayer in order to avoid dependencies..