Wistia oEmbed provider

// Register oEmbed providers
function wistia_oembed_provider() {

	wp_oembed_add_provider( '/https?://[^.]+.(wistia.com|wi.st)/(medias|embed)/.*/', 'http://fast.wistia.com/oembed', true );

}
add_action( 'init', 'wistia_oembed_provider' );