Thumbnail Video

cb_get_embedded_media.php

// Function
function cb_get_embedded_media( $type = array() ){
	$content = do_shortcode( apply_filters( 'the_content', get_the_content() ) );
	$embed = get_media_embedded_in_content( $content, $type );
	
	if( in_array( 'audio' , $type) ):
		$output = str_replace( '?visual=true', '?visual=false', $embed[0] );
	else:
		$output = $embed[0];
	endif;
	
	return $output;
}

index.php

// Call
<?php echo cb_get_embedded_media( array('video','iframe') ); ?>