Enabling wrapper "rtmp" to media.php

Hi guys,

by trying to play some stream from an external server, the following message is showing up

Warning: file_exists() [function.file-exists]: Unable to find the wrapper “rtmp” – did you forget to enable it when you configured PHP? in…./media.php on line xxxx

I looked in that file and it appears like that. How do i change it, so the stream is working correctly?

/**
 * Retrieve metadata from a video file's ID3 tags
 *
 * @since 3.6.0
 *
 * @param string $file Path to file.
 * @return array|boolean Returns array of metadata, if found.
 */
function wp_read_video_metadata( $file ) {
	if ( ! file_exists( $file ) )
		return false;

https://ww.wp.xz.cn/plugins/jw-player-plugin-for-wordpress/