Hi,
if you check your site with rtmpdump then you see you get some conn string paramters you need to use.Only 2 hash values.The first does not play any role (you can fake it) but the second one you have to use.Just check this again.
Code:
rtmpdump -v -r "rtmp://stream13.videostar.pl:1935/158/_definst_//mp4:1583.stream" -C S:any_MD5_hash -C S:hashxy | "player.exe" -
greetz