udp://@... URL scheme handler not working correctly on Mac OS X
If you type something like "udp://@239.255.10.10:50000" in the Safari address bar and then hit Enter, VLC launches because it is the default handler for the udp URL scheme. (This is registered by its Info.plist file.) However, the URL gets munged somehow between Safari and the VLC URL handler.
If you look in the Playlist view, you see "239.255.10.10/50000". In Messages, you see this colon-to-slash transform, and in some URLs the @ sign is missing.
The symptom is that the multicast stream video doesn't appear.
If you say Cmd-N and paste the exact same URL into the box provided, the video displays as expected.
RTSP URLs of the form "rtsp://server:8554/foo.ts" don't seem to be affected. The reason for this difference may be due to the fact that there is a path component after the port number. I tried appending a trailing slash to the udp URL, but this didn't help.
(Beware that if you want to try the rtsp test on OS X, you have to use RCDefaultApp or similar to change the default URL scheme handler from QuickTime to VLC first. udp URLs don't require any help because there's nothing installed on OS X by default that tries to grab this scheme, unlike with QuickTime and rtsp, so VLC's request to handle udp URLs goes uncontested.)
I have attached the Messages log after attempting to open this UDP stream from the browser. The complaint about "port 0" is doubtless due to this ':' to '/' translation and the confusion it causes within the VLC code.