Putting an rtsp:// stream URL into a Movie patch in Quartz Composer (QC) and rendering it onto a Billboard patch causes QC to hang. A number of commentators on the net have noted that QuickTime uses a different rendering path for streams than for local files, which seems to be the cause of this bug, but I can't find any suggested workarounds.
We want to be able to stream from an IP video camera generating MPEG-4 over RTSP into QC. The same stream URL in standalone QuickTime and VLC works fine.
Revisiting this with Mac OS X 10.6, and it works! Piping the same RTSP MPEG-4 stream into a Movie Importer patch now works fine in QC.
So, answer to question is: upgrade to 10.6.