The following shows how to record Sopcast stream with Mplayer. The instructions use MPlayer GUI, but I recommend to use the command line mplayer for recording instead.

How to record Sopcast stream with Mplayer for Mac OS X

1. Open the location with MPlayer as mentioned above.
2. To record Sopcast straem, go to MPLayer preferences. Under miscellaneous, select "Advanced setting". Enter the following:
   
   Code:

   -dumpstream mms://127.0.0.1:8902

   You may need to change the port to 8903 or 8912.
3. Click OK and MPlayer should restart. It will look like frozen. The GUI may even crash. But you will get a files called stream.dump
   on the top level of your hard drive directory of Macintosh HD.
   
   If the recording is working, the file size will be growing.
   
   To stop the stream, you will need to kill the process from the terminal:
   
   Code:

   kill -9 (PID of mplayer)

   Don't use the PID of MPlayer OS instead.
4. Return to MPlayer preferences and uncheck "Advanced setting".
5. Rename stream.dump to some_name.wmv, and open the file in MPlayer, Quicktime with Flip4MacWMV or VLC