But you still don't tell us what the problem is. Do you get a compiler error? An exception during runtime? Unexpected results? Or don't you know how to continue after that?
If it's the latter, I think you have to use one of the DataSource sub classes. If iDS is a PullDataSource, cast to PullDataSource and use the result of getStreams(). Likewise for the other known sub classes of DataSource.
Please UseCodeTags next time. Make sure to preserve your indentation as well. I've added both for you this time.
Are you sure you have a capture device installed on your system? Because CaptureDeviceManager can't find any. Perhaps you need to install them first. I can't help you with that though, since I'm not very experienced in JMF.