query - internationalization

Hello,

I have an application which stores data from varied sources which send data
in differing encodings.
However, coming from the application, its users want a consistent encoding
format.
since it is hard to convince diverse clients to change and send data in a
uniform format, i would appreciate to receive pointers to the following:

- a technique to detect the encoding format of an input stream, and
- a technique to automatically convert various formats to a standard
encoding - say utf8.

Thanks in advance for the help,
Varun Mathur