Upsampling while decoding

Hello!

I would like to know if it is possible to request encoding to a higher 
samplerate than the original data.
For example my uncompressed data was 22 kHz, and I would now like to 
decode the compressed data to 48 kHz (to feed it to a filter which 
expects a high "input" format).
Is this possible with Speex?

Thank you.
Hermie