When using the above listed feature - it looks like it requires the use of the "Built-In Bridge" available in some phone models.
When looking at the documentation for using BIB (Built-In Bridge), most of the informaiton I've been able to find I've located in the documentation for using the feature "Barge". In that documentation, it appears that only G.711 is supported.
However, in the above listed link, there's a comment in the documentation that states the following:
"Because the codecs for recording calls match the codecs for agent-customer calls, you may need to insert transcoders if the recorder does not support the matching codecs."
That leads me to beleive that the recording stream codec coming from the phone (destined for the recorder) matches whatever the ACTUAL codec being used for the stream from the agent to the customer is using.
Can anybody comment on what codecs are supported when using the built-in CUCM Monitoring and Recording feature?