Yes, you can, using Event_Impl::GetDeviceDataFromDatabase().
From src/DCE/Event_Impl.h:
/**
* @brief gets the specified parameter from the specified device and returns it's value in the sResult parameter
* @warning not implemented here
*/
string GetCurrentDeviceData( int PK_Device, int PK_DeviceData ); // Get it from the device itself
string GetDeviceDataFromDatabase( int PK_Device, int PK_DeviceData ); // Get the latest value from the router
Each Command_Impl implementation, after ::Connect() is run, will have assigned a pointer to the matching Event_Impl class in m_pEvent, so you can do the following inside StartMedia:
string sPort = m_pEvent->GetDeviceDataFromDatabase(pMediaStream->m_pMediaDevice_Source->m_pDeviceData_Router->m_dwPK_Device,DEVICEDATA_Port_CONST);
The device data constants, can of course be read from pluto_main/Define_DeviceData.h,
and the various pointers to classes etc, can all be gleaned from various classes in src/DCE.. the .h files are very helpful in determining what member variables are part of a class.
-Thom