Changes in physical input and audio encoding are not handled. The Colossus is able to encode PCM to AAC or pass through AC3. Changing between channels with AAC and AC3 audio leads to silence. Also, the Colossus and HDPVR have a number of physical inputs. If one channel is available from one set of inputs and a second channel is available from a second set of inputs then it is currently not possible to switch between them without rebuilding the graph.