We were given a brief by the client to create idents that were picture postcard scenes of Welsh life. We wanted to produce idents that could bring those scenes to life in real time. We came up with the idea of developing voice reactive imagery that would be entirely unique each time it screened. In order to achieve this we built a real time compositing engine.By using 10 background plates, the broadcast announcer can, in real time, affect the imagery within each scene. Elements randomly move based on the volume and frequency of the announcer's voice. The idents stand on their own without voice, but speech breathes life into the scenes.The project took over a year to develop, from conception, R&D, live-action shoot, post, coding, and integration. We developed the S4C application completely from scratch by writing video decoding, compositing, colour correction, etc and using open source libraries. There are approximately 50,000 lines of code in the final product. The system behaves like a digi deck as it is installed at the broadcaster's office, communicating with their scheduling system; switch audio and output synchronized digital video and audio using broadcast standard signals.