You need to go and evaluate the video chips supplied by Philips. I do not recall the part number but they have (or at least had about 4 years ago) a PIP controller that was able to accept various video input materials and frame it down to show multiple channels on one output screen. These chips require the use of additional components including video encoders, video decoders, video switch (mux) chips, and DRAM buffers that hang on the side of the PIP controller. You may also need an 8051 type microcontroller to manage an I2C bus to setup and initialize all the various chips.

Michael Karas