| 摘要 |
A controller, in accordance with a preferred embodiment provides, in a specified region of first television picture generated by a first digitally compressed video signal, an overlay of a second picture embodied in a second video signal. The controller includes an I-frame buffer for storing updated macroblock pixel data in I-frame format derived from the second signal. The controller also has a matte mask storage register for storing data that identifies the specified region by means of macroblocks. A matte substitution processor is in communication with the matte mask storage register and has as an input the first signal and provides an overlayed output; the controller inhibits transmission to the output of any macroblock, of the first signal's data stream, lying in the specified region. It also functions to substitute for such macroblock a corresponding macroblock from the I-frame buffer. Further embodiments permit overlay of a graphic display for interactive television on a picture derived from a digitally compressed video signal. |
