摘要 |
<p>A picture-in-picture video signal generator includes a source (50) of an auxiliary video signal, and a producer (60) of successive samples representing the auxiliary video signal. A self-sequencing memory (70) includes a data input terminal coupled to the producer ofauxiliary video samples; a write address input terminal, for receiving an initial write address; a data output terminal; and a read address input terminal for receiving an initial read address. Write control circuitry (80,90) is coupled to the write address terminal of the self-sequencing. memory, and generates initial write addresses in synchronism with horizontal line intervals of the auxiliary video signal. A source (10) of a main video signal is also provided. Read control circuitry (100,110) is coupled to the read address terminal of the self-sequencing memory, and generates initial read addresses in synchronism with horizontal line intervals of the main video signal. Means (20,30) are provided for combining the main video signal with samples from the self-sequencing memory to form a video signal representing a picture-in- picture image.</p> |