Processing high definition video data

1. A method for producing a high definition video signal comprising:

performing by at least one circuit:

demuxing a high definition program stream into at least one high definition video data stream component and a plurality of companion component data streams;

muxing the plurality of companion component data streams with a standard resolution video stream into a standard definition video program stream;

demuxing the standard definition program stream into a standard definition video data stream, and a subpicture data stream;

scaling the standard definition video stream to a resolution consistent with the high definition video data stream;

overlaying the scaled standard definition video stream with the demuxed subpicture data stream;

and replacing the standard definition video stream with the at least one high definition video data stream to produce a high definition video data signal.

2. The method of claim 1 further including, prior demuxing the high definition program stream, receiving a program data stream.

3. The method of claim 2 further including determining if the received program data stream is a high definition program data stream.

4. The method of claim 1 wherein the plurality of companion component data streams comprises one or more of audio data stream, a subpicture data stream, and a navigational data stream.

5. The method of claim 1 wherein the high definition program stream is in encrypted format.

6. The method of claim 5 further comprising, prior to demuxing the high definition program stream, decrypting the encrypted high definition program stream.

7. The method of claim 1 wherein the at least one high definition video data stream component is in compressed format.

8. The method of claim 7 further comprising, prior to the replacing step, decompressing the high definition video data stream.

9. The method of claim 1 further comprising generating the standard resolution video stream.

10. The method of claim 9 wherein the generated standard resolution video stream comprises a blue screen video elementary stream.

11. An apparatus for use in producing a high definition video data signal, comprising:

a high definition program stream demuxer for extracting a plurality of component data streams from a high definition program stream, the plurality of component data streams comprising at least one high definition video data stream and a set of other component data streams;

a generator for generating a standard definition video stream;

a muxer for combining the generated standard definition video stream with the set of other component data streams into a standard definition program stream;

a video scaler for increasing the resolution of the standard definition video stream to a resolution consistent with the high definition video stream;

a video mixer for replacing the scaled up standard definition video stream with the high definition video data stream;

and an encrypter for creating a high definition video data signal from the high definition video data stream and the set of other component data streams.

12. The apparatus of claim 11 further including a receiver for receiving a program data stream.

13. The apparatus of claim 12 wherein the received program data stream is in encrypted format.

14. The apparatus of claim 13 further including a decrypter for decrypting the encrypted program data stream.

15. The apparatus of claim 12 further including a router for determining if the received program data stream is a high definition program stream.