Method of picture-in-picture for multimedia applications

1. A method for preparing a media stream for picture-in-picture applications, said media stream containing a plurality of component streams, the method comprising:

generating picture-in-picture information from the plurality of component streams contained in the media stream, wherein said picture-in-picture information comprises position information, said position information indicating the position of a component stream when displayed in picture-in-picture mode; and

inserting the picture-in-picture information into the media stream.

2. The method of claim 1 , further comprising

updating the picture-in-picture information according to changes in the plurality of component streams.

3. The method of claim 2 , wherein the inserting step comprises

building picture-in-picture data units according to the generated picture-in-picture information; and

inserting the picture-in-picture data units into the media stream.

4. An apparatus for preparing a media stream for picture-in-picture applications, said media stream containing a plurality of component streams, the apparatus comprising:

a correlator for generating picture-in-picture information from the plurality of component streams contained in the media stream, wherein said picture-in-picture information comprises position information, said position information indicating the position of a component stream when displayed in picture-in-picture mode; and

an embedder for inserting the picture-in-picture information into the media stream.

5. The apparatus of claim 4 , wherein the media stream is one of a transport stream and a program stream.

6. The apparatus of claim 5 , further comprising

a picture-in-picture information builder for generating picture-in-picture information data units from the identified picture-in-picture information, the picture-in-picture information data units being fed into the embedder for inserting into the media stream.

7. A method for rendering a media stream in a picture-in-picture mode, said media stream containing a plurality of component streams, the method comprising:

obtaining picture-in-picture information related to the media stream, wherein said picture-in-picture information comprises position information, said position information indicating the position of a component stream when displayed in picture-in-picture mode;

extracting a plurality of component streams from the media stream according to the obtained picture-in-picture information; and

rendering the plurality of component streams according to the obtained picture-in-picture information.

8. The method of claim 7 , wherein the plurality of component streams comprises a master layer component stream and at least one slave layer component stream.

9. The method of claim 7 , further comprising if necessary, pre-processing at least one of the extracted plurality of component streams according to the picture-in-picture information prior to rendering.

10. The method of claim 9 , wherein the obtaining step comprises

extracting picture-in-picture information data units from the media stream; and

analyzing the picture-in-picture information data units to identify the picture-in-picture information.

11. The method of claim 7 , wherein the picture-in-picture information comprises information of layer, size, aspect ratio of the component streams in the picture-in-picture mode.

12. An apparatus for rendering a media stream in a picture-in-picture mode, said media stream containing a plurality of component streams, the apparatus comprising

an extractor for extracting, from the media stream, picture-in-picture information, and for extracting a plurality of component streams according to the picture-in-picture information, wherein said picture-in-picture information comprises position information, said position information indicating the position of a component stream when displayed in picture-in-picture mode;

a processor for processing the extracted plurality of component streams according to the picture-in-picture information.

13. The apparatus of claim 12 , wherein the extractor extracts picture-in-picture information data units from the media stream, the apparatus further comprising

an analyzer for analyzing the picture-in-picture information data units to get picture-in-picture information, and for providing references to the plurality of component stream to the extractor.

14. The apparatus of claim 12 , wherein the picture-in-picture information further comprises at least information of layer, size, and aspect ratio of the component streams in the picture-in-picture mode.

15. The apparatus of claim 12 , wherein the processor comprises a pre-processing unit for scaling the at least one component stream to a size specified in the picture-in-picture information.

16. The method of claim 3 , wherein the picture-in-picture data units comprise picture-in-picture descriptors, and the inserting step further comprises

including the picture-in-picture descriptors into a program map table of the media stream.

17. The method of claim 1 , wherein the picture-in-picture information further comprises information of layer, size, aspect ratio of the component streams in the picture-in-picture mode.

18. The apparatus of claim 6 , wherein the picture-in-picture data units comprise picture-in-picture descriptors, and the embedder further performs steps of

including the picture-in-picture descriptors into a program map table of the media stream.

19. The apparatus of claim 4 , wherein the picture-in-picture information further comprises at least information of layer, size, and aspect ratio of the component streams in the picture-in-picture mode.