Method, device, and computer program for signaling hidden toplevel boxes in an encapsulated media data file

Abstract

A method for encapsulating media data in a file, in a processing device, the file comprising a plurality of top-level boxes (file-level boxes) for encapsulating media data and metadata describing the

Claims

1. A method for encapsulating media data in a file, in a processing device, the file comprising a plurality of top-level boxes for encapsulating media data and metadata describing the media data, one of the top-level boxes having an undetermined size indication, the method comprising:encapsulating, in the file, metadata or media data in at least one top-level box located after the top-level box having the undetermined size indication,generating a location box comprising an item of information to locate, directly or indirectly, the at least one top-level box located after the top-level box having the undetermined size indication, andencapsulating the location box at the end of the file.

2. The method of claim 1, wherein the location box comprises an offset, the offset determining the location of the at least one top-level box located after the top-level box having the undetermined size indication, from the location of the location box or from the end of the file.

3. The method of claim 1 or claim 2, wherein the location box has a size, the size of the location box being predetermined.

4. The method of claim 1 or claim 2, wherein the location box has a size, the size of the location box being defined in the location box.

5. The method of any one of claims 1 to 4, wherein the location box comprises information to locate, directly or indirectly, each of a plurality of top-level boxes located after the top-level box having the undetermined size indication.

6. The method of any one of claims 1 to 5, further comprisinggenerating a plurality of location boxes, each of the generated location boxes comprising information to locate, directly or indirectly, a top-level box located after the top-level box having the undetermined size indication, andencapsulating each of the generated location boxes at the end of the file.

7. The method of claim 6, wherein at least one of the plurality of generated location boxes comprises an item of information to locate, directly or indirectly, another location box of the plurality of generated location boxes.

8. The method of any one of claims 1 to 7, further comprising encapsulating an indication, in a first top-level box of the file, to provide information about a presence of the location box at the end of the file.

9. A method for parsing media data encapsulated in a file, in a processing device, the method comprising:obtaining the file to be parsed, the obtained file comprising a plurality of top-level boxes encapsulating media data and metadata describing the media data, one of the top-level boxes having an undetermined size indication, at least one of the top-level boxes being located after the top-level box having the undetermined size indication, the file further comprising, at the end of the file, at least one location box comprising an item of information to locate, directly or indirectly, the at least one top-level box located after the top-level box having the undetermined size indication,identifying the at least one location box,determining, from the item of information of the identified at least one location box, a location of the at least one top-level box located after the top-level box having the undetermined size indication,accessing the at least one top-level box located after the top-level box having the undetermined size indication, andprocessing the file as a function of the at least one accessed top-level box.

10. The method of claim 9, wherein the location box comprises an offset, the method further comprising determining the location of the at least one top-level box located after the top-level box having the undetermined size indication, from the location of the location box or from the end of the file, using the offset.

11. The method of claim 9 or claim 10, wherein the location box has a size, the size of the location box being predetermined, the method further comprising accessing the location box using the predetermined size.

12. The method of claim 9 or claim 10, wherein the location box has a size, the size of the location box being defined in the location box, the method further comprising obtaining the size defined in the location box and accessing the location box using the obtained size.

13. The method of any one of claims 9 to 12, wherein the location box comprises items of information to locate, directly or indirectly, each of a plurality of top-level boxes located after the top-level box having the undetermined size indication, the method further comprising accessing each of the plurality of top-level boxes located after the top-level box having the undetermined size indication, using the items of information of the location box.

14. The method of any one of claims 9 to 13, further comprisingobtaining, from the end of the file, each of a plurality of location boxes and accessing, using each of the plurality of location boxes, a top-level box located after the top-level box having the undetermined size indication.

15. The method of claim 14, wherein at least one of the obtained location boxes is located using an item of information of another one of the obtained location boxes.

16. The method of any one of claims 9 to 15, further comprising obtaining an indication, from a first top-level box of the file, providing information about a presence of the location box at the end of the file, the identifying the at least one location box being carried out in response to the obtaining an indication providing information about a presence of the location box at the end of the file.

17. The method of any one of claims 1 to 16, wherein the file complies with the International Standard Organization Base Media File Format, ISOBMFF.

18. A computer program product for a programmable apparatus, the computer program product comprising instructions for carrying out each step of the method according to any one of claims 1 to 17 when the program is loaded and executed by a programmable apparatus.

19. A non-transitory computer-readable storage medium storing instructions of a computer program for implementing the method according to any one of claims 1 to 17.

20. A processing device comprising a processing unit configured for carrying out each 5 step of the method according to any one of claims 1 to 17.

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