Transport of partially encrypted media

• US 9,078,015 B2
• Filed: 01/13/2014
• Issued: 07/07/2015
• Est. Priority Date: 08/25/2010
• Status: Active Grant

• Current Assignee: Cable Television Laboratories Incorporated
• Original Assignee: Google Technology Holdings LLC (Alphabet Inc.), Cable Television Laboratories Incorporated
• Inventors: Kar, Mukta L., Narasimhan, Mandayam A.
• Primary Examiner(s): McNally, Michael S
• Application Number:
  US14/154,114
• Publication Number:
  US 20140192982A1
• Time in Patent Office: 540 Days
• Field of Search: 380/200
• US Class Current: 1/1
• CPC Class Codes: H04N 21/23476 by partially encrypting, e.g. encrypting the ending portion of a movie
• CPC Class Codes: H04N 21/23611 Insertion of stuffing data into a multiplex stream, e.g. to obtain a constant bitrate synchronisation arrangements in time-division multiplex systems using bit stuffing for systems with different or fluctuating information rates H04J3/073
• CPC Class Codes: H04N 21/23614 Multiplexing of additional data and video streams arrangements for simultaneous broadcast of plural pieces of information H04H20/28
• CPC Class Codes: H04N 21/2389 Multiplex stream processing, e.g. multiplex stream encrypting
• CPC Class Codes: H04N 21/23897 by partially encrypting, e.g. encrypting only the ending portion of a movie
• CPC Class Codes: H04N 21/6332 directed to client
• CPC Class Codes: H04N 21/8451 using Advanced Video Coding [AVC]

Abstract

A method of facilitating transport of partially encrypted video is disclosed. The method re-packetizes or otherwise de-concatenates packets carrying the partially encrypted video into packets where all the video in each packet is either encrypted or unencrypted. The re-packetized video packets may include data that identifies whether the packet is carrying encrypted or unencrypted video.

Claims

1. A computer-readable medium not including a signal and having stored thereon computer-executable instructions which when executed by a computer perform a method for re-packetizing partially encrypted video packets, the method comprising:

identifying at least one encrypted video slice and at least one unencrypted video slice within each partially encrypted video packet, each of the partially encrypted video packets including both encrypted video slices and unencrypted video slices;

de-concatenating each of the at least one encrypted video slice and the at least one unencrypted video slice into separate packets; and

generating at least one fully unencrypted video packet for each of the unencrypted video slices and at least one fully encrypted video packet for each of the encrypted video slices.

2. The computer-readable medium of claim 1 further comprising transmitting the fully encrypted and unencrypted video packets within a transport stream.

3. The computer-readable medium of claim 2 further comprising transmitting the fully encrypted and unencrypted video packets in a sequential order matching a sequential order in which respective video slices contained therein are arranged in the partially encrypted video packets.

4. The computer-readable medium of claim 2 wherein the transport stream is an MPEG transport stream.

5. The computer-readable medium of claim 1 further comprising identifying whether decryption is needed to playback the separate packets with data included a beginning of each of the separate packets.

6. The computer-readable medium of claim 1 wherein generating at least one fully encrypted video packet includes generating the at least one fully encrypted video packet without decrypting the encrypted video slice.

7. The computer-readable medium of claim 1 wherein de-concatenating includes de-concatenating each of the at least one encrypted video slice and the at least one unencrypted video slice by identifying boundaries between each of the encrypted and unencrypted video slices and adjoining data slices.

8. The computer-readable medium of claim 1 wherein generating at least one fully unencrypted video packet for each of the unencrypted video slices includes generating plurality of fully unencrypted video packet for each of the unencrypted video slices.

9. The computer-readable medium of claim 1 further comprising inserting additional content into the at least one fully encrypted video packet and/or the at least one fully unencrypted video packet.

10. The computer-readable medium of claim 1 further comprising adding stuffing bytes to one or more of the separate packets such that each of the separate packets includes the same total number of bytes.

11. The computer-readable medium of claim 10 further comprising adding the stuffing bytes such that a header, an adaptation field, and an adaptation field flag of each of the separate packets has the same total number of bytes and without decrypting the at least one encrypted video slice.

12. A method of re-packetizing partially encrypted media packets, the method comprising:

identifying media slices included within the plurality of partially encrypted packets as encrypted media slices and unencrypted media slices, each of the plurality of partially encrypted packets including both encrypted media slices and unencrypted media slices; and

re-packetizing the plurality of partially encrypted packets into a number of re-packetized packets without decrypting the encrypted media slices, each re-packetized packet having one but not both of encrypted media slices and unencrypted media slices.

13. The method of claim 12 further comprising re-packetizing the plurality of packets such that the number of re-packetized packets is at least equal to the number of unencrypted and encrypted media slices.

14. The method of claim 12 wherein the number of the plurality of packets is equal to P number and the plurality of packets include a total X number of unencrypted and encrypted media slices, and the method further comprises re-packetizing the P number of packets into at least P*X number of re-packetized packets.

15. The method of claim 12 further comprising re-packetizing the plurality of packets such that each re-packetized packet includes the same total number of bytes.

16. The method of claim 15 further comprising adding stuffing bytes to one or more of the re-packetized packets such that each of the re-packetized packets has the same total number of bytes.

17. The method of claim 16 further comprising adding the stuffing bytes without including an adaptation field flag and an adaptation field length of more than one byte each.

18. The method of claim 12 further comprising setting flags within headers of each of the re-packetized packets that identify whether the media slices within that packet are encrypted or unencrypted media slices.

19. The method of claim 18 wherein the media packets are video packets and further comprising setting an adaptation field flag of no more than one byte within each re-packetized packet to indicate whether included media includes an I-frame, B-frame, and P-frame.

20. The method of claim 18 further comprising setting an adaptation field length within the re-packetized packets of no more than one byte to indicate a number of included stuffing bytes.

21. The method of claim 12 further comprising re-packetizing the plurality of packets according to MPEG-2.

22. The method of claim 21 further comprising identifying each unencrypted and encrypted media byte comprising the unencrypted and encrypted media slices with one or more data bytes included within each re-packetized packet according to MPEG-2 identifiers.

23. The method of claim 21 wherein the partially encrypted media packets are Advanced Video Coding (AVC) access units.

24. A computer-readable medium not including a signal and having stored thereon computer-executable instructions which when executed by a computer perform the method of claim 12.

25. A computer-readable medium not including a signal and having stored thereon computer-executable instructions which when executed by a computer perform a method for re-packetizing partially encrypted media packets, the method comprising:

identifying encrypted media and unencrypted media slices included within each partially encrypted media packet, each of the partially encrypted media packets including both encrypted media slices and unencrypted media slices; and

de-concatenating each identified encrypted and unencrypted media slice into separate packets comprised of one of encrypted and unencrypted media slices.