System and method for transporting an ancillary data packet in the active area of a video stream

• US 8,724,023 B2
• Filed: 09/06/2005
• Issued: 05/13/2014
• Est. Priority Date: 09/09/2004
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Walker, Bradley William, Fritz, Matthew John
• Primary Examiner(s): Lee, Michael
• Application Number:
  US11/221,086
• Publication Number:
  US 20060053471A1
• Time in Patent Office: 3,171 Days
• Field of Search: 348/473, 348/474, 348461-468, 380200-242, 713/182, 713/183, 713/150, 713/184
• US Class Current: 348/473
• CPC Class Codes: H04N 21/4122 additional display device, e.g. video projector digital output for controlling a plurality of local displays G06F3/1423
• CPC Class Codes: H04N 21/4367 Establishing a secure communication between the client and a peripheral device or smart card
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

In accordance with the teachings of the present invention, a system and method for transporting an ancillary data packet in the active area of a video stream are provided. In particular embodiments of the present invention, the method includes coupling a playback server and a digital video projector with a DVI link; placing an ancillary data packet of link encryption metadata in a false line of video in an active area of a frame of video at the playback server, a remainder of the active area comprising true lines of video; transmitting the ancillary data packet from the playback server to a digital video projector through the DVI link; extracting the ancillary data packet from the frame of video at the digital video projector; and displaying the remainder of the active area of the frame of video at the digital video projector.

Claims

1. A method for transporting ancillary data in an active area of a video stream, comprising:

at a playback server coupled by a local video link to a projector, receiving an incoming stream of encrypted video image pixel data for projection by the projector;

at the playback server, decrypting and decompressing the encrypted data, resulting in unencrypted video image pixel data;

at the playback server, re-encrypting the unencrypted data into an outgoing stream of re-encrypted video image pixel data using a first random number generator and an encryption key, including formatting information on the encryption key into a same format as the re-encrypted video image pixel data;

transmitting the outgoing stream of video image pixel data including the same formatted encryption key information over the local video link to the projector; and

at the projector, extracting the encryption key from the encryption key information from the received outgoing stream, and decrypting the re-encrypted video image data from the received outgoing stream using a second random number generator and the encryption key, resulting in the unencrypted video image pixel data;

wherein the encryption key information is formatted as RGB video image pixel data of a DVI local video link.

2. The method of claim 1, wherein the incoming stream and the outgoing stream are divided into segments and the encryption key is different for each segment.

3. The method of claim 2, wherein the projector stores the encryption key in volatile memory until a time from receipt is greater than a given expiration time, until replaced by new key, or until manual deletion.

4. The method of claim 1, wherein the encryption key information is formatted as video image pixel data in a false active video data line of a frame of video image pixel data.

5. The method of claim 1, wherein the encryption key information includes a synchronization word;

extracting the encryption key includes extracting the synchronization word; and

the method further comprises, at the projector, generating a corresponding synchronization word and comparing the extracted synchronization word with the generated synchronization word.

6. The method of claim 1, wherein the re-encryption is done with a lower level of encryption than the level of encryption in the encrypted video image pixel data in the incoming stream.

7. The method of claim 1, wherein the encryption key information comprises a current link encryption key and a future link encryption key.

8. The method of claim 1, wherein the re-encryption and decryption of the re-encrypted data are performed using random number streams generated by the random number generators operating in a counter mode, using the encryption key and counter as inputs.

9. The method of claim 8, wherein the re-encryption is done with a lower level of encryption than the level of encryption in the encrypted video image pixel data in the incoming stream.

10. The method of claim 9, wherein the encryption key information includes a synchronization word;

extracting the encryption key includes extracting the synchronization word; and

the method further comprises, at the projector, generating a corresponding synchronization word and comparing the extracted synchronization word with the generated synchronization word.

11. The method of claim 10, wherein the encryption key information comprises a current link encryption key and a future link encryption key.

12. The method of claim 11, wherein the encryption key information is formatted as video image pixel data in a false active video data line of a frame of video image pixel data.

13. The method of claim 12, wherein the incoming stream and the outgoing stream are divided into segments and the encryption key is different for each segment.

14. The method of claim 12, wherein the projector stores the encryption key in volatile memory from a time from receipt is greater than a given expiration time, until replaced by new key, or until manual deletion.

15. The method of claim 1, further comprising, at the projector, projecting an image using the unencrypted video image pixel data.

16. A method for transporting ancillary data in an active area of a video stream, comprising:

coupling a playback server and a digital video projector with a local data link;

providing a video signal comprising a series of video frames, each video frame comprising an active data area beginning with a first portion of active image data for the video frame and ending with a last portion of active image data for the video frame;

placing an ancillary data packet of link encryption metadata in the active data area of a frame of video such that active image data of the video frame both precedes and follows the ancillary data packet;

transmitting the ancillary data packet and the active image data from the playback server to a digital video projector through the local video link; and

extracting the ancillary data packet from the frame of video at the digital video projector;

wherein providing the video data signal includes receiving, at the playback server, an incoming stream of encrypted video image pixel data for projection by the projector;

wherein placing the ancillary data packet of link encryption metadata in the active data area includes, at the playback server, decrypting and decompressing the encrypted data, resulting in unencrypted video image pixel data; and

, at the playback server, re-encrypting the unencrypted data into an outgoing stream of re-encrypted video image pixel data using a first random number generator and an encryption key, including formatting information on the encryption key into a same format as the re-encrypted video image pixel data; and

wherein transmitting the ancillary data packet and the active image data from the playback server to the projector includes transmitting the outgoing stream of video image pixel data including the same formatted encryption key information over the local video link to the projector; and

wherein extracting the ancillary data packet from the frame of video at the projector includes, at the projector, extracting the encryption key from the encryption key information from the received outgoing stream, and decrypting the re-encrypted video image data from the received outgoing stream using a second random number generator and the encryption key, resulting in the unencrypted video image pixel data.

17. The method of claim 16, further comprising displaying the remainder of the active area of the frame of video at the digital video projector.

18. The method of claim 17, wherein the local video link is a DVI link.