Speeding up channel change

• US 20060085828A1
• Filed: 10/14/2005
• Published: 04/20/2006
• Est. Priority Date: 10/15/2004
• Status: Abandoned Application

• Current Assignee: OpenTV, Inc. (Kudelski SA)
• Original Assignee: OpenTV, Inc. (Kudelski SA)
• Inventors: Dureau, Vincent, Zdepski, Joel, Kim, Patty
• Application Number:
  US11/250,593
• Publication Number:
  US 20060085828A1
• Time in Patent Office: Days
• US Class Current: 725/100
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/4263 involving specific tuning arrangements, e.g. two tuners
• CPC Class Codes: H04N 21/4383 Accessing a communication channel
• CPC Class Codes: H04N 21/4384 involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 5/50 Tuning indicators; Automatic tuning control
• CPC Class Codes: H04N 7/163 by receiver means only
• 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

A method and apparatus is described to reduce delay when changing channels in a television environment. The method may comprise receiving a plurality of television channels from a remote content provider wherein each channel includes channel information required to display the channel. At least one channel of the plurality of channels may be identified as a stored channel and channel information of the at least one stored channel may be stored in storage (e.g. in a circular buffer). Thereafter, upon selection of the stored channel, the stored channel information is accessed for display. In an example embodiment, the storage may be updated to maintain a most recently received I-frame and subsequent MPEG signals of the stored channel. Accordingly, when changing channels it may not be necessary to wait for the next I-frame to display a newly selected channel.

Claims

1. A method for reducing delay when changing channels in a television environment, the method comprising:

receiving a plurality of television channels from a remote content provider, each channel including channel information required to display the channel;

identifying at least one channel of the plurality of channels as a stored channel;

storing channel information of the at least one stored channel in storage; and

accessing the stored channel information for display upon selection of the at least one stored channel.

2. The method of claim 1, wherein the channel information identifies an entry point required for processing a television signal for display to a viewer.

3. The method of claim 2, which comprises updating the storage to maintain a most recently received entry point of the stored channel.

4. The method of claim 1, wherein the channel information comprises at least one of an MPEG video I-frame, an Entitlement Control Message, and an access control word.

5. The method of claim 1, which comprises storing an entry point of at least one channel other than a currently viewed channel.

6. The method of claim 5, wherein the entry point is an I-frame.

7. The method of claim 5, which comprises updating the storage to maintain a most recently received entry point and subsequent signals of the stored channel.

8. The method of claim 1, which comprises placing an entry point for the stored channel at a predefined point in the storage.

9. The method of claim 1, which comprises storing an encryption key of at least one channel other than a currently viewed channel.

10. The method of claim 9, wherein one of an Entitlement Control Message and a control word is stored.

11. The method of claim 1, wherein the stored channel is a second channel signal broadcast over a separate frequency, the method comprising supplying the stored second channel signal to a demodulator upon selection of the second channel.

12. The method of claim 1, further comprising:

decoding a first channel signal for display;

decoding a stored second channel signal, the stored second channel signal being broadcast over a separate frequency as the first channel signal; and

supplying the decoded stored second channel signal to a display buffer for display upon selection of the second channel.

13. The method of claim 1, further comprising:

decoding a first channel signal for display;

decoding a stored second channel signal, the stored second channel signal being broadcast over the same frequency as the first channel signal; and

supplying the decoded stored second channel signal to a display buffer for display upon selection of the second channel.

14. The method of claim 1, comprising decrypting the stored channel signal prior to selection of the stored channel for display.

15. The method of claim 1, which comprises decoding the stored channel signal prior to selection of the stored channel for display.

16. The method of claim 1, which comprises one of reducing display delay by lagging the displayed image behind an actual broadcast and accelerating playback of the stored channel to synchronize playback with a live broadcast.

17. The method of claim 1, which comprises identifying at least one channel of the plurality of channels as a stored channel based upon channel input selection rules.

18. The method of claim 17, wherein the selection rules comprise selecting at least one of a channel adjacent to a currently viewed channel, a favorite channel associated with the user, a channel frequently watched, and a list of channels specified by an operator.

19. A computer readable medium embodying instructions which, when executed by a computer, cause the computer perform the method of claim 1.

20. An apparatus to reduce delay when changing channels in a television environment, the apparatus comprising:

a receiver to receive a plurality of television channels from a remote content provider, each channel including channel information required to display the channel;

a processor to identify at least one channel of the plurality of channels as a stored channel, channel information of the at least one stored channel being stored in storage; and

a selector to access the stored channel information for display upon selection of the at least one stored channel.

21. The apparatus of claim 20, wherein the channel information identifies an entry point required for processing a television signal for display to a viewer.

22. The apparatus of claim 21, which comprises updating the storage to maintain a most recently received entry point of the stored channel.

23. The apparatus of claim 20, wherein the channel information comprises at least one of a MPEG video frame, an Entitlement Control Message, and an access control word.

24. The apparatus of claim 21, wherein the entry point of at least one channel other than a currently viewed channel are stored.

25. The apparatus of claim 24, wherein one of an Entitlement Control Message and a control word is stored.

26. The apparatus of claim 20, wherein an entry point for the stored channel is detected for placement at a predefined point in the storage.

27. The apparatus of claim 20, wherein an encryption key of at least one channel other than a currently viewed channel are stored.

28. The apparatus of claim 27, wherein one of an Entitlement Control Message and a control word is stored.

29. The apparatus of claim 20, wherein the stored channel is a second channel signal broadcast over a separate frequency, the apparatus including a demodulator and the stored second channel signal being supplied to the demodulator upon selection of the second channel.

30. The apparatus of claim 20, which comprises a decoder to decode a second channel signal broadcast over a separate frequency, the selector being to supply the decoded second channel signal to a display buffer for display upon selection of the second channel.

31. The apparatus of claim 20, which comprises a decoder to decode a second channel signal broadcast over the same frequency, the selector being to supply the decoded second channel signal to a display buffer for display upon selection of the second channel.

32. The apparatus of claim 20, wherein the stored channel signals are decrypted prior to selection of the stored channel for display.

33. The apparatus of claim 20, further comprising a decoder to decode the stored channel signals prior to selection of the stored channel for display.

34. The apparatus of claim 20, wherein display delay is reduced by one of lagging a displayed image behind an actual broadcast, and playback of the stored channel signal is accelerated to synchronize playback with a live broadcast.

35. The apparatus of claim 20, wherein at least one channel of the plurality of channels is identified as a stored channel based upon channel input selection rules.

36. The apparatus of claim 35, wherein the selection rules comprise selecting at least one of a channel adjacent to a currently viewed channel, a favorite channel associated with the user, a channel frequently watched, and a list of channels specified by an operator.

38. The conditional access device of claim 33, which comprises a rules module including a plurality of rules, wherein at least one channel of the plurality of channels is identified as a stored channel based on the rules to allow access to the stored channel information for display prior to selection of the at least one stored channel by a user.

37. A conditional access device to control access to a plurality of television channels, the device comprising:

a processor to process channel information required to display a channel of the plurality of channels received from a content distributor; and

a control word manager that queues Entitlement Control Messages and provides control words derived from the Entitlement Control Messages to descramble a video stream.

39. The device of claim 37, wherein the channel information comprises at least one of Entitlement Control Messages and control words of at least one channel other than a currently viewed channel.

40. The device of claim 37, wherein the rules comprise selecting at least one of a channel adjacent to a currently viewed channel, a favorite channel associated with the user, a channel frequently watched, and a list of channels specified by an operator.

41. The device of claim 37, wherein the device is selected from the group consisting of a smart card, a non-removable security device embedded in a received, and an authentication server.

42. Apparatus to reduce delay when changing channels in a television environment, the apparatus comprising:

means for receiving a plurality of television channels from a remote content provider, each channel including channel information required to display the channel;

means for identifying at least one channel of the plurality of channels as a stored channel;

means for storing channel information of the at least one stored channel in storage; and

means for accessing the stored channel information for display upon selection of the at least one stored channel.

43. A method to decrypt a plurality of incoming television channels, the method comprising:

receiving the plurality of television channels at a receiver;

receiving a plurality of encryption keys at the receiver, each encryption key required for decryption of an associated television channel;

communicating the encryption keys to a conditional access device;

time-shifting decryption of the encryption keys in the conditional access device; and

communicating the decrypted encryption keys to the receiver.

44. The method of claim 43, which comprises:

buffering video of more than one television channel; and

buffering in the conditional access device the encryption keys associated with the more than one television channel.

45. The method of claim 43, which comprises:

buffering video of more than one television channel; and

buffering in the conditional access device the encryption keys associated with the more than one television channel.

46. The method of claim 43, which comprises buffering one of Entitlement control Messages and control words in the conditional access device.

47. The method of claim 43, which comprises receiving the encryption keys for decrypting independently of the television channel.

48. The method of claim 43, wherein the conditional access device is selected from the group consisting of a smart card, a non-removable security device embedded in a received, and an authentication server.