SPEEDING UP CHANNEL CHANGE

• US 20070234395A1
• Filed: 06/13/2007
• Published: 10/04/2007
• 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:
  US11/762,348
• Publication Number:
  US 20070234395A1
• Time in Patent Office: Days
• US Class Current: 725/135
• 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 5/50 Tuning indicators; Automatic tuning control
• CPC Class Codes: H04N 7/163 by receiver means only

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 used 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 used 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;

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

storing an entry point of at least one channel other than a currently viewed channel; and

receiving a header from the remote service content provider to indicate presence of the entry point, wherein the header is selected from a group including a packet header having an indicator bit, an encrypted group of pictures header, and an encrypted sequence header.

2. The method of claim 1, wherein the entry point is an I-frame.

3. 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.

4. The method of claim 1, which comprises updating the storage to maintain a most recently received entry point and subsequent signals of the stored channel.

5. The method of claim 1, comprising decoding through a buffered stream from any point in a Group of Pictures associated with the group of pictures header at a speed greater than real-time until the entry point is found.

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

7. The method of claim 1, further comprising:

decoding a first channel signal for display;

decoding a stored second channel signal; and

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

8. 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.

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

10. 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 used 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, wherein the channel information identifies an entry point used for processing a television signal for display,

wherein the receiver is to receive a header, selected from a group including an encrypted Group of Pictures header, an encrypted sequence header, and a packet header having an indicator bit, from the remote service content provider to indicate presence of the entry point.

11. The apparatus of claim 10, which comprises updating the storage to maintain a most recently received entry point of the stored channel.

12. The apparatus of claim 10, wherein the channel information comprises at least one of a MPEG video frame, an Entitlement Control Message, and an access control word.

13. 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 used 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;

communicating the decrypted encryption keys to the receiver; and

caching program specific information.

14. The method of claim 13, wherein the program specific information is cached in one of a native format and a new format after processing.

15. The method of claim 14, which comprises buffering one of Entitlement control Messages and control words in the conditional access device.

16. The method of claim 14, 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.

17. The method of claim 13, 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.

18. 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 used to display the channel;

identifying at least one channel of the plurality of channels as a stored channel based upon channel input selection rules;

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.

19. The method of claim 18, 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.

20. The method of claim 19, further comprising:

shifting a first buffer list associated with a first buffer in a channel change direction as the adjacent channel is repeatedly selected, wherein the currently viewed channel is within a second buffer list associated with a second buffer, and wherein the first buffer list extends the second buffer list in the channel change direction.