Method and apparatus for masking the effects of latency in an interactive information distribution system

• US 5,781,227 A
• Filed: 10/25/1996
• Issued: 07/14/1998
• Est. Priority Date: 10/25/1996
• Status: Expired due to Term

• Current Assignee: Comcast IP Holdings I LLC (Comcast Corporation)
• Original Assignee: DIVA Systems Corporation
• Inventors: Goode, Christopher, Gordon, Donald, Thomas, Philip A., Illowsky, Daniel, Conover, Mark D., Cole, Brooks
• Primary Examiner(s): Powell, Mark R.
• Assistant Examiner(s): LE, UYEN T
• Application Number:
  US08/738,361
• Time in Patent Office: 627 Days
• Field of Search: 348/7, 348/10, 348/11, 348/12, 348/13, 348/578, 348/584, 348/586, 348/594, 348/595, 348/601, 455/6.2, 455/6.3, 455/5.1, 455/4.2
• US Class Current: 725/32
• CPC Class Codes: H04N 21/4384 involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency

Abstract

A method and apparatus for masking the effects of latency within an information distribution system. The apparatus comprises a set top terminal that requests and receives information from an information server within the information distribution system. The information is generally displayed upon a conventional television that is coupled to the set top terminal. The set top terminal contains a central processing unit and an information stream decoder that are programmed to implement the method. The method is a routine which is executed when a subscriber selects certain functions, usually via a remote control, that are available for the set top terminal to perform. Upon execution, the method recalls a predefined image from memory and begins to fade the presently displayed image into a predefined image, e.g., a white screen. Simultaneously, the presently playing sound is also faded into the predefined sound, e.g., no sound. The decoder within the set top terminal is reset to flush from its buffer and residual sound or video information from the previously decoded video. Lastly, once the new video stream has arrived and begins to be decoded, the set top terminal fades up from the pre-defined image to the new video stream and from the pre-defined audio to the audio stream that accompanies the video stream. At this point, the subscriber'"'"'s selected function has been fully implemented without display of the detrimental affects usually associated with a latency delay.

Claims

1. In a set top terminal used for decoding and displaying imagery associated with information streams transmitted to said set top terminal via an information distribution system, a method for masking latency within said information distribution system, where said latency occurs while transitioning from a first information stream to a second information stream, said method comprising the steps of:

responding to a user command entered into said set top terminal and, simultaneously, sending an upstream data command to the information distribution system to implement said user command;

recalling a predefined image from an image memory;

fading at least a portion of imagery decoded from said first information stream into said predefined image;

resetting a signal decoder within said set top terminal;

fading from said predefined image into imagery decoded from said second information stream; and

displaying said imagery from said second information stream.

2. The method of claim 1 further comprising the steps of:

fading an audio signal associated with said imagery of said first information stream into a predefined audio signal as said imagery of said first information stream is faded into said predefined image; and

fading from said predefined audio signal into an audio signal associated with said second information stream as said predefined image is faded into said imagery of said second information stream.

3. The method of claim 1 wherein said predefined image is a white screen, a white screen containing at least one geometric object, animation, or a video clip.

4. The method of claim 3 wherein said predefined audio signal produces no sound or a sound that compliments the predefined image.

5. The method of claim 1 further comprising the steps of:

displaying, in response to said user command, a function selection indicator that identifies a function that corresponds to the user command.

6. The method of claim 1 wherein said predefined image is a portion of a frozen video frame.

7. In a set top terminal used for decoding and displaying imagery associated with information streams transmitted to said set top terminal via an information distribution system, a method for masking latency within said information distribution system, where said latency occurs while transitioning from a first information stream to a second information stream, said method comprising the steps of:

responding to a user command entered into said set top terminal and, simultaneously, sending an upstream data command to the information distribution system to implement said user command;

freezing an image frame of said first information stream and, simultaneously, activating a transition timer;

fading at least a portion of said frozen image frame by masking said portion using an on-screen display overlay;

resetting a signal decoder within said set top terminal;

upon time out of the transition timer, fading from the masked frozen image into imagery decoded from said second information stream; and

displaying said imagery from said second information stream.

8. The method of claim 7 wherein said on-screen display overlay is a white screen that covers at least a portion of said frozen image frame.

9. The method of claim 7 further comprising the steps of:

displaying, in response to said user command, a function selection indicator that identifies a function that corresponds to the user command.

10. The method of claim 7 wherein said on-screen display overlay covers all but an object in said frozen image frame and the object is contained in the second information stream, where having said object in both said first information stream to provide said frozen image frame containing the object and said second information stream provides spacial continuity from the first information stream to the second information stream.

11. In a set top terminal used for decoding and displaying imagery associated with information streams transmitted to said set top terminal via an information distribution system, apparatus for masking latency within said information distribution system, where said latency occurs while transitioning from a first information stream to a second information stream, said apparatus comprising:

means for responding to a user command entered into said set top terminal and for simultaneously sending an upstream data command to the information distribution system to implement said user command;

memory access means for recalling a predefined image from an image memory in response to said user command being entered;

first image processing means for fading at least a portion of imagery decoded from said first information stream into said predefined image;

controller means for resetting a signal decoder within said set top terminal;

second image processing means for fading from said predefined image into imagery decoded from said second information stream; and

means for displaying said imagery of said second information stream.

12. The apparatus of claim 11 further comprising:

means, coupled to said first image processing means, for fading an audio signal associated with said imagery of said first information stream into a predefined audio signal as said imagery of said first information stream is faded into said predefined image; and

means, coupled to said second image processing means, for fading from said predefined audio signal into an audio signal associated with said second information stream as said predefined image is faded into said imagery of said second information stream.

13. The apparatus of claim 11 wherein said predefined image is a white screen, a white screen containing at least one geometric object, animation, or a video clip.

14. The apparatus of claim 12 wherein said predefined audio signal produces no sound or a sound that compliments the predefined image.

15. The apparatus of claim 11 further comprising:

means for displaying, in response to said user command, a function selection indicator that identifies a function that corresponds to the user command.

16. The apparatus of claim 11 wherein said predefined image is a portion of a frozen video frame.

17. The apparatus of claim 16 wherein said predefined image contains an on-screen display overlay that covers all but an object in said frozen image frame and the object is also contained in the second information stream, where having said object in both said first information stream to provide said frozen image frame containing the object and said second information stream provides spacial continuity from the first information stream to the second information stream.