Output Circuit, Control Program Product, and Control Method

• US 20090210588A1
• Filed: 07/03/2006
• Published: 08/20/2009
• Est. Priority Date: 07/06/2005
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd., Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Adachi, Makoto, Sugihara, Noboru, Nakao, Atsushi, Ito, Hiromichi
• Application Number:
  US11/988,287
• Publication Number:
  US 20090210588A1
• Time in Patent Office: Days
• US Class Current: 710/60
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04N 21/4305 Synchronising client clock from received content stream, e.g. locking decoder clock with encoder clock, extraction of the PCR packets arrangements for synchronising receiver with transmitter by comparing receiver clock with transmitter clock H04L7/0012; arrangements for synchronising receiver with transmitter wherein the receiver takes measures against momentary loss of synchronisation H04L7/0083
• CPC Class Codes: H04N 21/4334 Recording operations recording of a television signal H04N5/76; arrangements for recording or accumulating broadcast information or broadcast-related information H04H60/27
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer
• 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 21/6437 Real-time Transport Protocol [RTP]

Abstract

A computation unit computes an elapse time until second data stored in a storage unit is outputted since first data is stored in the storage unit. An output request unit changes a speed at which an output unit outputs data based on the elapse time.

Claims

1. An output circuit comprising:

a storage unit to store data;

an accumulation unit to store the data in said storage unit;

an output request unit to provide an output request for the data stored in said storage unit;

an output unit to output the data stored in said storage unit in response to said output request; and

a computation unit to compute an elapse time until said output unit outputs second data stored in said storage unit since said accumulation unit stores first data in said storage unit, wherein

said output request unit changes a speed at which said output unit outputs the data based on said elapse time.

2. The output circuit according to claim 1, wherein said output request unit increases the speed at which said output unit outputs the data when said elapse time reaches a predetermined upper limit, and said output request unit decreases the speed at which said output unit outputs the data when said elapse time reaches a predetermined lower limit.

3. The output circuit according to claim 1, wherein

said computation unit computes a characteristic of said elapse time for a predetermined time by a predetermined calculation using predetermined pieces of information on said elapse time which is changed based on the data stored in said storage unit, and

said output request unit changes the speed at which said output unit outputs the data based on the characteristic of said elapse time.

4. The output circuit according to claim 3, wherein said predetermined calculation is a calculation by a least-square method.

5. The output circuit according to claim 1, wherein said elapse time is a time period corresponding to a difference between time at which said accumulation unit stores said first data in said storage unit and time at which said output unit outputs said second data stored in said storage unit.

6. The output circuit according to claim 1, wherein said elapse time is a time period based on the number of clock counts counted until said output unit outputs said second data stored in said storage unit since said accumulation unit stores said first data in said storage unit.

7. The output circuit according to claim 1, wherein said first data and said second data are the same data.

8. The output circuit according to claim 1, wherein predetermined pieces of data are stored in said storage unit during a period until said second data is stored in said storage unit since said first data is stored in said storage unit.

9. An output circuit comprising:

a storage unit to store data;

an accumulation unit to store encrypted data in said storage unit;

an output request unit to provide an output request for the encrypted data stored in said storage unit;

a first output unit to output the encrypted data from said storage unit in response to said output request;

a decryption unit to decrypt the encrypted data outputted from said first output unit;

a second output unit to output the decrypted data decrypted by said decryption unit; and

a computation unit to compute an elapse time until said first output unit outputs second encrypted data stored in said storage unit since said accumulation unit stores first encrypted data in said storage unit, wherein

said second output unit changes a speed at which said decrypted data is outputted based on said elapse time.

10. The output circuit according to claim 9, wherein said second output unit increases the speed at which said decrypted data is outputted when said elapse time reaches a predetermined upper limit, and said second output unit decreases the speed at which said decrypted data is outputted when said elapse time reaches a predetermined lower limit.

11. The output circuit according to claim 9, wherein

said computation unit computes a characteristic of said elapse time for a predetermined time by a predetermined calculation using predetermined pieces of information on said elapse time which is changed based on the encrypted data stored in said storage unit, and

said second output unit changes the speed at which said decrypted data is outputted based on the characteristic of said elapse time.

12. The output circuit according to claim 11, wherein said predetermined calculation is a calculation by a least-square method.

13. The output circuit according to claim 9, wherein said first encrypted data and said second encrypted data are the same data.

14. An output circuit comprising:

a storage unit to store data;

an accumulation unit to store encrypted data in said storage unit;

a first output unit to output the encrypted data from said storage unit;

a decryption unit to decrypt the encrypted data outputted from said first output unit;

a second output unit to output the decrypted data decrypted by said decryption unit in response to an output request;

an output request unit to provide said output request to said second output unit; and

a computation unit to compute an elapse time until said first output unit outputs second encrypted data stored in said storage unit since said accumulation unit stores first encrypted data in said storage unit, wherein

said output request unit changes a speed at which said second output unit outputs said decrypted data based on said elapse time.

15. The output circuit according to claim 14, wherein said output request unit increases the speed at which said second output unit outputs said decrypted data when said elapse time reaches a predetermined upper limit, and said output request unit decreases the speed at which said second output unit outputs said decrypted data when said elapse time reaches a predetermined lower limit.

16. The output circuit according to claim 14, wherein

said computation unit computes a characteristic of said elapse time for a predetermined time by a predetermined calculation using predetermined pieces of information on said elapse time which is changed based on the encrypted data stored in said storage unit, and

said output request unit changes the speed at which said second output unit outputs said decrypted data based on the characteristic of said elapse time.

17. The output circuit according to claim 16, wherein said predetermined calculation is a calculation by a least-square method.

18. The output circuit according to claim 14, wherein said first encrypted data and said second encrypted data are the same data.

19. An output circuit which outputs data in response to an output request from an external circuit, the output circuit comprising:

a storage unit to store data;

an accumulation unit to store the data in said storage unit;

an output unit to output the data stored in said storage unit in response to said output request; and

a computation unit to compute an elapse time until said output unit outputs second data stored in said storage unit since said accumulation unit stores first data in said storage unit, and to notify said external circuit of said elapse time as information for controlling timing of said output request.

20. The output circuit according to claim 19, wherein said elapse time is a time period corresponding to a difference between time at which said accumulation unit stores said first data in said storage unit and time at which said output unit outputs said second data stored in said storage unit.

21. The output circuit according to claim 19, wherein said elapse time is a time period based on the number of clock counts counted until said output unit outputs said second data stored in said storage unit since said accumulation unit stores said first data in said storage unit.

22. The output circuit according to claim 19, wherein said first data and said second data are the same data.

23. The output circuit according to claim 19, wherein predetermined pieces of data are stored in said storage unit during a period until said second data is stored in said storage unit since said first data is stored in said storage unit.

24. An output circuit which outputs data in response to an output request from an external circuit, the output circuit comprising:

a storage unit to store data;

an accumulation unit to store the data in said storage unit;

an output unit to output the data stored in said storage unit in response to said output request; and

a notification unit to notify said external circuit of time at which said accumulation unit stores first data in said storage unit and time at which said output unit outputs second data stored in said storage unit as information for controlling timing of said output request.

25. The output circuit according to claim 24, wherein said first data and said second data are the same data.

26. A control program product which causes a computer to perform data processing, the control program product causing the computer to execute the steps of:

storing data in a storage unit of the computer;

providing an output request for the data stored in said storage unit;

outputting the data stored in said storage unit in response to said output request;

computing an elapse time until second data stored in said storage unit is outputted since first data is stored in said storage unit; and

changing a speed at which the data is outputted based on said elapse time.

27. The control program product according to claim 26, wherein said first data and said second data are the same data.

28. A control method performed by an output circuit provided with a storage unit, said control method comprising the steps of:

storing data in said storage unit;

providing an output request for the data stored in said storage unit;

outputting the data stored in said storage unit in response to said output request;

computing an elapse time until second data stored in said storage unit is outputted since first data is stored in said storage unit; and

changing a speed at which the data is outputted based on said elapse time.

29. The control method according to claim 28, wherein said first data and said second data are the same data.