Frequency converter system

• US 6,421,636 B1
• Filed: 05/30/2000
• Issued: 07/16/2002
• Est. Priority Date: 10/12/1994
• Status: Expired due to Term

• Current Assignee: Pixel Instruments Corporation
• Original Assignee: Pixel Instruments Corporation
• Inventors: Anderson, Steve, Cooper, J. Carl
• Primary Examiner(s): EDOUARD, PATRICK NESTOR
• Application Number:
  US09/579,479
• Time in Patent Office: 777 Days
• Field of Search: 704/205, 704/206, 704/207, 704/211, 704/258, 704/268, 704/500, 704/503
• US Class Current: 704/205
• CPC Class Codes: G10L 21/04 Time compression or expansion
• CPC Class Codes: G11B 20/00007 Time or data compression or expansion audio compression based on psychoacoustics G10L19/00; data processing for reproducing audio data at different playback speeds G10L21/04; video compression H04N19/00; data compression per se H03M7/30
• CPC Class Codes: H04B 1/662 using a time/frequency relationship, e.g. time compression or expansion
• CPC Class Codes: H04N 21/4126 The peripheral being portable, e.g. PDAs or mobile phones
• CPC Class Codes: H04N 21/4147 PVR [Personal Video Recorder] H04N5/76 takes precedence ; arrangements for broadcast with accumulation-type receivers H04H20/40
• CPC Class Codes: H04N 21/42204 User interfaces specially adapted for controlling a client device through a remote control device; Remote control devices therefor constructive details of casings for the remote control device H01H9/0235; user interfaces for controlling a tuning device of a television receiver through a remote control H03J9/00; remote control of peripheral devices connected to a television receiver through the remote control device of the television receiver H04B1/205
• CPC Class Codes: H04N 21/42209 for displaying non-command information, e.g. electronic program guide [EPG], e-mail, messages or a second television channel
• CPC Class Codes: H04N 21/42222 Additional components integrated in the remote control device, e.g. timer, speaker, sensors for detecting position, direction or movement of the remote control, microphone or battery charging device
• CPC Class Codes: H04N 21/42227 the keys being reprogrammable, e.g. soft keys
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/4316 for displaying supplemental content in a region of the screen, e.g. an advertisement in a separate window
• CPC Class Codes: H04N 21/4331 Caching operations, e.g. of an advertisement for later insertion during playback
• CPC Class Codes: H04N 21/4333 Processing operations in response to a pause request
• CPC Class Codes: H04N 21/47 End-user applications
• CPC Class Codes: H04N 21/47214 for content reservation or setting reminders; for requesting event notification, e.g. of sport results or stock market stock exchange data over packet-switching network H04L12/1804; push services over packet-switching network H04L12/1859; notification of incoming messages in packet switching networks H04L51/224
• CPC Class Codes: H04N 21/482 End-user interface for program selection broadcast systems using EPGs H04H60/72
• CPC Class Codes: H04N 21/485 End-user interface for client configuration
• CPC Class Codes: H04N 5/76 Television signal recording
• CPC Class Codes: H04N 5/775 between a recording apparatus and a television receiver
• CPC Class Codes: H04N 5/783 Adaptations for reproducing at a rate different from the recording rate
• CPC Class Codes: H04N 9/8042 : involving data reduction

Abstract

An apparatus and method is disclosed for converting an input signal having frequency related information sustained over a first duration of time into an output signal sustained over a second duration of time at substantially the same first frequency by adding or subtracting to the effective wave length of the output signal. Preferably, the signals are converted in digital form with samples added or subtracted to frequency convert the signal.

Claims

1. A method of converting an input signal having frequency related sampled information with a contiguous alpha reproduced over a first time period to an output signal having frequency related sampled information with a contiguous alpha length reproduced over a second time period,

said apparatus comprising determining the ratio between the second frequency and first frequency and then altering the contiguous alpha length of the output signal by said ratio by adding and/or deleting samples.

2. The method of claim 1 characterized in that the output signal is reproduced over a different time period than the input signal and said determining the ratio between the second frequency and first frequency includes comparing the time period of reproduction of the output signal to the time period of reproduction of the input signal in order to provide an output signal having the same frequency related information as the input signal now reproduced over a second different time period.

3. The method of claim 1 wherein the input signal has frequency information to be synchronized to a second signal on an associated channel and characterized by the addition of determining the time differential of synchronization between the input signal and the second signal on the associated channel and then using said time differential in determining the ratio between the second frequency and the first frequency so as to synchronize the output signal to the second signal.

4. A method of converting an input signal having frequency related information having a contiguous alpha length reproduced over a first time period to an output signal having frequency related information having a contiguous alpha length reproduced over a second time period, said method comprising determining the ratio between the second frequency and first frequency, altering the contiguous alpha length of the output signal by said ratio,

and said altering the alpha length of the output signal includes digitally sampling one of the input or output signal and then modifying the number of samples of the digitally sampled signal.

5. The method of claim 4 characterized in that at least said number of samples is stored in a memory.

6. The method of claim 5 characterized in that the number of samples are modified prior to storage in memory.

7. The method of claim 5 characterized in that the number of samples are modified after storage in memory.

8. The method of claim 5 wherein at least said number of samples are stored in a memory having a limited value

and characterized in that the memory has first and second signals by the addition of a resetting of the memory upon the comparison of said first and second signals.

9. The method of claim 8 characterized in that the output signal is compared to the input signal to trigger resetting.

10. The method of claim 8 characterized in that at least said number of samples is stored in two memories having outputs and reset areas, one of which is active for modifying the number of samples, with said resetting of the memories including switching from the active memory to the reset area in the inactive memory.

11. The method of claim 10 characterized in that the output of the inactive memory is compared to the active memory to trigger resetting.

12. An apparatus for converting an input signal having frequency related sampled information with a contiguous alpha length reproduced over a first time period to an output signal having substantially the same frequency related sampled information having an alpha length reproduced over a second, different time period,

said apparatus comprising means for determining the desired ratio between the input frequency and the output frequency,

and means for altering the contiguous alpha length of the output signal by adding and/or deleting samples by said desired ratio.

13. An apparatus for converting an input signal having frequency related sampled information with a contiguous alpha length reproduced over a first time period to an output signal having substantially the same frequency related sampled information having an alpha length reproduced over a second, different time period,

said apparatus comprising means for determining the desired ratio between the input frequency and the output frequency,

means for altering the contiguous alpha length of the output signal by adding and/or deleting samples by said desired ratio,

and said means for altering the alpha length of the output signal includes means for digitally sampling one of the input or output signal and means for modifying the number of samples of the digitally sampled signal.

14. The apparatus of claim 13 characterized by the addition of means for storing at least said number of samples in a memory.

15. The apparatus of claim 14 characterized in that the number of samples are modified prior to storage in memory.

16. The apparatus of claim 14 characterized in that the number of samples are modified after storage in memory.

17. The apparatus of claim 14 wherein at least said number of samples are stored in a memory having a limited value

and characterized in that the memory has first and second signals and by the addition of a means for resetting of memory upon the comparison of said first and second signals.

18. The apparatus of claim 17 characterized by the addition of means to store at least said number of samples in two memories having outputs and reset areas, one of which is active for modifying the number of samples, with said means for resetting the memories including means for switching from the active memory to the reset area of the inactive memory.

19. A method of converting an input signal having frequency related information reproduced over a first time period to an output signal having substantially the same frequency related information reproduced over a second, different time period,

said method comprising getting an input signal, over sampling said input signal through an over sampling device to produce a first set of digital samples,

determining the desired ratio between the frequency of the input signal and the frequency of the output signal, modifying said first set of said digital samples in a signal modification circuit in accord with said desired ratio to produce a second set of digital samples,

converting said second set of digital samples to produce an output signal having an alpha length altered in the signal modification circuit by said desired ratio, and remitting said output signal.

20. The method of claim 19 characterized in that the input signal is clocked relative to an input clock and the output signal is clocked relative to an output clock and characterized by the addition of clocking the input signal with the output clock prior to said oversampling.

21. The method of claim 19 characterized in that the input signal is clocked relative to an input clock and the output signal is clocked relative to an output clock and characterized by the addition of clocking the first set of digital samples relative to the output clock prior to said modification in the signal modification circuit.

22. The method of claim 19 characterized in that the input signal is clocked relative to an input clock and the output signal is clocked relative to an output clock and characterized by the addition of clocking said second set of digital samples relative to the output clock prior to said converting.

23. The method of claim 19 characterized in that altering the alpha length of the output signal includes digitally sampling one of the input or output signal and then modifying the number of samples of the digitally sampled signal.

24. The method of claim 19 characterized in that at least said number of samples is stored in a memory.

25. The method of claim 24 wherein at least said number of samples are stored in a memory having a limited value

and characterized in that the memory has first and second signals and by the addition of a resetting of the memory upon the comparison of said first and second signals.

26. The method of claim 19 whereof the output signal needs to be synchronized with associated channel and characterized by altering the alpha length of the output signal to also synchronize it to the associated channel.

27. An apparatus for converting an input signal having frequency related information reproduced over a first time period to an output signal having substantially the same frequency related information reproduced over a second, different time period,

said apparatus comprising means to get an input signal, means for over sampling said input signal through an over sampling device to produce a first set of digital samples,

means for determining the desired ratio between the frequency of the input signal and the frequency of the output signal, means for modifying said first set of said digital samples in a signal modification circuit in accord with said desired ratio to produce a second set of digital samples,

means for converting said second set of digital samples to produce an output signal having an alpha length altered in the signal modification circuit by said desired ratio, and remitting said output signal.

28. The apparatus of claim 27 characterized in that the input signal is clocked relative to an input clock and the output signal is clocked relative to an output clock and characterized by the addition of means to clock the input signal with the output clock prior to said oversampling.

29. The apparatus of claim 27 characterized in that the input signal is clocked relative to an input clock and the output signal is clocked relative to an output clock and characterized by the addition of means to clock the first set of digital samples relative to the output clock prior to said modification in the signal modification circuit.

30. The apparatus of claim 27 characterized in that the input signal is clocked relative to an input clock and the output signal is clocked relative to an output clock and characterized by the addition of means to clock said second set of digital samples relative to the output clock prior to said converting.

31. The apparatus of claim 27 characterized in that said means for altering the alpha length of the output signal includes means to digitally sampling one of the input or output signals and means to modify the number of samples of the digitally sampled signal.

32. The apparatus of claim 27 characterized in that at least said number of samples is stored in a memory.

33. The apparatus of claim 32 wherein at least said number of samples are stored in a memory having a limited value

and characterized in that the memory has first and second signals and by the addition of means for resetting of the memory upon the comparison of said first and second signals.

34. The apparatus of claim 33 characterized in that at least said number of samples is stored in two memories having outputs and reset areas, one of which is active for modifying the number of samples, with said means for resetting of the memories including means to change over from the active memory to the reset area of the inactive memory.

35. The apparatus of claim 34 characterized in that there is a first modification circuit associated with one of the memories and a second signal modification circuit associated with the other of the memories and characterized by the additional step of means for cross fading between the output of the first signal modification circuit and the second signal modification circuit.