Comparing CODEC input/output to adjust psycho-acoustic parameters

• US 6,041,295 A
• Filed: 04/10/1996
• Issued: 03/21/2000
• Est. Priority Date: 04/10/1995
• Status: Expired due to Term

• Current Assignee: Megawave Audio LLC (Intellectual Ventures LLC)
• Original Assignee: Corporate Computer Systems
• Inventors: Hinderks, Larry W.
• Primary Examiner(s): Knepper, David D.
• Application Number:
  US08/630,790
• Time in Patent Office: 1,441 Days
• Field of Search: 395/2.09, 395/2.1, 395/2.12-2.15, 395/2.38, 395/2.39, 395/2.87, 704/200, 704/201, 704/203-206, 704/229, 704/230, 704/278
• US Class Current: 704/206
• CPC Class Codes: H04B 1/665 using psychoacoustic properties of the ear, e.g. masking effect

Abstract

An adjustable CODEC receives a signal and compresses a received audio signal based on a psycho-acoustic compression system. The psycho-acoustic compression system includes several psycho-acoustic parameters which may be adjusted by the user to optimize the compression system for a specific application, transmission medium, or end user, for example. The compression and the adjustment of compression parameters may occur simultaneously in real time without interruption of the compressed signal. Additionally, the parameters may be adjusted in smart groups of a plurality of parameters that are, for example, sympathetic or are often adjusted together. An additional signal may also be combined with the compressed signal and the resultant combined signal may be transmitted over a single transmission path. For example, the additional signal may be multiplexed into the compressed data stream for TDMA transmission. Additionally, the parameters selected at a local, user-adjusted CODEC may be transmitted to a plurality of remote CODEC for remote use.

Claims

1. An adjustable CODEC for compression and decompression of signals including:

an input for receiving an audio signal;

a parameter input unit cooperatively connected to an encoder for inputting and adjusting at least one parameter level of a plurality of pscho-acoustic parameter levels, said encoder containing a compression unit for compressing said signal based on said parameter levels of said plurality of psycho-acoustic parameters to form a first compressed digital bit stream;

a decoder containing a decompression unit for decompressing a received compressed digital data bit stream to a decompressed signal;

an output connected to the decoder for outputting said decompressed signal; and

a comparing device for comparing the responses of said audio signal and said decompressed digital bit stream;

whereby the comparison provided by the comparing device may be the basis for adjusting said parameter level of said plurality of psycho-acoustic parameter levels.

2. The adjustable CODEC of claim 1 wherein said compression unit performs said compression in real time and said decompression unit performs said decompression in real time.

3. The adjustable CODEC of claim 1 wherein at least one psycho-acoustic parameter is adjusted while said compression unit is performing said compression.

4. The adjustable CODEC of claim 1 wherein said psycho-acoustic parameters are adjusted in smart groups of a plurality of psycho-acoustic parameters.

5. The adjustable CODEC of claim 1 wherein said input unit further modifies the set of available psycho-acoustic parameters to alter the number of psycho-acoustic parameters used in said compression unit.

6. The adjustable CODEC of claim 1 wherein said input unit comprises at least one of a computer, a visual user interface, a keyboard, a keypad, a mouse, and a knob.

7. The adjustable CODEC of claim 1 wherein said responses include at least frequency responses.

8. The adjustable CODEC of claim 1 wherein at least one of said parameter levels of said plurality of psycho-acoustic parameters is transmitted to a remote CODEC.

9. The adjustable CODEC of claim 1 further comprising a digital loopback control unit.

10. The adjustable CODEC of claim 1 further including at least one digital interface module connected to said encoder for converting said compressed data bit stream into at least one predetermined digital format.

11. The adjustable CODEC of claim 10 wherein said compression unit performs said compression in real time and said decompression unit performs said decompression in real time.

12. The adjustable CODEC of claim 10 wherein at least one psycho-acoustic parameter is adjusted while said compression unit is performing said compression.

13. The adjustable CODEC of claim 10 wherein said psycho-acoustic parameters are adjusted in smart groups of a plurality of psycho-acoustic parameters.

14. The adjustable CODEC of claim 10 wherein said input unit further modifies the set of available psycho-acoustic parameters to alter the number of psycho-acoustic parameters used in said compression unit.

15. The adjustable CODEC of claim 10 wherein said input unit comprises at least one of a computer, a visual user interface, a keyboard, a keypad, a mouse, and a knob.

16. The adjustable CODEC of claim 10 wherein said said characteristics include at least frequency characteristics.

17. The adjustable CODEC of claim 10 wherein at least one of said parameter levels of said plurality of psycho-acoustic parameters is transmitted to a remote CODEC.

18. The adjustable CODEC of claim 10 wherein said auxiliary signal comprises a plurality of ancillary bit streams multiplexed to form said auxiliary signal.

19. The adjustable CODEC of claim 10 wherein said decompressed auxiliary signal comprises said plurality of ancillary bit streams and further comprising a demultiplexor to demultiplex said plurality of ancillary bit streams into individual bit streams.

20. The adjustable CODEC of claim 10 further including at least one digital interface module connected to said encoder for converting said compressed data bit stream into at least one predetermined digital format.

21. The adjustable CODEC of claim 10 further comprising a digital loopback control unit.

22. An adjustable CODEC for compression and decompression of signals including:

a first input for receiving a first signal;

an auxiliary input for receiving an auxiliary signal;

a parameter input unit cooperatively connected to an encoder for inputting and adjusting at least one parameter level of a plurality of psycho-acoustic parameter levels, said encoder containing a compression unit for compressing said first signal and said auxiliary signal and compressing at least said first signal based on said parameter levels of said plurality of psycho-acoustic parameters to form a compressed digital bit stream;

a decoder containing a decompression unit for decompressing said compressed digital bit stream to form at least a decompressed first signal and a decompressed auxiliary signal;

an output connected to the decoder for outputting said decompressed first signal;

an auxiliary output connected to the decoder for outputting said decompressed auxiliary signal; and

a comparing device for comparing characteristics of said first signal and said decompressed first signal whereby the comparison provided by the comparing device may be the basis for adjusting said parameter level of said plurality of psycho-acoustic parameter levels.

23. A method of compression and decompression of signals comprising the steps of:

receiving an audio signal;

inputting at least one parameter level of a plurality of psycho-acoustic parameter levels;

compressing said received signal based on said parameter levels of said plurality of psycho-acoustic parameters to form a compressed digital bit stream;

decompressing said compressed digital bit stream to form a decompressed signal;

outputting said decompressed signal; and

comparing the characteristics of said audio signal and said decompressed signal and adjusting an adjustable parameter input unit in order to modify said at least one parameter level based on said comparison.

24. The method of claim 23 wherein said compression step compresses in real time and said decompression step decompresses in real time.

25. The method of claim 23 wherein at least one psycho-acoustic parameter is adjusted while said compression unit is performing said compression.

26. The method of claim 23 wherein said psycho-acoustic parameters are adjusted in smart groups of a plurality of psycho-acoustic parameters.

27. The method of claim 23 further including the step of modifying the set of available psycho-acoustic parameters to alter the number of psycho-acoustic parameters used in said compression unit.

28. The method of claim 23 wherein the parameter level of said inputting step is input by at least one of a computer, a visual user interface, a keyboard, a keypad, a mouse, and a knob.

29. The method of claim 23 wherein said characteristics include at least frequency characteristics.

30. The method of claim 23 further comprising the step of transmitting at least one of said parameter levels of said plurality of psycho-acoustic parameters to a remote CODEC.

31. The method of claim 23 further including the step of converting said compressed data bit stream into at least one predetermined digital format.

32. The method of claim 23 further comprising the step of controlling said compressing step by using a digital loopback control unit.

33. The method of claim 23 further including the steps of:

receiving an auxiliary signal where said compressing step compresses said audio signal and said auxiliary signal and said decompressing step decompresses said digital bit stream to form a decompressed audio signal and a decompressed auxiliary signal; and

outputting said decompressed auxiliary signal.

34. The method of claim 33 wherein said compression step compresses in real time and said decompression step decompresses in real time.

35. The method of claim 33 wherein at least one psycho-acoustic parameter is adjusted while said compression unit is performing said compression.

36. The method of claim 33 wherein said psycho-acoustic parameters are adjusted in smart groups of a plurality of psycho-acoustic parameters.

37. The method of claim 33 further including the step of modifying the set of available psycho-acoustic parameters to alter the number of psycho-acoustic parameters used in said compression unit.

38. The method of claim 33 wherein the parameter level of said inputting step is input by at least one of a computer, a visual user interface, a keyboard, a keypad, a mouse, and a knob.

39. The method of claim 33 wherein said characteristics include at least frequency characteristics.

40. The method of claim 33 further comprising the step of transmitting at least one of said parameter levels of said plurality of psycho-acoustic parameters to a remote CODEC.

41. The method of claim 33 wherein said auxiliary signal comprises a plurality of ancillary bit streams multiplexed to form said auxiliary signal.

42. The method of claim 33 wherein said decompressed auxiliary signal comprises said plurality of ancillary bit streams and further comprising demultiplexing said plurality of ancillary bit streams into individual bit streams.

43. The method of claim 33 further including the step of converting said compressed data bit stream into at least one predetermined digital format.

44. The method of claim 33 further comprising the step of controlling said compressing step by using a digital loopback control unit.