Method and apparatus of mixing audios

• US 7,020,613 B2
• Filed: 07/26/2002
• Issued: 03/28/2006
• Est. Priority Date: 07/27/2001
• Status: Expired due to Fees

• Current Assignee: At Chip Corporation
• Original Assignee: At Chip Corporation
• Inventors: Chen, Ching-Chang, Chang, Pao-Chi
• Primary Examiner(s): Knepper, David D.
• Application Number:
  US10/202,863
• Publication Number:
  US 20030023428A1
• Time in Patent Office: 1,341 Days
• Field of Search: None
• US Class Current: 704/278
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: G10L 19/12 the excitation function being a code excitation, e.g. in code excited linear prediction [CELP] vocoders
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10

Abstract

A method and system of mixing audios to convert a plurality of input voices into a single output voice is described. The system of mixing audios has a decoding device, an audio mixing device and a frame package unit. The input voices including a plurality of audio frames are partially decoded to acquire audio parameters of the input voices by the decoding device. One audio frame of the input voices is selected by the audio mixing device to obtain a target frame according to the audio parameters later. The target frame is then packaged so as to be identical to the original format of the input voices by the frame package unit.

Claims

1. A method of mixing audios to transmit a plurality of input voices, said method comprising the steps of:

decoding a portion of each of said input voices to acquire a plurality of audio parameters responsive to said input voices to reduce a transmission delay of said input voices, wherein each of said input voices is compactly encoded and includes a plurality of audio frames;

performing an audio decision and classification on said audio parameters responsive to said input voices to determine an audio type of each of said input voices;

selecting a target frame from said audio frames of said input voices according to a signal intensity of said audio frames; and

packaging said target frame to generate a plurality of output voices having an audio format identical to said input voices to convey readily said output voices.

2. The method of claim 1, wherein the step of decoding said portion of each of said input voices comprises executing a parameter decoding in a parameter decoder.

3. The method of claim 2, wherein the step of executing a parameter decoding comprises executing a CELP algorithm in said parameter decoder.

4. The method of claim 1, wherein said audio parameters includes a pitch signal, a pitch gain, a fixed codebook vector, a fixed codebook gain or a combination thereof.

5. The method of claim 1, wherein the step of performing said audio decision and classification further comprises the steps of:

verifying a header of said audio frames to determine a plurality of classes of said audio frames; and

identifying said audio parameters responsive to said input voices to determine said audio type of each of said input voices.

6. The method of claim 5, wherein the step of identifying said audio parameters comprises using a pitch gain threshold and a pitch difference threshold.

7. The method of claim 5, wherein the step of performing said audio decision and classification comprises computing sequentially a plurality of pitch difference absolute values of said audio frames by a backward computation and adding said pitch difference absolute values to obtain a sum of said pitch difference absolute values.

8. The method of claim 1, wherein said audio type of each of said input voices includes a quasi-voice frame, a quasi-dumb frame or a combination thereof.

9. The method of claim 8, wherein the step of selecting a target frame from said audio frames comprises selecting one of said audio frames having a higher signal intensity in adaptive excitation signals responsive to said input voices as said target frame if said input voices includes totally quasi-voice frames.

10. The method of claim 8, wherein the step of selecting a target frame from said audio frames comprises selecting one of said audio frames having a higher signal intensity in adaptive excitation signals responsive to said input voices as said target frame if said input voices includes totally quasi-dumb frames.

11. The method of claim 8, wherein the step of selecting a target frame from said audio frames comprises selecting one of said audio frames having a higher signal intensity in adaptive excitation signals responsive to said input voices as said target frame if said input voices includes a single quasi-dumb frame.

12. A method of mixing audios to transmit a plurality of input voices, said method comprising the steps of:

decoding a portion of each of said input voices to acquire a plurality of audio parameters responsive to said input voices to reduce a transmission delay of said input voices, wherein each of said input voices compactly encoded includes a plurality of audio frames;

performing an audio decision and classification on said audio parameters responsive to said input voices to determine an audio type of each of said input voices, wherein the step of performing said audio decision and classification further comprises the steps of;

verifying a header of said audio frames to determine a plurality of classes of said audio frames; and

identifying said audio parameters responsive to said input voices to determine said audio type of each of said input voices;

selecting a target frame from said audio frames of said input voices according to a signal intensity of said audio frames; and

packaging said target frame to generate a plurality of output voices having an identical audio format to said input voices to convey readily said output voices.

13. The method of claim 12, wherein the step of decoding said portion of each of said input voices comprises executing a parameter decoding in a parameter decoder.

14. The method of claim 13, wherein the step of executing a parameter decoding comprises executing a CELP algorithm in said parameter decoder.

15. The method of claim 12, wherein said audio parameters include a pitch, a pitch gain, a fixed codebook vector, a fixed codebook gain or a combination thereof.

16. The method of claim 12, wherein the step of verifying a header of said audio frames to determine a plurality of classes of said audio frames include a voice frame, a transition frame, a reserved frame or a combination thereof.

17. The method of claim 12, wherein the step of identifying said audio parameters comprises using a pitch gain threshold and a pitch difference threshold.

18. The method of claim 12, wherein the step of performing said audio decision and classification comprises computing sequentially a plurality of pitch difference absolute values of said audio frames by a backward computation and adding said pitch difference absolute values to obtain a sum of said pitch difference absolute values.

19. The method of claim 12, wherein said audio type of each of said input voices includes a quasi-voice frame, a quasi-dumb frame or a combination thereof.

20. The method of claim 19, wherein the step of selecting a target frame from said audio frames comprises selecting one of said audio frames having a higher signal intensity in adaptive excitation signals responsive to said input voices as said target frame if said input voices includes totally quasi-voice frames.

21. The method of claim 12, wherein the step of selecting a target frame from said audio frames comprises selecting one of said audio frames having a higher signal intensity in adaptive excitation signals responsive to said input voices as said target frame if said input voices includes totally quasi-dumb frames.

22. The method of claim 12, wherein the step of selecting a target frame from said audio frames comprises selecting one of said audio frames having a higher signal intensity in adaptive excitation signals responsive to said input voices as said target frame if said input voices includes a single quasi-dumb frame.

23. An apparatus for mixing audios to transmit a plurality of input voices, said apparatus comprising:

a decoding device for decoding a portion of each of said input voices to acquire a plurality of audio parameters responsive to said input voices to reduce a transmission delay, wherein each of said input voices compactly encoded includes a plurality of audio frames;

an audio mixing device coupled to said decoding device for selecting one of said audio frames on the basis of said audio parameters of said input voices, wherein said audio mixing device further comprises;

a header verification unit coupled to said decoding device for checking a title of said audio frames to determine a plurality of classes of said audio frames;

an audio identification unit coupled to said header verification unit for determining an audio type of each of said input voices by a pitch difference absolute value of said audio frames and a pitch gain of said audio parameters;

an excitation computation unit coupled to said audio identification unit for computing a signal intensity of an excitation signal to determine said signal intensity of said audio frames;

an adaptive selecting unit coupled to said header verification unit for selecting a target frame from said audio frames; and

a voice selector coupled to said header verification unit to select a voice data stream; and

a frame package unit coupled to said excitation computation unit, said adaptive selecting unit and said voice selector, respectively, to package said target frame for generating a plurality of output voices having a format identical to said input voices to convey readily said output voices.

24. The audio mixing system of claim 23, wherein said decoding device comprises a parameter decoder for executing a parameter decoding.

25. The audio mixing system of claim 24, wherein said decoding device comprises a CELP algorithm executed on said parameter decoder.

26. The audio mixing system of claim 23, wherein said audio parameters include a pitch, a pitch gain or a combination thereof.

27. The audio mixing system of claim 23, wherein said audio parameters include a pitch, a pitch gain, a fixed codebook vector, a fixed codebook gain or a combination thereof.

28. The audio mixing system of claim 23, wherein said classes of said audio frames include a voice frame, a transition frame, a reserved frame or a combination thereof.

29. The audio mixing system of claim 23, wherein said audio identification unit comprises a pitch gain threshold and a pitch difference threshold.

30. The audio mixing system of claim 23, wherein said identification unit computes sequentially a plurality of pitch difference absolute values of said audio frames by a backward computation and obtains a sum of said pitch difference absolute values by an addition of said pitch difference absolute values.

31. The audio mixing system of claim 23, wherein said excitation signal includes a self-adaptive excitation signal, a fixed excitation signal or a combination thereof.

32. The audio mixing system of claim 23, wherein said audio type of each of said input voices includes a quasi-voice frame, a quasi-dumb frame or a combination thereof.

33. The audio mixing system of claim 32, wherein said adaptive selecting unit of said audio mixing device selects one of said audio frames having a higher signal intensity responsive to said input voices as said target frame if said input voices includes totally quasi-voice frames.

34. The audio mixing system of claim 32, wherein said adaptive selecting unit of said audio mixing device selects one of said audio frames having a higher signal intensity responsive to said input voices as said target frame if said input voices includes totally quasi-dumb frames.

35. The audio mixing system of claim 32, wherein said adaptive selecting unit of said audio mixing device selects one of said audio frames having a higher signal intensity responsive to said input voices as said target frame if said input voices includes a single quasi-dumb frame.