초록

Applications of dim-and-burst techniques to coding of wideband speech signals are described. Reconstruction of a highband portion of a frame of a wideband speech signal using information from a previous frame is also described.

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1. A method of processing a speech signal, said method comprising: based on a first active frame of the speech signal, producing a first speech packet that includes a description of a spectral envelope, over (A) a first frequency band and (B) a second frequency band that extends above the first freq

1. A method of processing a speech signal, said method comprising: based on a first active frame of the speech signal, producing a first speech packet that includes a description of a spectral envelope, over (A) a first frequency band and (B) a second frequency band that extends above the first frequency band, of a portion of the speech signal that includes the first active frame;based on a second active frame of the speech signal that occurs in the speech signal immediately after said first active frame, producing a second speech packet that includes a description of a spectral envelope, over the first frequency band, of a portion of the speech signal that includes the second active frame; andproducing an encoded frame that contains (A) the second speech packet and (B) a burst of an information signal that is separate from the speech signal,wherein the second speech packet does not include a description of a spectral envelope over the second frequency band. 2. The method of processing a speech signal according to claim 1, wherein said method comprises, based on a third active frame of the speech signal, producing a third speech packet that includes a description of a spectral envelope, over the first frequency band and the second frequency band, of a portion of the speech signal that includes the third active frame, wherein said third active frame occurs in the speech signal immediately after said second active frame. 3. The method of processing a speech signal according to claim 1, wherein the description of a spectral envelope of a portion of the speech signal that includes the first active frame includes separate first and second descriptions, wherein the first description is a description of a spectral envelope, over the first frequency band, of a portion of the speech signal that includes the first active frame, and wherein the second description is a description of a spectral envelope, over the second frequency band, of a portion of the speech signal that includes the first active frame. 4. The method of processing a speech signal according to claim 1, wherein the first and second frequency bands overlap by at least two hundred Hertz. 5. The method of processing a speech signal according to claim 4, wherein said overlap occurs in the range of from 3.5 to 7 kilohertz. 6. The method of processing a speech signal according to claim 1, wherein the length of the burst is less than the length of the second speech packet. 7. The method of processing a speech signal according to claim 1, wherein the length of the burst is equal to the length of the second speech packet. 8. The method of processing a speech signal according to claim 1, wherein the length of the burst is greater than the length of the second speech packet. 9. The method of processing a speech signal according to claim 1, wherein said producing the first speech packet is performed in response to a first state of a rate control signal, and wherein said producing the second speech packet is performed in response to a second state of the rate control signal that is different than said first state. 10. The method of processing a speech signal according to claim 1, wherein said method comprises: generating a dimming control signal, based on information from a mask file;in response to a first state of said dimming control signal, producing a first encoded frame that includes the first speech packet; andin response to a second state of said dimming control signal that is different than said first state, producing a second encoded frame that includes the second speech packet and does not include a description of a spectral envelope over the second frequency band. 11. A speech encoder, said speech encoder comprising: a packet encoder configured to produce (A), based on a first active frame of a speech signal and in response to a first state of a rate control signal, a first speech packet that includes a description of a spectral envelope over (1) a first frequency band and (2) a second frequency band that extends above the first frequency band and (B), based on a second active frame of the speech signal and in response to a second state of the rate control signal different than the first state, a second speech packet that includes a description of a spectral envelope over the first frequency band; anda frame formatter arranged to receive the first and second speech packets and configured to produce (A), in response to a first state of a dimming control signal, a first encoded frame that contains the first speech packet and (B), in response to a second state of the dimming control signal different than the first state, a second encoded frame that contains the second speech packet and a burst of an information signal that is separate from the speech signal,wherein the first and second encoded frames have the same length, the first speech packet occupies at least eighty percent of the first encoded frame, and the second speech packet occupies not more than half of the second encoded frame, andwherein said second active frame occurs immediately after said first active frame in the speech signal, andwherein the second speech packet does not include a description of a spectral envelope over the second frequency band, andwherein at least one among said packet encoder and said frame formatter includes a processor. 12. The speech encoder according to claim 11, wherein an overlap of the first and second frequency bands occurs in the range of from 3.5 to 4 kilohertz. 13. An apparatus for processing a speech signal, said apparatus comprising: means for producing, based on a first active frame of the speech signal, a first speech packet that includes a description of a spectral envelope, over (A) a first frequency band and (B) a second frequency band that extends above the first frequency band, of a portion of the speech signal that includes the first active frame;means for producing, based on a second active frame of the speech signal that occurs in the speech signal immediately after said first active frame, a second speech packet that includes a description of a spectral envelope, over the first frequency band, of a portion of the speech signal that includes the second active frame; andmeans for producing an encoded frame that contains (A) the second speech packet and (B) a burst of an information signal that is separate from the speech signal,wherein the second speech packet does not include a description of a spectral envelope over the second frequency band. 14. The apparatus for processing a speech signal according to claim 13, wherein an overlap of the first and second frequency bands occurs in the range of from 3.5 to 4 kilohertz. 15. The apparatus for processing a speech signal according to claim 13, wherein said apparatus comprises means for producing a third speech packet, based on a third active frame of the speech signal, that includes a description of a spectral envelope, over the first frequency band and the second frequency band, of a portion of the speech signal that includes the third active frame, wherein said third active frame occurs in the speech signal immediately after said second active frame. 16. A non-transitory computer-readable medium, said medium comprising: code for causing at least one computer to produce, based on a first active frame of the speech signal, a first speech packet that includes a description of a spectral envelope, over (A) a first frequency band and (B) a second frequency band that extends above the first frequency band, of a portion of the speech signal that includes the first active frame;code for causing at least one computer to produce, based on a second active frame of the speech signal that occurs in the speech signal immediately after said first active frame, a second speech packet that includes a description of a spectral envelope, over the first frequency band, of a portion of the speech signal that includes the second active frame; andcode for causing at least one computer to produce an encoded frame that contains (A) the second speech packet and (B) a burst of an information signal that is separate from the speech signal,wherein the second speech packet does not include a description of a spectral envelope over the second frequency band. 17. The medium according to claim 16, wherein an overlap of the first and second frequency bands occurs in the range of from 3.5 to 4 kilohertz. 18. A method of processing speech packets, said method comprising: based on information from a first speech packet from an encoded speech signal, obtaining a description of a spectral envelope of a first frame of a speech signal over (A) a first frequency band and (B) a second frequency band different than the first frequency band;based on information from a second speech packet from the encoded speech signal, obtaining a description of a spectral envelope of a second frame of the speech signal over the first frequency band;obtaining, from an encoded frame of the encoded speech signal, a burst of an information signal that is separate from the speech signal, wherein the encoded frame includes the second speech packet; andbased on a presence of the burst in the encoded frame, and based on information from the first speech packet, obtaining a description of a spectral envelope of the second frame over the second frequency band; andbased on information from the second speech packet, obtaining information relating to a pitch component of the second frame for the first frequency band. 19. The method of processing speech packets according to claim 18, wherein the description of a spectral envelope of a first frame of a speech signal comprises a description of a spectral envelope of the first frame over the first frequency band and a description of a spectral envelope of the first frame over the second frequency band. 20. The method of processing speech packets according to claim 18, wherein the information relating to a pitch component of the second frame for the first frequency band includes a pitch lag value. 21. The method of processing speech packets according to claim 18, wherein said method comprises calculating, based on the information relating to a pitch component of the second frame for the first frequency band, an excitation signal of the second frame for the first frequency band. 22. The method of processing speech packets according to claim 21, wherein said calculating an excitation signal is based on information relating to a second pitch component for the first frequency band, and wherein the information relating to a second pitch component is based on information from the first speech packet. 23. The method of processing speech packets according to claim 21, wherein said method comprises calculating, based on the excitation signal of the second frame for the first frequency band, an excitation signal of the second frame for the second frequency band. 24. The method of processing speech packets according to claim 18, wherein said obtained description of the spectral envelope of the second frame over the second frequency band is based on said description of the spectral envelope of the first frame over the second frequency band. 25. The method of processing speech packets according to claim 18, wherein the first and second frequency bands overlap by at least two hundred Hertz, and wherein said overlap occurs in the range of from 3.5 to 7 kilohertz. 26. The method of processing speech packets according to claim 18, wherein said obtaining a description of a spectral envelope of the second frame over the second frequency band is based on an indication of a narrowband coding scheme for the second frame. 27. An apparatus for processing speech packets, said apparatus comprising: means for obtaining, based on information from a first speech packet from an encoded speech signal, a description of a spectral envelope of a first frame of a speech signal over (A) a first frequency band and (B) a second frequency band different than the first frequency band;means for obtaining, based on information from a second speech packet from the encoded speech signal, a description of a spectral envelope of a second frame of the speech signal over the first frequency band;means for obtaining, based on information from an encoded frame of the encoded speech signal, a burst of an information signal that is separate from the speech signal, wherein the encoded frame includes the second speech packet; andmeans for obtaining, based on a presence of the burst in the encoded frame, and based on information from the first speech packet, a description of a spectral envelope of the second frame over the second frequency band; andmeans for obtaining, based on information from the second speech packet, information relating to a pitch component of the second frame for the first frequency band. 28. The apparatus for processing speech packets according to claim 27, wherein the description of a spectral envelope of a first frame of a speech signal comprises separate first and second descriptions, wherein the first description is a description of a spectral envelope of the first frame over the first frequency band, and wherein the second description is a description of a spectral envelope of the first frame over the second frequency band. 29. The apparatus for processing speech packets according to claim 27, wherein the information relating to a pitch component of the second frame for the first frequency band includes a pitch lag value. 30. The apparatus for processing speech packets according to claim 27, wherein said apparatus comprises means for calculating, based on the information relating to a pitch component of the second frame for the first frequency band, an excitation signal of the second frame for the first frequency band, and wherein said apparatus comprises means for calculating, based on the excitation signal of the second frame for the first frequency band, an excitation signal of the second frame for the second frequency band. 31. The apparatus for processing speech packets according to claim 27, wherein an overlap of the first and second frequency bands occurs in the range of from 3.5 to 4 kilohertz. 32. The apparatus for processing speech packets according to claim 27, wherein said means for obtaining a description of a spectral envelope of the second frame over the second frequency band is configured to obtain said description if a narrowband coding scheme is indicated for the second frame. 33. A non-transitory computer-readable medium, said medium comprising: code for causing at least one computer to obtain, based on information from a first speech packet from an encoded speech signal, a description of a spectral envelope of a first frame of a speech signal over (A) a first frequency band and (B) a second frequency band different than the first frequency band;code for causing at least one computer to obtain, based on information from a second speech packet from the encoded speech signal, a description of a spectral envelope of a second frame of the speech signal over the first frequency band;code for causing at least one computer to calculate, based on information from an encoded frame of the encoded speech signal, a burst of an information signal that is separate from the speech signal, wherein the encoded frame includes the second speech packet; andcode for causing at least one computer to obtain, based on a presence of the burst in the encoded frame, and based on information from the first speech packet, a description of a spectral envelope of the second frame over the second frequency band; andcode for causing at least one computer to obtain, based on information from the second speech packet, information relating to a pitch component of the second frame for the first frequency band. 34. The computer program product according to claim 33, wherein the description of a spectral envelope of a first frame of a speech signal comprises separate first and second descriptions, wherein the first description is a description of a spectral envelope of the first frame over the first frequency band, and wherein the second description is a description of a spectral envelope of the first frame over the second frequency band. 35. The computer program product according to claim 33, wherein the information relating to a pitch component of the second frame for the first frequency band includes a pitch lag value. 36. The computer program product according to claim 33, wherein said medium comprises code for causing at least one computer to calculate, based on the information relating to a pitch component of the second frame for the first frequency band, an excitation signal of the second frame for the first frequency band, and wherein said medium comprises code for causing at least one computer to calculate, based on the excitation signal of the second frame for the first frequency band, an excitation signal of the second frame for the second frequency band. 37. A speech decoder configured to calculate a decoded speech signal based on an encoded speech signal, said speech decoder comprising: control logic configured to generate a control signal comprising a sequence of values that is based on coding indices of speech packets from the encoded speech signal, each value of the sequence corresponding to a frame period of the decoded speech signal; anda packet decoder configured(A) to calculate, in response to a value of the control signal having a first state, a corresponding decoded frame based on a description of a spectral envelope of the decoded frame over (1) a first frequency band and (2) a second frequency band that extends above the first frequency band, the description being based on information from a speech packet from the encoded speech signal, and(B) to calculate, in response to a value of the control signal having a second state different than the first state, a corresponding decoded frame based on (1) a description of a spectral envelope of the decoded frame over the first frequency band, the description being based on information from a speech packet from the encoded speech signal, and (2) a description of a spectral envelope of the decoded frame over the second frequency band, the description being based on information from at least one speech packet that occurs in the encoded speech signal before the speech packet,wherein said control logic is configured to set a value of the control signal to have the second state if a corresponding frame of the encoded speech signal includes a burst of an information signal that is separate from the decoded speech signal, andwherein at least one among said control logic and said packet decoder includes a processor. 38. The speech decoder according to claim 37, wherein the description of a spectral envelope of the decoded frame over (1) a first frequency band and (2) a second frequency band that extends above the first frequency band comprises separate first and second descriptions, wherein the first description is a description of a spectral envelope of the decoded frame over the first frequency band, and wherein the second description is a description of a spectral envelope of the decoded frame over the second frequency band. 39. The speech decoder according to claim 37, wherein the information relating to a pitch component of the second frame for the first frequency band includes a pitch lag value. 40. The speech decoder according to claim 37, wherein said packet decoder is configured to calculate, in response to a value of the control signal having a second state, and based on the information relating to a pitch component of the second frame for the first frequency band, an excitation signal of the second frame for the first frequency band, and wherein said apparatus comprises means for calculating, based on the excitation signal of the second frame for the first frequency band, an excitation signal of the second frame for the second frequency band. 41. The speech decoder according to claim 37, wherein said description of the spectral envelope of the decoded frame over the second frequency band is based on a description, from said at least one speech packet that occurs in the encoded speech signal before the speech packet, of a spectral envelope over the second frequency band. 42. The speech decoder according to claim 37, wherein an overlap of the first and second frequency bands occurs in the range of from 3.5 to 4 kilohertz. 43. The speech decoder according to claim 37, wherein said control logic is configured to set the value of the control signal to have the second state if a narrowband coding scheme is indicated for the frame. 44. A method of processing a speech signal, said method comprising: based on a first frame of the speech signal, generating a rate selection signal that indicates a wideband coding scheme;based on information from a mask file, generating a dimming control signal;based on a state of the dimming control signal that corresponds to the first frame, overriding the wideband coding scheme selection to select a narrowband coding scheme; andencoding the first frame according to the narrowband coding scheme. 45. The method of processing a speech signal according to claim 44, wherein said encoding the first frame according to the narrowband coding scheme comprises encoding the first frame into a first speech packet, and wherein said method comprises producing an encoded frame that includes the first speech packet and a burst of an information signal separate from the speech signal. 46. The method of processing a speech signal according to claim 44, wherein said method comprises encoding a second frame of the speech signal according to the wideband coding scheme, wherein said second frame immediately follows said first frame in the speech signal. 47. The method of processing a speech signal according to claim 44, wherein said method comprises encoding a previous frame of the speech signal according to the wideband coding scheme, wherein said previous frame immediately precedes said first frame in the speech signal.