Voice transcoder
First Claim
1. A method of transcoding first encoded voice bits into second encoded voice bits, the method comprising:
- dividing the first encoded voice bits into one or more received frames, with each received frame containing multiple ones of the first encoded voice bits;
computing first parameter bits for at least one of the received frames by applying error control decoding to one or more of the encoded voice bits contained in the received frame;
computing speech parameters from the first parameter bits;
quantizing the speech parameters to produce second parameter bits;
determining whether the at least one of the received frames is invalid;
if the at least one of the received frames is invalid, substituting invalid frame bits for the second parameter bits;
forming a transmission frame by applying error control encoding to one or more of the second parameter bits or the invalid frame bits; and
including the transmission frame in the second encoded voice bits.
1 Assignment
0 Petitions
Accused Products
Abstract
First encoded voice bits are transcoded into second encoded voice bits by dividing the first encoded voice bits into one or more received frames, with each received frame containing multiple ones of the first encoded voice bits. First parameter bits for at least one of the received frames are generated by applying error control decoding to one or more of the encoded voice bits contained in the received frame, speech parameters are computed from the first parameter bits, and the speech parameters are quantized to produce second parameter bits. Finally, a transmission frame is formed by applying error control encoding to one or more of the second parameter bits, and the transmission frame is included in the second encoded voice bits.
42 Citations
54 Claims
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1. A method of transcoding first encoded voice bits into second encoded voice bits, the method comprising:
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dividing the first encoded voice bits into one or more received frames, with each received frame containing multiple ones of the first encoded voice bits; computing first parameter bits for at least one of the received frames by applying error control decoding to one or more of the encoded voice bits contained in the received frame; computing speech parameters from the first parameter bits; quantizing the speech parameters to produce second parameter bits; determining whether the at least one of the received frames is invalid; if the at least one of the received frames is invalid, substituting invalid frame bits for the second parameter bits; forming a transmission frame by applying error control encoding to one or more of the second parameter bits or the invalid frame bits; and including the transmission frame in the second encoded voice bits. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method for converting a sequence of first encoded voice bits into a sequence of second encoded voice bits, the method comprising:
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dividing the sequence of first voice bits into one or more input frames, with each of the input frames containing multiple ones of the first voice bits; reconstructing speech parameters for one or more of the input frames, wherein; the speech parameters reconstructed for a previous frame are stored and used during reconstruction of the speech parameters for a later frame, the speech parameters include a set of spectral magnitude parameters, and the spectral magnitudes parameters for the later frame are reconstructed by; computing a set of predicted magnitudes from spectral magnitude parameters stored from the previous frame; reconstructing spectral magnitude prediction residuals from the later frame; and combining the predicted magnitudes with the spectral magnitude prediction residuals to form the spectral magnitude parameters for the later frame; processing the speech parameters to produce an output frame of bits; and combining one or more of the output frames to form a sequence of second encoded voice bits. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54)
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Specification