United States Patent
US Patent 6199037: Joint quantization of speech subframe voicing…
US 6199037 · granted 2001-03-06
Abstract
Speech is encoded into a frame of bits. A speech signal is digitized into a sequence of digital speech samples that are then divided into a sequence of subframes. A set of model parameters is estimated for each subframe. The model parameters include a set of voicing metrics that represent voicing information for the subframe. Two or more subframes from the sequence of subframes are designated as corresponding to a frame. The voicing metrics from the subframes within the frame are jointly quantized. The joint quantization includes forming predicted voicing information from the quantized voicing information from the previous frame, computing the residual parameters as the difference between the voicing information and the predicted voicing information, combining the residual parameters from both of the subframes within the frame, and quantizing the combined residual parameters into a set of encoded voicing information bits which are included in the frame of bits. A similar technique is used to encode fundamental frequency information.
| Patent Number | 6199037 |
|---|---|
| Title | Joint quantization of speech subframe voicing metrics and fundamental frequencies |
| Filed | 1997-12-04 |
| Granted | 2001-03-06 |
| Inventor(s) | Hardwick; John C. |
| Assignee | Digital Voice Systems, Inc. |
| Number of Claims | 56 |
Abstract
Speech is encoded into a frame of bits. A speech signal is digitized into a sequence of digital speech samples that are then divided into a sequence of subframes. A set of model parameters is estimated for each subframe. The model parameters include a set of voicing metrics that represent voicing information for the subframe. Two or more subframes from the sequence of subframes are designated as corresponding to a frame. The voicing metrics from the subframes within the frame are jointly quantized. The joint quantization includes forming predicted voicing information from the quantized voicing information from the previous frame, computing the residual parameters as the difference between the voicing information and the predicted voicing information, combining the residual parameters from both of the subframes within the frame, and quantizing the combined residual parameters into a set of encoded voicing information bits which are included in the frame of bits. A similar technique is used to encode fundamental frequency information.
Claim 1
A method of encoding speech into a frame of bits, the method comprising: digitizing a speech signal into a sequence of digital speech samples; dividing the digital speech samples into a sequence of subframes, each of the subframes including multiple digital speech samples; estimating a fundamental frequency parameter for each subframe; designating subframes from the sequence of subframes as corresponding to a frame; jointly quantizing fundamental frequency parameters from subframes of the frame to produce a set of encoder fundamental frequency bits; and including the encoder fundamental frequency bits in a frame of bits, wherein the joint quantization comprises: computing fundamental frequency residual parameters as a difference between a transformed average of the fundamental frequency parameters and each fundamental frequency parameter; combining the residual fundamental frequency parameters from the subframes of the frame; and quantizing the combined residual parameters.
Claims
56 totalA method of encoding speech into a frame of bits, the method comprising: digitizing a speech signal into a sequence of digital speech samples; dividing the digital speech samples into a sequence of subframes, each of the subframes including multiple digital speech samples; estimating a fundamental frequency parameter for each subframe; designating subframes from the sequence of subframes as corresponding to a frame; jointly quantizing fundamental frequency parameters from subframes of the frame to produce a set of encoder fundamental frequency bits; and including the encoder fundamental frequency bits in a frame of bits, wherein the joint quantization comprises: computing fundamental frequency residual parameters as a difference between a transformed average of the fundamental frequency parameters and each fundamental frequency parameter; combining the residual fundamental frequency parameters from the subframes of the frame; and quantizing the combined residual parameters.