APPARATUS AND METHOD FOR IMPROVED CONCEALMENT OF THE ADAPTIVE CODEBOOK IN A CELP-LIKE CONCEALMENT EMPLOYING IMPROVED PITCH LAG ESTIMATION

• US 20160118053A1
• Filed: 12/21/2015
• Published: 04/28/2016
• Est. Priority Date: 06/21/2013
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Lecomte, Jeremie, Schnabel, Michael, Markovic, Goran, Dietz, Martin, Neugebauer, Bernhard
• Granted Patent: US 10,381,011 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G10L 19/005 Correction of errors induced by the transmission channel, if related to the coding algorithm
• CPC Class Codes: G10L 19/08 Determination or coding of the excitation function; Determination or coding of the long-term prediction parameters
• CPC Class Codes: G10L 19/107 Sparse pulse excitation, e.g. by using algebraic codebook
• CPC Class Codes: G10L 19/125 Pitch excitation, e.g. pitch synchronous innovation CELP [PSI-CELP]
• CPC Class Codes: G10L 2019/0002 Codebook adaptations
• CPC Class Codes: G10L 2019/0003 Backward prediction of gain
• CPC Class Codes: G10L 2019/0008 Algebraic codebooks
• CPC Class Codes: G10L 25/90 Pitch determination of speech signals

Abstract

An apparatus for determining an estimated pitch lag is provided. The apparatus includes an input interface for receiving a plurality of original pitch lag values, and a pitch lag estimator for estimating the estimated pitch lag. The pitch lag estimator is configured to estimate the estimated pitch lag depending on a plurality of original pitch lag values and depending on a plurality of information values, wherein for each original pitch lag value of the plurality of original pitch lag values, an information value of the plurality of information values is assigned to the original pitch lag value.

Claims

1. An apparatus for determining an estimated pitch lag, comprising:

an input interface for receiving a plurality of original pitch lag values, and

a pitch lag estimator for estimating the estimated pitch lag,

wherein the pitch lag estimator is configured to estimate the estimated pitch lag depending on a plurality of original pitch lag values and depending on a plurality of information values, wherein for each original pitch lag value of the plurality of original pitch lag values, an information value of the plurality of information values is assigned to said original pitch lag value.

2. An apparatus according to claim 1, wherein the pitch lag estimator is configured to estimate the estimated pitch lag depending on the plurality of original pitch lag values and depending on a plurality of pitch gain values as the plurality of information values, wherein for each original pitch lag value of the plurality of original pitch lag values, a pitch gain value of the plurality of pitch gain values is assigned to said original pitch lag value.

3. An apparatus according to claim 2, wherein each of the plurality of pitch gain values is an adaptive codebook gain.

4. An apparatus according to claim 2, wherein the pitch lag estimator is configured to estimate the estimated pitch lag by minimizing an error function.

5. An apparatus according to claim 4, wherein the pitch lag estimator is configured to estimate the estimated pitch lag by determining two parameters a, b, by minimizing the error function

6. An apparatus according to claim 4, wherein the pitch lag estimator is configured to estimate the estimated pitch lag by determining two parameters a, b, by minimizing the error function

7. An apparatus according to claim 4, wherein the pitch lag estimator is configured to determine the estimated pitch lag p according to

p=a·

i+b.

8. An apparatus according to claim 1, wherein the pitch lag estimator is configured to estimate the estimated pitch lag depending on the plurality of original pitch lag values and depending on a plurality of time values as the plurality of information values, wherein for each original pitch lag value of the plurality of original pitch lag values, a time value of the plurality of time values is assigned to said original pitch lag value.

9. An apparatus according to claim 8, wherein the pitch lag estimator is configured to estimate the estimated pitch lag by minimizing an error function.

10. An apparatus according to claim 9, wherein the pitch lag estimator is configured to estimate the estimated pitch lag by determining two parameters a, b, by minimizing the error function

11. An apparatus according to claim 9, wherein the pitch lag estimator is configured to estimate the estimated pitch lag by determining two parameters a, b, by minimizing the error function

12. An apparatus according to claim 10, wherein the pitch lag estimator is configured to determine the estimated pitch lag p according to

p+a·

i−

b.

13. A system for reconstructing a frame comprising a speech signal, wherein the system comprises:

an apparatus according to claim 1 for determining an estimated pitch lag, and

an apparatus for reconstructing the frame, wherein the apparatus for reconstructing the frame is configured to reconstruct the frame depending on the estimated pitch lag,

wherein the estimated pitch lag is a pitch lag of the speech signal.

14. An system for reconstructing a frame according to claim 13,

wherein the reconstructed frame is associated with at least one available frame, said at least one available frame being at least one of the preceding frames of the reconstructed frame and at least one succeeding frame of the reconstructed frame, wherein the at least one available frame comprises at least one pitch cycle as at least one available pitch cycle, and

wherein the apparatus for reconstructing the frame comprises

a determination unit for determining a sample number difference indicating a difference between a number of samples of one of the at least one available pitch cycle and a number of samples of a first pitch cycle to be reconstructed, and

a frame reconstructor for reconstructing the reconstructed frame by reconstructing, depending on the sample number difference and depending on the samples of said one of the at least one available pitch cycle, the first pitch cycle to be reconstructed as a first reconstructed pitch cycle,

wherein the frame reconstructor is configured to reconstruct the reconstructed frame, such that the reconstructed frame completely or partially comprises the first reconstructed pitch cycle, such that the reconstructed frame completely or partially comprises a second reconstructed pitch cycle, and such that the number of samples of the first reconstructed pitch cycle differs from a number of samples of the second reconstructed pitch cycle,

wherein the determination unit is configured to determine the sample number difference depending on the estimated pitch lag.

15. A method for determining an estimated pitch lag, comprising:

receiving a plurality of original pitch lag values, and

estimating the estimated pitch lag,

wherein estimating the estimated pitch lag is conducted depending on a plurality of original pitch lag values and depending on a plurality of information values, wherein for each original pitch lag value of the plurality of original pitch lag values, an information value of the plurality of information values is assigned to said original pitch lag value.

16. A computer program for implementing the method of claim 15 when being executed on a computer or signal processor.