Method for concatenating frames in communication system

1. A system for concatenating a first frame of samples and a subsequent second frame of samples in a digitized audio signal in a receiver, the system comprising:

one or more processor; and

one or more computer-readable memories, coupled to the one or more processors, comprising instructions executable by the one or more processors to configure the system to:

generate concealment samples from the subsequent second frame of samples of the digitized audio signal;

place the concealment samples in the signal such that the second frame follows the concealment samples;

initialize a parametric all pass filter in the receiver based on said concealment samples, thereby initializing filter coefficients of the parametric all pass filter; and

concurrently apply the parametric all pass filter to at least part of samples in at least two consecutive frames, so as to minimize a discontinuity at a boundary between the first and second frames of samples.

2. The system of claim 1 , wherein the at least two consecutive frames are said first and second subsequent frames.

3. The system of claim 1 , wherein the parametric all pass filter is applied to at least part of the samples in at least the second frame and to at least part of samples in at least one frame consecutive to the second frame.

4. The system of claim 2 , wherein the parametric all pass filter is applied to at least part of the samples in at least the second frame and to at least part of samples in at least two frames consecutive to the second frame.

5. The system of claim 1 , wherein the parametric all pass filter is applied to at least part of the samples in at least the first frame and to at least part of samples in at least one frame preceding the first frame.

6. The system of claim 5 , wherein the parametric all pass filter is applied to at least part of the samples in at least the first frame and to at least part of samples in at least two frames preceding the first frame.

7. The system of claim 1 , wherein the parametric all pass filter includes modifying a phase of a subsequence of at least one sample by a radian phase value of pi.

8. The system of claim 1 , wherein the parametric all pass filter includes between 1 and 20 non-zero coefficients.

9. The system of claim 1 , wherein the parametric all pass filter is time-varying wherein the parametric all pass filter is time-varying such that a response of the parametric all pass filter approximates a zero phase at a finite number of samples away from the boundary between the first and second frames.

10. The system of claim 1 , wherein a number of samples included from at least one of said concealment samples is selected to maximize a matching measure, wherein the matching measure includes a correlation.

11. The system of claim 10 , wherein the correlation is a normalized correlation.

12. The system of claim 1 , wherein for the generation concealment samples, the system is further configured to:

determine a mode based on a voicing indicator.

13. The system of claim 12 , the system is further configured to:

based on the mode, initiate a reversion of a temporal evolution of the signal samples.

14. The system of claim 13 , wherein the system is further configured to determine a criteria that is usable to determine to stop the reversion of the temporal evolution.

15. A receiver device for concatenating a first frame of samples and a subsequent second frame of samples in a digitized audio signal comprising:

a processor;

one or more memories, coupled to the processor, comprising instructions executable by the processor to perform operations comprising:

receiving the signal comprising the first frame of samples and the subsequent second frame of samples;

generating concealment samples from the subsequent second frame of samples of the digitized audio signal;

placing the concealment samples in the signal such that the second frame follows the concealment samples;

initializing a parametric all pass filter in the receiver based on said concealment samples, thereby initializing filter coefficients of the parametric all pass filter; and

concurrently applying the parametric all pass filter to at least part of samples in at least two consecutive frames, so as to minimize a discontinuity at a boundary between the first and second frames of samples.

16. The device of claim 15 , wherein the at least two consecutive frames are said first and second subsequent frames.

17. The device of claim 15 , wherein the parametric all pass filter is applied to at least part of the samples in at least the second frame and to at least part of samples in at least one frame consecutive to the second frame.

18. A method for concatenating a first frame of samples and a subsequent second frame of samples in a digitized audio signal in a receiver, the method comprising:

generating concealment samples from the subsequent second frame of samples of the digitized audio signal;

placing the concealment samples in the signal such that the second frame follows the concealment samples;

initializing a parametric all pass filter in the receiver based on said concealment samples, thereby initializing filter coefficients of the parametric all pass filter; and

concurrently applying the parametric all pass filter to at least part of samples in at least two consecutive frames, so as to minimize a discontinuity at a boundary between the first and second frames of samples.

19. The method of claim 18 , wherein the at least two consecutive frames are said first and second subsequent frames.

20. The method of claim 18 , wherein the parametric all pass filter is applied to at least part of the samples in at least the second frame and to at least part of samples in at least one frame consecutive to the second frame.