US 2012/0232889 A1 · METHOD AND APPARATUS FOR PERFORMING PACKET LOSS OR FRAME ERASURE CONCEALMENT

Abstract

A method for performing packet loss or Frame Erasure Concealment (FEC) for a speech coder receives encoded frames of compressed speech information transmitted from an encoder. The method determines whether an encoded frame has been lost, corrupted in transmission, or erased, synthesizes properly received frames, and decides on an overlap-add window to use in combining a portion of the synthesized speech signal with a subsequent speech signal resulting from a received and decoded packet, where the size of the overlap-add window is based on the unavailability of packets. If it is determined that an encoded frame has been lost, corrupted in transmission, or erased, the method performed an overlap-add operation on the portion of the synthesized speech signal and the subsequent speech signal, using the decided-on overlap-add window.

Claims20

Dependent claims

A method for creating an output signal in response to determining one or more unexpected packets, where an unexpected packet includes a packet that is lost, corrupted, erased or delayed, and where an expected packet includes a packet that is not lost, corrupted, erased or delayed,-the method comprising:

generating at least one synthesized audio signal segment corresponding to at least one unexpected packet;
determining a length of an overlap-add window to use in combining the at least one synthesized audio signal segment with a subsequent audio signal segment resulting from an expected packet being decoded by a receiver, wherein the expected packet is received subsequent to the at least one unexpected packet, wherein the length of the overlap-add window is determined based on a length of an erasure encompassing the at least one unexpected packet;
and
performing an overlap-add operation on the at least one synthesized audio signal segment and the subsequent audio signal segment using the determined length of the overlap-add window.

1 more element

A receiver for executing a method for creating an output signal in response to determining one or more unexpected packets, where an unexpected packet includes a packet that is lost, corrupted, erased or delayed, and where an expected packet includes a packet that is not lost, corrupted, erased or delayed,—the method comprising:

generating at least one synthesized audio signal segment corresponding to at least one unexpected packet;
determining a length of an overlap-add window to use in combining the at least one synthesized audio signal segment with a subsequent audio signal segment resulting from an expected packet being decoded by a receiver, wherein the expected packet is received subsequent to the at least one unexpected packet, wherein the length of the overlap-add window is determined based on a length of an erasure encompassing the at least one unexpected packet;
and
performing an overlap-add operation on the at least one synthesized audio signal segment and the subsequent audio signal segment using the determined length of the overlap-add window.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for performing packet loss or frame erasure concealment

Life of this patent

Method and apparatus for performing packet loss or frame erasure concealment

Life of this patent

Abstract

Claims20