System for concealing missing audio waveforms
AssigneeCisco Technology, Inc.
InventorsDuanpei Wu, Luke K. Surazski
Life of this patent
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Abstract
In one embodiment, a method can include: (i) establishing an internet protocol (IP) connection; (ii) forming a buffered version of a plurality of voice frame slices from received audio packets; and (iii) when an erasure is detected, performing a packet loss concealment (PLC) to provide a synthesized speech signal for the erasure, where the PLC can include: (a) identifying first and second pitches from the buffered version of the plurality of voice frame slices; and (b) forming the synthesized speech signal by using the first and second pitches, and more if needed, followed by an overlay-add (OLA).
Claims19
A method, comprising:
- establishing an internet protocol (IP) connection;
- forming a buffered version of a plurality of voice frame slices from a received audio waveform;
- detecting a presence of an erasure in the audio waveform, wherein the erasure spans a portion of the audio waveform;
- and
- upon detecting the erasure, performing a packet loss concealment (PLC) to provide a synthesized speech signal for the erasure, the PLC comprising:
- identifying first and second pitches from the buffered version of the plurality of voice frame slices and forming the synthesized speech signal by:
- using the first and second pitches, the first and second pitches directly connected to each other,
- applying a first overlay add (OLA) on a last quarter pitch wavelength of the audio waveform positioned before the erasure, and
- applying a second OLA on a first quarter pitch wavelength of the audio waveform positioned after the erasure,
- wherein the first and second pitches are positioned in between the first OLA and the second OLA.
An apparatus, comprising:
- an input configured to receive an audio waveform having audio information, the audio information being arranged in a plurality of voice frame slices;
- logic configured to identify first and second pitches from a buffered version of the plurality of voice frame slices;
- and
- logic configured to provide a synthesized speech signal for a missing portion of the audio information in the audio waveform, the synthesized speech signal comprising:
- the first and second pitches directly connected to each other,
- a first overlay-add (OLA) applied to a last quarter pitch wavelength of the audio waveform positioned before the missing portion, and
- a second OLA applied to a first quarter pitch wavelength of the audio waveform positioned after the missing portion,
- wherein the first and second pitches are positioned in between the first OLA and the second OLA.
A system, comprising:
- an internet protocol (IP) phone configured to receive an audio waveform having audio information, the audio information being arranged in a plurality of voice frame slices, the IP phone having an encoder/decoder (codec), the codec having:
- logic configured to identify first and second pitches from a buffered version of the plurality of voice frame slices;
- and
- logic configured to provide a synthesized speech signal for a missing portion of the audio information in the audio waveform, the synthesized speech signal comprising:
- the first and second pitches directly connected to each other,
- a first overlay-add (OLA) applied to a last quarter pitch wavelength of the audio waveform positioned before the missing portion, and
- a second OLA applied to a first quarter pitch wavelength of the audio waveform positioned after the missing portion,
- wherein the first and second pitches are positioned in between the first OLA and the second OLA.
Dependencies are inferred from the claim text.