Resampling an audio signal for low-delay encoding/decoding

Patent metadata

Field	Value
Publication number	US-2016232907-A1
Application number	US-201415025138-A
Country	US
Kind code	A1
Filing date	Sep 26, 2014
Priority date	Sep 30, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

A method and device for resampling an audio frequency signal in an audio frequency signal coding or decoding. The method includes the following acts for each signal block to be resampled: determining, by adaptive linear prediction, a number of future signal samples, this number being defined as a function of a chosen resampling delay; constructing a resampling support vector from at least samples of the current block and determined future signal samples; applying a resampling filter to the samples of the resampling support vector.

First claim

1 . A method comprising:
resampling an audio frequency signal by an audio frequency signal coding or decoding device, wherein resampling comprises the following acts for each signal block to be resampled:
determining, by adaptive linear prediction, a number of future signal samples, this number being defined as a function of a chosen resampling delay;
constructing a resampling support vector from at least samples of the current signal block and determined future signal samples; and
applying a resampling filter to the samples of the resampling support vector.

2 . The method as claimed in claim 1 , wherein the act of determining by adaptive linear prediction comprises:
obtaining coefficients of a linear prediction filter of predetermined order; obtaining future signal samples by application of the prediction filter obtained to an excitation signal of null value.

3 . The method as claimed in claim 2 , wherein the coefficients of the linear prediction filter are obtained by reading parameters stored by the device during a coding or decoding of the audio frequency signal.

4 . The method as claimed in claim 2 , wherein the coefficients of the linear prediction filter are obtained by analysis from at least samples of the current block.

5 . The method as claimed in claim 1 , wherein the linear prediction is performed on an audio frequency signal on which a pre-emphasis processing has been performed.

6 . The method as claimed in claim 1 , wherein the adaptive linear prediction is a prediction from one of the following methods:
short-term linear prediction; long-term linear prediction; combination of short-term linear prediction and long-term linear prediction; erased frame concealment process.

7 . A device for resampling an audio frequency signal in an audio frequency signal coder or decoder, wherein the device comprises:
an adaptive linear prediction module determining, for a signal block, a number of future signal samples defined as a function of a chosen resampling delay; a module constructing a resampling support vector from at least samples of the current signal block and determined future signal samples; and a resampling filter applied to the samples of the resampling support vector.

8 . The device as claimed in claim 7 , wherein the adaptive linear prediction module cooperates with a prediction analysis module included in a prediction coding or decoding module of the coder or decoder.

9 . An audio frequency signal coder, comprising at least one resampling device as claimed in claim 7 .

10 . The audio frequency signal coder as claimed in claim 9 , wherein the resampling device comprises at least two resampling filters having different delays, at least one of the filters being implemented such that the determination of the number of future signal samples is a function of the delay difference of the two resampling filters used.

11 . An audio frequency signal decoder, comprising at least one resampling device as claimed in claim 7 .

12 . The audio frequency signal decoder as claimed in claim 11 , wherein the resampling device comprises at least two resampling filters having different delays, at least one of the filters being implemented such that the determination of the number of future signal samples is a function of the delay difference of the two resampling filters used.

13 . (canceled)

14 . A non-transitory processor-readable storage medium, on which is stored a computer program comprising code instructions for executing a resampling method, when these instructions are executed by a processor of an audio frequency signal coding or decoding device, wherein the code instructions configure the processor to perform acts of:
resampling an audio frequency signal, comprising the following acts for each signal block to be resampled:
determining, by adaptive linear prediction, a number of future signal samples, this number being defined as a function of a chosen resampling delay;
constructing a resampling support vector from at least samples of the current signal block and determined future signal samples; and
applying a resampling filter to the samples of the resampling support vector.

Assignees

• Orange

Inventors

• Kovesi Balazs
• Ragot Stephane

Classifications

• G10L19/04 Primary

  using predictive techniques · CPC title

• G10L19/24

  Variable rate codecs, e.g. for generating different qualities using a scalable representation such as hierarchical encoding or layered encoding · CPC title

• H03H17/0621

  with input-sampling frequency and output-delivery frequency which differ, e.g. extrapolation; Anti-aliasing · CPC title

• G10L19/18

  Vocoders using multiple modes · CPC title

• G10L19/005

  Correction of errors induced by the transmission channel, if related to the coding algorithm · CPC title