Global Patent Index - EP 2023339 A1

EP 2023339 A1 2009-02-11 - A low-delay audio coder

Title (en)

A low-delay audio coder

Title (de)

Audiodekoder mit geringer Verzögerung

Title (fr)

Codeur audio à faible retard

Publication

EP 2023339 A1 (EN)

Application

EP 07113397 A

Priority

EP 07113397 A

Abstract (en)

The present invention relates to methods and devices for encoding and decoding digital audio signals, e.g. a speech signal. An audio coder and a decoder are provided wherein a modeller adds a first distribution model obtained from model parameters of past segments of the digital audio signal and a fixed distribution model, each of the models being multiplied by a weighting coefficient, for obtaining a combined distribution model. The weighting coefficients are selected to minimize a code length of a current segment of the digital audio signal. As the combined distribution model is a sum of several distribution models, wherein at least some of the models is based on the model parameters, flexibility is introduced in the signal model used to encode the digital audio signal. Thus, an audio coder and decoder providing a low bit rate in average, low bit rate variations and low error propagation are provided.

IPC 8 full level (invention and additional information)

G10L 19/00 (2006.01)

CPC (invention and additional information)

G10L 19/0017 (2013.01); H04R 25/552 (2013.01); H04R 2225/55 (2013.01)

Citation (search report)

  • [A] US 2007016418 A1 20070118 - MEHROTRA SANJEEV [US], et al
  • [A] US 2005012648 A1 20050120 - MARPE DETLEV [DE], et al
  • [A] EP 1355298 A2 20031022 - OKI ELECTRIC IND CO LTD [JP]
  • [PX] LI M ET AL: "A Low-Delay Audio Coder with Constrained-Entropy Quantization", 2007 IEEE WORSHOP ON ASPAA, 2007, pages 191 - 194, XP008087029
  • [A] M. MAHONEY: "Adaptive Weighing of Context Models for Lossless Data Compression", FLORIDA TECH. TECHNICAL REPORT CS-2005-16, 2005, XP002463606, Retrieved from the Internet <URL:http://www.cs.fit.edu/~mmahoney/compression/cs200516.pdf> [retrieved on 20071222]
  • [A] GOURNAY, PHILIPPE; GARCIA, JEAN-LUC; LEFEBVRE, ROCH: "Backward Linear Prediction for Lossless Coding of Stereo Audio", AUDIO ENGINEERING SOCIETY E-LIBRARY, 8 May 2004 (2004-05-08), XP002463607

Designated contracting state (EPC)

AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

Designated extension state (EPC)

AL BA HR MK RS

DOCDB simple family

EP 2023339 A1 20090211; EP 2023339 B1 20100825; AT 479182 T 20100915; DE 602007008717 D1 20101007; WO 2009015944 A1 20090205