CA2058984A1 - Polyphonic coding - Google Patents

Polyphonic coding

Info

Publication number
CA2058984A1
CA2058984A1 CA2058984A CA2058984A CA2058984A1 CA 2058984 A1 CA2058984 A1 CA 2058984A1 CA 2058984 A CA2058984 A CA 2058984A CA 2058984 A CA2058984 A CA 2058984A CA 2058984 A1 CA2058984 A1 CA 2058984A1
Authority
CA
Canada
Prior art keywords
adaptive filter
sum
filter
signal
decoder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CA2058984A
Other languages
French (fr)
Other versions
CA2058984C (en
Inventor
Christopher Ellis Holt
Edward Munday
Barry Michael George Cheetham
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
British Telecommunications PLC
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=10658483&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=CA2058984(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Individual filed Critical Individual
Publication of CA2058984A1 publication Critical patent/CA2058984A1/en
Application granted granted Critical
Publication of CA2058984C publication Critical patent/CA2058984C/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
    • H04H20/86—Arrangements characterised by the broadcast information itself
    • H04H20/88—Stereophonic broadcast systems
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
    • G10L19/00—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis
    • G10L19/008—Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
    • G10L19/00—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis
    • G10L19/04—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis using predictive techniques

Abstract

A polyphonic (e.g. stereo) audioconferencing system, in which input left and right channels are time-aligned by variable delay stages (10a, 10b), controlled by a delay calculator (9) (e.g. by deriving the maximum cross-correlation value), and then summed in an adder (2) and subtracted in subtracter (3) to form sum and difference signals. The sum signal is transmitted in relatively high quality; the difference signal is reconstructed at the decoder by prediction from the sum signal using an adaptive filter (5). The decoder adaptive filter (5) is configured either by received filter coefficients or, using backwards adaptation, from a received residual signal produced by a corresponding adaptive filter (4) in the coder, or both. Preferably, the adaptive filter (4) is a lattice filter, employing a gradient algorithm for coefficient update. The complexity of the adaptive filter (4) is reduced by pre-whitening, in the encoder, both the sum and difference signals using corresponding whitening filters (14a, 14b) derived from the sum channel.
CA002058984A 1989-06-15 1990-06-15 Polyphonic coding Expired - Lifetime CA2058984C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8913758.2 1989-06-15
GB898913758A GB8913758D0 (en) 1989-06-15 1989-06-15 Polyphonic coding

Publications (2)

Publication Number Publication Date
CA2058984A1 true CA2058984A1 (en) 1990-12-16
CA2058984C CA2058984C (en) 1998-12-01

Family

ID=10658483

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002058984A Expired - Lifetime CA2058984C (en) 1989-06-15 1990-06-15 Polyphonic coding

Country Status (13)

Country Link
EP (1) EP0478615B2 (en)
JP (1) JP2703405B2 (en)
AT (1) ATE121900T1 (en)
AU (1) AU640667B2 (en)
CA (1) CA2058984C (en)
DE (1) DE69018989T3 (en)
DK (1) DK0478615T3 (en)
ES (1) ES2071823T3 (en)
FI (1) FI915873A0 (en)
GB (1) GB8913758D0 (en)
HK (1) HK137196A (en)
NO (1) NO180030C (en)
WO (1) WO1990016136A1 (en)

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992012607A1 (en) * 1991-01-08 1992-07-23 Dolby Laboratories Licensing Corporation Encoder/decoder for multidimensional sound fields
US5274740A (en) * 1991-01-08 1993-12-28 Dolby Laboratories Licensing Corporation Decoder for variable number of channel presentation of multidimensional sound fields
DE4136825C1 (en) * 1991-11-08 1993-03-18 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung Ev, 8000 Muenchen, De
US5278909A (en) * 1992-06-08 1994-01-11 International Business Machines Corporation System and method for stereo digital audio compression with co-channel steering
EP0608937B1 (en) * 1993-01-27 2000-04-12 Koninklijke Philips Electronics N.V. Audio signal processing arrangement for deriving a centre channel signal and also an audio visual reproduction system comprising such a processing arrangement
DE4320990B4 (en) * 1993-06-05 2004-04-29 Robert Bosch Gmbh Redundancy reduction procedure
US5488665A (en) * 1993-11-23 1996-01-30 At&T Corp. Multi-channel perceptual audio compression system with encoding mode switching among matrixed channels
GB2303516A (en) * 1995-07-20 1997-02-19 Plessey Telecomm Teleconferencing
DE19526366A1 (en) 1995-07-20 1997-01-23 Bosch Gmbh Robert Redundancy reduction method for coding multichannel signals and device for decoding redundancy-reduced multichannel signals
US6016473A (en) * 1998-04-07 2000-01-18 Dolby; Ray M. Low bit-rate spatial coding method and system
DE19829284C2 (en) * 1998-05-15 2000-03-16 Fraunhofer Ges Forschung Method and apparatus for processing a temporal stereo signal and method and apparatus for decoding an audio bit stream encoded using prediction over frequency
SE519552C2 (en) * 1998-09-30 2003-03-11 Ericsson Telefon Ab L M Multichannel signal coding and decoding
SE519976C2 (en) * 2000-09-15 2003-05-06 Ericsson Telefon Ab L M Coding and decoding of signals from multiple channels
SE519981C2 (en) * 2000-09-15 2003-05-06 Ericsson Telefon Ab L M Coding and decoding of signals from multiple channels
SE519985C2 (en) * 2000-09-15 2003-05-06 Ericsson Telefon Ab L M Coding and decoding of signals from multiple channels
FR2821475B1 (en) * 2001-02-23 2003-05-09 France Telecom METHOD AND DEVICE FOR SPECTRALLY RECONSTRUCTING MULTI-CHANNEL SIGNALS, ESPECIALLY STEREOPHONIC SIGNALS
BRPI0517949B1 (en) * 2004-11-04 2019-09-03 Koninklijke Philips Nv conversion device for converting a dominant signal, method of converting a dominant signal, and computer readable non-transient means
JP5285626B2 (en) * 2007-03-01 2013-09-11 ジェリー・マハバブ Speech spatialization and environmental simulation
JPWO2009122757A1 (en) * 2008-04-04 2011-07-28 パナソニック株式会社 Stereo signal conversion apparatus, stereo signal inverse conversion apparatus, and methods thereof
RU2497204C2 (en) 2008-05-23 2013-10-27 Конинклейке Филипс Электроникс Н.В. Parametric stereophonic upmix apparatus, parametric stereophonic decoder, parametric stereophonic downmix apparatus, parametric stereophonic encoder
TR201901336T4 (en) 2010-04-09 2019-02-21 Dolby Int Ab Mdct-based complex predictive stereo coding.
EP2375409A1 (en) * 2010-04-09 2011-10-12 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Audio encoder, audio decoder and related methods for processing multi-channel audio signals using complex prediction
ES2953084T3 (en) 2010-04-13 2023-11-08 Fraunhofer Ges Forschung Audio decoder to process stereo audio using a variable prediction direction
UA107771C2 (en) 2011-09-29 2015-02-10 Dolby Int Ab Prediction-based fm stereo radio noise reduction
US9380387B2 (en) 2014-08-01 2016-06-28 Klipsch Group, Inc. Phase independent surround speaker

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU546069B2 (en) * 1981-09-07 1985-08-15 Kahn, Leonard Richard Am stereo distortion correction
JPH0761043B2 (en) * 1986-04-10 1995-06-28 株式会社東芝 Stereo audio transmission storage method
GB8628046D0 (en) * 1986-11-24 1986-12-31 British Telecomm Transmission system

Also Published As

Publication number Publication date
GB8913758D0 (en) 1989-08-02
DE69018989T2 (en) 1995-09-07
CA2058984C (en) 1998-12-01
ES2071823T3 (en) 1995-07-01
EP0478615B1 (en) 1995-04-26
NO914947D0 (en) 1991-12-13
FI915873A0 (en) 1991-12-13
WO1990016136A1 (en) 1990-12-27
HK137196A (en) 1996-08-02
AU5837990A (en) 1991-01-08
AU640667B2 (en) 1993-09-02
ATE121900T1 (en) 1995-05-15
DE69018989T3 (en) 1998-11-19
NO180030B (en) 1996-10-21
JPH04506141A (en) 1992-10-22
NO914947L (en) 1992-02-13
EP0478615A1 (en) 1992-04-08
NO180030C (en) 1997-01-29
EP0478615B2 (en) 1998-04-15
JP2703405B2 (en) 1998-01-26
DK0478615T3 (en) 1995-07-17
DE69018989D1 (en) 1995-06-01

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Effective date: 20100615