Temporal and spatial shaping of multi-channel audio signal

Patent metadata

Field	Value
Publication number	US-9361896-B2
Application number	US-201414151152-A
Country	US
Kind code	B2
Filing date	Jan 9, 2014
Priority date	Oct 12, 2005
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

A selected channel of a multi-channel signal which is represented by frames composed from sampling values having a high time resolution can be encoded with higher quality when a wave form parameter representation representing a wave form of an intermediate resolution representation of the selected channel is derived, the wave form parameter representation including a sequence of intermediate wave form parameters having a time resolution lower than the high time resolution of the sampling values and higher than a time resolution defined by a frame repetition rate. The wave form parameter representation with the intermediate resolution can be used to shape a reconstructed channel to retrieve a channel having a signal envelope close to that one of the selected original channel. The time scale on which the shaping is performed is shorter than the time scale of a framewise processing, thus enhancing the quality of the reconstructed channel. On the other hand, the shaping time scale is larger than the time scale of the sampling values, significantly reducing the amount of data needed by the wave form parameter representation.

First claim

The invention claimed is:

1. Transmission system comprising:
a transmitter comprising an encoder configured for generating an intermediate wave form parameter representation of a selected channel of a multi-channel signal, the encoder comprising:
a time resolution decreaser configured for deriving a low time resolution representation of the selected channel, the selected channel having a frame, the frame comprising sampling values having a sampling period, using the sampling values of the frame, the low time resolution representation having low time resolution values having associated a low time resolution period, the low time resolution period being larger than the sampling period; and
a wave form parameter calculator configured for calculating the intermediate wave form parameter representation representing a wave form of the low time resolution representation of the selected channel, wherein the wave form parameter calculator is adapted to generate, as the intermediate wave form parameter representation, a sequence of wave form parameters having an intermediate time resolution, the intermediate time resolution being lower than a time resolution of the sampling values and higher than a time resolution defined by a length of the frame; and

a receiver comprising a decoder for generating a multi-channel output signal, the decoder comprising:
an upmixer configured for generating a plurality of upmixed channels having a high time resolution, the high time resolution being higher than the intermediate time resolution, by upmixing a base signal derived from the multi-channel signal, a number of channels of the base signal being smaller than a number of channels of the multi-channel signal; and
a shaper configured for shaping a selected upmixed channel, wherein the selected upmixed channel is selected from the plurality of upmixed channels and corresponds to the selected original channel, and wherein the shaper is configured for shaping the selected upmixed channel having the high time resolution using the intermediate time resolution sequence of wave form parameters for the selected original channel.

2. Method of transmitting and receiving, comprising:
generating an intermediate wave form parameter representation of a selected channel of a multi-channel signal, comprising:
deriving a low time resolution representation of the selected channel, the selected channel having a frame, the frame comprising sampling values having a sampling period, using the sampling values of the frame, the low time resolution representation having low time resolution values having associated a low time resolution period, the low time resolution period being larger than the sampling period; and
calculating the intermediate wave form parameter representation representing a wave form of the low time resolution representation of the selected channel, wherein the wave form parameter calculator is adapted to generate, as the intermediate wave form parameter representation, a sequence of wave form parameters having an intermediate time resolution, the intermediate time resolution being lower than a time resolution of the sampling values and higher than a time resolution defined by a length of the frame; and

generating a multi-channel output signal, comprising:
generating a plurality of upmixed channels having a high time resolution, the high time resolution being higher than the intermediate time resolution, by upmixing a base signal derived from the multi-channel signal, a number of channels of the base signal being smaller than a number of channels of the multi-channel signal; and
shaping a selected upmixed channel, wherein the selected upmixed channel is selected from the plurality of upmixed channels and corresponds to the selected original channel, and wherein the selected upmixed channel having the high time resolution is shaped using the intermediate time resolution sequence of wave form parameters for the selected original channel.

3. Non-transitory storage medium having stored thereon a computer program for performing, when running on a computer, the method of transmitting and receiving, the method comprising:
generating an intermediate wave form parameter representation of a selected channel of a multi-channel signal, comprising:
deriving a low time resolution representation of the selected channel, the selected channel having a frame, the frame comprising sampling values having a sampling period, using the sampling values of the frame, the low time resolution representation having low time resolution values having associated a low time resolution period, the low time resolution period being larger than the sampling period; and
calculating the intermediate wave form parameter representation representing a wave form of the low time resolution representation of the selected channel, wherein the wave form parameter calculator is adapted to generate, as the intermediate wave form parameter representation, a sequence of wave form parameters having an intermediate time resolution, the intermediate time resolution being lower than a time resolution of the sampling values and higher than a time resolution defined by a length of the frame; and

generating a multi-channel output signal, comprising:
generating a plurality of upmixed channels having a high time resolution, the high time resolution being higher than the intermediate time resolution, by upmixing a base signal derived from the multi-channel signal, a number of channels of the base signal being smaller than a number of channels of the multi-channel signal; and
shaping a selected upmixed channel, wherein the selected upmixed channel is selected from the plurality of upmixed channels and corresponds to the selected original channel, and wherein the selected upmixed channel having the high time resolution is shaped using the intermediate time resolution sequence of wave form parameters for the selected original channel.

Assignees

• Disch Sascha
• Herre Juergen
• Neusinger Matthias
• Breebaart Dirk Jeroen
• Hotho Gerard
• Fraunhofer Ges Forschung

Inventors

• Disch Sascha
• Herre Juergen
• Neusinger Matthias
• Breebaart Dirk Jeroen
• Hotho Gerard

Classifications

• H04S3/008

  in which the audio signals are in digital form, i.e. employing more than two discrete digital channels (data reduction aspects thereof based on psychoacoustics G10L19/02) · CPC title

• G10L19/008 Primary

  Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing · CPC title

• H04S3/00

  Systems employing more than two channels, e.g. quadraphonic (H04S5/00, H04S7/00 take precedence) · CPC title

• H03M7/30

  Compression (speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N); Expansion; Suppression of unnecessary data, e.g. redundancy reduction · CPC title