Method and device for transcoding audio signals

一种音频信号、代码转换的技术,应用在代码转换、语音分析、声音输入/输出等方向,能够解决信号质量恶化、降低计算复杂度、串联差错等问题,达到防止信号恶化问题、小化量化以及不精确数值运算的广泛影响的效果

Inactive Publication Date: 2009-10-21
THOMSON LICENSING SA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

First, since the two modules DEC_A, ENC_B do not know each other, the time-frequency decomposition process may get out of synchronization: usually, a series of decoding (dequantization) and encoding (quantization) operations lead to a deterioration of the signal quality, the so-called concatenation error
Second, the computational complexity of this method is high, so it is necessary to significantly reduce the computational complexity

Method used

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  • Method and device for transcoding audio signals
  • Method and device for transcoding audio signals
  • Method and device for transcoding audio signals

Examples

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Embodiment Construction

[0040] Figure 5 shows direct transcoding in the parameter field between two formats with different parameter fields PD A 、PD B . A number of contiguous parameter frames 501 according to source format A (eg mp3) have previously been derived from a PCM audio signal by a time-frequency decomposition scheme of this source format. Each frame m-1, m, m+1 includes multiple parameters, so it can be regarded as the source parameter domain PD A The parameter vector in . Linear transformation matrix T T Applies to the input parameter vector 501 and provides the output parameter field PD with output format B B The output parameter vector 502 corresponding to the frame in .

[0041] For a single output frame n, the transformation or mapping is time-invariant. Either transform the matrix T T Apply to multiple input frames at the same time, or apply separate transformation matrices (simultaneously or sequentially) to the corresponding input frames and then add the partial results. S...

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Abstract

The present invention provides method and device for transcoding between audio coding formats with different time-frequency analysis domains, as used for example by MPEG-AAC and mp3, particularly for facilitated and faster transcoding between such audio signals. A method for transcoding a framed audio signal from a first parameter domain (PDA) into a second parameter domain (PDB) comprises linearly transforming (TT) two or more parameters of the first parameter domain (PDA) to at least one parameter of the second parameter domain (PDB), wherein the two or more parameters of the first parameter domain come from different frames of the audio signal in the first parameter domain. The linear transformation (TT) can be described as a matrix and implemented as a look-up table.

Description

technical field [0001] The invention relates to a method and a device for transcoding an audio signal. The present invention relates to the field of audio compression and more particularly to the field of transcoding between different perceptual audio coding formats. Advantageously, however, the basic concept of the invention can also be used in other audio processing applications. Background technique [0002] The term "audio transcoding" generally means deriving a bitstream representing an audio signal according to a particular audio coding format from another bitstream organized according to a different audio coding format. In this sense, "transcoding" denotes the entire process of obtaining, for example, an MPEG AAC compliant bitstream from an MPEG 1 layer III (mp3) compliant bitstream. [0003] However, in this document the term "audio transcoding" is used in a more technical sense to describe the conversion of an audio signal from one sub-band or transform domain to ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10L19/14G10L19/02G10L19/022G10L19/16
CPCG10L19/173G10L19/022G10L19/00G10L19/02H03M7/30G06F3/16G10L19/005G10L19/008H04B1/66
Inventor 彼得·杰克斯斯文·科登
Owner THOMSON LICENSING SA
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