Method, device and system for encoding and decoding audios

An audio encoding and encoding technology, which is applied in the fields of decoding and audio encoding, can solve problems affecting audio quality and the number of bits, and achieve the effect of reducing the number of bits and the number of parameters

Inactive Publication Date: 2010-03-03
魏芳
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  • Abstract
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AI Technical Summary

Problems solved by technology

[0010] In practical application, in the process of encoding the audio signal in the prior art, it generally needs to use more encoding bits to obtain a larger encoding bandwidth, which puts forward very high requirements on the bandwidth of the transmission channel; In the case of small bandwidth, it will affect the audio quality encoded by this technology
[0011] In the method of prior art 2, it is necessary to use more parameters to describe the signal at the encoding end in order to obtain a higher-quality synthetic audio signal at the decoding end; therefore, the bits that need to be transmitted when this technology is used in practical applications The number is also large; when the transmission capacity of the channel is further reduced, it will affect the audio quality encoded by this technology

Method used

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  • Method, device and system for encoding and decoding audios
  • Method, device and system for encoding and decoding audios

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Embodiment 1

[0079] In this embodiment, the encoder extracts the time-domain envelope parameters, frequency-domain envelope parameters, pitch parameters and harmonic interval parameters of the audio signal respectively. Since the harmonic interval of the audio signal and the first harmonic deviation The offset parameters are the same, so the step of extracting the first harmonic offset parameter is omitted; after receiving the above parameters, the decoder performs decoding according to the above parameters to obtain a synthesized audio signal.

[0080] The implementation process at the encoding end may specifically include:

[0081] (1): Extract the time-domain envelope parameters of the signal: For example, by calculating the sub-frame energy of the audio signal to obtain the time-domain envelope parameters of the signal, the sub-frame energy envelope {temp_env(0), temp( 1),..., temp(N-1)}, where N is the number of subframes, if the frame length is 15ms, and the subframe length is 3ms, t...

Embodiment 2

[0130]In this embodiment, the input audio signal is divided into a high frequency band signal and a low frequency band signal at the encoding end, and encoding processing is performed on the high frequency band signal and the low frequency band signal respectively.

[0131] Figure 5 It is a schematic diagram of the processing process at the encoding end in Embodiment 2 of the present invention, such as Figure 5 As shown, the encoding process includes:

[0132] 51: Filter and analyze the input audio signal; set the sampling rate of the input audio signal to 32KHz, and the processing frame length is 20ms; after the input signal is divided into frequency bands and down-sampled, the signals corresponding to the 0~8kHz frequency band are 320 sampling points, corresponding to 8~16kHz frequency band signal has 320 sampling points;

[0133] 52: Signals in the 0~8kHz frequency band are coded by core codes. In specific applications, core codes can be completed by G.729.1 codecs or b...

Embodiment 3

[0164] Compared with Embodiment 2, which adopts the method of first extracting the time domain envelope parameters and then extracting the frequency domain envelope parameters, Embodiment 3 adopts the method of first extracting the frequency domain envelope parameters to realize encoding (using the audio frequency domain in Embodiment 3) The signal and frequency division method are the same as those in Embodiment 2 as an example).

[0165] In this embodiment, the process of processing the high frequency band signal at the encoding end may specifically include:

[0166] (1): Determine the encoding mode parameter CM according to the method in (1) of the encoding end in Embodiment 2;

[0167] (2): The time domain signal in the 8~16kHz frequency band is transformed by MDCT to obtain a set of MDCT coefficients. Since the ultra-wideband part only processes the signal in the 8~14kHz frequency band, only {y_swb(0) is processed for the frequency domain signal , y_swb(1),...,y_swb(239)...

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Abstract

The invention provides a method, a device and a system for encoding and decoding audios. The method comprises the following steps of: extracting a time domain envelope parameter, a frequency domain envelope parameter, a tone parameter and a harmonic wave interval parameter, which are used for characterizing the audio signal; and encoding the time domain envelope parameter, the frequency domain envelope parameter, the tone parameter and the harmonic wave interval parameter and transmitting to a decoding end. In the method, a set of parameters containing the time domain envelope parameter, the frequency domain envelope parameter, the tone parameter and the harmonic wave interval parameter are used, so the number of parameters needed for decoding is reduced, the bit number needed when the parameters are used for encoding is reduced, and the aim of using less bit number to encode the signal is achieved.

Description

technical field [0001] The present invention relates to the technical field of audio coding and decoding, in particular to a method, device and system for parametric audio coding and decoding. Background technique [0002] An audio signal generally refers to a sound wave with a frequency of 20 Hz to 20 KHz that can be heard by the human ear, and a digital audio signal refers to an audio signal after analog-to-digital conversion. The conversion from analog to digital involves digital sampling at a specified sampling rate and scalar quantization of time-domain discrete signals at a specified resolution. [0003] Audio coding generally refers to the coding method RIRAC (Redundancy and Irrelevancy Removal AudioCoding), which eliminates statistical redundancy and perceptual insensitivity in audio signals, such as transform domain coding. Audio coding can use a lower bit rate to represent the signal, but at the same time coding noise will be introduced into the signal. Using the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H03M7/30G10L19/02
CPCG10L19/02
Inventor 张德明李海婷张立斌霍克·克鲁格本特·凯瑟皮特·瓦里
Owner 魏芳
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