Sound coding and decoding apparatus and sound coding and decoding method

A technology of sound encoding and decoding data, which is applied in speech analysis, instruments, etc., can solve problems such as aliasing noise, harmonic interference noise, and narrow transition band, so as to improve continuity, improve coding quality, and eliminate harmonic interference noise Effect

Active Publication Date: 2013-10-23
BEJING ANGEL VOICE DIGITAL TECH
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Problems solved by technology

[0008] According to the method proposed by ZL200610087481.X, because the technique of recovering the high frequency spectrum from the low frequency spectrum and the medium frequency spectrum changes the natural positional relationship and energy size between the frequency bands of the original signal, it will bring a series of problems, thus affecting the high frequency Coding quality of parameter encoding
For example: the frequency band division in the high-frequency parameter coding cuts off the correlation between the spectral lines of the original signal, especiall

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  • Sound coding and decoding apparatus and sound coding and decoding method
  • Sound coding and decoding apparatus and sound coding and decoding method
  • Sound coding and decoding apparatus and sound coding and decoding method

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Embodiment approach

[0311] Encoding mode selection implementation method 1: Use three encoding modes to encode and decode the low frequency spectrum in the two channels with the same number of bits respectively, and calculate the difference between the low frequency spectrum in the two channels restored by decoding and the low frequency spectrum before encoding. spectrum error, and select the coding mode with the smallest error as the coding mode of stereo coding. Output the encoding mode selection information as side information to the bit stream multiplexing module 1208;

[0312] Coding mode selection implementation method 2: For lower frequency sub-bands with frequencies lower than a certain value in the low frequency spectrum, such as sub-bands below 1kHz, respectively use the sum-difference stereo coding mode and the parametric stereo coding mode to encode and decode, and calculate and restore The error between the low frequency spectrum in the two channels and the low frequency spectrum bef...

Embodiment approach 1

[0323] The specific implementation method 1 of parametric stereo coding comprises the following steps:

[0324] Step 35-1a: In the sub-band k, for a certain channel, such as the right channel Calculate the weighting parameter g for this channel r (k), and get the scaled spectrum of the channel making the scaled and The energy is equal; g r (k) can be calculated using the following formula:

[0325] g r ( k ) = E R ( k ) E L ( k )

[0326] Among them, E R (k) and E L (k) are the energy of right channel and left channel in sub-band k respectively.

[032...

Embodiment approach 1

[0334] Compared with the specific implementation method 1, the parameter g in the specific implementation method 2 of the parametric stereo coding r (k), g d (k) and weighted sum spectrum It is calculated according to the principle of minimum error, including the following steps:

[0335] Step 35-2a: For sub-band k, calculate the first parameter g according to the following formula d (k):

[0336] g d ( k ) = - b ( k ) + b 2 ( k ) + a 2 ( k ) ...

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Abstract

The invention relates to a sound coding and decoding apparatus and a sound coding and decoding method, and particularly relates to a monophony sound coding and decoding apparatus, a monophony sound coding and decoding method, a stereo sound coding and decoding apparatus, and a stereo sound coding and decoding method. The sound coding and decoding method is characterized in that low frequency waveform coding is combined with high frequency parameter coding, and a specific frequency range of a low frequency spectrum is mapped to a specific frequency range of a high frequency spectrum; at a coding end, the high frequency spectrum before and after spectrum mapping operation is subjected to mapping domain boundary preprocessing, the high frequency spectrum after parameter decoding operation is subjected to mapping domain boundary post-processing, problems brought by frequency band dividing operation and low frequency spectrum to high frequency spectrum mapping operation in high frequency parameter coding operation are overcome, frequency spectrum continuity and frequency band signal naturalness are improved, harmonic wave interference noise and aliasing noise caused by sidelobe leakage are eliminated, and high frequency parameter coding quality is further improved under the condition of a low code rate.

Description

technical field [0001] The present invention relates to a sound codec device and method, in particular to a monophonic sound codec device and its method, and a stereo sound codec device and method thereof. Background technique [0002] Patent ZL200610087481.X discloses a sound encoding device and method, including: [0003] The time-varying predictive analysis module is used to perform time-varying predictive analysis on digital sound signals to obtain time-domain excitation signals; [0004] A time-frequency mapping module, configured to map the time-domain excitation signal to the transform domain, to obtain the excitation signal on the transform domain; [0005] The encoding module is used to quantize and encode the low frequency spectrum and the middle frequency spectrum in the excitation signal on the transform domain to obtain the low frequency waveform coded data and the intermediate frequency waveform code data; and according to the low frequency spectrum and the mi...

Claims

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Application Information

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IPC IPC(8): G10L19/02G10L19/008
Inventor 潘兴德李靓吴超刚
Owner BEJING ANGEL VOICE DIGITAL TECH
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