Bit distribution method, coding method, decoding method, coder and decoder

Abstract

The invention provides a bit distribution method comprising the following steps: carrying out perceptual sorting on all subbands of a signal according to the energy of the subband; according to the magnitude of frequency ranges corresponding to the subbands on a frequency domain and the energy difference of the subbands, adjusting the sequence of the subbands in the perceptual sorting; and distributing the bit resource according to the adjusted perceptual sorting sequence. The invention also provides a coding method, a coder, a bit distribution method, a decoding method and a decoder. By using the invention, the complexity of bit distribution can be lowered, and bit can be more reasonably distributed to the subbands with important perception, thereby ensuring that the coder and the decoder can generate better hearing feeling.

Description

technical field [0001] The present invention relates to codec technology, in particular to bit allocation technology. Background technique [0002] The sub-band coding technology is one of the commonly used coding and decoding technologies at present. Audio signals can be divided into multiple frequency bands from low to high in the frequency domain. A frequency band is called a sub-band, and subsequent encoding, decoding, and other work are performed on the basis of sub-bands. In the process of encoding and decoding, limited bit resources need to be allocated between subbands. Generally, the more bits a subband obtains, the smaller the error in quantization and the better the quality of encoding and decoding. On the contrary, if the subband The less bits the band gets, the greater the error in quantization and the worse the quality of the codec. [0003] The bit allocation is generally guided by the perceptual characteristics of the human ear. The physiological character...

AI Technical Summary

Problems solved by technology

Among them, the subbands with high perceptual importance will be preferentially coded and transmitted at lower layers, and will be decoded preferentially at the decoding end; the subbands with low perceptual importance will be coded and transmitted at higher layers, which may be affected by the transmission channel , the higher layer coded information cannot be received at the decoding end, in this case, it cannot be decoded

[0008] In the process of implementing the present invention, the inventors of the present invention found that in the bit allocation scheme 1, in order to achieve the purpose of high-efficiency coding, it is necessary to establish a fine perceptual model in real time, which requires a large amount of calculation, and then multiple iterations are required. In order to achieve the purpose of optimal bit allocation, the computational complexity of the whole process is very high; in bit allocation scheme 2, the perceptual importance of each sub-band is only measured according to the sub-band energy, and the sensitivity of the human ear to low-frequency signals is not considered The perceptual characteristics of high degree of sensitivity and low sensitivity of high-frequency signals, and the masking effect of low-frequency signals covering high-frequency signals are not considered, resulting in a mismatch between bit allocation and perceptual characteristics, which affects the quality of encoding and decoding.

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