System and method for encoding and decoding audio data

Abstract

The invention discloses an encoding and decoding system of audio data and a method thereof. The method comprises the steps as follows: A. whether the audio data input is subjected to MDCT or IMDCT is judged, step B is executed if MDCT is carried out; step C is executed if IMDCT is carried out and the audio data needs to carry out multiplex calculation; B, the audio data needing to carry out multiplex calculation is obtained after the audio data is subjected to MDCT preliminary treatment; and C, the audio data needing to carry out multiplex calculation is subjected to multiplex calculation, if the audio data is subjected to MDCT, the multiplex calculation result is taken as the result of the audio data subjected to MDCT; if the audio data is subjected to IMDCT, the multiplex calculation result is taken as the result of the audio data subjected to IMDCT after being subjected to IMDCT post treatment, therefore, the multiplexity of the audio data subjected to MDCT and IMDCT is realized.

Description

technical field [0001] The invention relates to audio data processing technology, in particular to an audio data encoding and decoding system and method. Background technique [0002] At present, when audio data is transmitted or stored, in order to reduce the capacity occupied by the transmitted or stored audio data, it is necessary to encode and decode the audio data to achieve the effect of compressing the audio data. Among them, Modified Discrete Cosine Transform (MDCT, Modified Discrete Cosine Transform) is a hardware implementation for encoding audio data, and Inverse Modified Discrete Cosine Transform (IMDCT, Inverse Modified Discrete Cosine Transform) is a method for encoding audio data. Hardware implementation for decoding. [0003] MDCT is to use the energy aggregation of discrete cosine transformation (DCT, Discrete Cosine Transform) to gather the energy of audio data to a small number of variation coefficients, thereby improving the effect of compressing audio d...

AI Technical Summary

Problems solved by technology

[0019] figure 1 This kind of hardware implementation directly adopts the method of multiplying and accumulating audio data encoding. The advantage is that the structure is relatively simple, that is, it can be realized by directly setting the multiplying and accumulating module, but its disadvantage is that the multiplication operation is very large.

The multiplication operation amount of the original algorithm provided by ISO MPEC is 648 (N is 36, using the formula (1)) to calculate, using figure 1 The method can reduce the amount of calculation to 324, but the amount of calculation of MDCT is still huge, which eventually leads to high power consumption of the hardware system and poor performance of the hardware module

Additionally, based on figure 1 The constructed hardware module can only implement MDCT, but not IMDCT. If IMDCT needs to be implemented on the chip, an additional hardware module needs to be added, which increases the circuit area of ​​the hardware system and increases the difficulty and cost of hardware system design.

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