Method and apparatus for encoding/decoding audio data with scalability

Abstract

An audio data encoding and decoding system and method are provided to adjust a bit rate lower than a complexity while they are offering an FGS(Fine Grain Scalability). The method comprises several steps. Additional data, including scale factor data and coding model data corresponding to the first layer, is encoded. Plural quantized samples are encoded by the unit of a symbol according to a sequence from a symbol with an MSB(Most Significant Bit) to a symbol with an LSB(Least Significant Bit). The number added at a layer is increased by one and the steps are repeated until the encoding process for all the layers are finished.

Description

technical field [0001] The present invention relates to encoding and decoding audio data, and more particularly, to methods and apparatus for encoding audio data such that the encoded audio bitstream has scalable bit rates, and methods and apparatus for decoding audio data. Background technique [0002] Due to the recent development of digital signal processing technology, audio signals are usually stored as digital signals and reproduced in many cases. A digital audio storage / recovery device converts an audio signal into a pulse code modulation (PCM), that is, a digital signal, by sampling and quantizing. Through such operations, the digital audio storage / reproduction apparatus stores PCM audio data in information storage media such as compact discs (CD) and digital video discs (DVD), and reproduces the stored signals in response to user commands so that the user can listen to the audio data. Digital storage / retrieval methods greatly improve audio quality and significantly...

AI Technical Summary

Problems solved by technology

Therefore, when the network is overloaded, or when the performance of the decoder is poor, or when the user requests a low bit rate, by using only part of the bit stream, it is possible to provide a service with a certain audio quality to the user, although the bit rate decreases with the bit rate. drop, the quality will inevitably drop proportionally

[0007] However, since the BSAC technique employs arithmetic coding, the complexity is high, and when the BSAC technique is implemented in an actual device, the cost increases

In addition, since BSAC technology utilizes Modified Discrete Cosine Transform (MDCT) to transform the audio signal, the audio quality in the lower layer will be severely damaged

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