Method and device for coding and/or devoding audio frequency data using bandwidth expanding technology

Abstract

A coding device band expand-codes audio data, outputs band restricted audio data, and generates band expanding information. The coding device performs a Huffman coding process in a layer structure having a base layer and at least one enhancement layer to control a bit rate of the band restricted data. The coding device multiplexes the Huffman-coded band restricted audio data and the band expanding information.

Description

[0001] This application claims priority to Korean Patent Application No. 2003-17977 filed with the Korean Intellectual Property Office on March 22, 2003, the entire disclosure of which is hereby incorporated by reference. technical field [0002] The present invention relates to encoding and decoding of audio data, in particular to a method and device for encoding and decoding audio data using bandwidth extension technology. Background technique [0003] With the development of digital signal processing technology, audio signals are usually stored and played as digital data in most cases. Digital audio storage and / or playback equipment samples and quantizes analog audio signals, converts analog audio signals into pulse code modulation (PCM) audio data, that is, digital signals, and stores PCM audio data in information storage media, such as optical discs ( CD) and Digital Versatile Disc (DVD), etc., so that a user can play data from an information storage medium when he / she ...

AI Technical Summary

Problems solved by technology

Since only part of the bit stream can be used for reconstruction, even if the network is overloaded, the performance of the decoder is poor, or the user requires a low bit rate, the service of moderate audio quality can be provided to the user, only using the part of the bit stream (although The performance of the decoder will deteriorate equally with the decrease of the bit rate)

However, at reduced bitrates, the performance of the decoder inevitably degrades

[0007] In addition, BSAC techniques are complex due to their algorithmic coding

Therefore, when the BSAC technique is actually used in an audio data encoding and decoding device, the cost increases due to the increased complexity

Moreover, the BSAC technique utilizes Modified Discrete Cosine Transform (MDCT) to transform the audio signal, and the audio quality generated from the lower layer will be seriously degraded

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