High Quality Audio Coding at Low Bit Rate Using Wavelet and Wavelet Packet Transform
نویسنده
چکیده
Audio coding is widely used in application such as digital broadcasting, Internet audio or music database to reduce the bit rate of high quality audio signal without comprising the perceptual quality. In this paper work high quality audio codec at low bit rate using wavelet transform and improvement in reconstructed wave using post filtering has been proposed. The major issues concerning the development of audio codec are choosing optimal wavelets for audio signals, decomposition level in the digital wavelet transform and threshold criteria for coefficient truncation which is the basis to provide compression ratio for audio with suitable peak signal to noise ratio (PSNR), wavelet packet compression technique has also been used to compare the performance of audio codec using wavelet transform. After reconstructing the audio signal a post filtering technique is used to improve the quality of reconstructed audio signal. The proposed audio codec has been implemented in MATLAB 7.0 and various audio signals of different time duration have been tested. Result obtained show that the proposed codec improves quality of the reconstructed audio signal after post filtering.
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