Comparison of different wavelet decomposition techniques for PEAQ model to assess the quality of audio codecs

摘要

Audio quality is one of the key factors when designing a digital system for broadcasting. The rapid prelude of bit-rate reduction schemes has led to paramount efforts in establishing and refining procedures for subjective assessments, simply because formal heedfully auricularly discerning tests have been the only germane method for judging audio quality. Perceptual Evaluation of audio quality (PEAQ) is the only available standardized method for the assessing the audio quality as of today. The PEAQ model is the FFT predicated standard. In this work we have proposed a novel method utilizing sundry wavelet decomposition techniques in lieu of FFT to implement PEAQ. Next step involves the comparison of objective difference grade (ODG) for the FFT predicated method and the novel proposed wavelet decomposition techniques, wavelet hoisting techniques. The input to the Proposed PEAQ model is a reference signal (wav) and test signal. The test signal is prepared by the reference wave file which is encoded (compressed) then decoded (decompressed) using the codecs like MP4, MP3, AAC, OGG and WMA(the decoded reference signal is again a wave file which will be treated as test signal). The output of proposed PEAQ model (excitation parameters) or variables are called Model Output Variables MOV. The final stage of the measurement model combines the MOV values to produce a single output value that directly corresponds to an expected result from a subjective quality assessment - ODG. In this work we implement a PEAQ using novel methods using different wavelet decomposition techniques and wavelet lifting techniques and then compare the ODG from actual PEAQ model (which is FFT based)and ODG from the different wavelet decomposition & wavelet lifting based PEAQ model.