We present in this paper a near-lossless full-band stereo compression scheme, Conditionally Lossless Encoding under Allowed Rates (CLEAR), aiming at its use in realtime transmission of sound data, sounds to be mixed or processed after transmitted. Using uniform quantizer with MPEG-4 Audio Lossless Coding (ALS) and adaptive pre- and post-processing, CLEAR controls the encoding bit rate with maximum fidelity of reconstructed signals. Objective experiments show an enhancement in signal to noise ratio (SNR) and from conventional low-delay codecs with compatible perceptual quality. Additionally, companding-based perceptual weighting designed for CLEAR is shown to make an improvement in Perceptual Evaluation of Audio Quality (PEAQ).
展开▼
