Fixed Length Coding by Nonuniform Scalar Quantization

Replacement of variable-length coding in the Verification Model (software reference model) by fixed-length coding are investigated. Trellis-coded quantization, iterative rate allocation and subsequent arithmetic coder are taken out. Instead, the wavelet coefficients are classified block-wise according to their variance (in terms of bit allocation) and quantized by a scalar non-uniform Lloyd-Max quantizer. The results show that the new system outperforms the old one for erroneous channel conditions with bit error rates above 10E-6 significantly, as well as in subjective assesments.