Alternative formulations for bit allocation with dependent quantization

We discuss formulations to solve the bit-allocation problem with dependencies. These formulations are more generic than those known earlier in that we relax a so-called causality assumption. We study the incremental improvement obtained by having a dependency structure in optimal quantization choices. As a way to solve this problem approximately, we discuss novel rounding procedures based on some relaxation of the original problem (either the LP relaxation or a Lagrange relaxation). The rounding algorithms perform extremely close to optimality. Our results also show an improvement of around 0.5 dB over the best causally-optimal solution.