Misleading time signal plot when quantizing stereo signals

[martinholters]

The signal plots are derived from a mono-downmix. Hence, when a stereo signal is processed with the quantization script, the time domain signal plot shows additional levels in between the quantization levels. If e.g. for a 2-bit quantizer, a sample is quantized to 0 in the left channel and to 0.5 in the right channel, the plot will show a value of 0.25, which should not occur with 2-bit quantization.