With respect to Figure 2 an example analysis processor 105 and Metadata encoder/quantizer 111 (as shown in Figure 1) according to some embodiments is described in further detail. The analysis processor 105 in some embodiments comprises a time- frequency domain transformer 201 . In some embodiments the time-frequency domain transformer 201 is configured to receive the multi-channel signals 102 and apply a suitable time to frequency domain transform such as a Short Time Fourier Transform (STFT) in order to convert the input time domain signals into a suitable time-frequency signals. These time-frequency signals may be passed to a spatial analyser 203 and to a signal analyser 205. Thus for example the time-frequency signals 202 may be represented in the time-frequency domain representation by Si(b, n), where b is the frequency bin index and n is the time-frequency block (frame) index and i is the channel index. In another expression, n can be considered as a time index with a lower sampling rate than that of the original time-domain signals. These frequency bins can be grouped into subbands that group one or more of the bins into a subband of a band index k = 0,. .., K-1 . Each subband k has a lowest bin b$_{klow}$ and a highest bin b$_{khigh}$ , and the subband contains all bins from b$_{klow}$ to b$_{khigh}$ . The widths of the subbands can approximate any suitable distribution. For example the Equivalent rectangular bandwidth (ERB) scale or the Bark scale. In some embodiments the analysis processor 105 comprises a spatial analyser 203. The spatial analyser 203 may be configured to receive the time- frequency signals 202 and based on these signals estimate direction parameters 108. The direction parameters may be determined based on any audio based ‘direction’ determination. For example in some embodiments the spatial analyser 203 is configured to estimate the direction with two or more signal inputs. This represents the simplest configuration to estimate a ‘direction’, more complex processing may be performed with even more signals.