Signal encoding and decoding system allowing adding of signals in a form

Abstract

In a signal compressing and encoding apparatus, a plurality of A/D converters sample input audio signals synchronously to produce time sample sequences. An audio encoding circuit transforms the time sample sequences in time/frequency by a frame interval to produce frequency sample sequences. The frequency sample sequences are compressed, encoded and formatted into a frame structure to generate audio bit streams. The audio bit streams are multiplexed by a formatter into a multiplexed bit stream. On the other hand, in a compressed signal decoding circuit, a quantization decoder decodes the frequency sample sequences for each bit stream separated and extracted selectively out of the multiplexed bit stream. Adding the result the decoded frequency sample sequences produces a summing result. The summing result is then transformed in frequency/time by a frequency/time mapping to produce the original time sample sequences.