Speech encoding device having TFO function and method

Abstract

The internal state matching of an encoder when switching from TFO mode to tandem connection is maintained while suppressing the corresponding increase in the amount of processing. In the TFO mode, PCM data and compressed data transmitted in multiplexed form are demultiplexed by a PCM data/compressed data demultiplexing unit, and the compressed data is selected by a selector for output. At the same time, an encoding functional unit continues to encode the demultiplexed PCM data so that the internal state matching of the encoder can be maintained in case of a fallback to the tandem connection. At this time, to alleviate the processing burden of the encoder, part of the demultiplexed encoded data, for example, stochastic codebook data, is extracted and supplied to the encoding functional unit.

Dependencies are inferred from the claim text.