Communication Device, Signal Encoding/Decoding Method

摘要

There is provided a communication device for effectively encoding an audio/music signal while maintaining a predetermined quality by controlling the transmission bit rate of the transmission side considering the use environment of the reception side. In this device, a transmission mode decision unit ( 101 ) detects an environment noise contained in the background of the audio/music signal in the input signal and decides the transmission mode controlling the transmission bit rate of the signal transmitted from a communication terminal device ( 150 ), which is a communication terminal of the partner side, according to the environment noise level. A signal decoding unit ( 103 ) decodes encoded information transmitted from the communication terminal device ( 150 ) via a transmission path ( 110 ) and outputs the obtained signal as an output signal. Here, the signal decoding unit ( 103 ) detects a transmission error by comparing the transmission mode information contained in the encoded information outputted from the transmission path ( 110 ), to the transmission mode information obtained by the transmission mode decision unit ( 101 ) while considering the transmission delay.