BAND SPLIT CODER

摘要

PROBLEM TO BE SOLVED: To improve coding sound quality with a simple configuration. SOLUTION: A sub band filter section 1 splits a frequency band of an input signal S101. A level information calculation section 2 detects a maximum amplitude in a frame for each frequency band based on a band split signal and calculates 1st level information S103 converted into level information for each frequency band. A level information estimate section 7 detects a zero cross number in a frame of th band split signal at a low frequency band of a band split signal S102 and estimates 2nd level information S108 dividing further the frequency band divided by the sub band filter section 1 based on the quantity information of the zero cross number and the 1st level information S103. An adaptive bit allocation calculation section 3 makes adaptive bit allocation based on the 2nd level information. Through the constitution above, the band split coding is conducted where coded sound quality is enhanced.