Indolinone compounds of formula or :wherein A, R1, R2, R3, R4, R5, R6, R7, and n are defined herein. The coding apparatus includes a first layer coding section that selects a first quantization target band of inputted spectrum and generates first layer coded information including first band information of the selected band. A differential pressure sensor has an optical fiber extending in a wall having a first side and a second side, each of the first and second sides being exposed to pressure in the flow passage. In another embodiment, a CELP encoder is provided that is capable of jointly optimizing andor sequentially optimizing multiple excitation vector-related parameters by reference to a joint search weighting factor, thereby invoking an optimal error minimization process.