Methods and systems for transcoding input audio data in a first encoding format to generate audio data in a second encoding format, and filterbanks for use in such systems. The jig further comprises a plurality of fixing elements inserted in the plurality of grooves to fix the flexible substrate to the glass plate. The current ripple rejecter includes: a low-pass-filter circuit, for filtering the ripple of the output current to generate a filtered current; and a current amplification circuit, which is coupled to the low-pass-filter circuit, for amplifying the filtered current to generate an amplified current; wherein the light emitting device current includes the amplified current. This document describes the process used in this method of early diagnosis.