Audio Signal Encoding Methods and Systems for True Voice and Audio Services with Adaptive Level Reduction Strategy

Abstract

This invention relates to a method for encoding / decoding audio signals using a down-leveling strategy when encoding, applied at the encoder, and a mixing / up-leveling strategy when decoding, applied at the decoder. Based on the type of down-leveling encoding scheme, this method includes the following steps: calculating the input down-leveling gain to be applied to the input audio signal to construct the main down-level channel; determining the proportional down-leveling gain to proportionally scale the main down-level channel; generating a predicted gain based on the input audio signal, input down-leveling gain, and proportional down-leveling gain; determining the residual channel(s) from the side channels by using the main down-leveling channel and predicted gain to generate side channel predictions and subtracting side channel predictions from the side channels; determining the decorrelation gain based on the energy in the residual channels; encoding the main down-level channel(s), the predicted gain, and the decorrelation gain; and send the bill to the decoder.The article also mentions the audio signal encoding system and the immutable means of reading computer screens.