Patent ID: 8751246

Claim:
An audio encoder apparatus adapted for encoding frames of a sampled audio signal to acquire encoded frames, wherein a frame comprises a number of time domain audio samples, comprising: a predictive coding analysis stage for determining information on coefficients of a synthesis filter and information on a prediction domain frame based on a frame of audio samples; a frequency domain transformer for transforming a frame of audio samples to the frequency domain to acquire a frame spectrum; an encoding domain decider for deciding whether encoded data for a frame is based on the information on the coefficients and on the information on the prediction domain frame, or based on the frame spectrum; a controller for determining information on a switching coefficient when the encoding domain decider decides that encoded data of a current frame is based on the information on the coefficients and the information on the prediction domain frame when encoded data of a previous frame was encoded based on a previous frame spectrum acquired by the frequency domain transformer; and a redundancy reducing encoder for encoding the information on the prediction domain frame, the information on the coefficients, the information on the switching coefficient and/or the frame spectrum, wherein the information on the switching coefficient comprises an information enabling an initialization of a predictive synthesis stage, and the controller is adapted for determining the information on the switching coefficient based on an LPC analysis of the previous frame, and the controller is adapted for determining the information on the switching coefficient based on a high pass filtered version of a decoded frame spectrum of the previous frame, wherein at least one of the predictive coding analysis stage, the frequency domain transformer, the encoding domain decider, the controller and the redundancy reducing encoder comprises a hardware implementation.