LPC residual signal encoding/decoding apparatus of modified discrete cosine transform (MDCT)-based unified voice/audio encoding device

An LPC residual signal encoding apparatus of an MDCT based unified voice and audio encoding device, comprising:

• a signal analyzing unit to analyze a property of an input signal and to select an encoding method of an LPC filtered signal;
• a first encoding unit to perform selectively one of a real filterbank based encoding and a complex filterbank based encoding, when the input signal is an audio signal;
• and
• a second encoding unit to encode the LPC residual signal based on an ACELP, when the input signal is a voice signal.

An LPC residual signal decoding apparatus of an MDCT based unified voice and audio decoding device, comprising:

• a voice decoding unit to decode an LPC residual signal encoded from a frequency domain, when the encoded LPC residual signal is a voice signal;
• an audio decoding unit to decode an LPC residual signal encoded from a time domain, when the encoded LPC residual signal is an audio signal;
• and
• a distortion controlling unit to compensate for a distortion between an output signal of the audio decoding unit and an output signal of the voice decoding unit,
• wherein the audio decoding unit comprises:
• a first decoding unit to decode an LPC residual signal encoded based on a real filterbank;
• and
• a second decoding unit to decode an LPC residual signal encoded based on a complex filterbank.

A processing method performed by one or more processors, comprising:

• identifying a first block included in a previous frame;
• identifying a second block included in a current frame;
• generating an intentional signal related to the first block;
• wherein the first block is processed by algebraic code excited linear prediction (ACELP), and the second block is processed by a modified discrete cosine transform (MDCT);
• first overlap-adding the first block applied to a first window into the intentional signal applied to a second window;
• and
• second overlap-adding the second block applied to a third window into the first overlapped result applied to the first window.