A method provides binaural sound to a person through electronic earphones. The binaural sound localizes to a sound localization point (SLP) in empty space that is away from but proximate to the person. When an event occurs, the binaural sound switches or changes to stereo sound, to mono sound, or to altered binaural sound.

Disclosed is an LPC residual signal encoding/decoding apparatus of an MDCT based unified voice and audio encoding device. The LPC residual signal encoding apparatus analyzes a property of an input signal, selects an encoding method of an LPC filtered signal, and encode the LPC residual signal based on one of a real filterbank, a complex filterbank, and an algebraic code excited linear prediction (ACELP).

Disclosed is an LPC residual signal encoding/decoding apparatus of an MDCT based unified voice and audio encoding device. The LPC residual signal encoding apparatus analyzes a property of an input signal, selects an encoding method of an LPC filtered signal, and encode the LPC residual signal based on one of a real filterbank, a complex filterbank, and an algebraic code excited linear prediction (ACELP).

The invention refers to audio encoders, audio decoders, and audio encoding methods and audio decoding methods. In some examples, the invention refers to improved stereo coding. An encoder provides an encoded representation of an audio signal. The encoder applies a spectral whitening to a separate-channel representation of the input audio signal, to obtain a whitened separate-channel representation of the signal. The audio encoder applies a spectral whitening to a mid-side representation of the signal, to obtain a whitened mid-side representation of the signal. The audio encoder decides whether to encode the whitened separate-channel representation of the signal, to obtain the encoded representation of the signal, or to encode the whitened mid-side representation of the signal, to obtain the encoded representation of the signal.

The invention refers to audio encoders, audio decoders, and audio encoding methods and audio decoding methods. In some examples, the invention refers to improved stereo coding. An encoder provides an encoded representation of an audio signal. The encoder applies a spectral whitening to a separate-channel representation of the input audio signal, to obtain a whitened separate-channel representation of the signal. The audio encoder applies a spectral whitening to a mid-side representation of the signal, to obtain a whitened mid-side representation of the signal. The audio encoder decides whether to encode the whitened separate-channel representation of the signal, to obtain the encoded representation of the signal, or to encode the whitened mid-side representation of the signal, to obtain the encoded representation of the signal.

A method, computer readable media and a system for determining a Voice over LTE (VoLTE) codec is presented. In one embodiment a method includes discovering a packet header size used in a session using a Silence Insertion Descriptor (SID); inspecting downlink packet sizes coming into a receive buffer; determining when three consecutive packet sizes are greater than zero, then setting a first factor, a second factor, and a third factor equal to zero; calculating a header size; and determining a voice encoding codec by subtracting a header overhead value from the packet size.

A method, computer readable media and a system for determining a Voice over LTE (VoLTE) codec is presented. In one embodiment a method includes discovering a packet header size used in a session using a Silence Insertion Descriptor (SID); inspecting downlink packet sizes coming into a receive buffer; determining when three consecutive packet sizes are greater than zero, then setting a first factor, a second factor, and a third factor equal to zero; calculating a header size; and determining a voice encoding codec by subtracting a header overhead value from the packet size.

A method includes establishing communication between a first user device and a second user device using a first codec and filtering an input signal indicating an estimated unfiltered available bandwidth for the communications by applying a current filter including one of a first filter when the estimated unfiltered available bandwidth is less than a first threshold value or greater than a second threshold value or a second filter when the estimated unfiltered available bandwidth is between and including the first and second threshold values. The method includes adaptively switching the current filter as a function of the filtered input signal and the first and second threshold values. When the filtered input signal satisfies a channel bandwidth threshold for at least a predetermined period of time, the method includes switching from using the first codec to using a second codec for the communication between the first and second user devices.

A stereo signal encoding method includes obtaining indication information of an encoding mode of a residual signal of a current frame, where the indication information includes at least one of an encoding status of a residual signal of a previous frame, a value of an updating manner flag for a long-term smooth parameter of the current frame, or a value of a status change parameter of the current frame relative to a stereo signal of the previous frame, and determining the encoding mode of the residual signal of the current frame based on the indication information of the encoding mode of the residual signal of the current frame, where the encoding mode indicates whether to encode the residual signal of the current frame.

A stereo signal encoding method includes obtaining indication information of an encoding mode of a residual signal of a current frame, where the indication information includes at least one of an encoding status of a residual signal of a previous frame, a value of an updating manner flag for a long-term smooth parameter of the current frame, or a value of a status change parameter of the current frame relative to a stereo signal of the previous frame, and determining the encoding mode of the residual signal of the current frame based on the indication information of the encoding mode of the residual signal of the current frame, where the encoding mode indicates whether to encode the residual signal of the current frame.