Abstract: A device includes a receiver configured to receive an inter-channel prediction gain parameter and an encoded audio signal. The encoded audio signal includes an encoded mid signal. The device also includes a decoder configured to generate a synthesized mid signal based on the encoded mid signal. The decoder is configured to generate an intermediate synthesized side signal based on the synthesized mid signal and the inter-channel prediction gain parameter. The decoder is further configured to filter the intermediate synthesized side signal to generate a synthesized side signal.

Abstract: A method includes generating a synthesized non-reference high-band channel based on a non-reference high-band excitation corresponding to a non-reference target channel. The method further includes estimating one or more spectral mapping parameters based on the synthesized non-reference high-band channel and a high-band portion of the non-reference target channel. The method also includes applying the one or more spectral mapping parameters to the synthesized non-reference high-band channel to generate a spectrally shaped synthesized non-reference high-band channel. The method further includes generating an encoded bitstream based on the one or more spectral mapping parameters and the spectrally shaped synthesized non-reference high-band channel.

Abstract: A method includes decoding a low-band mid channel bitstream to generate a low-band mid signal and a low-band mid excitation signal. The method further includes decoding a high-band mid channel bandwidth extension bitstream to generate a synthesized high-band mid signal. The method also includes determining an inter-channel bandwidth extension (ICBWE) gain mapping parameter corresponding to the synthesized high-band mid signal. The ICBWE gain mapping parameter is based on a selected frequency-domain gain parameter that is extracted from a stereo downmix/upmix parameter bitstream. The method further includes performing a gain scaling operation on the synthesized high-band mid signal based on the ICBWE gain mapping parameter to generate a reference high-band channel and a target high-band channel. The method includes outputting a first audio channel and a second audio channel. The first audio channel is based on the reference high-band channel, and the second audio channel is based on target high-band channel.

Abstract: A device includes a receiver and a decoder. The receiver is configured to receive bitstream parameters corresponding to at least an encoded mid signal. The decoder is configured to generate a synthesized mid signal based on the bitstream parameters. The decoder is also configured to generate a synthesized side signal selectively based on the bitstream parameters in response to determining whether the bitstream parameters correspond to an encoded side signal.

Abstract: A method includes selecting, at an encoder of a first device, a left channel or a right channel as a non-reference target channel based on a high-band reference channel indicator. The method also includes generating a synthesized non-reference high-band channel based on a non-reference high-band excitation corresponding to the non-reference target channel. The method also includes generating a high-band portion of the non-reference target channel. The method further includes estimating one or more spectral mapping parameters based on the synthesized non-reference high-band channel and the high-band portion of the non-reference target channel. The method also includes applying the one or more spectral mapping parameters to the synthesized non-reference high-band channel to generate a spectrally shaped synthesized non-reference high-band channel.

Abstract: A device includes a receiver and a decoder. The receiver is configured to receive bitstream parameters corresponding to at least an encoded mid signal. The decoder is configured to generate a synthesized mid signal based on the bitstream parameters. The decoder is also configured to generate a synthesized side signal selectively based on the bitstream parameters in response to determining whether the bitstream parameters correspond to an encoded side signal.

Abstract: A method includes decoding a low-band portion of an encoded mid channel to generate a decoded low-band mid channel. The method also includes filtering the decoded low-band mid channel according to one or more filter coefficients to generate a low-band filtered mid channel. The method also includes generating an inter-channel predicted signal based on the low-band filtered mid channel and the inter-channel prediction gain. The method further includes generating a low-band left channel and a low-band right channel based on an up-mix factor, the decoded low-band mid channel, and the inter-channel predicted signal.

Abstract: A device includes a processor that is configured to determine an inter-channel mismatch value indicative of a temporal misalignment between a frequency-domain reference channel and a frequency-domain target channel. The processor is also configured to adjust the frequency-domain target channel based on the inter-channel mismatch value to generate an adjusted frequency-domain target channel. The processor is further configured to perform a down-mix operation, based on the frequency-domain reference channel and the adjusted frequency-domain target channel, to generate a mid channel and a side channel. The processor is also configured to generate a predicted side channel based on the mid channel. The processor is further configured to generate a residual channel based on the side channel and the predicted side channel. The processor is also configured to encode the residual channel as part of a bitstream.

Abstract: A method includes decoding a low-band portion of an encoded mid channel to generate a decoded low-band mid channel. The method also includes filtering the decoded low-band mid channel according to one or more filter coefficients to generate a low-band filtered mid channel. The method also includes generating an inter-channel predicted signal based on the low-band filtered mid channel and the inter-channel prediction gain. The method further includes generating a low-band left channel and a low-band right channel based on an up-mix factor, the decoded low-band mid channel, and the inter-channel predicted signal.

Abstract: A method includes processing a time-domain decoded high-band mid signal to generate a time-domain high-band residual prediction signal. The method also includes generating a high-band left channel and a high-band right channel based on the time-domain decoded high-band mid signal and the time-domain high-band residual prediction signal.

Abstract: A device includes an encoder and a transmitter. The encoder is configured to generate a first high-band portion of a first signal based on a left signal and a right signal. The encoder is also configured to generate a set of adjustment gain parameters based on a high-band non-reference signal. The high-band non-reference signal corresponds to one of a left high-band portion of the left signal or a right high-band portion of the right signal as a high-band non-reference signal. The transmitter is configured to transmit information corresponding to the first high-band portion of the first signal. The transmitter is also configured to transmit the set of adjustment gain parameters corresponding to the high-band non-reference signal.

Abstract: A residual scaling unit is configured to determine a scaling factor for a residual channel based on an inter-channel mismatch value. The inter-channel mismatch value is indicative of a temporal misalignment between a reference channel and a target channel. The residual scaling unit is further configured to scale (e.g., attenuate) the residual channel by the scaling factor to generate a scaled residual channel. A residual channel encoder is configured to encode the scaled residual channel as part of a bitstream.

Abstract: A method includes decoding a low-band portion of an encoded mid signal to generate a decoded low-band mid signal. The method also includes processing the decoded low-band mid signal to generate a low-band residual prediction signal and generating a low-band left channel and a low-band right channel based partially on the decoded low-band mid signal and the low-band residual prediction signal. The method further includes decoding a high-band portion of the encoded mid signal to generate a time-domain decoded high-band mid signal and processing the time-domain decoded high-band mid signal to generate a time-domain high-band residual prediction signal. The method also includes generating a high-band left channel and a high-band right channel based on the time-domain decoded high-band mid signal and the time-domain high-band residual prediction signal.

Abstract: A method includes performing modifying, at a decoder, at least a portion of inter-channel phase difference (IPD) parameter values based on a mismatch value to generate modified IPD parameter values. The mismatch value is indicative of an amount of temporal misalignment between an encoder-side reference channel and an encoder-side target channel. The modified IPD parameter values are applied to a decoded frequency-domain mid channel during an up-mix operation.

Abstract: A stereo parameter conditioner performs a conditioning operation on a first value of a stereo parameter and a second value of the stereo parameter to generate a conditioned value of the stereo parameter. The first value is associated with a first frequency range, and the second value is associated with a second frequency range. The conditioned value is associated with a particular frequency range that is a subset of the first frequency range or a subset of the second frequency range.

Abstract: A device includes an encoder and a transmitter. The encoder is configured to generate a first high-band portion of a mid signal based on a left signal and a right signal, to generate a first synthesized signal based on a first gain and linear predictive coefficient (LPC) parameters, and to generate a second synthesized signal based at least in part on a second gain and the LPC parameters. The encoder is also configured to generate a set of first gain parameters based on a comparison of the first synthesized signal and the mid signal, and to generate a set of adjustment gain parameters based on the second synthesized signal and a high-band non-reference signal. The transmitter is configured to transmit information corresponding to the first high-band portion of the mid signal. The transmitter is also configured to transmit the set of adjustment gain parameters corresponding to the high-band non-reference signal.

Abstract: A method of encoding audio channels includes receiving two or more channels at an encoder and identifying a target channel and a reference channel. The target channel and the reference channel are identified from the two or more channels based on a mismatch value. The method also includes generating a modified target channel by temporally adjusting the target channel based on the mismatch value. The mismatch value is indicative of an amount of temporal mismatch between the target channel and the reference channel. The method also includes determining a temporal correlation value indicative of a temporal correlation between a first signal associated with the reference channel and a second signal associated with the modified target channel. The method also includes comparing the temporal correlation value to a threshold. The method further includes generating missing target samples based on the comparison, a coder type, or both.

Abstract: A method includes performing modifying, at a decoder, at least a portion of inter-channel phase difference (IPD) parameter values based on a mismatch value to generate modified IPD parameter values. The mismatch value is indicative of an amount of temporal misalignment between an encoder-side reference channel and an encoder-side target channel. The modified IPD parameter values are applied to a decoded frequency-domain mid channel during an up-mix operation.

Abstract: A stereo parameter conditioner performs a conditioning operation on a first value of a stereo parameter and a second value of the stereo parameter to generate a conditioned value of the stereo parameter. The first value is associated with a first frequency range, and the second value is associated with a second frequency range. The conditioned value is associated with a particular frequency range that is a subset of the first frequency range or a subset of the second frequency range.

Abstract: An apparatus includes a receiver and a decoder. The receiver is configured to receive a bitstream that includes an encoded mid channel and a quantized value representing a shift between a reference channel associated with an encoder and a target channel associated with the encoder. The quantized value is based on a value of the shift. The value of the shift is associated with the encoder and has a greater precision than the quantized value. The decoder is configured to decode the encoded mid channel to generate a decoded mid channel and to generate a first channel based on the decoded mid channel. The decoder is further configured to generate a second channel based on the decoded mid channel and the quantized value. The first channel corresponds to the reference channel and the second channel corresponds to the target channel.