Abstract: An apparatus includes a decoder configured to receive, from an encoder, a frame associated with an audio bitstream and with a first sampling rate. The decoder is configured to perform a frequency-domain upmix on data associated with the frame to generate left and right frequency-domain signals and is further configured to generate, based on the left and right frequency-domain signals, left and right time-domain signals that each have a second sampling rate. The second sampling rate is determined by the decoder, based on one or both of the first sampling rate and an output sampling rate, and is adjustable by the decoder to enable different frames to be decoded at different second sampling rates. The decoder is further configured to generate, based on the left and right time-domain signals, left and right resampled signals that each have the output sampling rate.

Abstract: A device includes a receiver configured to receive an encoded bitstream from a second device. The encoded bitstream includes a temporal mismatch value. The device also includes a decoder configured to decode the encoded bitstream to generate a first signal and a second signal. Based on the temporal mismatch value, the decoder is configured to map one of the first signal or the second signal as a decoded target channel. The decoder is also configured to perform a shift operation on the decoded target channel based on the temporal mismatch value to generate an adjusted decoded target channel. The device also includes an output device configured to output a first output signal and a second output signal. The second output signal is based on the adjusted decoded target channel.

Abstract: A method of coding for multi-channel audio signals includes estimating comparison values at an encoder indicative of an amount of temporal mismatch between a reference channel and a corresponding target channel. The method includes smoothing the comparison values to generate short-term and first long-term smoothed comparison values. The method includes calculating a cross-correlation value between the comparison values and the short-term smoothed comparison values. The method also includes adjusting the first long-term smoothed comparison values in response to comparing the cross-correlation value with a threshold. The method further includes estimating a tentative shift value and non-causally shifting the target channel by a non-causal shift value to generate an adjusted target channel. The non-causal shift value is based on the tentative shift value. The method further includes generating, based on reference channel and the adjusted target channel, at least one of a mid-band channel or a side-band channel.

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 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 receiving, at an audio encoder, multiple streams of audio data. The method includes assigning a priority to each stream of the multiple streams and determining, based on the priority of each stream of the multiple streams, a permutation sequence for encoding of the multiple streams. The method also includes encoding at least a portion of each stream of the multiple streams according to the permutation sequence.

Abstract: A method for multi-channel audio or speech signal processing includes receiving a reference channel and a target channel, determining a variation between a first mismatch value and a second mismatch value, and comparing the variation with a first threshold that may have a pre-determined value or may be adjusted based on a frame type or a smoothing factor. The method also includes adjusting a set of target samples of the target channel based on the variation and based on the comparison to generate an adjusted set of target samples. Adjusting the set of target samples includes selecting one among a first interpolation and a second interpolation based on the variation. The method further includes generating at least one encoded channel based on a set of reference samples and the adjusted set of target samples. The method also includes transmitting the at least one encoded channel to a second device.

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 receiving, at an audio encoder, multiple streams of audio data, where N is the number of the received multi streams. The method includes determining a similarity value for each stream of the multiple streams and comparing the similarity value for each stream of the multiple streams with a threshold. The method also includes identifying, based on the comparison, L (L<N) number of streams to be encoded among the N number of the multiple streams. The method includes encoding the identified L number of streams to generate an encoded bitstream.

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 device for signal processing with a receiver that receives an encoded audio signal comprising a parameter, and based on the value of parameter selects one non-linear processing function for generating a first excitation signal, a second non-linear processing function for generating a second excitation signal, and generates a high-band excitation signal based on the first excitation signal and second excitation signal.

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 one or more upmix parameters. An upmix parameter of the one or more upmix parameters having a first value or a second value based on determining whether the bitstream parameters correspond to an encoded side signal. The first value is based on a received downmix parameter. The second value is based at least in part on a default parameter value. The decoder is further configured to generate an output signal based on the synthesized mid signal and the one or more upmix parameters.

Abstract: A device includes a multi-channel encoder configured to receive a first audio signal and a second audio signal, to perform a downmix operation on the first audio signal and the second audio signal to generate a mid signal, to generate a low-band mid signal and a high-band mid signal based on the mid signal, and to determine, based at least partially on a low band voicing value corresponding to the low band signal and a gain value corresponding to the high-band mid signal, a value of a multi-source flag that flag associated with the high-band mid signal. The multi-channel encoder is configured to generate a high-band mid excitation signal based on the multi-source flag and to generate a bitstream based on the high-band mid excitation signal. The device also includes a transmitter configured to transmit the bitstream and the multi-source flag to a second device.

Abstract: An apparatus includes a receiver and a decoder. The receiver is configured to receive a bitstream that includes a first frame and a second frame. The first frame includes a first portion of a mid channel and a first quantized stereo parameter. The second frame includes a second portion of the mid channel and a second quantized stereo parameter. The decoder is configured to generate a first portion of a channel based on the first portion of the mid channel and the first quantized stereo parameter. The decoder is configured to, in response to the second frame being unavailable for decoding operations, estimate the second quantized stereo parameter based on stereo parameters of one or more preceding frames and generate a second portion of the channel based on the estimated second quantized stereo parameter. The second portion of the channel corresponds to a decoded version of the second frame.

Abstract: An apparatus includes a receiver and an up-mixer. The receiver is configured to receive a bitstream that includes an encoded mid signal and encoded stereo parameter information. The encoded stereo parameter information represents a first value of a stereo parameter and a second value of the stereo parameter. The first value is associated with a first frequency range. The second value is associated with a second frequency range that is distinct from the first frequency range. The up-mixer is configured to perform an up-mix operation on a frequency-domain decoded mid signal generated from the encoded mid signal. A particular value based on the first value and the second value is applied to the frequency-domain decoded mid signal during the up-mix operation.

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.

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 a receiver and a decoder. The receiver is configured to receive one or more upmix parameters, one or more inter-channel bandwidth extension parameters, one or more inter-channel prediction gain parameters, and an encoded audio signal. The encoded audio signal includes an encoded mid signal. The decoder is configured to generate a synthesized mid signal based on the encoded mid signal. The decoder is also configured to generate a synthesized side signal based on the synthesized mid signal and the one or more inter-channel prediction gain parameters. The decoder is further configured to generate one or more output signals based on the synthesized mid signal, the synthesized side signal, the one or more upmix parameters, and the one or more inter-channel bandwidth extension parameters.

Abstract: An apparatus includes a receiver configured to receive at least one encoded signal that includes inter-channel bandwidth extension (BWE) parameters. The device includes a decoder configured to generate a mid-channel time-domain high-band signal by performing bandwidth extension based on the at least one encoded signal. The decoder is configured to generate, based on the mid-channel time-domain high-band signal and the inter-channel BWE parameters, a first channel time-domain high-band signal and a second channel time-domain high-band signal. The first channel time-domain high-band signal is selectively based on an adjustment spectral shape parameter responsive to whether the inter-channel BWE parameters include an adjustment spectral shape parameter. The decoder is configured to generate a target channel signal based at least in part on the first channel time-domain high-band signal, and to generate a reference channel signal based at least in part on the second channel time-domain high-band 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.