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 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 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 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 device for processing audio signals includes an interchannel phase difference (IPD) mode selector and an IPD estimator. The IPD mode selector is configured to select an IPD mode based on at least a strength value associated with a temporal misalignment between a first audio signal and a second audio signal. The IPD estimator is configured to determine IPD values based on the first audio signal and the second audio signal. The IPD values have a resolution corresponding to the selected IPD mode.

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 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: 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 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 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 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 for processing a signal includes receiving a first frame of an input audio bitstream at a decoder. The first frame includes at least one signal associated with a frequency range. The method also includes decoding the at least one signal to generate at least one decoded signal having an intermediate sampling rate. The intermediate sampling rate is based on coding information associated with the first frame. The method further includes generating a resampled signal based at least in part on the at least one decoded signal. The resampled signal has an output sampling rate of the decoder.

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 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 device includes a receiver configured to receive an encoded bitstream from a second device. The encoded bitstream includes a temporal mismatch value determined based on a reference channel captured at the second device and a target channel captured at the second device. The device also includes a decoder configured to decode the encoded bitstream to generate a first frequency-domain output signal and a second frequency-domain output signal. The decoder is configured to perform inverse transform operations on the frequency-domain output signals to generate a first and second time-domain signals. Based on the temporal mismatch value, the decoder is configured to map the time-domain signals to a decoded target channel and a decoded reference channel. The decoder is also configured to perform a causal time-domain shift operation on the decoded target channel based on the temporal mismatch value to generate an adjusted decoded target channel.

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 device for processing audio signals includes an interchannel temporal mismatch analyzer, an interchannel phase difference (IPD) mode selector and an IPD estimator. The interchannel temporal mismatch analyzer is configured to determine an interchannel temporal mismatch value indicative of a temporal misalignment between a first audio signal and a second audio signal. The IPD mode selector is configured to select an IPD mode based on at least the interchannel temporal mismatch value. The IPD estimator is configured to determine IPD values based on the first audio signal and the second audio signal. The IPD values have a resolution corresponding to the selected IPD mode.

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 alignment 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 device includes a processor and a transmitter. The processor is configured to determine a first mismatch value indicative of a first amount of a temporal mismatch between a first audio signal and a second audio signal. The processor is also configured to determine a second mismatch value indicative of a second amount of a temporal mismatch between the first audio signal and the second audio signal. The processor is further configured to determine an effective mismatch value based on the first mismatch value and the second mismatch value. The processor is also configured to generate at least one encoded signal having a bit allocation. The bit allocation is at least partially based on the effective mismatch value. The transmitter configured to transmit the at least one encoded signal to a second device.

Abstract: A method includes generating a windowed time-domain mid channel by applying two first asymmetric windows to a first frame of a time-domain mid channel and applying two second asymmetric windows to a second frame of the time-domain mid channel. The method includes transforming the windowed time-domain mid channel to a transform domain to generate sets of transform-domain mid channel data including first transform-domain mid channel data corresponding to a first mid channel window of the first frame and second transform-domain mid channel data corresponding to a second mid channel window of the first frame. The method includes performing an up-mix operation using the sets of transform-domain mid channel data, stereo parameters from the bit stream, and an interpolated parameter determined using an unevenly weighted interpolation between a first stereo parameter value associated with the first frame and a second stereo parameter value associated with the second frame.