Huawei Technologies Co., Limited

Wenhai Wu

Yue Lang

Lei Miao

Zexin Liu

Chen Hu

Qing Feng Zhang

Dejun Zhang

David Virette

Liang Zhang

Lixiong Li

Tinghong Wang

Qi Zhang

Bo Liu

Wei Hu

Qing Zhang

Wei Xiao

Fuwei Ma

Xingtao Zhang

Chao Zhou

Chan Hu

Tian Wang

A point cloud decoding method related to the field of coding technologies and includes reconstructing a point cloud comprising one or more patches. The one or more patches comprise a current patch. The reconstructing process may include transforming coordinates (x2, y2) of a second point of the current patch in a second coordinate system to coordinates (x1, y1) of a first point of the current patch in a first coordinate system, where the coordinates (x1, y1) of the first point of the current patch in the first coordinate system may be obtained based on the coordinates (x2, y2) of the second point of the current patch in the second coordinate system and a transform matrix.

Point cloud encoding method and decoding method using rotation matrixes, encoder, and decoder

Present disclosure discloses a method and an apparatus for encoding a stereo phase parameter, which relate to the field of information technologies and can improve an effect of stereo audio phase information. The method includes: first, acquiring a global stereo phase parameter of a current frame; then, determining a value of the global stereo phase parameter of the current frame, and adjusting the value of the global stereo phase parameter of the current frame according to a determining result of the value of the global stereo phase parameter of the current frame; and finally, encoding an adjusted value of the global stereo phase parameter of the current frame. The embodiments of the present disclosure are applicable to recovering stereo phase information.

Method and apparatus for encoding stereo phase parameter

A method, an apparatus, and a system for encoding and decoding multi-channel signals are disclosed. The method for encoding multi-channel signals includes: determining the category of an index corresponding to a channel level difference (CLD) which needs to be quantized in a current frame; quantizing the CLD of at least one frequency band whose index category is the same as the determined category of the index in the current frame, and obtaining quantized data.

Method, apparatus, and system for encoding and decoding multi-channel signals

According to the invention, a device for post-processing at least one channel signal of a plurality of channel signals of a multi-channel signal is described, the at least one channel signal being generated from a decoded downmix signal by a low-bit-rate audio coding/decoding system, the device comprising: a receiver for receiving the at least one channel signal generated from the decoded downmix signal, a time envelope of the decoded downmix signal, an interchannel time difference between the channel signal and the downmix signal, and a classification indication indicating a transient type of the downmix signal; and a post-processor for post-processing the at least one channel signal based on the time envelope of the decoded downmix signal weighted by a respective weighting factor and in dependence on the classification indication and the interchannel time difference.

Device and method for postprocessing a decoded multi-channel audio signal or a decoded stereo signal

A stereo decoding method and apparatus are disclosed. The method includes: restoring a monophonic signal from a received code stream through decoding; restoring an interchannel level difference, a group delay, and a group phase from the received code stream through decoding; and processing the monophonic signal according to the interchannel level difference, group delay, and group phase to obtain a first channel signal and a second channel signal. According to the stereo decoding method and apparatus provided in embodiments of the present invention, the first and second channel signals are obtained according to the monophonic signal, ILD, group delay, and group phase by referring to not only the ILD but also the group delay and group phase, thereby yielding favorable stereo sound field effect for the obtained first and second channel signals.

Stereo decoding method and apparatus using group delay and group phase parameters

An embodiment of the present invention provides a method for generating a downmixed signal, including: performing a time-frequency transform on a received left sound channel signal and a received right sound channel signal to obtain a frequency domain signal, and dividing the frequency domain signal into several frequency bands; calculating a sound channel energy ratio and a sound channel phase difference of each frequency band; calculating a phase difference between the downmixed signal and a first sound channel signal in each frequency band according to the sound channel energy ratio and the sound channel phase difference; and calculating a frequency domain downmixed signal according to the left sound channel signal, the right sound channel signal, and the phase difference between the downmixed signal and the first sound channel signal in each frequency band. This method effectively improves quality of stereo encoding and decoding.

Method and apparatus for generating and restoring downmixed signal

Stereo decoding method and apparatus

A method and an apparatus for estimating an interchannel delay of a sound signal are, related to the communication field and capable of realizing a stable sound field in a crosstalk. The method includes calculating an error between an actual interchannel phase difference and a predicted interchannel phase difference of a sound signal. The predicted interchannel phase difference is predicted according to a predetermined interchannel delay of the sound signal. The method also includes determining whether the sound signal is a sound signal in a crosstalk according to the error. The method further includes, if the sound signal is a sound signal in the crosstalk, setting an interchannel delay corresponding to the sound signal to a fixed value. The apparatus is configured to perform the method.

Method and apparatus for estimating interchannel delay of sound signal

Embodiments of the present invention provide a stereo signal down-mixing method, encoding/decoding apparatus and system. The down-mixing method includes: converting a first channel time-domain signal and a second channel time-domain signal into a first channel frequency-domain signal and a second channel frequency-domain signal; obtaining a frequency-domain channel signal level difference and a frequency-domain channel signal phase difference between the two channel frequency-domain signals; for each frequency bin in each frequency band, using a function based on the frequency-domain channel signal level difference and frequency-domain channel signal phase difference to obtain a down-mixed signal phase that is located between phases of the two channel frequency-domain signals, and obtaining a down-mixed signal amplitude through calculation; and obtaining a frequency-domain down-mixed signal according to the phase and amplitude.

Stereo signal down-mixing method, encoding/decoding apparatus and encoding and decoding system

According to the invention, a device (') for postprocessing at least one channel signal of a plurality of channel signals of a multi-channel signal is described, the at least one channel signal being generated from a decoded downmix signal by a low-bit-rate audio coding/decoding system, the device comprising: a receiver (&#x2032;) for receiving the at least one channel signal generated from the decoded downmix signal, a time envelope of the decoded downmix signal and a classification indication indicating a transient type of the at least one channel signal, wherein the classification indication is associated to the at least one channel signal, and a postprocessor (&#x2032;) for postprocessing the at least one channel signal based on the time envelope of the decoded downmix signal weighted by a respective weighting factor and in dependence on the classification indication.

Embodiments of the present invention provide a method and an apparatus for generating a sideband residual signal. The method includes: comparing energy of a first signal input by a first sound channel with energy of a second signal input by a second sound channel; if the energy of the first signal is greater than the energy of the second signal, generating a sideband residual signal by allocating a monophonic quantization error to the first signal; and if the energy of the first signal is smaller than the energy of the second signal, generating a sideband residual signal by allocating a monophonic quantization error to the second signal. By using the method and apparatus provided in the embodiments of the present invention, it can be avoided that a monophonic quantization error has a greater impact on a signal whose energy is smaller.

Method and apparatus for generating sideband residual signal

A stereo coding method includes transforming a stereo left channel signal and a stereo right channel signal in a time domain to a frequency domain to form a left channel signal and a right channel signal in the frequency domain; down-mixing the left channel signal and the right channel signal in the frequency domain to generate a monophonic down-mix signal, and transmitting bits obtained after quantization coding is performed on the down-mix signal; extracting spatial parameters of the left channel signal and the right channel signal in the frequency domain; estimating a group delay and a group phase between stereo left and right channels by using the left channel signal and the right channel signal in the frequency domain; and performing quantization coding on the group delay, the group phase and the spatial parameters, so as to obtain a high-quality stereo coding performance at a low bit rate.

Stereo coding method and apparatus

A stereo encoding method, a stereo encoding device, and an encoder are provided. The stereo encoding method includes: obtaining a left channel energy relation coefficient and a right channel energy relation coefficient; obtaining a left energy sum and a right energy sum respectively; performing cross correlation between sub-bands of a first monophonic signal at a wave trough and sub-bands of the left channel signal according to the left channel energy relation coefficient, and performing cross correlation between sub-bands of the first monophonic signal at the wave trough and sub-bands of the right channel signal according to the right channel energy relation coefficient; obtaining a scaling factor by using the left energy sum, the right energy sum, and cross correlation results; and encoding the stereo left and right channel signals according to the scaling factor.

Stereo encoding method, stereo encoding device, and encoder

A multi-channel signal encoding method includes: determining a sum of channel level differences (CLDs) of a current frame of a multi-channel signal in a certain frequency band area; determining an average value of sums of channel level differences of at least two frames before the current frame in the certain frequency band area; according to the sum of channel level differences of the current frame of the multi-channel signal in the certain frequency band area, the average value of the sums of channel level differences of at least two frames before the current frame in the certain frequency band area, and a preset threshold, judging whether the channel level differences of the current frame are in a transient state or a non-transient state, and obtaining a judgment result; and according to the judgment result, performing quantization processing on the channel level differences of the current frame of the multi-channel signal.

Multi-channel signal encoding and decoding method, apparatus, and system

A coding method is adapted to select different codebook search algorithms according to varied types of input signals. An encoder using the coding method is also provided. As appropriate search algorithms may be selected according to all possible structural features of the input signals, certain types of signals for which satisfactory results may be obtained through simple computations may match with search algorithms suitable for these signal types and having low computation complexities, so as to achieve better performance with fewer system resources. Meanwhile, other types of signals that need complicated computations may be processed by more sophisticated search algorithms, thereby ensuring the coding quality.

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Beijing, China

Wenhai Wu