Abstract: A method for estimating inter-channel delay and an apparatus for estimating inter-channel delay and an encoder are provided by the embodiments of the present invention. The method includes: obtaining signal sound field information from a cross-correlation function and a cumulative cross-correlation function of synthetic signals of left and right sound channels respectively; obtaining adjustment information of the cumulative cross-correlation function according to the sound field information that is respectively obtained; adjusting the cumulative cross-correlation function by using the adjustment information, so as to obtain the adjusted cumulative cross-correlation function; and determining a time corresponding to a maximum value in the adjusted cumulative cross-correlation function as an inter-channel delay. Therefore, the delay between the signals of the left and right sound channels can be estimated correctly, so as to improve the stability of the synthetic stereo sound field.

Abstract: A method, device and system for signal encoding and decoding are disclosed. The method includes: encoding a core layer signal to obtain a core layer signal code; selecting an enhancement sample point that requires enhancement layer signal encoding according to the core layer signal code and the number of bits that can be used by an enhancement layer; obtaining an enhancement layer signal code of the enhancement sample point; and outputting a bit stream, where the bit stream includes the core layer signal code and the enhancement layer signal code. In embodiments of the present invention, according to the number of bits that can be used by the enhancement layer, the enhancement sample point that requires enhancement layer signal encoding is selected; the enhancement layer signal of the selected enhancement sample point is encoded and decoded; when no sufficient bits are available for the enhancement layer, the enhancement quality of the core layer can be improved.

Abstract: Embodiments of the present invention provide an audio signal coding and decoding method and device. The coding method includes: dividing a frequency band of an audio signal into a plurality of sub-bands, and quantifying a sub-band normalization factor of each sub-band; determining signal bandwidth of bit allocation according to the quantified sub-band normalization factor, or according to the quantified sub-band normalization factor and bit rate information; allocating bits for a sub-band within the determined signal bandwidth; and coding a spectrum coefficient of the audio signal according to the bits allocated for each sub-band. According to embodiments of the present invention, during coding and decoding, signal bandwidth of bit allocation is determined according to the quantified sub-band normalization factor and bit rate information. In this manner, the determined signal bandwidth is effectively coded and decoded by centralizing the bits, and audio quality is improved.

Abstract: 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.

Abstract: A method, a device, and a system for transcoding between two embedded codecs are disclosed. The method includes: delaying a first encoded stream in input streams for integer number of frames, where the first encoded stream includes a stream of at least one extension layer in the input streams obtained after input signals are encoded by using a first codec; and using the first codec to decode other encoded streams in the input streams to obtain the first decoded signal; and performing delay aligning and adjusting to obtain an adjusted signal so as to reduce the transcoding complexity and enhance quality of the transcoded signals.

Abstract: A method and an apparatus for switching speech or audio signals, wherein the method for switching speech or audio signals includes when switching of a speech or audio, weighting a first high frequency band signal of a current frame of speech or audio signal and a second high frequency band signal of the previous M frame of speech or audio signals to obtain a processed first high frequency band signal, where M is greater than or equal to 1, and synthesizing the processed first high frequency band signal and a first low frequency band signal of the current frame of speech or audio signal into a wide frequency band signal. In this way, speech or audio signals with different bandwidths can be smoothly switched, thus improving the quality of audio signals received by a user.

Abstract: A method, a device, and a system for transcoding between two embedded codecs are disclosed. The method includes: delaying a first encoded stream in input streams for integer number of frames, where the first encoded stream includes a stream of at least one extension layer in the input streams obtained after input signals are encoded by using a first codec; and using the first codec to decode other encoded streams in the input streams to obtain the first decoded signal; and performing delay aligning and adjusting to obtain an adjusted signal so as to reduce the transcoding complexity and enhance quality of the transcoded signals.

Abstract: A method, device and system for signal encoding and decoding, the method comprising: encoding a core layer signal to obtain a core layer signal code; selecting an enhancement sample point that requires enhancement layer signal encoding according to the core layer signal code and the number of bits that can be used by an enhancement layer; obtaining an enhancement layer signal code of the enhancement sample point; and outputting a bit stream, where the bit stream includes the core layer signal code and the enhancement layer signal code. In embodiments of the present invention, according to the number of bits that can be used by the enhancement layer, the enhancement sample point that requires enhancement layer signal encoding is selected; the enhancement layer signal of the selected enhancement sample point is encoded and decoded; when no sufficient bits are available for the enhancement layer, the enhancement quality of the core layer can be improved.

Abstract: Methods and apparatuses for encoding a signal and decoding a signal and a system for encoding and decoding are provided. The method for encoding a signal includes performing a classification decision process on high frequency signals of input signals, adaptively encoding the high frequency signals according to the result of the classification decision process, and outputting a bitstream including codes of low frequency signals of the input signals, adaptive codes of the high frequency signals, and the result of the classification decision process. The classification decision process is performed on the high frequency signals, and adaptive encoding or adaptive decoding is performed according to the result of the classification decision process, so the quality of voice and audio output signals is improved.

Abstract: A device relating to information processing technologies and including an encoding and decoding method configured to solve the poor decoding quality problem. The method includes: encoding each sample of an input signal to generate an encoded signal of a core layer; comparing residuals of all or a part of the samples of the input signal with encoding thresholds, where the residuals are generated by core layer encoding, and performing encoding according to comparison results to generate an encoded signal of an enhancement layer; and writing the encoded signal of the core layer and the encoded signal of the enhancement layer into a bitstream to generate an encoded signal of the input signal.

Abstract: A signal delay detection method, a detection apparatus, and a coder are disclosed to improve accuracy of detecting the signal delay. The method includes: obtaining a first cumulative cross-correlation function according to cross-correlation functions between channel signals; determining a first delay between the channel signals corresponding to the first cumulative cross-correlation function; adjusting a second cumulative cross-correlation function according to a relationship between the first delay and a second delay that exist between the channel signals, where the second delay is obtained at time of adjusting the second cumulative cross-correlation function and an initial value of the second delay is determined according to an initial value of a second weighting coefficient of the second cumulative cross-correlation function; and determining the second delay corresponding to the adjusted second cumulative cross-correlation function as a delay detected between the channel signals.

Abstract: In the field of audio encoding/decoding technologies, a signal de-noising method is provided. The method includes: selecting, according to a degree of inter-frame correlation of a frame where a spectral coefficient to be adjusted resides, at least two spectral coefficients having high correlation with the spectral coefficient to be adjusted; performing weighting on the at least two selected spectral coefficients and the spectral coefficient to be adjusted to acquire a predicted value of the spectral coefficient to be adjusted; and adjusting a spectrum of a decoded signal by using the acquired predicted value, and outputting the adjusted decoded signal. A signal de-noising apparatus corresponding to the signal de-noising method and an audio decoding system using the signal de-noising apparatus are also provided.

Abstract: A signal classification processing method, a classification processing device, and an encoding system are provided. The signal classification processing method includes: obtaining a high band input signal; determining a signal type of the obtained high band input signal according to a time domain characteristic parameter and/or a frequency domain characteristic parameter of the high band input signal; and determining an encoding mode corresponding to the signal type. The classification processing device includes: a receiving unit, configured to obtain a high band input signal; and a processing unit, configured to determine a signal type of the obtained high band input signal according to a time domain characteristic parameter and/or a frequency domain characteristic parameter of the high band input signal and determine an encoding mode corresponding to the signal type. An encoding system is also provided.

Abstract: A method for switching signal delay disclosed in the embodiments of the present invention includes: detecting a signal delay being currently transmitted; judging whether an adjacent delay transmitted successfully is equal to the signal delay being transmitted currently if it is detected that the signal delay being transmitted is switchable; and switching the signal delay being currently transmitted if it is determined that the adjacent delay transmitted successfully is not equal to the signal delay being transmitted currently. An apparatus for switching signal delay is also disclosed. The embodiments of the present invention are applicable to a scenario of switching delay of left-channel signals and right-channel signals.

Abstract: A method for estimating inter-channel delay and an apparatus for estimating inter-channel delay and an encoder are provided by the embodiments of the present invention. The method includes: obtaining signal sound field information from a cross-correlation function and a cumulative cross-correlation function of synthetic signals of left and right sound channels respectively; obtaining adjustment information of the cumulative cross-correlation function according to the sound field information that is respectively obtained; adjusting the cumulative cross-correlation function by using the adjustment information, so as to obtain the adjusted cumulative cross-correlation function; and determining a time corresponding to a maximum value in the adjusted cumulative cross-correlation function as an inter-channel delay. Therefore, the delay between the signals of the left and right sound channels can be estimated correctly, so as to improve the stability of the synthetic stereo sound field.

Abstract: A method and an apparatus for processing a signal are provided. The method includes: obtaining an energy average value of each sub-band for a current frame frequency-domain signal; obtaining a current frame modification coefficient of each sub-band for the current frame frequency-domain signal according to a spectral envelope and the energy average value of each sub-band; obtaining a weighted modification coefficient of each sub-band for the current frame frequency-domain signal by using the current frame modification coefficient and a relevant frame modification coefficient; and modifying the spectral envelope of each sub-band for the current frame frequency-domain signal by using the weighted modification coefficient.

Abstract: 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.

Abstract: A stereo encoding method and apparatus are provided, so as to reduce distortion caused by delay adjustment. The stereo encoding method includes: extracting a current interchannel delay of a stereo signal and a previous delay adjacent to the current interchannel delay; performing adjustment frame judgment according to characteristics of the current stereo signal when the current delay and the previous delay are different; and performing delay adjustment on the stereo signal by using the current interchannel delay if it is judged that a frame where the current delay occurs is an adjustment frame.

Abstract: A method, device and system for signal encoding and decoding, the method comprising: encoding a core layer signal to obtain a core layer signal code; selecting an enhancement sample point that requires enhancement layer signal encoding according to the core layer signal code and the number of bits that can be used by an enhancement layer; obtaining an enhancement layer signal code of the enhancement sample point; and outputting a bit stream, where the bit stream includes the core layer signal code and the enhancement layer signal code. In embodiments of the present invention, according to the number of bits that can be used by the enhancement layer, the enhancement sample point that requires enhancement layer signal encoding is selected; the enhancement layer signal of the selected enhancement sample point is encoded and decoded; when no sufficient bits are available for the enhancement layer, the enhancement quality of the core layer can be improved.

Abstract: A transient signal encoding method and device, decoding method and device, and processing system, where the transient signal encoding method includes: obtaining a reference sub-frame where a maximal time envelope having a maximal amplitude value is located from time envelopes of all sub-frames of an input transient signal; adjusting an amplitude value of the time envelope of each sub-frame before the reference sub-frame in such a way that a first difference is greater than a preset first threshold, in which the first difference is a difference between the amplitude value of the time envelope of each sub-frame before the reference sub-frame and the amplitude value of the maximal time envelope; and writing the adjusted time envelope into bitstream.