Abstract: A method for decoding an audio signal includes: obtaining a lower-band signal component of an audio signal corresponding to a received code stream when the audio signal switches from a first bandwidth to a second bandwidth which is narrower than the first bandwidth; extending the lower-band signal component to obtain higher-band information; performing a time-varying fadeout process on the higher-band information to obtain a processed higher-band signal component; and synthesizing the processed higher-band signal component and the obtained lower-band signal component. With the methods provided in the embodiments of the invention, when an audio signal has a switch from broadband to narrowband, a series of processes such as bandwidth detection, artificial band extension, time-varying fadeout process, and bandwidth synthesis, may be performed to make the switch to have a smooth transition from a broadband signal to a narrowband signal so that a comfortable listening experience may be achieved.

Abstract: An environmentally degradable composite having between 20 and 80 weight parts of a moderately cross-linked copolymer of aliphatic polyesteramide comprising random blocks, between 10 and 70 weight parts of a renewable raw material, between 5 and 20 weight parts of an additive, and between 0 and 30 weight parts of a filler. The composite has good mechanical properties, with a tensile strength of between 15 and 30 MPa, elongation at break of between 300 and 1000%, bending strength of between 10 and 25 MPa, and notched impact strength of between 20 and 90 kJ/m2. The composite has good environmental degradability and after 12 weeks' composting, the biodegradation rate thereof exceeds 90%. The composite has good formation performance, and can be processed using conventional plastics processing equipment by extruding, injection molding, blow molding, and hot pressing for preparation of a variety of products.

Abstract: An encoding method includes extracting background noise characteristic parameters within a hangover period, for a first superframe after the hangover period, performing background noise encoding based on the extracted background noise characteristic parameters, for superframes after the first superframe, performing background noise characteristic parameter extraction and DTX decision for each frame in the superframes after the first superframe, and for the superframes after the first superframe, performing background noise encoding based on extracted background noise characteristic parameters of the current superframe, background noise characteristic parameters of a plurality of superframes previous to the current superframe, and a final DTX decision. Also, a decoding method and apparatus and an encoding apparatus are disclosed. Bandwidth occupancy may be reduced substantially while the signal quality may be guaranteed.

Abstract: A method and apparatus for generating an excitation signal for background noise are provided. The method includes: generating a quasi excitation signal by utilizing coding parameters in a speech coding/decoding stage and a transition length of an excitation signal; and obtaining the excitation signal for background noise in a transition stage by generating a weighted sum of the quasi excitation signal and a random excitation signal of a background noise frame. Moreover, the apparatus includes: a quasi excitation signal generation unit and a transition stage excitation signal acquisition unit. Through the synthesizing scheme of comfortable background noise according to the present invention, the transition of a synthesized signal from speech to background noise could be more natural, smooth and continuous, which makes the listeners feel more comfortable.

Abstract: A method and an apparatus for generating comfortable noises so as to improve user experience are disclosed. The method includes: if a received data frame is a noise frame, calculating a corresponding energy attenuation parameter based on the noise frame and a data frame received earlier than the noise frame; and attenuating noise energy based on the energy attenuation parameter to obtain a comfortable noise signal. An apparatus for generating comfortable noise is also provided.

Abstract: Embodiments of the present invention disclose an audio decoding method, including: determining that bitstreams to be decoded are monophony coding layer and first stereo enhancement layer bitstreams; decoding the monophony coding layer to obtain a monophony decoded frequency-domain signal; reconstructing left and right channel frequency-domain signals in a first sub-band region by utilizing the monophony decoded frequency-domain signal after an energy adjustment; and reconstructing left and right channel frequency-domain signals in a second sub-band region by utilizing the monophony decoded frequency-domain signal without the energy adjustment.

Abstract: A method and an apparatus for adjusting a channel delay parameter of a multi-channel signal are provided in the embodiments of the present invention. The method includes: performing down-mixing processing on a multi-channel signal to obtain a processed signal (101); calculating energy distribution of the processed signal (102); and judging whether a comb filtering effect occurs in the processed signal according to the energy distribution of the processed signal, and adjusting a channel delay parameter of the multi-channel signal if the comb filtering effect occurs in the processed signal (103).

Abstract: An encoding method includes extracting background noise characteristic parameters within a hangover period; for a first superframe after the hangover period, performing background noise encoding based on the extracted background noise characteristic parameters; for superframes after the first superframe, performing background noise characteristic parameter extraction and DTX decision for each frame in the superframes after the first superframe; and for the superframes after the first superframe, performing background noise encoding based on extracted background noise characteristic parameters of the current superframe, background noise characteristic parameters of a plurality of superframes previous to the current superframe, and a final DTX decision. Also, a decoding method and apparatus and an encoding apparatus are disclosed.

Abstract: A method for speech signal processing is provided. Energy attenuation gain values are set for background noise signals corresponding to obtained background noise frames subsequent to an erasure concealment frame, so that differences between the energy attenuation gain values of the background noise signals corresponding to the background noise frames and the energy attenuation gain values of signals corresponding to their respective previous frames are within a threshold range. Energy attenuation of the background noise signals corresponding to the background noise frames is controlled by using the energy attenuation gain values. An apparatus for speech signal processing is also provided in embodiments of the present invention. By using the embodiments of the present invention, the energy transition between the area of erasure concealment signal and the area of background noise signal may be made natural and smooth, so as to improve the audio comfortable sensation of the listener.

Abstract: An environmentally degradable composite having between 20 and 80 weight parts of a moderately cross-linked copolymer of aliphatic polyesteramide comprising random blocks, between 10 and 70 weight parts of a renewable raw material, between 5 and 20 weight parts of an additive, and between 0 and 30 weight parts of a filler. The composite has good mechanical properties, with a tensile strength of between 15 and 30 MPa, elongation at break of between 300 and 1000%, bending strength of between 10 and 25 MPa, and notched impact strength of between 20 and 90 kJ/m2. The composite has good environmental degradability and after 12 weeks' composting, the biodegradation rate thereof exceeds 90%. The composite has good formation performance, and can be processed using conventional plastics processing equipment by extruding, injection molding, blow molding, and hot pressing for preparation of a variety of products.

Abstract: A method and apparatus for generating an excitation signal for background noise are provided. The method includes: generating a quasi excitation signal by utilizing coding parameters in a speech coding/decoding stage and a transition length of an excitation signal; and obtaining the excitation signal for background noise in a transition stage by generating a weighted sum of the quasi excitation signal and a random excitation signal of a background noise frame. Moreover, the apparatus includes: a quasi excitation signal generation unit and a transition stage excitation signal acquisition unit. Through the synthesizing scheme of comfortable background noise according to the present invention, the transition of a synthesized signal from speech to background noise could be more natural, smooth and continuous, which makes the listeners feel more comfortable.

Abstract: A method and an apparatus for generating comfortable noises so as to improve user experience are disclosed. The method includes: if a received data frame is a noise frame, calculating a corresponding energy attenuation parameter based on the noise frame and a data frame received earlier than the noise frame; and attenuating noise energy based on the energy attenuation parameter to obtain a comfortable noise signal. An apparatus for generating comfortable noise is also provided.

Abstract: A method for generating background noise and a noise processing apparatus are provided in order to improve user experience. The method includes: if an obtained signal frame is a noise frame, a high band noise encoding parameter is obtained from the noise frame; weighting and/or smoothing is performed on the high band noise encoding parameter to obtain a second high band noise encoding parameter; and a high band background noise signal is generated according to the second high band noise encoding parameter. A noise processing apparatus is also provided.

Abstract: An encoding method includes extracting background noise characteristic parameters within a hangover period; for a first superframe after the hangover period, performing background noise encoding based on the extracted background noise characteristic parameters; for superframes after the first superframe, performing background noise characteristic parameter extraction and DTX decision for each frame in the superframes after the first superframe; and for the superframes after the first superframe, performing background noise encoding based on extracted background noise characteristic parameters of the current superframe, background noise characteristic parameters of a plurality of superframes previous to the current superframe, and a final DTX decision. Also, a decoding method and apparatus and an encoding apparatus are disclosed.

Abstract: An encoding method includes extracting background noise characteristic parameters within a hangover period, for a first superframe after the hangover period, performing background noise encoding based on the extracted background noise characteristic parameters, for superframes after the first superframe, performing background noise characteristic parameter extraction and DTX decision for each frame in the superframes after the first superframe, and for the superframes after the first superframe, performing background noise encoding based on extracted background noise characteristic parameters of the current superframe, background noise characteristic parameters of a plurality of superframes previous to the current superframe, and a final DTX decision. Also, a decoding method and apparatus and an encoding apparatus are disclosed. Bandwidth occupancy may be reduced substantially while the signal quality may be guaranteed.

Abstract: A method for speech signal processing is provided. Energy attenuation gain values are set for background noise signals corresponding to obtained background noise frames subsequent to an erasure concealment frame, so that differences between the energy attenuation gain values of the background noise signals corresponding to the background noise frames and the energy attenuation gain values of signals corresponding to their respective previous frames are within a threshold range. Energy attenuation of the background noise signals corresponding to the background noise frames is controlled by using the energy attenuation gain values. An apparatus for speech signal processing is also provided in embodiments of the present invention. By using the embodiments of the present invention, the energy transition between the area of erasure concealment signal and the area of background noise signal may be made natural and smooth, so as to improve the audio comfortable sensation of the listener.

Abstract: A method for decoding an audio signal includes: obtaining a lower-band signal component of an audio signal corresponding to a received code stream when the audio signal switches from a first bandwidth to a second bandwidth which is narrower than the first bandwidth; extending the lower-band signal component to obtain higher-band information; performing a time-varying fadeout process on the higher-band information to obtain a processed higher-band signal component; and synthesizing the processed higher-band signal component and the obtained lower-band signal component. With the methods provided in the embodiments of the invention, when an audio signal has a switch from broadband to narrowband, a series of processes such as bandwidth detection, artificial band extension, time-varying fadeout process, and bandwidth synthesis, may be performed to make the switch to have a smooth transition from a broadband signal to a narrowband signal so that a comfortable listening experience may be achieved.

Abstract: An encoding method includes: extracting core layer characteristic parameters and enhancement layer characteristic parameters of a background noise signal, encoding the core layer characteristic parameters and enhancement layer characteristic parameters to obtain a core layer codestream and an enhancement layer codestream. The disclosure also provides an encoding device, a decoding device and method, an encapsulating method, a reconstructing method, an encoding-decoding system and an encoding-decoding method. By describing the background noise signal with the enhancement layer characteristic parameters, the background noise signal can be processed by using more accurate encoding and decoding method, so as to improve the quality of encoding and decoding the background noise signal.

Abstract: The invention relates to adjustable stop-wagon retarders with locking function for wagons at high speed and disposal methods thereof, which are suitable for railway marshaling yards or rail lines where it is required to prevent wagons from running away, which are hydraulic equipment of no external energy source to automatically regulate wagon's speed and disposal methods of such equipment. The stop-wagon retarder is characterized in that a uni-directional return unit comprising a sealing valve plate and adjustable throttle valve, and a locking control valve composing of switch valve and positioning unit are mounted in the piston assembly, which make the returning speed and the locking speed for wagon at high speed adjustable, thus the aim of setting the retarder with different control levels and thresholds according to the wagon speed is realized.