Abstract: An audio time stretch method and associated apparatus is provided. The method includes steps of calculating an energy level according to amplitudes of a plurality of received data, and determining whether the audio data requires audio time stretch according to the energy level. Audio data with lower energy level and volume are selectively time-stretched to alleviate audio quality degradation.

Abstract: The present invention provides a signal filtering apparatus, which comprises a control circuit and a filter for receiving a transmitted input signal and generating an output signal. The filter comprises multiple filter taps for processing the transmitted input signal corresponding to different timings with different filter coefficients, respectively, to generate the output signal. The control circuit is configured to shrink at least part of the low-frequency-response filter taps having filter coefficients less than a predetermined value.

Abstract: A method for determining a data format of linear pulse-code modulation is provided. The method includes steps of reading a plurality of bytes of the linear pulse-code modulation data; obtaining a data property by performing a predetermined calculation on the plurality of bytes; and determining the data format of the linear pulse-code modulation data according to the data property.

Abstract: An inverse quantization processing method and associated device is provided comprising a determining unit, a bit reduction unit, a frequency/time-domain conversion unit, and a bit addition unit which collectively perform an inverse quantization processing method by receiving a plurality of quantized frequency-domain data, performing a bit reduction on a current quantized frequency domain data according to an adjusting factor, generating a bit-reduced quantized frequency-domain data when an accumulated count value of a plurality of valid bit numbers of the plurality of quantized frequency-domain data greater than a first threshold reaches a second threshold, performing a frequency/time domain conversion on the bit-reduced quantized frequency-domain data to obtain a bit-reduced time-domain PCM data, and performing a bit addition on the bit-reduced time-domain PCM data according to the adjusting factor, so as to obtain a time-domain PCM data.

Abstract: A multi-channel audio signal decoding method and device is provided. The multi-channel audio signal decoding method includes receiving a first multi-channel audio signal; performing a first decoding procedure on the first multi-channel audio signal to generate a second multi-channel audio signal; performing a second decoding procedure on a first single-channel audio data of the second multi-channel audio signal to generate a first single-channel audio signal when the first single-channel audio data belongs to a first classification; and performing a third decoding procedure on a second single-channel audio data of the second multi-channel audio signal to generate a second single-channel audio signal when the second single-channel audio data belongs to a second classification. The number of instructions of the third decoding procedure is less than that of the second decoding procedure.

Abstract: An adaptive differential pulse-code modulation-demodulation system and method thereof is provided. The method includes steps of modulating an analog audio input signal into a data packet, including a plurality of digital data through adaptive differential pulse-code modulation, an initial value and a scale factor associated with the digital data, to be sent to the communication network, and demodulating the data packet according to the digital data, the initial value and the scale factor, thereby reconstructing the data packet to an analog audio output signal.

Abstract: An audio time stretch method and associated apparatus is provided. The method includes steps of calculating an energy level according to amplitudes of a plurality of received data, and determining whether the audio data requires audio time stretch according to the energy level. Audio data with lower energy level and volume are selectively time-stretched to alleviate audio quality degradation.

Abstract: A method for auto-detecting a frame header is provided. By searching and comparing content of input frames and predetermined sync words, decoding efficiency is increased and the probability of incurring program errors is reduced. Once decoding errors occur, an auto-recovery mechanism soon recovers the audio decoding system operation.

Abstract: A multi-channel audio signal decoding method and device is provided. The multi-channel audio signal decoding method includes receiving a first multi-channel audio signal; performing a first decoding procedure on the first multi-channel audio signal to generate a second multi-channel audio signal; performing a second decoding procedure on a first single-channel audio data of the second multi-channel audio signal to generate a first single-channel audio signal when the first single-channel audio data belongs to a first classification; and performing a third decoding procedure on a second single-channel audio data of the second multi-channel audio signal to generate a second single-channel audio signal when the second single-channel audio data belongs to a second classification. The number of instructions of the third decoding procedure is less than that of the second decoding procedure.

Abstract: An inverse quantization processing method and device thereof is provided. The inverse quantization processing device includes a determining unit, a bit reduction unit, a frequency/time-domain conversion unit and a bit addition unit. The inverse quantization processing method includes receiving a plurality of quantized frequency-domain data; performing a bit reduction on a current quantized frequency domain data according to an adjusting factor, such that a bit-reduced quantized frequency-domain data is generated when an accumulated count value of a plurality of valid bit numbers of the plurality of quantized frequency-domain data greater than a first threshold reaches a second threshold; performing a frequency/time domain conversion on the bit-reduced quantized frequency-domain data to obtain a bit-reduced time-domain PCM data; and performing a bit addition on the bit-reduced time-domain PCM data according to the adjusting factor, so as to obtain a time-domain PCM data.

Abstract: An adaptive differential pulse-code modulation-demodulation system and method thereof is provided. The method includes steps of modulating an analog audio input signal into a data packet, including a plurality of digital data through adaptive differential pulse-code modulation, an initial value and a scale factor associated with the digital data, to be sent to the communication network, and demodulating the data packet according to the digital data, the initial value and the scale factor, thereby reconstructing the data packet to an analog audio output signal.

Abstract: A packet transceiver system includes a detection module (210), a dropped rate determination module (110), a transmitting module (120), and a recalculation module (230). The detection module detects a network congestion status. The dropped rate determination module determines a packet dropped rate based on the network congestion status. The transmitting module transmits voice packets, dropping voice packets according to the packet dropped rate, ensuring an even distribution of dropped voice packets during the transmission. The recalculation module receives the un-dropped voice packets, and recalculates the dropped voice packets. A packet transceiver method is also provided.

Abstract: A media gateway testing device (10) is used for testing a media gateway. The media gateway testing device includes at least one calling module, an instruction module (161), a receiving module (162), a determining module (164), and a message producing module (165). The at least one calling module simulates at least one Voice over Internet Protocol phone. The instruction module sends a communication instruction to the at least one calling module. The at least one calling module executes the communication instruction to make the media gateway generate a communication request. The receiving module receives the communication request from the media gateway. The determining module determines whether the communication request received by the receiving module complies with a predefined protocol. The message producing module produces a message according to the determined result of the determining module.

Abstract: A packet transceiver system includes a detection module (210), a dropped rate determination module (110), a transmitting module (120), and a recalculation module (230). The detection module detects a network congestion status. The dropped rate determination module determines a packet dropped rate based on the network congestion status. The transmitting module transmits voice packets, dropping voice packets according to the packet dropped rate, ensuring an even distribution of dropped voice packets during the transmission. The recalculation module receives the un-dropped voice packets, and recalculates the dropped voice packets. A packet transceiver method is also provided.

Abstract: An access node connected to a local exchange is provided, the access node including a V5 interface, a first timer and a first detection module. The V5 interface starts a V5 connection between the access node and the local exchange. The first timer times according to a first timing period if the V5 connection is started, and comprises a first timing-detection sub-module. The first detection module detects whether the access node receives variant and interface ID information within the first timing period. The first timing-detection sub-module detects whether the first timer times out if the access node does not receive the variant and interface ID information. A method for starting V5 connection is also disclosed.

Abstract: A network device is provided, the network device connected to a local exchange, and comprising a main interface system, a backup interface system, and a management system. The main interface system comprises a main transceiving module that receives an instruction from the local exchange, and transmits time information in the main interface system to the backup interface system. The backup interface system comprises a backup transceiving module, a backup counting module, and a backup starting module. The backup transceiving module determines whether a replacement message is received from the management system, and transmits an acknowledgement message to the local exchange if the replacement message is received. The backup counting module counts time from receiving the instruction from the local exchange to transmitting the acknowledgement message thereto. The backup starting module starts the backup counting module according to counted time. A time synchronization method is also provided.

Abstract: A communication device (30) for avoiding deadlock of a terminal device, includes a transceiver module (300), a timer module (310), and a network module (320). The transceiver module receives a communication termination signal from a local exchange (LE) and generates a timing signal. The timer module receives the timing signal to start timing. The network module includes a time processing sub-module (321), a signal determining sub-module (322), and a signal sending sub-module (323). The time processing sub-module sends a query signal to the terminal device for querying a state of the terminal device after the timer module has timed out. The signal determining sub-module receives a state signal and determining whether the state signal includes a communication completion state, and if the state signal includes a communication completion state, sending it. The signal sending sub-module receives the communication completion signal, and sends to the LE via the transceiver module.

Abstract: A network device connected between a client and a local exchange is provided, and includes a status information system, an interface system, and a management system. The status information system includes a main and a backup status information module for recording status information of the client. The interface system includes a main and a backup interface module for recording status information of the client, and for detecting whether the status information is the same as that recorded by the status information system. The management system detects whether the main status information module and/or the main interface module fail, and if failure occurs, replaces the failed main status information module and/or the failed main interface module with the backup status information module and the backup interface module respectively, auditing the status information recorded by the status information system, and transmits a replacement message to the interface system.

Abstract: A system for translating messages includes a local exchange (20), a terminal (30), and an access node (10) connecting the local exchange and the terminal. The access node includes a translation system (100) connectable to the local exchange, and a terminal management module (120) connectable to the terminal and the translation system. The translation system translates between V5 messages and text messages. The terminal management module translates between the text messages and signals from the terminal.

Abstract: A network device (10) for establishing communications between a first terminal device (30) and a second terminal device (50) connected to a local exchange (LE) (20) sending a communication request signal from the second terminal device to the first terminal device, includes a signal processing module (100), a timing module (110), an interface module (130), and a timeout processing module (120). The signal processing module receives a communication response signal from the first terminal device, and sends the communication response signal to the interface module. The timing module includes a first timer and a second timer. The interface module receives the communication response signal, sends the communication response signal to the LE, starts the first timer, receives a communication ready signal from the LE, and starts the second timer. The timeout processing module sends an acknowledgement (ACK) signal to the LE after the second timer has timed out.