Abstract: A snowmobile includes an engine including an engine head including a cylinder head, a supercharger, an intake manifold, throttle bodies, first joints that connect the intake manifold to the throttle bodies, second joints that connect the throttle bodies to the cylinder head, and a restrictor that connects the engine head to the first joints. The restrictor includes an engaging member that fits into grooves of the first joints, and connectors that connect the engaging member and the engine head to each other. A steering shaft is inserted between two mutually adjacent first joints which have a distance from each other greater than a distance between the other two mutually adjacent first joints.

Abstract: A snowmobile includes an engine including an engine head including a cylinder head, a supercharger, an intake manifold, throttle bodies, first joints that connect the intake manifold to the throttle bodies, second joints that connect the throttle bodies to the cylinder head, and a restrictor that connects the engine head to the first joints. The restrictor includes an engaging member that fits into grooves of the first joints, and connectors that connect the engaging member and the engine head to each other. A steering shaft is inserted between two mutually adjacent first joints which have a distance from each other greater than a distance between the other two mutually adjacent first joints.

Abstract: Disclosed is a code conversion method to convert a first code sequence conforming to a first speech coding scheme into a second code sequence conforming to a second speech coding scheme. The method includes the following steps. The first step discriminates whether the first code sequence corresponds to a speech part or to a non-speech part, and generates a numerical value that indicates the discrimination result as a control flag. The second step converts the first code sequence into the second code sequence and outputs said second code sequence, when the value of the control flag corresponds to the speech part. The third step outputs the second code sequence that corresponds to the value of the control flag, when the value of the control flag corresponds to the non-speech part.

Abstract: When performing audio communication by using different encoding/decoding methods, a code obtained by encoding audio by a certain method is converted into a code decodable by another method with a high audio quality and a small calculation amount. In a code conversion device for converting a first code string into a second code string, an audio decoding circuit acquires a first linear prediction coefficient and excitation signal information from the first code string and drives the filter having the first linear prediction coefficient by the excitation signal obtained from the excitation signal information, thereby creating a first audio signal. A fixed codebook code generation circuit uses the fixed codebook information and minimizes the distance between the second audio signal generated from the information obtained from the second code string and the first audio signal, thereby obtaining the fixed codebook information in the second code string.

Abstract: A gateway apparatus for conducting connection between different types of communication networks, that are a line-switched network and a packet-switched network, there are provided a method and an apparatus in which sound breaks otherwise caused by delay or loss of speech encoded data is eliminated and deterioration of the speech quality is minimized to assure short delay in speech communication. A speech data processing circuit of the gateway apparatus compares the number of speech encoded data actually acquired with an expected value. The speech data processing circuit packetizes the so generated speech encoded data, along with the speech encoded data, to send the packetized data from a transmission circuit to the packet-switched network. The resulting data is sent from a data multiplexing circuit and a line-switched network terminating circuit to the line-switched network.

Abstract: An audio decoding device (1) generates a first decoded audio from a first code string by a first decoding method, AN audio encoding device (2) judges whether the first decoded audio is an audio signal or a non-audio signal by using the information contained in the first code string and generates a second code string by encoding the first decoded audio by the second encoding method according to the judgment. Thus, there are provided a device and a method for converting a code obtained y encoding audio by a certain method into a code decodable by the other method with a low calculation amount.

Abstract: Provided is a code conversion device that is capable of converting codes even if an input code sequence is invalid, and is able to reduce the amount of processing. When a first code sequence is input, the code conversion device generates a decoded signal by decoding the codes of normal frames of the first code sequence at Step S1, stores and holds the decoded signal at Step S2, generates a signal corresponding to an invalid frame by interpolation with the decoded signal that is stored and held, at Step S3. Subsequently, the code conversion device generates codes corresponding to the invalid frame by encoding the generated signal at Step S4, and makes the normal frames of the first code sequence without conversion be the frames of the second code sequence while making the generated codes be the frame of the second code sequence, in place of the codes of the invalid frame, at Step S5.

Abstract: A first filter (2061 in FIG. 1) calculates a long-time average of first change quantities based on a difference between a line spectral frequency of an input voice signal and a long-time average thereof. A second filter (2062 in FIG. 1) calculates a long-time average of second change quantities based on a difference between a whole band energy of the input voice signal and a long-time average thereof. A third filter (2063 in FIG. 1) calculates a long-time average of third change quantities based on a difference between a low band energy of the input voice signal and a long-time average thereof. A fourth filter (2064 in FIG. 1) calculates a long-time average of fourth change quantities based on a difference between a zero cross number of the input voice signal and a long-time average thereof. A voice/non-voice determining circuit (1040 in FIG.

Abstract: In a speech signal decoding method, information containing at least a sound source signal, gain, and filter coefficients is decoded from a received bit stream. Voiced speech and unvoiced speech of a speech signal are identified using the decoded information. Smoothing processing based on the decoded information is performed for at least either one of the decoded gain and decoded filter coefficients in the unvoiced speech. The speech signal is decoded by driving a filter having the decoded filter coefficients by an excitation signal obtained by multiplying the decoded sound source signal by the decoded gain using the result of the smoothing processing. A speech signal decoding apparatus is also disclosed.

Abstract: The object of this invention is converting a code that has been obtained by encoding speech by one particular system is converted to code that can be decoded by another system with high speech quality, and moreover, with a low computational load in transmitting speech signal between different systems. This invention comprising an adaptive codebook (ACB) delay search range control circuit (1250 in FIG. 7) for calculating a search range control value from first adaptive codebook delay that is stored and held and said second adaptive codebook delay that is stored and held, and an adaptive codebook encoding circuit (1220 in FIG.

Abstract: A code conversion method for converting first code string data conforming to a first speech coding scheme into second code string data conforming to a second speech coding scheme has the steps of decoding the first code string data to generate a first decoded speech, correcting the signal characteristics of the first decoded speech to generate a second decoded speech, and encoding the second decoded speech in accordance with the second speech coding scheme to generate the second code string data.

Abstract: Provided is a code conversion device that is capable of converting codes even if an input code sequence is invalid, and is able to reduce the amount of processing. When a first code sequence is input, the code conversion device generates a decoded signal by decoding the codes of normal frames of the first code sequence at Step S1, stores and holds the decoded signal at Step S2, generates a signal corresponding to an invalid frame by interpolation with the decoded signal that is stored and held, at Step S3. Subsequently, the code conversion device generates codes corresponding to the invalid frame by encoding the generated signal at Step S4, and makes the normal frames of the first code sequence without conversion be the frames of the second code sequence while making the generated codes be the frame of the second code sequence, in place of the codes of the invalid frame, at Step S5.

Abstract: In a speech signal decoding method, information containing at least a sound source signal, gain, and filter coefficients is decoded from a received bit stream. Voiced speech and unvoiced speech of a speech signal are identified using the decoded information. Smoothing processing based on the decoded information is performed for at least either one of the decoded gain and decoded filter coefficients in the unvoiced speech. The speech signal is decoded by driving a filter having the decoded filter coefficients by an excitation signal obtained by multiplying the decoded sound source signal by the decoded gain using the result of the smoothing processing. A speech signal decoding apparatus is also disclosed.

Abstract: In a speech signal decoding method, information containing at least a sound source signal, gain, and filter coefficients is decoded from a received bit stream. Voiced speech and unvoiced speech of a speech signal are identified using the decoded information. Smoothing processing based on the decoded information is performed for at least either one of the decoded gain and decoded filter coefficients in the unvoiced speech. The speech signal is decoded by driving a filter having the decoded filter coefficients by an excitation signal obtained by multiplying the decoded sound source signal by the decoded gain using the result of the smoothing processing. A speech signal decoding apparatus is also disclosed.

Abstract: A code converting apparatus for converting a first code sequence conforming to a first system to a second code sequence conforming to a second system, in which a speech decoding circuit acquires a first linear prediction coefficient and the information on an excitation signal from the first code sequence, and actuates a filter having the aforementioned first linear prediction coefficient with the excitation signal obtained from the information on the excitation signal, to generate a first speech signal. A gain code generating circuit calculates a gain minimizing the distance between a second speech signal, obtained from the second code sequence, and the first speech signal (optimum gain), and corrects the optimum gain. The gain code generating circuit then finds the gain information in the second code sequence, using an evaluation function which will reduce time variations of the gain of the second system.

Abstract: A second evaluation value calculation circuit calculates an evaluation value from a first linear prediction coefficient, a second linear prediction coefficient stored and held, a third linear prediction coefficient read from a table in which a plurality of linear prediction coefficients are stored in advance, and a fourth linear prediction coefficient selected, stored and held among the third linear prediction coefficients read from the table in the past, while a second evaluation value minimizing circuit selects the third linear prediction coefficient with which the evaluation value is the minimum and outputs a code corresponding to the selected third linear prediction coefficient as a code decodable by a second coding and decoding system.

Abstract: In a gateway apparatus for conducting connection between different types of communication networks, that are a line-switched network and a packet-switched network, there are provided a method and an apparatus in which sound breaks otherwise caused by delay or loss of speech encoded data is eliminated and deterioration of the speech quality is minimized to assure short delay in speech communication. A speech data processing circuit 550 of the gateway apparatus compares the number of speech encoded data actually acquired with an expected value, that is, the number of speech encoded data, which is the number of the encoded data expected to be output every unit period from a multiplexed data demultiplexing circuit 200. If the number of speech encoded data actually acquired is less than the expected value, the speech data processing circuit generates speech encoded data for a destination terminal of transmission to execute error concealment processing.

Abstract: A code converting apparatus for converting a first code sequence conforming to a first system to a second code sequence conforming to a second system, in which a speech decoding circuit acquires a first linear prediction coefficient and the information on an excitation signal from the first code sequence, and actuates a filter having the aforementioned first linear prediction coefficient with the excitation signal obtained from the information on the excitation signal, to generate a first speech signal. A gain code generating circuit calculates a gain minimizing the distance between a second speech signal, generated from the information, obtained from the second code sequence, and the first speech signal (optimum gain), and corrects the optimum gain and the gain code generating circuit then finds the gain information in the second code sequence, based on the optimum gain as corrected (optimum gain corrected), the above optimum gain and a gain read out from a gain codebook of the second system.

Abstract: A first filter (2061 in FIG. 1) calculates a long-time average of first change quantities based on a difference between a line spectral frequency of an input voice signal and a long-time average thereof. A second filter (2062 in FIG. 1) calculates a long-time average of second change quantities based on a difference between a whole band energy of the input voice signal and a long-time average thereof. A third filter (2063 in FIG. 1) calculates a long-time average of third change quantities based on a difference between a low band energy of the input voice signal and a long-time average thereof. A fourth filter (2064 in FIG. 1) calculates a long-time average of fourth change quantities based on a difference between a zero cross number of the input voice signal and a long-time average thereof. A voice/non-voice determining circuit (1040 in FIG.

Abstract: An audio decoding device (1) generates a first decoded audio from a first code string by a first decoding method, AN audio encoding device (2) judges whether the first decoded audio is an audio signal or a non-audio signal by using the information contained in the first code string and generates a second code string by encoding the first decoded audio by the second encoding method according to the judgment. Thus, there are provided a device and a method for converting a code obtained y encoding audio by a certain method into a code decodable by the other method with a low calculation amount.