Improving the quality of output audio signal,transferred as coded speech to subscriber's terminal over a network, by speech coder and decoder tandem pre-processing
View Patent ↗A method of pre-processing an audio signal transmitted to a user terminal via a communication network and an apparatus using the method are provided. The method of pre-processing the audio signal may prevent deterioration of a sound quality of the audio signal transmitted to the user terminal by pre-processing the audio signal, and by enabling a codec module, encoding the audio signal, to determine the audio signal as a speech signal. The method of pre-processing may include encoding the audio signal using a speech codec and decoding the encoded audio signal using the speech codec. A codec module, transmitting the decoded audio signal to the user terminal via the communication network, may determine whether a speech interval or a speechless interval with respect to at least one frame is included in the audio signal and transmit at least one parameter with respect to the at least one frame as a result of the determination.
1. A method of pre-processing an audio signal transmitted to a user terminal via a communication network, the method comprising:
encoding the audio signal using a speech codec; and
decoding the encoded audio signal using the speech codec,
wherein a codec module, transmitting the decoded audio signal to the user terminal via the communication network, comprises
determining whether a speech interval or a speechless interval with respect to at least one frame is included in the audio signal; and
transmitting at least one parameter with respect to the at least one frame as a result of the determination.
2. The method of claim 1 , wherein the codec module uses any one of an adaptive multi-rate voice activity detector (AMR VAD) option 1 and an AMR VAD option 2 .
3. The method of claim 2 , wherein the codec module includes a voice activity detection (VAD) module and a discontinuous transmission (DTX) module.
4. The method of claim 1 , wherein the encoding the audio signal using the speech codec comprises:
extracting at least one parameter with respect to the audio signal using the speech codec; and
encoding the audio signal by including the extracted parameter.
5. A computer-readable storage medium storing a program for implementing a method of pre-processing an audio signal transmitted to a user terminal via a communication network, the method comprising:
encoding the audio signal using a speech codec; and
decoding the encoded audio signal using the speech codec,
wherein a codec module, transmitting the decoded audio signal to the user terminal via the communication network, comprises
determining whether a speech interval or a speechless interval with respect to at least one frame is included in the audio signal; and
transmitting at least one parameter with respect to the at least one frame as a result of the determination.
6. An apparatus of pre-processing an audio signal transmitted to a user terminal via a communication network, the apparatus comprising:
a speech codec encoding the audio signal and decoding the encoded audio signal, wherein a codec module transmitting the decoded audio signal to the user terminal via the communication network comprises
a voice activity detection (VAD) module determining whether a speech interval or a speechless interval with respect to at least one frame is included in the audio signal; and
a discontinuous activity detection module transmitting at least one parameter with respect to the at least one frame as a result of the determination.
7. The apparatus of claim 6 , wherein the codec module uses any one of an AMR VAD option 1 and an AMR VAD option 2 .
8. The apparatus of claim 6 , wherein the speech codec extracts at least one parameter with respect to the audio signal using the speech codec, and encoding the audio signal by including the extracted parameter.