TWI865895B - Audio compression system and audio compression method for wireless communication - Google Patents

Abstract

The present invention provides an audio compressing system and an audio compression method for wireless communication. The audio compression device comprises a first transceiver and a first processor. The first transceiver is connected to the first processor. The processor obtains an audio signal and an available bandwidth, and the processor performs an audio compression encoding on the audio signal to obtain a sample audio signal, and then compares with the audio signal and the sample audio signal to generate a residual signal, and the residual signal is transmitted according to the available bandwidth. The audio signal can be completely transmitted to an audio decompression device to reduce the distortion of the audio signal.

Description

Audio compression system and audio compression method for wireless communication

The present invention provides a signal compression device, a signal compression system and a signal compression method, in particular, an audio signal compression device, an audio signal compression system and an audio signal compression method.

With the popularization and advancement of mobile devices and Internet technology, the frequency of people listening to audio signals (such as online media, music, radio, etc.) through mobile devices via the Internet has increased significantly. In order to provide listeners with better auditory enjoyment, creators have refined the details of audio signals more carefully, thus greatly increasing the signal bandwidth of audio signals.

Currently on the market, the audio compression system includes a mobile device and a wireless Bluetooth headset. The mobile device is connected to the wireless Bluetooth headset via a Bluetooth signal protocol. The mobile device compresses and encodes an audio signal according to the Bluetooth signal protocol, and then transmits the compressed and encoded audio signal to the wireless Bluetooth headset. When the wireless Bluetooth headset receives the compressed and encoded audio signal, it decodes the compressed and encoded audio signal to generate the audio signal.

However, in the audio compression system of the prior art, when the mobile device transmits the audio signal, it is limited by the bandwidth specified by the communication protocol. Therefore, the mobile device compresses and encodes the audio signal by removing redundant information, so that part of the data of the audio signal is discarded. When the wireless Bluetooth headset receives the compressed and encoded audio signal and decodes it, the audio signal decoded by the wireless Bluetooth headset and the audio signal of the mobile device will be different because part of the data is discarded, causing the audio signal to be distorted, so that people cannot fully obtain the audio signal.

Therefore, the existing technology does need to provide better improvement solutions.

In view of the above-mentioned deficiencies of the prior art, the main purpose of the present invention is to provide an audio compression device, an audio compression system and an audio compression method for wireless communication, which transmits a residual signal through the available bandwidth so that the audio signal can be completely transmitted to an audio decompression device to achieve the purpose of reducing the distortion of an audio signal.

The main technical means adopted to achieve the above-mentioned purpose is to make the above-mentioned audio compression system for wireless communication include: an audio compression device for wireless communication, which includes: a first signal transceiver; a first processor connected to the first signal transceiver and obtaining an audio signal and an available bandwidth; a coding module connected to the first signal transceiver; wherein the first processor is connected to the first signal transceiver and obtains an audio signal and an available bandwidth; A processor performs an audio compression coding on the audio signal to obtain a sample audio signal, performs a comparison procedure on the audio signal and the sample audio signal to generate a residual signal, and performs a signal modulation on the residual coded signal to generate a plurality of residual coded frames. The coding module performs the audio compression coding according to the residual signal to obtain a plurality of residual headers. and a residual coded signal, and transmits the residual signal according to the available bandwidth; an audio decompression device, which is wirelessly connected to the audio compression device for wireless communication, the audio decompression device comprising: a second signal transceiver, which is communicatively connected to the first signal transceiver and receives the residual coded signal frames; and a second processor, which is connected to the second signal transceiver The residual coding frames are connected, and according to the plurality of headers of the residual coding frames, the residual coding frames are moved from the available bandwidth to an original time point; wherein, when the audio decompression device receives the residual coding frames, the residual coding frames are subjected to an audio compression decoding to generate a residual signal, and a signal superposition operation is performed according to the residual signal to generate an audio signal.

Through the above structure, the audio compression device for wireless communication transmits the residual coded frames to the audio decompression device through the available bandwidth. The audio decompression device further decodes the residual coded signal and performs the signal superposition operation to generate the audio signal. In this way, the residual signal will not be lost and can be restored to the audio signal, thereby achieving the purpose of reducing the distortion of the audio signal.

Another main technical means adopted to achieve the above-mentioned purpose is to make the above-mentioned audio compression method for wireless communication mainly executed in an audio compression device for wireless communication, the method comprising the following steps: receiving an audio signal; performing a linear prediction coding on the audio signal to obtain a plurality of linear prediction sample residue coding coefficients corresponding to a sample residue coding signal; setting a plurality of sample residue headers according to the linear prediction sample residue coding coefficients; performing a lossless audio decoding on the sample residue coding signal to obtain a sample audio signal; performing a comparison procedure on the audio signal and the sample audio signal to generate A residual signal; obtaining a transmission bandwidth according to a wireless communication signal link; performing a sampling process on the sample residual coded signal with a sampling rate information to obtain an occupied bandwidth; performing a bandwidth difference operation according to the transmission bandwidth and the occupied bandwidth to generate the available bandwidth; performing the audio Frequency compression coding is performed to obtain a plurality of residual headers and a residual coding signal; a signal modulation is performed on the residual headers and the residual coding signal to generate a plurality of residual coding frames; and according to the residual coding frames and the available bandwidth, the residual coding frames are sequentially moved to the available bandwidth.

By using the above method, the residual signal can be transmitted through the available bandwidth, so that the residual signal will not be lost, thereby achieving the purpose of reducing the distortion of the audio signal.

10: Audio compression device

11: First signal transceiver

12: First processor

120: Encoding module

1201: Linear prediction coding module

1202: Linear prediction decoding module

121: First processing module

20: Audio decompression device

21: Second signal transceiver

22: Second processor

220: Storage module

221:Decoding module

222: Second processing module

223: Output module

S _o :Audio signal

S ₁ : Sample residual coded signal

S _sample : sample audio signal

S _d : residual signal

BW _tra : Transmission bandwidth

BW _usa : Available bandwidth

S: Sample residual coding frame

_H1 , _H2 : Residual header frame

C ₁ , C ₂ , C ₃ , C ₄ : residual coding frame

FIG. 1 is a device diagram of an embodiment of the audio compression device for wireless communication of the present invention; FIG. 2 is another device block diagram of an embodiment of the audio compression device for wireless communication of the present invention; FIG. 3 is another device block diagram of an embodiment of the audio compression device for wireless communication of the present invention; FIG. 4A is a schematic diagram of an audio compression signal for wireless communication of the present invention; FIG. 4B FIG. 5 is a block diagram of the audio compression system for wireless communication of the present invention; FIG. 6 is a block diagram of the audio decompression device for wireless communication of the present invention; FIG. 7 is a flow chart of an embodiment of the audio compression method for wireless communication of the present invention; FIG. 8 is a flow chart of the audio compression method for wireless communication of the present invention; FIG. 9 is a flowchart of another embodiment of the audio compression method for wireless communication of the present invention; FIG. 10 is a flowchart of another embodiment of the audio compression method for wireless communication of the present invention; FIG. 11 is a flowchart of another embodiment of the audio compression method for wireless communication of the present invention; FIG. 12 is a flowchart of another embodiment of the audio compression method for wireless communication of the present invention; FIG. 13 is a flowchart of another embodiment of the audio compression method for wireless communication of the present invention; FIG. 14 is a flowchart of another embodiment of the audio compression method for wireless communication of the present invention; and FIG. 15 is a flowchart of another embodiment of the audio compression method for wireless communication of the present invention.

Regarding an embodiment of the present invention, as shown in FIG1 , the present invention provides an audio compression device 10 for wireless communication, the audio compression device 10 for wireless communication includes a first signal transceiver 11 and a first processor 12, the first signal transceiver 11 is electrically connected to the first processor 12. In this embodiment, the audio compression device 10 for wireless communication can be a desktop host, a notebook computer, a mobile device, an audio player, etc.

Specifically, the first processor 12 obtains an audio signal and an available bandwidth, and performs an audio compression encoding on the audio signal to obtain a sample audio signal, performs a comparison procedure on the audio signal and the sample audio signal to generate a residual signal, and transmits the residual signal through the first signal transceiver 11 according to the available bandwidth.

In this embodiment, as shown in FIG. 2 , the first processor 12 includes a coding module 120 and a first processing module 121. The coding module 120 is connected to the first signal transceiver 11 and the first processing module 121. The coding module 120 performs the audio compression coding on the audio signal S _o to obtain the sample audio signal S _sample . Then, the sample audio signal S _sample is transmitted to the first processing module 121. The first processing module 121 performs the comparison procedure on the audio signal S _o and the sample audio signal S _sample to generate the residual signal S _d Then, the first processing module 121 obtains the transmission bandwidth according to a wireless communication signal connection, obtains an occupied bandwidth used by the sample audio signal, and performs a bandwidth difference operation according to the transmission bandwidth and the occupied bandwidth to generate the available bandwidth. At the same time, the residue signal _Sd is transmitted to the encoding module 120 to perform the audio compression coding to obtain a plurality of residue headers and a residue coding signal.

In this embodiment, as shown in FIG. 3 , the encoding module 120 includes a linear prediction encoding module 1201 and a linear prediction decoding module 1202. The linear prediction encoding module 1201 is connected to the first signal transceiver 11, and the linear prediction decoding module 1202 is connected to the linear prediction encoding module 1201 and the first processing module 121. When the linear prediction coding module 1201 receives the audio signal S _o , it performs a lossless audio coding on the audio signal S _o to obtain a sample residual coding signal S ₁ . Then, the sample residual coding signal S ₁ is transmitted to the linear prediction decoding module 1202 . The linear prediction decoding module 1202 performs a lossless audio decoding on the sample residual coding signal S ₁ to obtain the sample audio signal S _sample .

In this embodiment, the first processing module 121 performs the comparison procedure according to the audio signal S _o and the sample audio signal S _sample . The comparison procedure performs a phase difference operation on the audio signal S _o and the sample audio signal S _sample to generate the residual signal S _d , which is the signal difference between the audio signal S _o and the sample audio signal S _sample .

In detail, the linear prediction coding module 1201 performs a linear prediction audio coding on the audio signal S _o to generate a plurality of linear prediction sample residue coding coefficients and a sample residue coding signal S ₁ . The first processing module 121 sets a plurality of sample residue headers according to the linear prediction sample residue coding coefficients. Then, the linear prediction decoding module 1202 performs a linear prediction audio decoding on the sample residue coding signal S ₁ to correspondingly generate the sample audio signal S _sample .

Next, the sample audio signal S _sample is transmitted to the first processing module 121. The first processing module 121 performs the phase difference operation according to the audio signal S _o and the sample audio signal S _sample to generate the residual signal S _d . _d is transmitted to the encoding module 120 to perform the audio compression encoding to generate the sample residual headers and the residual coded signal. Then, the first processing module 121 performs a signal modulation on the sample residual headers, the sample residual coded signal, the residual headers and the residual coded signal to generate a plurality of sample residual header frames, a plurality of sample residual coded frames and a plurality of sample residual coded frames respectively. Then, the first processing module 121 sequentially moves the residue header frames and the residue coding frames from an original time point to the available bandwidth according to the residue header frames, the residue coding frames and the available bandwidth, and the first signal transceiver 11 transmits the residue header frames and the residue coding frames via the available bandwidth.

In the above embodiment, as shown in FIG. 4A and FIG. 4B , the available bandwidth is obtained based on a transmission bandwidth BW _tra defined by a wireless communication signal connection for signal transmission by the audio compression device 10 for wireless communication, and then, the sample residual header frames and the sample residual coding frames (i.e., marked S) are obtained at an occupied bandwidth (i.e., marked S, C ₁ , C ₂ , C ₃ , C ₄ ) required for the transmission bandwidth, and then, a phase difference operation is performed based on the transmission bandwidth BW _tra and the occupied bandwidth to generate the available bandwidth BW _usa . In this embodiment, the residual header frames H ₁ and H ₂ are 3 bytes, and the residual coding frames C ₁ , C ₂ , C ₃ , and C ₄ are 8 bytes.

In addition, another embodiment of the present invention is an audio compression system for wireless communication. As shown in FIG5 , the audio compression system for wireless communication includes the above-mentioned audio compression device 10 for wireless communication and an audio decompression device 20. The audio decompression device 20 is connected to the audio compression device 10 for wireless communication via a wireless communication signal connection. In this embodiment, the wireless communication signal connection can be a Bluetooth signal, a Wi-Fi signal, etc.

Next, the audio decompression device 20 receives a plurality of residual coding frames from the audio compression device 10 for wireless communication, performs an audio compression decoding on the residual coding frames to generate the residual signal, and performs a signal superposition operation according to the residual signal to generate the audio signal S _o .

In this embodiment, the audio decompression device 20 includes a second signal transceiver 21 and a second processor 22. The second signal transceiver 21 is connected to the first signal transceiver 11 by a wireless signal, and the second processor 22 is connected to the second signal transceiver 21. Then, the second signal transceiver 21 receives the residual coding frames from the first signal transceiver 11, and then, the second processor 22 moves the residual coding frames from the available bandwidth to the original time point t ₀ according to a plurality of headers of the residual coding frames.

In this embodiment, as shown in FIG. 6 , the second processor 22 includes a storage module 220, a decoding module 221, a second processing module 222 and an output module 223. The storage module 220 is connected to the second signal transceiver 21 and the decoding module 221, and the second processing module 222 is connected to the decoding module 221 and the output module 223. When the second signal transceiver 21 receives the residual coding frames, the residual coding frames are stored in the storage module 220. When a play time of the output module 223 is moved to the original time point _t0 , the second processing module 222 will request the decoding module 221 to perform the audio compression decoding on the residual coding frames to generate the residual signal, and according to the headers and the original time point _t0 , the residual signal _Sd is moved to the original time point _t0 to output the audio signal _S0 . In this embodiment, the wireless signal can be a Bluetooth signal, a wireless network signal, etc. In this embodiment, the audio decompression device 20 may be a wireless signal headset (eg, a Bluetooth headset or a wireless network signal headset).

Therefore, the present invention utilizes the transmission bandwidth defined by the wireless communication signal connection. When the sample audio frame is transmitted through the transmission bandwidth, the occupied bandwidth is deducted from the occupied bandwidth used by the sample audio frame to obtain the available bandwidth. The residual coding frames are transmitted using the available bandwidth, so that the residual coding frames will not be discarded due to insufficient transmission bandwidth. In this way, the audio signal distortion can be reduced.

In addition, an embodiment of the audio compression method for wireless communication of the present invention is shown in FIG7. The audio compression method is performed by an audio compression device 10 for wireless communication and includes the following steps: receiving an audio signal (S70); performing an audio compression encoding on the audio signal to obtain a sample audio signal (S71); performing a comparison procedure on the audio signal and the sample audio signal to generate a residual signal (S72); obtaining an available bandwidth (S73); transmitting the residual signal according to the available bandwidth (S74).

Another embodiment of the audio compression method for wireless communication of the present invention is shown in FIG8 , wherein the step of "transmitting the residual signal according to the available bandwidth (S74)" includes the following sub-steps: performing the audio compression coding on the residual signal to obtain a plurality of residual headers and a residual coding signal (S740); moving the residual headers and the residual coding signal to the available bandwidth (S741).

Another embodiment of the audio compression method for wireless communication of the present invention is shown in FIG9 , wherein the step of “moving the residue headers and the residue coded signal to the available bandwidth (S741)” includes the following sub-steps: performing a signal modulation on the residue headers and the residue coded signal to generate a plurality of residue coded frames (S7410); and moving the residue coded frames to the available bandwidth in sequence according to the residue coded frames and the available bandwidth (S7411).

Another embodiment of the audio compression method for wireless communication of the present invention is shown in FIG10 , wherein the step of “performing the audio compression encoding on the audio signal to obtain the sample audio signal (S71)” includes the following sub-steps: performing a lossless audio encoding on the audio signal to obtain a sample residual coded signal (S710); performing a lossless audio decoding on the sample residual coded signal to obtain the sample audio signal (S711).

Another embodiment of the audio compression method for wireless communication of the present invention is shown in FIG11 , wherein the step of “performing the lossless audio encoding on the audio signal to obtain the sample residue coding signal (S710)” includes the following sub-steps: performing a linear prediction encoding on the audio signal to obtain a plurality of linear prediction sample residue coding coefficients corresponding to the sample residue coding signal (S7101); and setting a plurality of sample residue headers according to the linear prediction sample residue coding coefficients (S7102).

Another embodiment of the audio compression method for wireless communication of the present invention is shown in FIG12, wherein the step of "obtaining the available bandwidth (S73)" includes the following sub-steps: obtaining a transmission bandwidth according to a wireless communication signal connection (S730); obtaining an occupied bandwidth used by a plurality of sample residual coding frames (S731); performing a phase difference operation bandwidth difference operation according to the transmission bandwidth and the occupied bandwidth to generate the available bandwidth (S732).

Another embodiment of the audio compression method for wireless communication of the present invention is shown in FIG13, wherein the step of "obtaining the occupied bandwidth used by the sample residual coding frame (S731)" includes the following sub-steps: Performing a sampling process on the sample residual coding signal with a sampling rate information to obtain the occupied bandwidth (S7311); in this embodiment, the sampling rate information is a sampling frequency and a sampling bandwidth size, and the sampling rate information is less than a communication sampling rate information of the wireless communication signal link.

Another embodiment of the audio compression method for wireless communication of the present invention is shown in FIG14, wherein after the step of "setting the sample residue headers (S7102) according to the linear prediction sample residue coding coefficients", the following steps are included: performing the signal modulation on the sample residue coding signal to generate the sample residue coding frames (S7103); transmitting the sample residue coding frames and the residue coding frames (S7104).

Another embodiment of the audio compression method for wireless communication of the present invention is shown in FIG15 , wherein the step of “performing the comparison procedure on the audio signal and the sample audio signal to generate the residual signal (S72)” includes the following sub-steps: performing a phase difference operation on the audio signal and the sample audio signal to generate the residual signal (S720).

In summary, the audio compression device 10 for wireless communication of the present invention uses the available bandwidth to move the residual signal from the original time point to the available bandwidth before transmitting the residual signal to the audio decompression device 20. Then, after the audio decompression device 20 receives the residual signal, it identifies the position of the residual signal in the available bandwidth according to the residual headers, and sequentially moves the residual signal to the original time point. In this way, the audio signal can be prevented from losing the residual coding frames due to compression during the transmission process, thereby achieving the purpose of reducing the distortion of the audio signal.

10: Audio compression device

11: First signal transceiver

12: First processor

Claims (5)

An audio compression system for wireless communication includes: an audio compression device for wireless communication, including: a first signal transceiver; a first processor connected to the first signal transceiver and obtaining an audio signal and an available bandwidth; a coding module connected to the first signal transceiver; wherein the first processor performs an audio compression on the audio signal The audio signal is subjected to frequency compression coding to obtain a sample audio signal, a comparison procedure is performed on the audio signal and the sample audio signal to generate a residual signal, and a signal modulation is performed on the residual coded signal to generate a plurality of residual coded frames. The coding module performs the audio compression coding according to the residual signal to obtain a plurality of residual headers and a residual coded signal. and transmitting the residual signal according to the available bandwidth; an audio decompression device, which is wirelessly connected to the audio compression device for wireless communication, the audio decompression device comprising: a second signal transceiver, which is communicatively connected to the first signal transceiver and receives the residual coded signal frames; and a second processor, which is connected to the second signal transceiver and transmits the residual signal according to the available bandwidth; The plurality of headers of the residual coding frames move the residual coding frames from the available bandwidth to an original time point; and wherein, when the audio decompression device receives the residual coding frames, the residual coding frames are subjected to an audio compression decoding to generate the residual signal, and a signal superposition operation is performed according to the residual signal to generate the audio signal. The audio compression system for wireless communication as described in claim 1, wherein the second processor comprises: a storage module connected to the second signal transceiver and storing the residual coding frames; a decoding module connected to the storage module and performing the audio compression decoding on the residual coding frames to generate the residual signal; a second processing module connected to the decoding module ; an output module connected to the second processing module to output the residual signal; and wherein, when a playback time of the output module moves to the original time point, the second processing module will request the decoding module to perform the audio compression decoding on the residual coding frames to generate the residual signal, and according to the headers and the original time point, move the residual signal to the original time point. A method for compressing audio for wireless communication is provided. The method is performed by an audio compression device for wireless communication and includes the following steps: receiving an audio signal; performing a linear prediction coding on the audio signal to obtain a plurality of linear prediction sample residue coding coefficients corresponding to a sample residue coding signal; setting a plurality of sample residue headers according to the linear prediction sample residue coding coefficients; performing a lossless audio decoding on the sample residue coding signal to obtain a sample audio signal; performing a comparison procedure on the audio signal and the sample audio signal to generate a residue signal; and performing a comparison procedure on the audio signal and the sample audio signal according to a wireless communication. The invention relates to a method for obtaining a transmission bandwidth by connecting the sample residual coded signal to the transmission bandwidth; performing a sampling process on the sample residual coded signal with a sampling rate information to obtain an occupied bandwidth; performing a bandwidth difference operation according to the transmission bandwidth and the occupied bandwidth to generate the available bandwidth; performing the audio compression coding on the residual signal to obtain an available bandwidth; Obtain a plurality of residual headers and a residual coding signal; perform a signal modulation on the residual headers and the residual coding signal to generate a plurality of residual coding frames; and Move the residual coding frames to the available bandwidth in sequence according to the residual coding frames and the available bandwidth. The audio compression method for wireless communication as described in claim 3, wherein after the step of "setting the sample residual headers according to the linear prediction sample residual coding coefficients", the following steps are included: performing the signal modulation on the sample residual coding signal to generate the sample residual coding frames; and transmitting the sample residual coding frames and the residual coding frames. As described in claim 4, the audio compression method for wireless communication, wherein the step of "performing the comparison procedure on the audio signal and the sample audio signal to generate the residual signal" includes the following sub-steps: performing a phase difference operation on the audio signal and the sample audio signal to generate the residual signal.

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