AUDIO PROCESSING DEVICE AND AUDIO PROCESSING METHOD THEREOF

The present disclosure provides an audio processing device including a positioning unit and a digital signal processor. The positioning unit detects the original position and the up-to-date position and calculates an offset between the up-to-date position and the original position. The digital signal processor, electrically connected to the positioning unit, receives audio data to generate a surround sound field having a plurality of virtual speaker sound effects and receives the offset to adjust the virtual speaker sound effects of the surround sound field according to the offset.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is based on, and claims priority from, Taiwan Application Number 106130068, filed Aug. 31, 2017, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to an audio processing device, and in particular it relates to an audio processing device and a method thereof for changing a sound field as a user changes position.

Description of the Related Art

At present, when a user watches a movie, plays a video game or uses a Virtual Reality (VR) device using a general audio/video (A/V) equipment, as shown inFIG. 1, no matter whether the position of the user100changes relative to a curved screen110or not, the volume of the sound heard by the user100through a headphone120is the same. No matter whether the headphone120or another physical speaker is used, the generated sound field will not change as the position of the user100changes. As a result, the direction of the sound field of the A/V content felt by the user100may not be correct.

BRIEF SUMMARY OF THE INVENTION

The present disclosure provides an audio processing device and a method thereof for changing a sound field as the user changes position.

The present disclosure provides an audio processing device comprising a positioning unit and a digital signal processor. The positioning unit detects the original position and the up-to-date position and calculates the offset between the up-to-date position and the original position. The digital signal processor, electrically connected to the positioning unit, receives audio data to generate a surround sound field having a plurality of virtual speaker sound effects and receives the offset to adjust the virtual speaker sound effects of the surround sound field according to the offset.

The present disclosure further provides an audio processing method for an audio processing device. The audio processing method comprises receiving audio data at a digital signal processor of the audio processing device to generate a surround sound field having a plurality of virtual speaker sound effects; detecting the original position and the up-to-date position using a positioning unit of the audio processing device; calculating the offset between the up-to-date position and the original position; and receiving the offset at the digital signal processor, and adjusting the virtual speaker sound effects of the surround sound field according to the offset.

DETAILED DESCRIPTION OF THE INVENTION

The following description is of the best-contemplated mode of carrying out the disclosure. This description is made for the purpose of illustrating the general principles of the disclosure and should not be taken in a limiting sense. The scope of the disclosure is best determined by reference to the appended claims.

FIG. 2Aschematically shows a block diagram of an audio processing device200according to a first embodiment of the present disclosure. The audio processing device200mainly includes an input interface unit210, a positioning unit220, a digital signal processor230and an output interface unit240. The audio processing device200receives audio/video data (A/V data) from a personal computer (PC)260. After being processed by the audio processing device200, the audio output device270outputs the audio to a user (not shown). The audio processing device200may be a headphone, a gaming headphone, smart glasses, a head mounted display, a head mounted virtual reality device, or a wearable device.

In this embodiment, according to the A/V content played by the user, the personal computer260sends the A/V data to the audio processing device200via a universal serial bus (USB), a high definition multimedia interface (HDMI) or other transmission interface that can transfer the A/V data. The personal computer260may also directly send audio data to the audio processing device200. In other embodiments, the audio processing device200may also receive the A/V data or the audio data from game consoles, multimedia players (such as DVD players and Blu-ray Disc players), portable music players, smartphones, tablets and notebooks, but it is not limited thereto.

The input interface unit210receives the A/V data from the personal computer260, and converts the A/V data into image data and audio data. The image data are displayed by a display device after necessary processing, and the audio data are sent to the digital signal processor230. The audio data can be stereo two-channel audio data. When the personal computer260transmits the audio data, the input interface unit210directly transmits the audio data to the digital signal processor230without conversion. The audio data may be transmitted to the digital signal processor230through any audio format interface such as Integrated Interchip Sound (I2S), High Definition Audio (HDA) and Pulse-Code Modulation (PCM).

The positioning unit220is a nine-axis sensor constituted by a three-axis Accelerometer, a three-axis Magnetometer and a three-axis Gyroscope for detecting the user's up-to-date position and the original position. The user's position information detected by the positioning unit220may be defined according to a Cartesian coordinate system, a polar coordinate system, or a cylindrical coordinate system, but it is not limited thereto. When the positioning unit220receives a calibration instruction (XYZ_CAL) from the user via the digital signal processor230, the positioning unit220sets the current position of the user to the original position (X, Y, Z). Then, the positioning unit220continues to detect whether the user has rotation or movement. If the user rotates or moves, the positioning unit220detects the up-to-date position (X1, Y1, Z1) and calculates an offset (X1-X, Y1-Y, Z1-Z) between the up-to-date position and the original position. The positioning unit220transmits the offset to the digital signal processor230. The method for receiving the calibration instruction from the user includes that setting a button on the audio processing device200or setting an input option in the software interface of the personal computer260for the user inputting the calibration instruction and sending to the digital signal processor230. TakingFIG. 3Aas an example, when the user wears the headphone300facing the center (or a predetermined area) of the screen320and inputs the calibration instruction, the positioning unit detects the user's current position as the original position. After that, if the user moves or rotates, the latest position after moving or rotating is detected to obtain the offset between the up-to-date position and the original position.

The digital signal processor230may be a codec which electrically connected to the input interface unit210and the positioning unit220. The digital signal processor230receives the audio data to generate a virtual surround sound having a plurality of virtual speaker sound effects. The digital signal processor230utilizes the listening effect of human ears to create a virtual surround sound source located in the rear side or the side of the user from a plurality of virtual speakers by using the simulation methods of sound localization. The simulation methods includes using the sound intensity, phase difference, time difference and the Head Related Transfer Function (HRTF) to generate the virtual surround sound field, which is not described in detail herein. For example, the digital signal processor230can generate a surround sound field of five virtual speaker sound effects in different directions, and adjust the gain and/or the output intensity of the specific virtual speaker for different directions respectively.

The digital signal processor230receives the offset from the positioning unit220, and adjusts the virtual speaker sound effects of the surround sound field according to the offset. The digital signal processor230calculates the offset and converts the offset to an offset angle. The digital signal processor230determines whether the offset angle is greater than a predetermined angle (e.g., 5 degrees). If the offset angle is greater than the predetermined angle, the digital signal processor230adjusts the virtual speaker sound effects. If the offset angle is less than or equal to the predetermined angle, the digital signal processor230does not adjust the virtual speaker sound effects. The digital signal processor230correspondingly adjusts the gain of the virtual speaker sound effects and/or the output intensity of the virtual speaker sound effects according to the offset angle.

The output interface unit240receives the surround sound field processed by the digital signal processor230to be output to the audio output device270. The output interface unit240includes a Digital-to-Analog Converter (DAC) (not shown) for converting the digital signal of the surrounding sound field into an analog signal and transmitting the analog signal to an amplifier (not shown). Then, the amplifier outputs the analog signal to the audio output device270.

The audio output device270may be a stereo headset, a headphone, a two-channel speaker, a multi-channel speaker and the like, but it is not limited thereto. The audio output device270receives the surround sound field from the output interface unit240and plays it to the user through a two-channel speaker or a multi-channel speaker.

FIG. 2Bschematically shows a block diagram of an audio processing device200according to a second embodiment of the present disclosure. The audio processing device200mainly includes an input interface unit210, a positioning unit220, a digital signal processor230, an output interface unit240and a microphone250. In this embodiment, elements having the same names as those in the first embodiment also have the same functions as described above, and details are not described herein again. The main difference betweenFIG. 2Band FIG.2A is that the audio processing device200further includes a microphone (MIC)250for receiving sound data from outside or from the user. The digital signal processor230further includes a microphone interface231for receiving the sound data from the microphone250. The sound data can be transmitted to the PC260for further processing or outputted to a headphone271or a multi-channel speaker272through the output interface unit240. The microphone interface231may be an interface which integrated a Pulse-Density Modulation and an Analog to Digital Converter (ADC). In addition, the digital signal processor230can receive setting instructions from the user. The setting instructions include functions such as volume up (VOL_UP), volume down (VOL_DOWN) and mute (MUTE). The user's setting instructions can be set through a plurality of buttons provided on the audio processing device200or a plurality of input options in the software interface of the personal computer260for the user to input the personalized setting instructions. Therefore, the audio-visual function of the audio processing device200is further improved.

In addition, in this embodiment, the output interface unit240further includes a plurality of digital to analog converters (DAC)241, a headphone amplifier242and a multi-channel amplifier243for outputting the surround sound field to the corresponding audio output device. The audio output device is a headphone271or a multi-channel speaker272. The digital signal processor230selects whether to output the surround sound field to the corresponding headphone271or multi-channel speaker272via the headphone amplifier242or multi-channel amplifier243according to the audio output device used by the user. The headphone271may be a stereo two-channel headphone or a two-channel speaker, and includes a left channel and a right channel output. The multichannel speaker272may be a multichannel speaker group such as 2.1 channel, 3.1 channel, 4.1 channel, 5.1 channel, 6.1 channel, 7.1 channel, 10.2 channel, 20.1 channel and the like, but it is not limited thereto. The multi-channel speaker272may surround the user's periphery to form a surround sound effect for the home theater.

FIG. 3AandFIG. 3Bschematically show the relative position of the user310, the audio processing device300and the screen320. In this embodiment, the user310plays A/V content through a multimedia player (not shown) such as a personal computer, a game console or a mobile device, and the user310puts on the audio processing device300to watch a movie, play a video game or watch A/V content with the screen320. The screen320may be a display device such as a curved screen, a liquid-crystal display, an OLED display and the like. The screen320may further include a screen stand321for supporting the screen320. The audio processing device300receives the A/V content to create a surround sound field having a plurality of virtual speaker sound effects. The surround sound field is played to the user310via a stereo two-channel headphone301, so that the user feels as if the virtual speakers set in the surrounding sound. In this embodiment, the audio processing device300virtualizes five virtual speakers330beside the user310, and the virtual speakers are namely A to E, respectively. After the user310sets the calibration instruction of the audio processing device300, the positioning unit of the audio processing device300sets the current position of the user310to the original position and continuously detects the up-to-date position of the user310. In the schematic view ofFIG. 3A, the original position of the user310is opposite the screen320, and the offset angle is 0 degrees.

Next, referring toFIG. 3B, the user310rotates clockwise by an offset angle (δ) relative to the screen320. The positioning unit of the audio processing device300detects the up-to-date position of the user310and calculates the offset between the up-to-date position and the original position. The positioning unit sends the offset to the digital signal processor of the audio processing device300. The digital signal processor calculates an offset angle of the offset and determines whether the offset angle is greater than a predetermined angle. For instance, the predetermined angle is 5 degrees. If the offset angle is greater than 5 degrees, the surround sound field is changed using a preset gain mapping table (as shown in Table 1). Based on the gain mapping table, the gains of the virtual speakers A to E are respectively adjusted according to the offset angle of the user310to change different output intensities (in decibels, dB), so as to achieve the effect of changing the sound field. In one embodiment, when the user310rotates clockwise from 0 degrees to 60 degrees relative to the original position, the virtual speaker A increases from the original +6 dB to +9 dB; the virtual speaker B increases from the original +3 dB to +6 dB; the virtual speaker C increases from the original +0 dB to +3 dB; the virtual speaker D decreases from the original +3 dB to +0 dB; the virtual speaker E decreases from +6 dB to +3 dB.

In Table 1, the corresponding output intensity of each offset angle is not specified in detail, but the corresponding output intensities of other offset angles should be understood by a person skilled in the art. Furthermore, it should be understood that, in this embodiment, the user310uses the headphone301to listen to the surround sound field. In other embodiments, the user310may replace the headphone301with a physical 5.1-channel speaker and play the surround sound field.

FIG. 4schematically shows a flow chart of an audio processing method for an audio processing device according to the first embodiment of the present disclosure. Referring toFIG. 2Aof the first embodiment of the present disclosure, in step401, a calibration instruction from a user is received by the digital signal processor230of the audio processing device200, and the positioning unit220sets the original position of the user. In step402, audio data are received by the digital signal processor230of the audio processing device200to generate a surround sound field having a plurality of virtual speaker sound effects, and the audio data are outputted to the audio output device270and played to the user for listening. In step403, the positioning unit220of the audio processing device200detects an up-to-date position of the user and calculates the offset between the up-to-date position and the original position. In step404, the digital signal processor230determines whether the offset is greater than a predetermined angle. If the offset is less than or equal to the predetermined angle, the virtual speaker sound effects are not adjusted, and the flow chart returns to step403. If the offset is greater than the predetermined angle, the flow chart proceeds to step405. In step405, the virtual speaker sound effects of the surround sound field are adjusted according to the offset by the digital signal processor230. Wherein the virtual speaker sound effects are adjusted according to the user's offset angle, and the gain of the virtual speaker sound effects and/or the output intensity of the virtual speaker sound effects are adjusted correspondingly so as to achieve the effect of changing the surround sound field.

Further, in step402, the method further includes A/V data are received by the input interface unit210of the audio processing device200. The A/V data are converted into the audio data and sent to the digital signal processor230for subsequent processing. In addition, the surround sound field is also received by the output interface unit240of the audio processing device200to be output to the audio output device270. The output interface unit240includes a headphone amplifier and a multi-channel amplifier for outputting the surround sound field to the corresponding audio output device270. The audio output device270is a headphone or a multi-channel speaker. The digital signal processor230outputs the surround sound field to the corresponding headphone or the multi-channel speaker via the headphone amplifier or the multi-channel amplifier according to the audio output device270.

Accordingly, through the audio processing device and the audio processing method of the present disclosure, when a user watches A/V content, the user can listen to not only the surround sound field but also the effect of changing the sound field according to the up-do-date position of the user. Allowing the user feels more immersive when watching a video, and has a better experience of watching A/V content.