JP2002500495A - PC surround sound circuit - Google Patents

Abstract

(57) [Summary] A PC (personal computer) surround sound device configured to generate a multi-channel simulated surround sound output signal. The PC surround sound device preferably generates a simulated surround sound output signal channel from a PC source signal having two or more source signal channels. SOLUTION: This PC surround sound apparatus has input means for receiving first and second PC source signal channels, and receives the first and second PC source signal channels, and receives a low signal from the source signal channels. A high-pass filter configured to remove the high-frequency components and pass only the high-frequency components to the first and second output signal channels. Further, the present PC surround sound apparatus receives the first and second source signal channels from the input means, removes the high frequency from the source signal channel, and removes only the low frequency from the third and fourth signals. And a low-pass filter configured to pass up to the output signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Description of related application]

This application claims the benefit of US Provisional Application No. 60 / 064,046, filed November 3, 1997, which is hereby incorporated by reference.

The present invention relates to a PC (personal computer) surround sound circuit, and more particularly, to a two-channel input signal received from a personal computer,
Preferably, it relates to a circuit configured to generate a simulated surround audio output having three or more output channels.

[0003] Currently, most PC systems are configured to generate an audio output signal having two channels-typically left and right stereo channels. For example, when reproducing an audio file stored in a digital format such as a MIDI or WAVE file, a PC generally generates only two channels. Similarly, when a PC plays audio from a CD, the output is usually only two channels. Thus, most PC audio card and speaker configurations are only equipped to process two-channel audio signals. However, PCs can now also handle very complex multimedia applications, including advanced video games and movies, currently under development and recorded on DVDs and CDs with encoded surround audio audio. Therefore, it is desirable for a PC system to be able to play and process coded surround sound applications.

[0004] Further, even though some new computer video games and DVD videos are currently being manufactured in an encoded surround format, many games and other computer applications are encoded in a surround sound encoding format. It has not been. However, even if many of the applications that many users are running cannot create various surround sound channels, they still want to experience the excitement of surround sound. For example, a typical surround sound encoding application would generate six audio channels, while an uncoded application would only generate an audio signal with two channels, as described above. Therefore, in a surround sound environment, P
It is desirable to have a system that can reproduce a surround sound encoding application on C and a system that can generate a simulated surround sound signal from a normal two-channel PC audio signal. For example, it would be desirable to have a system that utilizes the left and right stereo channels of a game, movie, music track, or audio file and produces a multi-channel audio output that simulates a surround sound encoding application.

Accordingly, an advantage of the present invention is to provide a PC surround sound device that overcomes the disadvantages of the prior art.

[0006] Another advantage of the present invention is that the PC surround sound device is configured to play games, movies, and other applications that include an audio signal encoded in a surround sound encoding scheme. .

[0007] Yet another advantage of the present invention is that a PC surround sound device can generate a multi-channel simulated surround sound output signal.

[0008] Yet another advantage of the present invention is that a PC surround sound device mixes an encoded surround sound signal with a simulated surround sound output signal generated from a two-channel PC signal to provide a single multi-channel surround sound signal. That is, an audio output signal can be generated.

Yet another advantage of the present invention is that a PC surround sound device can generate a multi-channel simulated surround sound output signal that can accommodate all types of PC speaker systems.

The above and other advantages of the invention are implemented in one form by a PC surround sound device configured to generate a multi-channel simulated surround sound output signal. Preferably, the PC surround sound device generates a simulated surround sound output signal channel from a PC source signal having two or more source signal channels. Further, it is preferable that the PC surround sound device includes input means for receiving the first and second source signal channels. In addition, the apparatus receives first and second source signal channels from the input means, removes low frequencies from the source signal channels, and removes only high frequencies from the first and second output signal channels. And a high-pass filter configured to pass through the high-pass filter. Finally, P
The C surround sound device receives the first and second source signal channels from the input means, removes the high frequency band from the source signal channel, and outputs only the low frequency band to the third and fourth output signal channels. A low-pass filter configured to pass through the low-pass filter. According to this aspect of the invention, the high frequency of the input channel is separated and directed to the first and second output signal channels, the low frequency of the input channel is separated and the third and fourth output signal channels are separated. A simulated surround sound output signal is generated.

The present invention is a circuit or system for generating a multi-channel simulated PC surround audio signal from two or more PC signal channels. Although the embodiments of the invention shown and described herein generally relate to analog signal processing circuits, digital signal processing circuits and / or software applications may be implemented to implement the invention. It will be apparent to those skilled in the art that they can be used. Accordingly, the present invention is not limited to the illustrated embodiment.

Referring now to FIG. 1, there is shown a computer system 10 embodying the PC surround sound circuit of the present invention. In particular, computer system 10 may comprise any suitable computer system, such as a home PC system or other similar computer workstation system.
The computer system 10 includes a processing device 12, a monitor 14, a keyboard 16,
A mouse 18 and a plurality of speakers 20-30 may be appropriately provided. As will be apparent to those skilled in the art, the computer system 10 may include various other computer peripherals not shown in FIG.

According to most surround sound systems, computer system 10
It is preferable to provide six speakers for receiving and reproducing the surround sound signal of the channel. According to this aspect of the invention, the speaker configuration of computer system 10 preferably comprises a front left speaker 20, a front right speaker 22, a rear left speaker 24, a rear right speaker 26, a center channel speaker 28, and a subwoofer speaker. Most of the surround sound systems currently known in the art have six speakers driven by six channels of surround sound signals, but the computer system 10 can have any number of speakers and surround sound channels. The good will be apparent to those skilled in the art. For example, the computer system 10 may include only three-channel speakers, such as a front left speaker, a front right speaker, and a center channel speaker configuration. According to this aspect of the invention, computer system 10 will generate only three channel signals.

The processing device 12 preferably includes a processor 32, a memory 34, a storage device 36, a surround sound circuit 38, a sound card 40, a floppy disk drive 42, and an optical disk drive 44. Processor 32 may comprise any suitable computer processor, such as an Intel X86 processor, a RISK processor, other processors now known in the art, or those to be developed in the future. Similarly, the memory 34 is an SRAM, a DRAM,
And any suitable random access memory device such as a flash memory. Note that a part of the memory 34 may be configured as a cache memory. The storage device 36 includes a hard disk drive, a flash memory,
Alternatively, it may comprise any suitable computer storage device configured to store application programs, data, and the like.

In addition to the common processors, memories, and storage devices included in most computer systems, it is desirable for the processing unit 12 to further include a surround sound circuit 38 and a sound card 40. As described in detail below, the surround sound circuit 38 is configured to generate a simulated surround sound output from a two-channel sound input signal. Further, the surround sound circuit 38 may be configured to receive and decode the encoded surround sound signal, and to mix the decoded surround sound signal with the simulated surround sound signal. The voice card 40 includes a speaker 20-
A suitable P configured to generate an analog audio signal driving any of
Any C voice card may be used. Computer system 1
2, the surround sound circuit 38 and the sound card 40 are illustrated as having separate devices or circuit cards.
It will be apparent to those skilled in the art that the audio card 40 may be omitted, depending on the configuration of the surround sound circuit 38.

Finally, as shown in FIG. 1, the processing device 12 includes a floppy disk drive 4
2 and / or an optical disk drive 44. Floppy disk drive 42 may be any suitable floppy disk drive, such as a 3 "or 5" floppy disk drive. Further, the optical disk drive 44 may be made of any suitable optical disk drive such as a CD or DVD device. As described in detail below, the optical disk drive 44
May be configured to play music, movies, or games that include the surround sound encoded audio signal. According to this aspect of the invention, the processing device 12 may include a surround sound decoding circuit (not shown), and the surround sound circuit 38 includes an encoded surround sound circuit decoding circuit, as described in detail below. May be included.

As briefly mentioned above, the functionality of the surround sound circuit 38 can be embodied in a software application program, rather than an electrical circuit. In such a case, the surround sound application program can be loaded into the computer system 12 using the floppy disk drive 42 or the optical disk drive 44, in particular, the storage device 36 and / or the memory 34.

Referring to FIG. 2, a second embodiment 100 of a PC surround sound circuit is addressed. In detail, the PC surround sound circuit 100 includes a first input 102, a second input 104, an audio signal enhancement circuit 106, a high-pass filter 108 that can be turned on and off, a low-pass filter 110, and an addition or mixing circuit 112. Is preferred. According to this aspect of the invention, inputs 102 and 104 preferably comprise left and right stereo channels from a PC system. For example, inputs 102 and 104 may be inputs from a CD or DVD, and inputs 102 and 104 may consist of audio data channels from MIDI or WAVE files. The audio signal from a PC is generally in digital form, so if P
If the C surround sound system 100 is an analog signal processing system, the input 1
02 and 104 first pass through a digital-to-analog converter (not shown) before being processed by the system 100.

As shown in FIG. 1, inputs 102 and 104 will first pass through a stereo enhancement circuit 106. For example, the stereo enhancement circuit 10
One type of 6 may consist of a sound effects circuit configured to generate a simulated three-dimensional sound effect from a two-channel signal. According to one aspect of the invention, the stereo enhancement circuit 106 processes the inputs 102 and 104 by processing the inputs 102 and 104 according to specialized functions such as, for example, the following:
It is preferable to give a three-dimensional effect, that is, a spatial effect to the image.

L ′ = function (LINOPL, LINOPR) R ′ = function (LINOPR, LINOPL) where L ′ and R ′ are outputs 114 and 116 of the stereo enhancement circuit 106, respectively, and LINOPL and LINOPR are respectively Inputs 102 and 104. Further, the stereo enhancement circuit 106 can be enabled (disabled) or controlled (disabled) by controlling the state of the input signal 118. That is, when the input 118 is activated, ie, enabled, the stereo enhancement circuit 106 is turned on, while when the input 118 is disabled, the stereo enhancement circuit 106 is turned off. Further, as will be apparent to those skilled in the art, PC
The surround sound circuit 100 may be configured so as not to include the stereo enhancement circuit 106.

As shown in FIG. 2 and briefly described above, the stereo enhancement circuit 1
06 generates output signals 114 and 116. Signals 114 and 116 preferably serve as input signals to on / off high-pass filter 108 and surround mode selection circuit 120. As will be appreciated by those skilled in the art, if the stereo enhancement circuit 106 is disabled or if the stereo enhancement circuit 106 is all removed from the PC surround audio circuit 100, the signals 114 and 116 will be the input signals, respectively. Should be the same as 102 and 104.

The on / off high pass filter 108 preferably comprises any suitable filtering circuit configured to remove low frequencies from the signals 114 and 116. According to this aspect of the invention, high pass filter 108 removes all frequencies in the range of about 1.5 KHz or less and filters all frequencies in the range of about 1.5 KHz or more with first and second frequencies. Simulated surround sound output channels 126 and 128.

In general, there are approximately two main types of PC speaker systems currently on the market. The first type generally comprises two front active speakers capable of reproducing a fairly full range of audio frequencies. To obtain this type of loudspeaker configuration, a low-pass frequency is removed using a high-pass filter. As a result, the two front speakers can reproduce only the high frequency portion of the signal.

[0024] The second type of loudspeaker configuration currently sold in the PC market generally comprises a single subwoofer configured to drive two satellite high frequency speakers. In the case of such a special configuration, if a high-pass filter is used to remove low-frequency components, the sound output from the front speaker should be of low quality. This is because the subwoofer is a low-frequency output device. In order to solve this problem, the on / off high-pass filter 108 is
08 (SPK-M) for controlling the operation of the input signal 08 to enable the input signal.
(Also denoted as ODE). Thus, when the input 138 generates an active state signal, the on / off high pass filter 108 is turned on and only the high frequency portions of the signals 114 and 116 are subjected to the first and second simulated surround sound. Proceed to output channels 126 and 128. Conversely, input 1
When 38 generates an inactive state signal (eg, no signal), high pass filter 108 is turned off and the entire frequency range of signals 114 and 116 is advanced to output channels 126 and 128. Therefore, if a particular PC system has two front speakers covering the entire frequency range, the high-pass filter 108 is normally on, and the high-pass filter 108 and the low-pass filter 110 Different frequency ranges of the signal channel are separated and directed to the front speaker and the rear speaker. On the other hand, if the PC system is equipped with a subwoofer-type front speaker, the PC surround audio circuit 100 switches off the high-pass filter 108 so that the sound quality obtained from the subwoofer-based speaker configuration is not disturbed. .

As described briefly above, the signals 114 and 116 from the stereo enhancement circuit 106 also serve as inputs to a surround mode selection circuit 120 that acts as a control circuit for a simulated surround sound mode. Accomplish. According to this aspect of the invention, the surround mode selection circuit 120 includes the input signal 140 (
This input signal 140, when activated, switches on the center and subwoofer channels after the simulated surround sound circuit 100. For example, as shown more clearly in FIG.
When 40 is turned off, input signal 130 to high-pass filter 108 is also turned off, disabling the simulated surround sound mode. In this way, input signal channels 102 and 104 (LINOPL and LINOPR) pass to first output channel 126 and second output channel 128 without undergoing surround mode processing. However, when the input signal 140 is activated,
The surround sound circuit is turned on, and then the center and subwoofer channels are activated. Therefore, the output of the PC surround sound circuit 100 is preferably a simulated 5.1 channel surround sound output. Furthermore, if the input signal 140 is turned on and the input signal 138 is turned off, the output of the surround sound circuit 100 will be a 6-channel output, but the user will not be able to switch between the front and rear speakers. You will not experience frequency separation. This is because the high-pass filter is off.

When the surround mode selection circuit 120 is turned on, the signals 114 and 116
Pass through a low pass filter 110 that removes high frequencies from these signals. The output of the low pass filter 110 is a third output channel 130 and a fourth output signal channel 132, which preferably comprise signal frequencies in the range of about 1.5 KHz or less.

As shown in FIG. 2, signals 114 and 116 may first pass through bass boost circuit 122 before passing through low pass filter 110. Bass boost circuit 122
Preferably enhances the low frequency portions of the signals 114 and 116 before entering the low pass filter. As will be apparent to those skilled in the art, enhancing the low frequency portion of these signals will also enhance the output of low pass filter 110. Although the embodiment shown in FIG. 2 shows a PC surround sound system 100 with a bass boost circuit 122, those skilled in the art will recognize that the bass boost circuit 122 can be removed from this system without departing from the spirit of the invention. It will be obvious.

The signals 114 and 116 pass through a bass boost circuit 122 and a low pass filter 110 and then to an add or mix circuit 112 that adds or mixes the signals 114 and 116 into a single signal 142. desirable. Signal 142 then preferably proceeds to fifth and sixth simulated surround audio output signal channels 134 and 136. However, before going to channel 136, signal 142
First, it may pass through a low-pass filter 124.

According to one embodiment of the present invention, the first output signal channel 126 and the second output signal channel 128 preferably comprise right front and left front output channels;
The third output signal channel 130 and the fourth output signal channel 132 preferably comprise right rear and left rear output channels; the fifth output signal channel 134 comprises a central output channel. Preferably, the sixth output signal channel 136 comprises a subwoofer output channel. Thus, as described briefly above, when the PC surround sound circuit 100 is operating in the simulated surround sound mode, the high frequencies of the input channel are separated and directed to the front speakers, while the input channel The low frequency is separated and directed to the rear speaker. Thus, by performing frequency separation for the various speaker channels, the user is given the impression that the front speakers can extract different information than the rear speakers, ie, the essence of the coded surround sound system. become. Thus, by performing this frequency separation, a multi-channel (preferably 6-channel) surround sound system can be simulated from a 2-channel input.

Referring to FIG. 4, another embodiment 300 of a PC surround audio circuit is shown. Like the PC surround sound circuit 100, the PC surround sound circuit 300 is configured to receive a two-channel input signal from a PC and generate a multi-channel surround sound output signal from the two-channel signal. However, in addition to this,
The PC surround sound circuit 300 is configured to receive, decode, and reproduce a multi-channel surround sound encoded signal. For example, PC surround sound circuit 3
00 is a 5.1 channel surround sound encoding format, for example, Dolby St.
ereo Digital (DSD), Digital Theater System (DTS), or Sony Dynamic Digita
l It can decode and play well-known surround sound encoding formats such as Sound (SDDS).

To generate a simulated PC surround sound output from a two-channel input source, the PC surround sound circuit 300 operates similarly to the PC surround sound circuit 100. Specifically, PC surround audio circuit 300 is configured to receive two input channels 102 and 104 from a PC system. As described above with reference to FIG. 2 and the PC surround sound circuit 100, the PC surround sound circuit 3
00 is the input channels 102 and 10 that generate signals 114 and 116, respectively.
4 may include a stereo enhancement circuit 106 that spatially enhances 4. Stereo enhancement circuit 106 is switched on and / or off by input signal 118. If the stereo enhancement circuit 106
Will be in the off state, signals 114 and 116 should be the same as input channels 102 and 104, respectively. Further, the PC surround sound circuit 300 may be configured without the stereo enhancement circuit 106, but again the signals 114 and 116 should be the same as the input channels 102 and 104, respectively.

In the simulated surround sound mode, signals 114 and 116 are configured to be inputs to on / off high-pass filter 108, surround mode enhancement circuit 302, and multiplexing and mixing circuits 308 and 310. .
The on / off high pass filter 108 operates similarly to the on / off high pass filter described above with respect to FIG. 2 and the PC surround audio circuit 100. Specifically, if the PC system has two front speakers that can cover all or almost all frequencies, the on / off high-pass filter 108 is activated, resulting in signals 114 and 1
Only the high frequencies of the 16 are passed to the high filter outputs 126 and 128. Similarly, if the PC system includes a front loudspeaker configuration with a subwoofer driving two high frequency speakers, the on / off high frequency filter 108 is deactivated and the entire frequency range of signals 114 and 116 is reduced. It is preferable that the signal passes through the subwoofer and the satellite speaker. As will be appreciated by those skilled in the art, if the on / off high pass filter 108 is active and only the high frequencies of the signals 114 and 116 pass to the subwoofer, the subwoofer and the satellites driven thereby The sound quality obtained from the loudspeakers should be significantly degraded.

As shown in FIG. 4, the output signals 126 and 1 from the on / off high-pass filter 108
28 first passes through mixing and / or multiplexing circuits 304 and 306 before proceeding to the first and second surround audio output signal channels 314 and 316, respectively. According to this aspect of the invention, when PC surround sound circuit 300 is in the simulated PC surround sound mode state, multiplexing circuits 304 and 306
Signals 126 and 128 are passed from high pass filter 108 to output channels 314 and 316.
Through. Similarly, as described in detail below, when the PC surround sound circuit 300 is in the coded surround sound mode, the multiplexing circuits 304 and 306
The front left signal 326 and front right signal 328 (AL and AR, respectively) are passed from the 6-channel coded surround audio input to output channels 314 and 316.

The signals 114 and 116 are not only inputs to the high-pass filter 108 that can be turned on and off, but also inputs to the surround mode enhancement circuit 302. According to this aspect of the invention, the surround mode enhancement circuit 302 preferably includes an audio enhancement circuit, which, when activated, provides additional audio space separation to the rear speaker channel. For example, a typical formula for enhancing a post-channel signal is:

L * = L′−R ′ R * = R′−L ′ where L * and R * are signals 330 and 332, respectively, and L ′ and R ′ are signals from signals 114 and 116, respectively. Become.

The user is typically given the freedom to activate or deactivate the surround mode enhancement circuit 302. According to this aspect of the invention, input 334 is configured to control operation of audio mode enhancement circuit 302. Thus, when the input signal 334 is activated, the surround mode enhancement circuit 302 is turned on, while when the input signal 334 is deactivated, the surround mode enhancement circuit 302 is activated.
Is turned off. As will be apparent to those skilled in the art, the surround mode enhancement circuit 302 may help improve the sound quality of the surround sound of the signal, but on the other hand, the audio signal processing of the circuit may cause the signal to lose some directionality. May be. Thus, some users may not like the effect of the surround mode enhancement circuit 302 on the signal. Therefore, the user can freely select to stop the operation of the surround mode enhancement circuit 302 according to his / her preference.

The outputs 330 and 332 from the surround mode enhancement circuit 302 are inputs to a low pass filter 110 configured to remove all high frequencies in the signal and pass only low frequencies. Is preferred. In addition, signal 330
And 332 may first pass through the bass boost circuit 122 before entering the low-pass filter 110 to enhance the low-frequency portion of the same signal before entering the low-pass filter. The PC surround sound circuit 300 may or may not include the bass boost circuit 122.

Next, the output signals 130 and 132 from the low pass filter 110 enter a mixing and / or multiplexing circuit 312. PC surround sound circuit 300 is a simulated PC
When operating in the surround sound mode, multiplexing circuit 312 passes signals 130 and 132 to surround sound output channels 318 and 320, respectively. Similarly, when the PC surround sound circuit 300 is operating in the coded surround sound mode, the multiplexing circuit 312 outputs the coded surround sound channel 336.
And 338 (also indicated as ALS and ARS, respectively) to output channels 318 and 320.

As will be described in detail below, the PC surround sound circuit 300 can also operate in a mixed mode of the simulated surround sound mode and the encoded surround sound mode. In such a case, multiplexing and / or mixing circuit 312 desirably mixes signals 130 and 132 with signals 336 and 338 and passes the mixed signal to output channels 318 and 320.
According to this aspect of the invention, the input signal 340 (DVD-EN) is configured to control the operation of the switching circuit 312. For example, depending on the state of the input signal 340, the circuit 312 may output the signals 130, 132 or
To the output channels 318 and 120, or as a mixer to add the signals 130 and 132 with the signals 318 and 320. Also, the input signal 342 (SURRND-EN)
) Is used to activate and / or deactivate the circuit 310 to enable or disable the output channels 318 and 320. Thus, when input signal 342 is active, circuit 312 outputs a signal to output channel 318.
And 320. Similarly, when input signal 342 is inactive, circuit 312 is off, thus switching off output channels 318 and 320.

As mentioned briefly above, signals 114 and 116 also serve as inputs to multiplexing and / or mixing circuits 308 and 310. According to this aspect of the invention, when PC surround audio circuit 300 is in the simulated PC surround audio mode, mixing circuit 308 adds signals 114 and 116 to generate surround audio output channel 322. It is configured to be. Similarly, mixing circuit 3
10 adds signals 114 and 116 to form a surround sound output channel 324.
Is generated. As in the case of the PC surround sound circuit 100 in FIG. 2, the output channel 324 may first pass through the low-pass filter 124 to remove all high-frequency portions of the signal. Since output channel 324 is typically a subwoofer channel, a low pass filter should help enhance the low frequency output of subwoofer channel 324. The PC surround sound circuit 300 may or may not include the low-pass filter 124.

The mixing and / or multiplexing circuits 308 and 310 may include an input signal 342 (SURR ND-EN). This input signal 342 may be configured to activate or deactivate output channels 322 and 324, as described above with respect to circuit 312. According to this aspect of the invention, when the input signal 342 is inactive, the respective surround audio output channels 322 and 324 from the circuits 308 and 310 are turned off.

As described above, the PC surround sound circuit 300 may be configured to reproduce an audio signal encoded by the surround sound encoding method. However, as shown in FIG. 4, the coded surround sound mode input signal to the PC surround sound circuit 300 comprises a 6-channel input signal. Therefore, the encoded surround sound signal is preferably decoded before reaching the circuit 300. However, as will be apparent to those skilled in the art, the circuit 300 may include a circuit, not shown, for decoding the encoded surround audio signal prior to processing. For example, the circuit 300 can include an AC3 surround audio decoder. Accordingly, the invention is not limited to the illustrated embodiment.

Preferably, the PC surround audio circuit 300 includes six encoded surround audio input channels and six surround audio output channels when in the encoded surround audio mode state. According to this aspect of the invention, the six input channels are typically front left 326, front right 328, back left 336, back right 338, center channel 344, and subwoofer 346. The 6-channel output of the PC surround sound circuit 300 is composed of outputs 314-324.
4 comprises front left, front right, rear left, rear right, center, and subwoofer channel outputs, respectively, according to a preferred embodiment of the present invention. Thus, when operating in the encoded surround audio mode, the multiplexing circuits 304 and 306 pass the front left 328 and front left 326 surround audio input channels to the front right output channel 314 and the front right output channel 316, respectively. Similarly, the circuit 312 includes a rear left 338 and a rear right 33
The six input channels are divided into left rear output channel 318 and right rear output channel 32, respectively.
It is configured to pass through zero.

Finally, in coded surround sound mode, circuits 308 and 310 are configured to pass center channel input signal 344 to center output channel 322 and pass subwoofer input signal 346 to subwoofer output channel 324. ing.

As described above, the PC surround sound circuit 300 may be configured so that the operation in the simulated surround sound mode and the operation in the coded surround sound mode are performed in parallel. For example, certain PC applications, such as video games and movies, require some signal from the PC itself (eg, MIDI or WA).
VE file data), while other audio and / or video signals can be generated by surround sound encoding from a PC device such as a DVD or VCD device. According to this aspect of the invention, the PC surround audio circuit 300 includes a two-channel input from a PC, for example, input channels 102 and 104.
Etc., and a PC or other PC-related device, such as a DVD or VC
A 6-channel surround sound input may be received from a device D or the like. In this manner, the PC surround sound circuit 300 outputs the two-channel input signals 102 and 104.
And generate a 6-channel simulated surround audio output from the input signal as described above. Thereafter, circuit 300 mixes the simulated surround audio channel with the six-channel coded surround audio input to produce a synthesized surround audio output.

According to this aspect of the invention, the mixing circuit 304 mixes or adds the signal 126 from the high-pass filter 106 with the front left input channel 328 of the coded surround sound input to produce a front left surround sound output. It may be configured to generate a channel 314. Similarly, circuit 306 mixes signal 128 from high pass filter 106 with right front surround audio input channel 326 to form right front output channel 316.
May be generated. Further, as described above, the multiplexing / mixing circuit 31
2 may be configured to add signals 130 and 132 with signals 336 and 338 to generate left rear output channel 318 and right rear output channel 320, respectively. Finally, mixing circuit 308 may be configured to add center channel input 344 with mixing signals 114 and 116 to generate center channel output 322, and mixing circuit 310 may configure subwoofer input channel 346. It may be configured to sum with signals 114 and 116 to produce subwoofer channel output 324. Thus, the output channels 314-324 will consist of a combination of a simulated surround audio channel and an encoded surround audio channel.

Referring now to FIG. 5, a flow chart 500 is shown illustrating a method of generating a simulated surround audio signal from an input signal having two or more signal channels. The input signal may have more than two signal channels, but for ease of understanding, the method described here is applied only to two-channel signals. According to one aspect of the invention, a method for generating a simulated surround audio signal comprises:
Preferably, it starts with the reception of the two-channel input signal (step 502).
Next, it is determined whether the input signal is to be spatially enhanced (step 504). Specifically, as described above, by spatially enhancing the input signal, the signal is given a dimensional, or spatial, effect, improving the sound quality of stereo or surround sound. If the spatial enhancement aspect of the method is turned on, the input signal is spatially enhanced (step 506). On the other hand, if the spatial enhancement aspect of the method is not turned on, the signal will bypass step 506 (see path 508).
.

Next, according to the preferred method of the present invention as shown in FIG.
It is determined whether low frequencies should be filtered out of the input signal (step 510), and the surround mode is switched on so that the right rear, left rear, center,
And whether a subwoofer channel is to be generated (step 512).

As described above with respect to FIGS. 2 and 4, different PC systems may have different pre-speaker configurations, eg, two full frequency speakers, or a subwoofer speaker driving two high frequency speakers. You may have When the front speaker configuration for a PC system consists of two full frequency speakers, it is generally desirable to filter out low frequencies from the input signal before passing the signal through the front speakers. As described above, by dividing the high frequency of the input signal to the front speaker and the low frequency of the input signal to the rear speaker, the effect of different audio information coming from different speakers (ie, surround audio effect). Is obtained. On the other hand, when using a subwoofer and high frequency speaker configuration, it is generally best not to filter out low frequencies from the input signal. As described above, depending on the configuration of the front speaker of the system, before passing the signal through the front speaker, the low-frequency component may be removed from the signal by a filter, or may not be removed. If filtering is used, the low frequency is removed from the input signal (step 51).
4) The high frequency portion of the input signal goes to the left and right front speaker channels of the simulated surround sound system (step 516). If you do not use filtering,
The entire frequency range of the input signal goes to the left and right front speaker channels of the simulated surround sound system (step 518).

Next, referring to step 512 of FIG. 5, if the simulated surround sound mode is not switched on, neither the later, center nor subwoofer channels are generated (step 520). On the other hand, if the simulated surround sound mode is switched on, then the later, center, and subwoofer channels are created. More specifically, when generating the left and right simulated surround sound channels, the high frequency components of the input signal are filtered out (step 522), and only the low frequency components are output from the left and right simulated surround audio output channels. (Step 524). Also, when generating the center and subwoofer channels, two or more channels of the input signal are combined into a single channel (step 526), where the single channel is both a center channel and a subwoofer simulated surround audio output channel. (Step 528). In this way, a six-channel simulated surround audio output signal is created from the two-channel input signal.

Referring to FIG. 6, a flowchart 600 illustrates a method for generating a simulated surround audio signal from a two-channel input signal and a method for adding the simulated surround audio signal to a six-channel coded surround audio signal. ing. In particular, the method illustrated in FIG. 6 includes first generating a simulated surround audio signal in the same manner as described above with respect to FIG. Specifically, first, a two-channel input signal is received (step 602), and the signal is spatially enhanced (step 606). Alternatively, as described above, the spatial enhancement aspects of the method may be omitted (path 608).

As described above with reference to FIG. 5, depending on the configuration of the front speaker of the PC system, the low frequency band of the input signal may or may not be removed by the filter ( Step 610). If the low frequencies are filtered out, step 614 is processed, otherwise step 614 is skipped.
Similarly, as described above, if the surround sound mode is not switched on (step 612), then neither the center nor the subwoofer channel is generated (step 616). However, when the surround sound mode is switched on, the high frequency is filtered out of the input signal before the input signal advances to the left and right rear speakers.

Still referring to FIG. 6, according to one aspect of the present invention, a six-channel coded surround audio signal may be received and added or mixed with a simulated surround audio signal. At step 620, it is determined whether there is a six-channel coded surround audio input signal. If there is no 6-channel coded surround audio input signal, the high frequency of the input signal goes to the left and right front simulated surround audio output channel (step 622), and the low frequency of the input signal channel is left and right rear simulated. The process proceeds to the surround sound output channel (step 624).
As with the method shown in FIG. 5 and described above, when generating the center and subwoofer simulated surround audio channels, the two input signal channels are combined (step 626) and the combined signal is Proceed to both the center and subwoofer simulated surround audio output channels (step 628).

If a six-channel coded surround audio input signal is present, the left and right front channels of the coded surround audio signal are received (step 630) and added to the left and right front simulated surround audio channels (step 632), A previous output channel is generated (step 634). Similarly, the left and right coded surround audio channels are received (step 636) and added to the left and right simulated surround audio channels (step 638) to generate left and right rear output channels (step 640).
). Finally, the center and subwoofer channels of the six-channel surround audio signal are received (step 642) and added to the center and subwoofer simulated surround audio channels (step 644) to produce a center and subwoofer simulated surround audio output channel. (Step 646).

In conclusion, the present invention provides a novel method and apparatus for generating a PC surround sound output from a two-channel PC input, as well as a system for reproducing a six-channel surround sound encoded signal from a PC. . While the presently preferred embodiments of the invention have been described in detail, it will be apparent to those skilled in the art that various changes, modifications, and equivalents are possible. For example, while embodiments of the present invention have been described herein with reference to analog signal processing circuits, it should be understood that digital surround processing or software applications could be used to generate PC surround sound without departing from the spirit of the present invention. It will be clear to those skilled in the art. Therefore, the above description should not be taken as limiting the scope of the invention, which is defined by the appended claims.

[Brief description of the drawings]

FIG. 1 is a diagram of a computer system embodying a PC surround sound circuit.

FIG. 2 is a circuit schematic diagram of a first embodiment of a PC surround sound circuit.

FIG. 3 is a chart showing a relationship between two input signals to the PC surround sound circuit of FIG. 2;

FIG. 4 is a detailed circuit diagram of a second embodiment of the PC surround sound circuit.

FIG. 5 is a flowchart showing a method for generating a simulated surround sound.

FIG. 6 is a flowchart illustrating a method for generating a simulated surround audio signal and mixing the simulated surround audio signal with an encoded surround audio signal.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), DE, GB, JP, SG (72) Inventor Neo Jeongsilon Singapore Singapore 521149 Tampins Tampins Street 12-♯09-96 Block 149 F Term (Reference) 5D062 BB03

Claims (59)

[Claims] An apparatus for receiving a personal computer (PC) source signal having two or more source signal channels and generating a simulated surround audio output signal having three or more output signal channels from the PC source signal. Receiving the two or more source signal channels from a PC and reducing the low frequency of the two or more source signal channels such that only the high frequency is passed to the first and second output signal channels. A high-pass filter configured to remove; and the two or more sources receiving the two or more source signal channels from the PC such that only low-pass frequencies are passed to at least one output signal channel. A low-pass filter configured to remove a high-frequency component of the signal channel. Towards the second output signal channels,
An apparatus for generating a simulated surround audio output signal by separating and directing said low frequency to said at least one output signal channel. 2. The apparatus of claim 1, wherein the two or more source signal channels of the source signal include left and right stereo signal channels. 3. The apparatus of claim 1, wherein the two or more source signal channels include audio signal channels generated by a MIDI command sound generator. 4. The apparatus of claim 1, wherein the two or more source signal channels include a WAVE signal channel. 5. The apparatus according to claim 1, wherein said at least one output signal channel comprises a third output signal channel, wherein said two or more source signal channels are added to said third output signal channel. The device of claim 1, further comprising: 6. The apparatus of claim 1, wherein said at least one output signal channel includes a third output signal channel and a fourth output signal channel. 7. The apparatus according to claim 6, further comprising an adder circuit for adding said two or more source signal channels to a fifth output signal channel and a sixth output signal channel. 8. The first output signal channel comprises a right front output signal channel, the second output signal channel comprises a left front output signal channel, and the third output signal channel comprises a right rear output signal channel. Wherein the fourth output signal channel comprises a left rear output signal channel, the fifth output signal channel comprises a center output signal channel, and the sixth output signal channel comprises a subwoofer output signal channel. An apparatus according to claim 7, wherein 9. The apparatus of claim 8, wherein said subwoofer output signal channel passes through a low pass filter before proceeding to a subwoofer speaker. 10. A first adder for adding the two or more source signal channels to a fifth output signal channel, and adding the two or more source signal channels to a sixth output signal channel. And a second summing circuit for: 11. The apparatus according to claim 10, wherein said fifth output signal channel is a center output signal channel and said sixth output signal channel is a subwoofer output signal channel. 12. The input signal of claim 1, wherein the simulated surround audio mode is disabled such that the output signal of the device is a two-channel output signal. An apparatus, further comprising: 13. The high-pass filter disables the high-pass filter such that all frequencies of the two or more source signal channels are passed to the first and second output signal channels. The apparatus of claim 1, comprising a configured input signal. 14. The apparatus of claim 8, further configured to receive a second source signal having six source signal channels. 15. The apparatus of claim 14, wherein the six source signal channels comprise a front right, front left, rear right, rear left, center, and subwoofer channel. 16. The apparatus of claim 15, wherein the first output signal channel is selected from the high pass filter or the right front channel is selected from the second source signal. A first multiplexer configured to be the first output signal channel; and selecting the second output signal channel from the high-pass filter or changing the left front signal channel from the second source signal. Selecting said second of said device
A second multiplexer to be an output signal channel, and selecting the third output signal channel from the low-pass filter, or selecting the right rear channel from the second source signal, A third multiplexing device to be the third output signal channel of the device; and selecting the fourth output signal channel from the low-pass filter or the left output signal from the second source signal. Select the post-channel and select the fourth channel from the device.
A fourth multiplexing device for selecting the fifth output signal channel from the first adding means, or selecting the central channel from the second source signal. And a fifth multiplexing device for providing the fifth output signal channel, and selecting the sixth output signal channel from the second adding means, or selecting the sixth output signal channel from the second source signal. A sixth multiplexing device for selecting a subwoofer channel to be the sixth output signal channel of the device. 17. The apparatus according to claim 17, wherein the first, second, third, fourth, fifth, and sixth multiplexers can form a single 12-channel to 6-channel multiplexer. An apparatus according to claim 16. 18. The apparatus according to claim 15, wherein the first output signal channel from the high-pass filter is added to the right front channel of the second source signal and the summed second signal of the apparatus is added. A third summing circuit for generating one output signal channel; summing the second output signal channel from the high-pass filter with the left front channel of the second source signal; A fourth adding circuit for generating a second output signal channel obtained by adding the third output signal channel from the low-pass filter to the right rear channel of the second source signal; A fifth summing circuit for generating a summed third output signal channel of the device; and a fourth output signal channel from the low pass filter for the left rear channel of the second source signal. A sixth summing circuit for summing to produce a summed fourth output signal channel of the device, wherein the first summing circuit converts the first and second source signal channels. The second source signal is configured to sum with the center channel to generate a summed fifth output signal channel of the device, and wherein the second summing circuit includes the first and second summing circuits. A source signal channel of the second source signal and the sub-woofer channel of the second source signal to generate a summed sixth output signal channel of the device. 19. The summed first output signal channel comprises a right front output signal channel, the summed second output signal channel comprises a left front output signal channel, and the summed third output signal channel. The channel comprises a right rear output signal channel, the summed fourth output signal channel comprises a left rear output signal channel, the summed fifth output signal channel comprises a center output signal channel,
19. The apparatus of claim 18, wherein the summed sixth output signal channel comprises a subwoofer output signal channel. 20. A system for generating and reproducing a simulated surround audio output signal having three or more output signal channels from a PC source signal having two or more source signal channels, comprising: a processor; a PC surround audio circuit; The PC surround sound circuit receives the two or more source signal channels from a PC, and passes only high frequency frequencies to the first and second output signal channels. A high-pass filter configured to remove low-frequency frequencies of the two or more source signal channels; and receiving the two or more source signal channels from the PC, wherein only the low-frequency signal has at least one output signal. A low frequency configured to reject high frequencies of the two or more source signal channels so as to be passed to the channel. A filter, toward the first and second output signals channel by separating the high-frequency,
Generating a simulated surround audio output signal by separating and directing the low frequency to the at least one output signal channel; receiving the output signal channel from the surround audio circuit; A system comprising: three or more speakers configured to reproduce a signal. 21. The two or more source signal channels of the source signal,
The system of claim 20, comprising left and right stereo signal channels. 22. The system of claim 20, wherein the two or more source signal channels include an audio signal channel generated by a MIDI command audio generator. 23. The system of claim 20, wherein the two or more source signal channels include a WAVE signal channel. 24. The at least one output signal channel includes a third output signal channel, and wherein the surround audio circuit adds the two or more source signal channels to the third output signal channel. The system of claim 20, further comprising a summing circuit. 25. The system of claim 20, wherein said at least one output signal channel includes a third output signal channel and a fourth output signal channel. 26. The surround sound circuit further includes an adder circuit for adding the two or more source signal channels to a fifth output signal channel and a sixth output signal channel. The system according to claim 25. 27. The system of claim 27, wherein the first output signal channel comprises a right front output signal channel, the second output signal channel comprises a left front output signal channel,
Output signal channel comprises a right rear output signal channel, said fourth output signal channel comprises a left rear output signal channel, said fifth output signal channel comprises a center output signal channel, and said sixth output signal channel. 27. The system of claim 26, wherein the channels comprise subwoofer output signal channels. 28. The system of claim 27, wherein said subwoofer output signal channel passes through a low pass filter before traveling to a subwoofer speaker. 29. A surround sound circuit comprising: a first adder for adding the two or more source signal channels to a fifth output signal channel; and a sixth adder for adding the two or more source signal channels to a sixth output signal channel. 21. The system of claim 20, further comprising: a second summing circuit for summing to the output signal channel. 30. The system of claim 28, wherein the fifth output signal channel is a center output signal channel and the sixth output signal channel is a subwoofer output signal channel. 31. The system of claim 20, wherein the surround sound circuit is configured to disable a simulated surround sound mode such that an output signal of the system is a two-channel output signal. The system further comprising a signal. 32. The high-pass filter disables the high-pass filter such that all frequencies of the two or more source signal channels are passed to the first and second output signal channels. The system of claim 20, comprising a configured input signal. 33. The system of claim 27, wherein the surround sound circuit is further configured to receive a second source signal having six source signal channels. 34. The system of claim 33, wherein the six source signal channels comprise a front right, front left, rear right, rear left, center, and subwoofer channel. 35. The surround sound circuit comprising: selecting the first output signal channel from the high-pass filter or selecting the right front channel of the second source signal; A first multiplexing device to be a first output signal channel, and selecting the second output signal channel from the high-pass filter or selecting the left front signal channel of the second source signal And a second multiplexing device configured to be the second output signal channel of the surround sound circuit, and selecting the third output signal channel from the low-pass filter, or A third multiplexer for selecting the right rear channel from a source signal so as to be the third output signal channel of the surround sound circuit; Or selecting the fourth output signal channel from the second source signal or selecting the rear left channel from the second source signal so as to be the fourth output signal channel from the surround sound circuit. And selecting the fifth output signal channel from the first adding means, or selecting the left center channel from the second source signal, and selecting the fifth output signal channel A fifth multiplexer that selects the sixth output signal channel from the second adder, or selects the subwoofer channel from the second source signal, and 35. The system of claim 34, further comprising: a sixth multiplexer for providing the sixth output signal channel of an audio circuit. 36. The first, second, third, fourth, fifth, and sixth multiplexers may include a single 12-channel to 6-channel multiplexer. Item 36. The system according to Item 35. 37. The surround sound circuit includes: adding the first output signal channel from the high-pass filter to the right front channel of the second source signal; A third adding circuit for generating an output signal channel of the surround sound circuit, and adding the second output signal channel from the high-pass filter to the left front channel of the second source signal. Second added
A fourth adding circuit for generating an output signal channel of the second audio signal; and a third output signal channel from the low-pass filter added to the right rear channel of the second source signal. The third of
A fifth adding circuit for generating an output signal channel of the second audio signal, and a fourth output signal channel from the low-pass filter is added to the left rear channel of the second source signal, thereby forming the surround sound circuit. The fourth of
A sixth adder circuit for generating an output signal channel of the second source signal, wherein the first adder circuit connects the first and second source signal channels with the central channel of the second source signal. Summing to generate a summed fifth output signal channel of the surround sound circuit, and the second summing circuit converts the first and second source signal channels to the second signal signal. 35. The system of claim 34, wherein the system is configured to sum a source signal with the subwoofer channel to generate a summed sixth output signal channel of the surround sound circuit. 38. The summed first output signal channel comprises a right front output signal channel, the summed second output signal channel comprises a left front output signal channel, and the summed third output signal channel. The channel comprises a right rear output signal channel, the summed fourth output signal channel comprises a left rear output signal channel, the summed fifth output signal channel comprises a center output signal channel,
The system of claim 37, wherein the summed sixth output signal channel comprises a subwoofer output signal channel. 39. A method for generating a simulated surround audio signal having three or more signal channels from a PC signal having two or more channels, comprising: receiving the two or more PC signal channels from a PC. , Filtering low frequency from the two or more PC signal channels and replacing the two or more PC signal channels having only high frequency with a first of one or more simulated surround audio signal channels. Passing to the set, filtering high frequencies from the two or more channels and removing the two or more channels having only low frequencies from a second one or more simulated surround audio signal channels. Separating the higher frequencies of the two or more channels into one or more simulations. To the first set of round audio signal channels, and to separate and direct the low frequency of the two or more channels to the second set of one or more simulated surround audio signal channels; A method comprising generating a simulated surround audio signal. 40. The method of claim 39, wherein the two or more PC signal channels include left and right stereo channels. 41. The method of claim 39, wherein the two or more PC signal channels include two audio signal channels generated by a MIDI command audio generator. 42. The method of claim 39, wherein the two or more PC signaling channels include a WAVE signaling channel. 43. The method of claim 39, wherein said first set of one or more simulated surround audio signal channels comprises a right channel and a left channel. 44. The method of claim 43, wherein said second set of one or more simulated surround audio signal channels comprises a single channel. 45. The left and right channels comprise right front and left front channels.
The method of claim 43, wherein the second set of one or more simulated surround audio signal channels comprises right rear and left rear channels. 46. The method further comprising mixing the two or more PC signal channels to form a single channel that is routed to a third set of one or more simulated surround audio signal channels. 40. The method of claim 39, wherein the method comprises: 47. The method of claim 46, wherein said third set of one or more simulated surround audio signal channels comprises a center channel and a subwoofer channel. 48. The method of claim 47, further comprising filtering out high frequencies from the subwoofer channel so that only low frequencies are passed to the subwoofer speakers. 49. Omitting the step of filtering out the low frequency band,
40. The method of claim 39, wherein all frequencies of the two or more PC signal channels can be passed up to the first set of one or more simulated surround audio signal channels. . 50. A method for reproducing an encoded surround audio signal having at least three channels or generating a simulated surround audio signal having three or more signal channels from a PC signal having two or more channels. Selecting one of a simulated surround sound mode and an encoded surround sound mode, wherein if the simulated surround sound mode is selected, the method comprises: Receiving a PC signal channel; filtering low-frequency components from the two or more PC signal channels to filter the two or more PC signal channels having only high-frequency components into one or more surround sound signals; Passing up to a first set of output channels; filtering high frequency from the two or more channels And passing the two or more signal channels having only low frequency frequencies up to a second set of one or more surround sound output channels. Separate high frequencies for the first set of one or more surround audio signal channels and separate the low frequencies of the two or more channels for one or more surround audio output channels. Directing the second set to generate a simulated surround audio signal, wherein the coded audio mode is selected, the method comprises: providing the at least three coded surround audio channels with at least 3 Passing through to one surround audio output channel. 51. When the simulated surround mode is selected,
The method of claim 50, further comprising mixing the two or more PC signal channels to form a single channel that is routed to a third set of one or more surround audio output channels. The described method. 52. The first set of one or more surround audio output channels comprises a right front channel and a left front channel, and the second set of one or more surround audio output channels comprises a right rear channel. 52. The method of claim 51, wherein the third set of one or more surround audio output channels comprises a center channel and a subwoofer channel, comprising a channel and a left rear channel. 53. The method of claim 52, further comprising filtering the high frequency from the subwoofer channel so that only low frequency is passed to the subwoofer speaker. 54. Omitting the step of filtering out the low frequency band,
51. The method of claim 50, wherein all frequencies of the two or more PC signal channels can be passed up to the first set of one or more surround audio output channels. 55. A simulated surround sound signal having at least signal channels S1, S2, S3 and S4 is generated from a PC signal having at least channels PC1 and PC2, and the simulated surround sound signal is converted into at least a signal channel E1. , E2, E3 and E4 mixed with coded surround sound to produce at least the channels O1, O2, O3 and O4, comprising: receiving the PC signal channels PC1 and PC2 from a PC; Filtering the low frequency from the channels PC1 and PC2 to produce filtered PC signal channels PCH1 and PCH2 having only the high frequency, and filtering said filtered PC signal channels PCH1 and PCH2; Pass through signal channels S1 and S2 Filtering out the high frequency from the PC signal channels PC1 and PC2 to produce filtered PC signal channels PCL1 and PCL2 having only low frequency, and the filtered PC signal channel PCL1. And PCL2 to the signal channels S3 and S4; receiving the coded surround audio signal channels E1, E2, E3 and E4; and the simulated surround audio signal channels S1, S2 and S3. And S
Mixing the encoded surround audio signal channels E1, E2, E3, and E4 to generate the surround audio signal output channels O1, O2, O3, and O4. . 56. The method further comprising mixing the PC signal channels PC1 and PC2 to generate a mixed PC signal channel PCM and passing the mixed PC signal channel PCM to the simulated surround sound signal channels S5 and S6. The method of claim 55, wherein: 57. The method further comprises mixing the simulated surround audio signals S5 and S6 with encoded surround audio signals E5 and E6 to generate surround audio signal output channels O5 and O6. Item 56. The method according to Item 56. 58. Surround audio signal channels O1, O2, O3, 04, 0
58. The method of claim 57, wherein 5 and 06 comprise front right, front left, rear right, rear left, center, and subwoofer channels, respectively. 59. The method of claim 58, further comprising passing a low pass filter before mixing said simulated surround audio signal channel S6 with an encoded surround audio signal channel E6. .