KR0146602B1 - Automatic audio state setting apparatus for optical disc player - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for automatically setting an audio state of an optical disc reproducing system for automatically setting a de-emphasis state of an audio signal for analog conversion when an audio signal is reproduced on a disc recorded with moving picture information. The MPEG audio decoder 44 Audio state auto-setting means 52 for automatically setting an audio signal de-emphasis state for the data conversion means 48 under a fixed state of frequency for the audio signal based on the bit stream of the audio data decoded in Delay means 53 is further provided for generating a switching signal and an audio muting signal for setting the audio frequency and the de-emphasis state by the audio state automatic setting means 52 at the start of the program, and during analog conversion of the audio signal. Audio status setting is done automatically.

Description

Audio state automatic setting device of optical disc playback system

1 is a block diagram showing an optical disc reproducing system to which an automatic audio state setting device according to the present invention is applied.

2 is a diagram showing the detailed configuration of an audio state automatic setting apparatus of the optical disc reproducing system according to the present invention shown in FIG.

* Explanation of symbols for main parts of the drawings

10: function setting section 12: CD-microcom

14: servo control unit 16: spindle motor

18: optical pickup 20: RF amplifier

22: CD-digital processing unit 24: CD-ROM decoder

26: first memory 28: MPEG-microcom

30: second memory 32: MPEG-Video decoder

34: third memory 36: timing signal generator

38: RGB data converter 40: RGB encoder

42,46: filter / amplifier 44: MPEG audio decoder

46: switching unit 48: data conversion unit

50: filter / amplifier 52: audio state automatic setting unit

54: data serial-parallel conversion unit 56: counter

58: NAND gate 60: data latch unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for automatically setting audio state of an optical disc reproducing system, and more particularly, to reproduce a disc-type recording medium in which moving picture information and audio information are extruded and recorded by a predetermined data compression algorithm (for example, MPEG algorithm). The present invention relates to an audio state automatic setting apparatus of an optical disc reproducing system, which automatically sets an audio state of an optical disc reproducing system which automatically sets an audio state including an audio frequency and a de-emphasis state during digital-to-analog conversion of data.

Recently, when a movie program or a video flexible program is reproduced using a video CD disc as a disc-shaped recording medium in which moving picture / audio information is compressed and recorded by the MPEG algorithm, which is a data compression technique, the video CD disc is reproduced. In the optical disc reproducing system, digital information read from the disc is processed by the digital processing means, and then the compressed data is restored by the MPEG video decoder and the MPEG audio decoder based on the MPEG algorithm.

According to such a video CD disc, a lead-in area including management information of the video CD disc and at least one crack in which MPEG audio / video information processed by the MPEG method are usually allocated, while heterogeneous tracks are allocated. ), A program area capable of selectively allocating at least one CD-DA track and a lead-out area indicating the last section of information recording of the disc.

At least one track in which MPEG audio / video information is recorded is allocated to the program area, and the first track is a video CD data track, which indicates a state in which video flexible information is recorded on a PVD area and a corresponding disk. Karaoke basic information area, video CD information area, segment play item area and CD-I application area are included. In the second to Nth tracks (including up to 99 tracks), MPEG audio / video information compressed by the MPEG algorithm is recorded. In some cases, CD-DA information is recorded from the Nth track toward the inner track direction. One or more recorded CD-DA tracks can be selectively assigned.

According to an exemplary configuration of an optical disc reproducing system for reproducing image information by handling a video CD disc as a recording medium on which the above image image or movie is recorded, a signal (e.g., a power supply) for initial start of disc reproduction in a function setting means is provided. ON) is input to the CD microcomputer, the CD microcomputer controls the servo control means so that the spindle servo and focusing servo signals for the spindle motor and the optical pickup are applied to the spindle driving means and the optical pickup driving means. Accordingly, the spindle drive means drives the spindle motor 18 at constant speed so that the disc as the recording medium is rotated at constant speed, while the optical pickup drive means performs a focusing servo on the disc of the optical pickup.

In such a state, before the input for displaying the initial screen is input from the function setting means, the CD-microcomputer controls the optical pickup driving means to read the information of the lead-in area of the disk by the optical pickup. Then, the information is amplified by the RF amplifying means, and the lead-in information processed by the CD-digital processing means is applied to the CD-microcomputer.

Then, the CD-microcomputer controls the servo control means in response to the reproduction information (e.g., music selection information in the case of a disk on which image flexible is recorded) applied from the function setting means, and the spindle suitable for the track of the selected position. Tracking control of the servo and optical pickup is performed, and in this state, the image flexible data read from the disc is amplified by the RF amplifying means, and then digitally processed by the CD-digital processing means, and processed by the CD-digital processing means. If the disc is a CD or CDG disc, information read from the disc is applied to the CD disc processing system, while information read from a disc on which moving picture image recordings are recorded is applied to the CD-ROM decoder. -Decoded in ROM format, the decoded video / audio information is under the control of MPEG Microcom MPEG Audio Decoder / Video Decoder Is applied to and decoded by the MPEG algorithm.

The moving picture signal decoded by the MPEG video decoder is converted into an RGB signal for display on an RGB encoder, then filtered and amplified by a filter / amplification means, and displayed on a display device (i.e., a CRT device). The audio signal decoded by the decoder is converted into an analog signal by a data conversion means consisting of a digital-analog converter, then filtered and amplified by a filter / amplification means, and reproduced by a voice output device (ie, a speaker).

In this case, in the MPEG audio decoder which performs the restoration process of the audio information, it is necessary to properly set the audio frequency and the processing mode of the de-emphasis of the audio signal when encoding for recording the audio signal on the disc. Becomes possible. Here, the audio frequency applied to the disc,

00: 44.1KHz

01: 48KHz

10: 32KHz

11: spare

And the deemphasis state accordingly,

00: nothing

01: 50/15 μsec

10: spare

11: CCITT J.17

Is defined as

Therefore, a bit stream of information from a disc that has been digitally processed and decoded by a CD-ROM decoder is usually transferred to an MPEG audio decoder under the control of an MPEG microcomputer equipped in the optical disc playback system. The audio information is classified into, and the status information (ie, audio sampling frequency and deemphasis mode) for the classified audio information is output in series, and the audio status information is determined by the MPEG microcomputer and the Since the analog audio conversion of the audio signal is possible in the MPEG audio decoder, the sampling frequency (i.e., audio frequency) and the de-emphasis state of the audio signal set for the disc are eventually used for the data conversion means for analog conversion of the audio data. Must be set correctly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to automatically set an audio state including an audio frequency and a de-emphasis state based on a data bitstream reproduced by an MPEG audio / video decoder for recovering optical disc data. It is an object of the present invention to provide an audio state automatic setting device of an optical disc playback system.

In order to achieve the above object, according to a preferred embodiment of the present invention, an MPEG audio / video decoder corresponding to a data compression / restoration algorithm is reproduced from a disc on which moving picture information is recorded, and digital audio data reconstructed by the MPEG audio decoder. An optical disc reproducing system having data conversion means for performing analog conversion of digital data on the basis of state information, wherein the audio signal is fixed under a fixed frequency of an audio signal based on a bit stream of audio data decoded by the MPEG audio decoder. Audio state automatic setting means for automatically setting the de-emphasis of the delay means and delay means for generating a switching signal and an audio muting signal for setting the audio frequency and the de-emphasis state by the audio state automatic setting means at the start position of the program. This is further equipped with light An audio state automatic setting device of a disc playback system is provided.

Preferably, the audio state automatic determining means includes a data converting means for serial-parallel converting the audio data bitstream output from the MPEG audio coder and a counter for counting a system clock based on a frame start signal output from the MPEG audio coder. Means for latching parallel data converted by the data converting means according to the count result of the counter means to provide a de-emphasis state to the data converting means, and audio frequency / de-emphasis output from the data latching means. It comprises a switching device for switching the status output.

The switching element comprises a first switching element connected to a first de-emphasis output side via a first audio frequency output side and a first inverter of the data latch means, a second audio frequency output side and a second inverter of the data latch means. A second switching element connected to a second de-emphasis output side by means of the first and second switching elements connected to the de-emphasis output side at the start position of the program, and the first and second switching elements It is configured to be connected to the frequency output side.

According to the present invention, a logic means for generating a data latch clock signal for the data latch means by logic processing the system clock signal from the MPEG audio decoder and the count output of the counter means is provided.

Preferably, the logic means is connected to the system clock signal output side of the MPEG audio decoder and the count carry output side of the counter means to logically NAND process the system clock signal and the carry signal at a high level of the system clock signal and the count output. And a NAND gate for generating a clock signal for the data latching means.

The delay means includes timer means for outputting a high level at a start position of the program for a time constant time to switch the audio frequency / de-emphasis setting by the audio state automatic setting means and to generate an audio mute signal; Logic OR means for generating an audio mute signal by performing a logic OR process on the output of the timer means and an external forced audio mute signal.

According to the audio state automatic setting state of the optical disc reproducing system according to the present invention configured as described above, MPEG audio for decoding the MPEG audio during reproduction of a video / audio compressed by a predetermined data compression / restoration algorithm (MPEG algorithm) The audio frequency information adaptive to the disc is automatically set by automatically setting the audio frequency and the de-emphasis state of the data conversion means (digital-analog converter) that performs analog conversion of the data based on the audio data bit stream at the decoder. It will be set automatically.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

FIG. 1 is a block diagram of an optical disc reproducing system to which image information is reproduced, for example, by handling a video CD disc as a recording medium on which image flexible is recorded, and to which an automatic audio state setting device according to the present invention is added. The function setting unit indicated by 10 is provided to enable setting of the overall control function of the corresponding optical disc playback system, and the CD-microcomputer indicated by 12 indicates the video as a recording medium based on the function or mode set by the function setting unit 10. In order to reproduce information on a CD disc (hereinafter referred to as a disc), overall function control of spindle servo, focusing / tracking servo, and information reproduction processing is performed.

The servo control unit denoted by 14 servo controls the spindle motor 16 which drives the disk D at constant speed in response to the servo control of the CD-microcomputer 12, and the optical pickup 18 as the laser information reading means. It will control the focusing / tracking servo.

In addition, the RF amplification unit denoted by 20 amplifies the RF signal read out from the disc D by the optical pickup 18, and the CD-digital signal processor denoted by 22 denotes the RF amplified by the RF amplifier 20. When the disc D to be reproduced is a CD or a CDG, the signal digitally processed by the CD-digital signal processing unit 22 is subjected to CD / CD G processing means (not shown). Subsequent processing is performed to reproduce.

The CD-ROM decoder indicated by 24 decodes the reproduced signal processed by the CD-digital signal processing unit 22 into CD-ROM data, and the CD-ROM decoder 24 is composed of an SRAM as a work area. One memory 26 is provided.

In addition, the MPEG microcomputer indicated by 28 performs control on the processing of moving picture / audio information read from the disc D by interaction with the CD-microcomputer 12, and the MPEG microcomputer 28 The second memory 30 made of SRAM for storing data read from the disk D is added for the work area during moving picture / audio processing.

In addition, the MPEG video decoder indicated by 32 is provided with a third memory 34 made of RAM as a working area and decodes the signal read out from the disc D into a video signal under the control of the MPEG microcomputer 28. , The timing signal generator shown in FIG. 36 generates and provides a timing signal as a reference during the restoration process for the video signal, and the MPEG video decoder 32 is applied to the timing signal generated by the timing signal generator 36. On the basis of this, the video signal of the moving picture is reconstructed. The RGB data converter 38 denotes analog conversion of the digital video signal reconstructed by the MPEG video decoder 32 based on the timing signal generated by the timing signal generator 36, and the RGB encoder 40 The analog-converted video signal is converted into an RGB signal for screen display, and the filter / amplifier 42 filters and amplifies the RGB signal to provide an output (Vout) signal.

In addition, the MPEG audio decoder denoted by 44 recovers the MPEG audio signal applied through the MPEG video decoder 32, and the switching unit 46 outputs the MPEG audio decoder 44 and the CD-digital signal. The output of the processing unit 22 is outputted in a switching manner, and the data conversion unit 48 converts the audio signal switched by the switching unit 46 into an analog conversion. In addition, the filter / amplification unit denoted by 50 to filter and amplify the analog-converted voice signal to provide an output (Aout) signal.

The audio state automatic setting device portion 52 denotes the state of the data conversion portion 48 based on the audio state (i.e., audio frequency and de-emphasis) of the disc D provided from the MPEG audio decoder 44. It is set to correspond to the audio frequency and de-emphasis of the disk (D). The delay unit denoted by 53 denotes that the disc D is a video flexible disk including at least one video audio frame, for example, at an open position of each video program (i.e., between music and music; P-channel signal in the western code of the disk). The audio state automatic setting unit 52 generates a switching signal and an audio muting signal for setting the audio frequency and the de-emphasis state.

According to the optical disk reproducing system configured as described above, when a signal (for example, power ON) for the screen display function is input to the CD-microcom 12 in the function setting unit 10, the CD-microcom 12 The servo control unit 14 controls the spindle servo and the focusing servo for the spindle motor 16 and the optical pickup 18. Accordingly, the spindle motor 16 is driven at a constant speed so that the disk D as an image flexible medium. The optical pickup 18 performs a focusing servo on the disc D.

In such a state, before the input for display of the initial screen is input from the function setting section 10, the CD-microcomputer 12 controls the optical pickup 18 so that the optical pickup 18 controls the disc. Information of the lead-in area of (D) is read, and the information is amplified by the RF amplifier 20, and the lead-in information processed by the CD-digital processing unit 22 is applied to the CD-microcomputer 12. .

In this state, the CD-microcom 12 controls the servo control unit 14 in response to the music selection information applied from the function setting unit 10, so that the spindle servo and the optical pickup 18 suitable for the track of the selected position. Tracking control is performed, and in this state, the image flexible data read from the disc D is amplified by the RF amplifier 20, and then digitally processed by the CD-digital processing unit 22. The signal processed by the digital processing unit 22 is that when the disc D is, for example, a CD or CDG disc, information read from the disc is applied to the CD disc processing system (not shown), while the disc D is a moving picture. In the case of a video CD disc in which a video audio recording is recorded, information read from the disc D is applied to the CD-ROM decoder 24 and decoded in a CD-ROM format, and the decoded video / audio information is MP EG microcomputer. MPEG video under control of 28 The audio signal is applied to the audio decoder 32 and decoded by the MPEG algorithm based on the timing signal generated by the timing signal generator 36.

The video signal decoded by the MPEG video decoder 32 is converted into an analog signal by the RGB data converter 38 and then by the RGB encoder 40 into an RGB signal for display by the filter / amplifier 42. Filtered and amplified and displayed on a screen display (i.e., CRT device; not shown).

In addition, the MPEG audio signal is applied to the MPEG audio decoder 44 from the MPEG video decoder 32 and decoded, and the decoded voice signal is filtered and amplified by the filter / amplifier 50 to output the output signal (Aout). Is provided.

In this case, the audio state automatic setting device 52 determines the audio state provided from the MPEG audio decoder 44 (that is, audio frequency → 44.1 KHz, de-emphasis) to reproduce the MPEG audio signal. By setting the audio state in the conversion unit 48, conversion of the digital audio signal restored by the MPEG audio decoder 44 into an analog signal is appropriately performed.

FIG. 2 is a diagram showing the detailed configuration of the audio state automatic setting device 52 shown in FIG. 1. In the output terminal BOF ', SCLK, SDATA of the MPEG audio coder indicated by reference numeral 44, the frame of the audio information is A BOF '(Bit of frame) signal, a status clock signal (SCLK) and a data status signal (Data status) SDATA, which are output each time, are provided, and the output terminal LRCLK of the MPEG audio decoder 44 is provided. , SCLK, and PCMout) output the audio signals of the decoded L channel and R channel, and are input to the data converter 48 through the switching unit 46 which is switched under the control of the CD-microcom 12 (LRCK, DCK). , SDATA).

According to the present invention, the audio state automatic device setting unit 52 for setting the state of the data conversion unit 48 according to the audio state information provided from the MPEG audio decoder 44 is characterized by that of the MPEG audio decoder 44. Cleared at the beginning of the frame by the frame start signal BOF 'and clock-controlled by the clock signal provided from the clock signal stage SCLK of the MPEG audio decoder 44 to output the data of the data output stage of the MPEG audio decoder 44. Clock-controlled by a data serial-parallel converter 54 for converting audio signal data provided from SDATA into parallel data and a clock signal provided from a clock signal stage SCLK of the MPEG audio decoder 44. The load terminal LD is controlled by the frame start signal BOF 'of the MPEG audio decoder 44 to perform an 8-bit binary count, and outputs a carry signal from the output terminal RCO. Counter 56 NAND gate 58 for generating a clock signal for data latch by performing logic NAND processing on a signal provided from a re-output terminal RCO and a clock signal terminal SCLK of the MPEG audio decoder 44, and a data input terminal D0-D7. Is connected to the output side of the data latch section 54, and its clock stage CLK is connected to the output side of the NAND gate 58, indicating a de-emphasis of the audio signal at its audio state output side Q3. A data latch unit 60 for providing a switching element 62 for switching an audio frequency / de-emphasis state output output from the data latch unit 60 by a switching signal provided from the delay unit 53; It is configured to include.

According to the present invention, the switching element 62 is connected to the first de-emphasis output side Q5 via the first audio frequency output side Q3 and the first inverter 64 of the data latch unit 60. The second switching element 62b connected to the second de-emphasis output side Q6 via the switching element 62a and the second audio frequency output side Q4 and the second inverter 65 of the data latch unit 60. In the start position of the program, the first and second switching elements 62a and 62b are connected to the de-emphasis output side Q5 and Q6 in response to a switching signal provided from the delay unit 53. During reproduction, the first and second switching elements 62a and 62b are configured to be connected to the audio frequency output sides Q3 and Q4.

In addition, the output side of each of the switching elements 62a and 62b of the switching element 62 and the audio state setting stages DEM1 and DEM2 of the data changer 48 each have audio at the switching elements 62a and 62b. Pull-up resistors 66 and 67 for setting the potential in the frequency / de-emphasis state are provided between the power supply (+ 5V).

In addition, the delay unit 53 is connected to a resistor 72 for filtering the P-channel signal of the disk D and a clock terminal CLK 'at the rear end of the capacitor 74, so that the time constant element at the start of the program can be connected. Outputs a high level for the time constant time determined by (R, C) to set the audio frequency / de-emphasis setting by the switching element 62 of the automatic audio state setting device 52, and the audio mute signal. Logic OR for generating an audio mute signal by performing a logic OR processing on a timer 76 for generating a signal and an output of the timer 76 and an external forced audio mute signal (usually provided by the CD-microcomputer 12). And a gate 78.

According to the audio state automatic setting apparatus of the optical disc playback system according to the present invention configured as described above, the MPEG audio signal read from the disc (D) is applied to the MPEG audio decoder 44 through the MPEG video decoder 32. When the MPEG audio decoder 44 outputs a BOF 'signal, a SCLK signal, and a SDATA signal for each frame start, it is applied to the data serial-to-parallel conversion unit 54, and the status clock signal SCLK and BOF' signals are output. The data state signal SDATA is applied to the binary counter 56 by the state clock signal SCLK in a state where the data serial-parallel conversion unit 54 is cleared for each frame by the BOF 'signal. Latches while shifting.

In this state, the binary counter 56 binaryly counts the state clock signal SCLK and outputs an 8-bit count result to one end of the NAND gate 58 through the carry output terminal RCO. The NAND gate 58 performs a logic NAND process on the carry signal of the status clock signal SCLK applied from the MPEG audio decoder 44 and the binary counter 58 to perform the logic operation of the state clock signal SCLK and the counter ( A low level output is generated at the rising edge of the high level of the carry signal of 58 and applied to the clock terminal CLK of the data latch unit 60.

In general, in the audio output bitstream provided by the MPEG audio decoder 44, the 28th and 29th bits indicate whether or not deemphasis, and the 31st and 32nd bits are audio recorded on the corresponding disk D. The data serial-parallel converter 54 shifts the SDATA output of the MPEG audio decoder 44 based on the SCLK signal to convert the data into parallel data. The binary counter 56 counts the SCLK signal provided from the MPEG audio decoder 44 and outputs a high level signal from the carry output terminal RCO when the predetermined count is reached. The NAND gate 58 In the logical counter NAND process of the count result of the binary counter 56 and the SCLK signal of the MPEG audio decoder 44 to be applied as a clock signal for data latching to the clock terminal CLK of the data latch unit 60. do.

The data latch section 60 latches the parallel data of the data serial-to-parallel conversion note 54 based on the clock signal provided from the NAND gate 58 within one frame period, and latches the data. Outputs the audio frequency of the audio signal (typically '0 0' when the audio signal is sampled at 44.1 KHz as described above) from the audio state output side Q3, Q4, while the audio signal is not de-emphasized. If not, the high level is output from the audio state output sides Q5 and Q6 as described above.

In such a state, when the start position of the program of the disc D, i.e., the P channel signal, is input to the delay unit 53, the P channel signal is filtered by the resistor 72 and the capacitor 74, and then the timer ( It is input to the clock stage CLK 'of 76, and accordingly, the timer 76 outputs a high level for a time constant time determined by the time constant elements R and C. Therefore, each switching element 62a, 62b of the switching element 62 is connected to the output side Q5, Q6 of the data latch unit 60. As described above, the signal indicating the de-emphasis state is brought to a high level. When the high level signal is outputted, the high level signal is inverted to the low level in each inverter 64 and 65, and the low level signal is converted by the switching elements 62a and 62b to the audio state setting stage DEM1, DEM2), so that the de-emphasis state for the data converter 48 is automatically set at the start of the program.

Subsequently, at the reproduction position of the program, the output of the timer 76 becomes low level, so that each of the switching elements 62a and 62b is connected to the audio state output terminals Q3 and Q4 of the data latch unit 60. And the audio frequency (i.e., '0 0' in case of 44.1 KHz) of the disk D which is latched and output to the data latch unit 60 is output through the switching elements 62a and 62b. Audio status output terminals DEM1 and DEM2 of 48 are applied. Here, the pull-up resistors 66 and 67 allow the power supply (+ 5V) to be maintained at the ground potential when the output state of the switching elements 62a and 62b is at the low level, whereas the pull-up resistors 66a and 67b of the switching elements 62a and 62b The output state is changed according to the audio frequency and / or the de-emphasis state applied to the disk D so that, for example, when a high level is output from one of the switching elements 62a and 62b, the potential of the power supply (+ 5V) As a result, the potential of the audio state setting stages DEM1 and DEM2 of the data converter 48 can be maintained.

The high level signal at the program start position generated by the timer 76 is applied to the logic OR gate 78 to act to mute the audio signal between the programs.

Therefore, as described above, according to the apparatus for automatically setting the audio state of the optical disc reproducing system according to the present invention, the audio state (especially the audio frequency and Since the audio state setting is automatically performed for the data conversion unit for analog-converting the audio signal according to the de-emphasis state, the algorithm for reproducing the disc can be greatly simplified and the de-emphasis applied to the video disc It is possible to cope with the change appropriately.

Claims (5)

MPEG video decoders / audio decoders 32 and 44 for reproducing corresponding to the data compression / restoration algorithm from the disc D having video information recorded therein, and the state information of the digital audio data restored by the MPEG audio decoder 44 Data conversion means 48 for performing analog conversion on the basis of digital data, and a CD-digital processing signal read out from the disc D and processed by the CD-digital processing means 22 and the MPEG audio decoder 44. In an optical disc reproducing system having a switching means 46 for switching the output of the data disc, the data converting means under a fixed state of frequency for an audio signal based on a bit stream of audio data decoded by the MPEG audio decoder 44 ( An audio state automatic setting means 52 for automatically setting an audio signal de-emphasis state for the signal 48), and said audio state at the start of the program. An apparatus for automatically setting an audio state of an optical disc reproducing system, further comprising a delay means 53 for generating a switching signal and an audio muting signal for setting the audio frequency and the de-emphasis state by the setting means 52. . 2. The audio state automatic setting means (52) according to claim 1, characterized in that the audio state automatic setting means (52) comprises data serial-parallel conversion means (54) for serial-parallel converting the audio data bitstream output from the MPEG audio decoder (44). The counter means 56 counting the system clock by the frame start signal output from the decoder 44, and the parallel data converted by the data serial-to-parallel conversion means 54 according to the count result of the counter means 56. Latching data latch means 60 for providing the de-emphasis state to the data conversion means 48, and switching element 62 for switching the audio frequency / de-emphasis state output output from the data latch means 60; An apparatus for automatically setting audio status of an optical disc playback system, characterized in that it comprises a. 3. The switching element (62) according to claim 2, wherein the switching element (62) is connected to the first de-emphasis output side (Q5) via the first audio frequency output side (Q3) and the first inverter (64) of the data latch means (60). A second switching element connected to a second de-emphasis output side Q6 via a first switching element 62a, a second audio frequency output side Q4 of the data latch means 60, and a second inverter 65; The first and second switching elements 62a and 62b are connected to the de-emphasis output side at the start position of the program, and the first and second switching elements 62a and 62b are connected to the audio frequency during the reproduction of the program. A device for automatically setting audio status of an optical disc playback system, characterized in that it is configured to be connected to the output side (Q3, Q4). The data latch clock signal for the data latch means 60 is generated by performing logic processing on the system clock signal SCLK from the MPEG audio decoder 44 and the count output of the counter means 56. And an audio state automatic setting device for an optical disc reproducing system, characterized by further comprising a logic means (58). 2. The audio source according to claim 1, wherein the delay means (53) outputs a high level at a start position of a program for a time constant time to switch the audio frequency / de-emphasis setting by the automatic audio state setting means (52). A timer means 76 for generating a mute signal, and a logic OR means for generating an audio mute signal by performing a logic OR process on the output of the timer means 76 and an external forced audio mute signal. An automatic audio state setting device for an optical disc playback system.