KR100466265B1 - audio out selecting apparatus in a digital video disc player - Google Patents

Abstract

The present invention relates to an audio output selection apparatus in a digital video disc player which enables to automatically change the output mode to 5.1CH, 4CH, 2CH, etc. according to the connection state of the speaker when outputting AC-3 or MPEG-2 audio decoding. An audio decoder unit 80 which decodes and outputs an audio digital bit stream compressed in an AC-3 or MPEG-2 scheme into a plurality of channels under the control of the microcomputer 20, and the audio decoder unit 80. A digital video disc player having an audio DAC 100 for converting each output signal from the analog signal into an analog signal and outputting an audio signal for each channel applied from the audio DAC 100. In the present invention, the speaker system 200 is connected to the audio signal applied from the audio DAC unit 100, each speaker provided in the speaker system 200 A speaker connection and connection detection unit 110 that detects the presence or absence of current flow and outputs a connection detection signal, and a connection state of the speaker for each channel based on the connection detection signal from the speaker connection and connection detection unit 110. The microcomputer 20 controls the audio decoder unit 80 to decode the audio signal to control the output signal to all channels or to decode the audio signal by downmixing only the channel where the speaker connection is detected. The cumbersome key operation can eliminate the inconvenience of controlling the output of the audio.

Description

Audio output selecting apparatus in a digital video disc player}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio output selection device in a digital video disc player. In particular, an output mode is automatically changed to 5.1CH, 4CH, 2CH, etc. according to a connection state of a speaker when AC-3 or MPEG-2 audio is output from a digital video disc. And an audio output selection device in a digital video disc player.

In general, computer and communication technologies have developed remarkably toward the information society, and accordingly, the amount of information such as voice, image, and document information is increasing at a tremendous speed, and the system and information recording medium which can effectively store and process it rapidly Development is active.

As such an information recording medium, magnetic tapes and magnetic disks to which magnetic recording has been applied have been mainly applied. However, as the amount of information increases, a new high density recording medium capable of storing a large amount of information per unit area has emerged.

As such a high-density recording medium, as optical recording technology is realized due to the recent breakthrough in optical technologies such as lasers, optical discs have come into the spotlight as a new large-capacity information storage medium. It is becoming.

On the other hand, such an optical disc has a CD (Compact Disc) in which audio information is recorded, and a VCD (Video Compact) in which audio information and video information are compressed and recorded by a predetermined algorithm (for example, MPEG-1 or MPEG-2). Disc), DVD (Digital Video Disc), and the like, and each optical disc includes disc information including address information of each track (logical track, not physical track) in a predetermined section (e.g., TOC area). The optical disc system can read the disc information and perform a random play and search function.

Meanwhile, as described above, a system using a disk as a storage medium employs a new technology for digitally processing a video signal and an audio signal for high quality video and audio. In the case of an audio signal, many audio signals are encoded / decoded by encoding and compressing the audio signal, transmitting or storing the audio signal, and restoring the audio signal with an error that cannot be recognized by a human. Therefore, in accordance with the research and development of various audio signal encoding / decoding techniques, international standardization of ISO MPEG has been conducted for encoding and decoding audio signals for digital audio devices and multimedia. MPEG-2 audio standard has been proposed.

In addition, US-based Dolby's proprietary compression algorithm, AC-3, centered on the US film industry, is now the US standard for HDTV digital audio. However, media such as digital video discs will decide to choose between audio compression schemes of MPEG and AC-3.For compatibility, audio bitstreams encoded by MPEG and AC-3 compression algorithms can be decoded. An apparatus for decoding MPEG-2 and AC-3 digital audio signals has been developed.

On the other hand, a digital video disc player is a device for playing a disc in which a video and audio signal compressed using the video and audio compression algorithm described above to decode and output the video and audio signal, as shown in FIG. A key input and display unit 10 having a plurality of keys including a play key for reproducing, outputting a key signal corresponding to a user's key operation, and displaying a current operation state under the control of the microcomputer 20. And a microcomputer 20 for controlling the overall operation of the digital video disc player by controlling each component based on the key signal from the key input and display unit 10, and rotation of the disc under the control of the microcomputer 20. A servo controller 30 which outputs various drive control signals for controlling each actuator for tracking / focusing; Driven based on various drive control signals from the beam control unit 30, a mechanism for loading / unloading a disc, an optical pickup diode for reading data written on the disc based on laser light, and an optical pickup diode Optical pick-up transfer motor (Sled Motor) to move the disk, Fine Actuator (Fine Actuator) to find the target position of the disc finely, Disk Spindle Motor, etc. The deck unit 40 reads the digital bit stream including the laser light based on the laser light, the RF amplifier 50 amplifies and outputs the digital bit stream read out from the deck unit 40, and the microcomputer 20. By reading the digital bit stream applied from the RF amplifying unit 50 and performing channel demodulation by control, the frame synchronization signal can be detected, an error detection and error correction can be performed. A digital signal processor (DSP) unit 60 which extracts and applies TOC information to the microcomputer 20 and separates and outputs the digital bit stream into an audio digital bit stream and an image digital bit stream. A video decoder unit 70 which decodes and outputs a video digital bit stream modulated by an applied MPEG-2 compression algorithm, and modulates by an MPEG-2 or AC-3 compression algorithm applied from the DSP unit 60. An audio decoder 80 for decoding and outputting the audio digital bit stream, an RGB decoder 90 for converting and outputting a digital video signal applied from the video decoder 70 into an RGB signal, and an audio decoder And an audio DAC unit 100 for converting the digital audio signal applied from 80 into an analog signal and outputting the analog audio signal.

In such a configuration, in particular, the audio decoder unit 80 decodes the audio digital bit stream modulated according to the compression algorithm of MPEG-2 or AC-3 to give a 5.1CH, for example, a center speaker signal (C), a woofer. The speaker signal W, the stereo signal L / R, and the surround stereo signal SL / SR are separated and output.

On the other hand, in a system using a digital video disk as a source, the audio signal is separated and output to all channels regardless of the speaker system to be connected at all times. The speaker system provided by the user is, for example, a stereo speaker system ( 2CH: L / R), stereo speaker system with woofer (3CH: W, L / R), or surround stereo speaker system (4CH: L / R, SL / SR). There was an inconvenient problem of adjusting to an optimal sound quality suitable for a speaker system manually selected by a predetermined key operation.

Accordingly, the present invention seeks to find a way to automatically adjust the audio output to match the speaker system that is provided.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is the state of a speaker system that is currently connected when outputting an AC-3 or MPEG type multichannel audio signal reproduced from a digital video disc player or the like. The present invention provides an audio output selection apparatus of a digital video disc player capable of detecting and outputting an audio signal through a channel suitable for a state of a speaker system.

An audio output selection device in a digital video disc player according to the present invention comprises: an audio decoder unit for decoding and outputting an audio digital bit stream compressed by an AC-3 or MPEG-2 method into a plurality of channels under the control of a microcomputer; And an audio DAC unit for converting each output signal from the audio decoder unit into an analog signal and outputting the analog signal, and a speaker system for outputting audio signals of respective channels applied from the audio DAC unit. A speaker connection and a connection detection unit which connects an audio signal applied from the audio DAC unit to a speaker system, and outputs a connection detection signal by detecting the flow of current to each speaker provided in the speaker system, and the speaker connection and connection Based on the connection detection signal from the detection unit, each And the micom for controlling the audio decoder to decode and output the audio signal to all channels according to the connection state of the speaker for each null, or to decode the audio signal by downmixing only to the channel where the speaker connection is detected. It is done.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the invention described below with reference to the accompanying drawings by those skilled in the art.

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

2 is a block diagram of a digital video disk player and a speaker system including an audio output selection device according to the present invention. The digital video disk includes a conventional key input and display unit 10, a microcomputer 20, and a servo controller 30. ), Deck unit 40, RF amplifier unit 50, DSP unit 60, video decoder unit 70, audio decoder unit 80, RGB decoder unit 90, audio DAC unit 100, and other speakers It further comprises a connection and connection detection unit 110 is configured to connect to the speaker system 200.

In this configuration, the other components are the same as the conventional configuration, the speaker connection and connection detection unit 110 is configured between the audio DAC unit 100 and the speaker system 200 is applied from the audio DAC unit 100. The audio signal of the channel is connected to the speaker system 200 through a predetermined jack, and the connection to the channel where the connected speaker exists by detecting whether a current flows through each speaker of the speaker system 200 through each connection jack. The detection signal is output to the microcomputer 20.

The microcomputer 20 is a means for controlling the overall operation of the digital video disc player, and corresponds to a speaker currently provided in the speaker system 200 based on a connection detection signal applied from the speaker connection and connection detection unit 110. The audio decoder 80 is controlled to output an audio signal through only a channel.

On the other hand, the audio decoder unit 80 decodes the audio digital bit stream modulated according to the compression algorithm of MPEG-2 or AC-3, for example, 5.1CH, for example, a center speaker signal (C), a woofer speaker signal (W). ), And output as a stereo signal (L / R), surround stereo signal (SL / SR), but output all audio channels under the control of the microcomputer 20, or if all channels are not selected The audio signal is down mixed and output only to the selected channel.

Next, the operation process of the audio output selection device in the digital video disc player having the above-described configuration will be described in detail.

First, when a predetermined playback key provided in the key input and display unit 10 is operated based on a user, the microcomputer 20 performs the servo control unit 30 and the DSP based on the playback key signal applied from the key input and display unit 10. The unit 60 is to be controlled.

Then, the disc loaded in the deck unit 40 is rotated under the control of the servo control unit 30, and the digital bit stream read out based on the optical pickup is amplified by the RF amplifying unit 50 so that the DSP unit 60 is rotated. Is applied.

Then, the BSP unit 60 reads the digital bit stream applied under the control of the microcomputer 20, performs channel demodulation, detects the frame synchronization signal, performs error detection and error correction, and then extracts the extracted digital bit stream. The separated audio digital bit stream is separated into a digital bit stream and an image digital bit stream, and output to the audio decoder unit 80.

Then, the audio decoder unit 80 decodes and decodes the applied audio digital bit string using the AC-3 scheme to perform 5.1CH, for example, a center speaker signal (C), a woofer speaker signal (W), and a stereo signal ( L / R) and surround stereo signals (SL / SR) are output separately.

At this time, the speaker connection and connection detection unit 110 detects the presence or absence of each speaker provided in the speaker system 200, the detection method is the current flowing through the jack for each channel provided in the speaker connection and connection detection unit 110 The presence or absence of a current flowing through each speaker is detected, and the detection result is applied to the microcomputer 20 as a connection detection signal.

Then, the microcomputer 20 is based on the connection detection signal applied from the speaker connection and connection detection unit 110, the corresponding speaker (for example, woofer speaker (W), stereo speaker (L /) present in the speaker system 200 R), surround stereo speakers SL / SR, etc.) to control the audio decoder unit 80 to output audio signals only.

Then, the audio decoder unit 80 decodes the audio signal to all channels including the center speaker signal C, the woofer speaker signal W, the stereo signal L / R, and the surround stereo signal SL / SR. Downmixing the audio digital bit stream applied from the DSP unit 60 under the control of the microcomputer 20 to output an audio signal only to a channel corresponding to the speaker provided in the speaker system 200. By decoding, the optimum audio signal is output only to the corresponding channel to which the speaker is connected.

Therefore, the trouble of the user adjusting the audio output to a predetermined key operation corresponding to the speaker system 200 provided by the user is eliminated.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

As described above, according to the present invention, a digital video disc player that decodes and outputs a digital audio signal modulated according to AC-3 or MPEG-2 can be used. Automatically downmix the system to match the speaker system and output the audio signal to the channel to which the speaker is connected, eliminating the inconvenience of controlling the output of the audio through cumbersome key operation when the speaker system is changed. It can be effected.

1 is a block diagram of a typical typical digital video disc player.

2 is a block diagram of a digital video disc player and speaker system incorporating an audio output selection device in accordance with the present invention.

<Explanation of symbols for the main parts of the drawings>

10: key input and display unit 20: microcomputer

30: servo control unit 40: deck unit

50: RF amplification unit 60: DSP unit

70: video decoder unit 80: audio decoder unit

90: RGB decoder unit 100: audio DAC unit

110: speaker connection and connection detection unit 200: speaker system

Claims (1)

From the audio decoder unit 80 and the audio decoder unit 80 which decodes and outputs an audio digital bit stream compressed by an AC-3 or MPEG-2 method under a control of the microcomputer 20 into a plurality of channels. In the digital video disc player having an audio DAC (100) section for converting each output signal to an analog signal and outputting, and a speaker system (200) for outputting the audio signal of each channel applied from the audio DAC section (100) , An audio signal applied from the audio DAC unit 100 is connected to the speaker system 200, and each speaker provided in the speaker system 200 includes at least one of a woofer speaker, a stereo speaker, and a surround stereo speaker. On the basis of the speaker connection and connection detection unit 110 for outputting a connection detection signal by detecting the flow of current to the speaker and the connection detection signal from the speaker connection and connection detection unit 110, And the micom 20 for controlling the audio decoder unit 80 to decode and output audio signals to all channels or to demix audio signals by downmixing only the channels where speaker connections are detected. Audio output selection device in digital video disc player.