KR20040093774A - Dolby prologic audio apparatus - Google Patents

Abstract

PURPOSE: A Dolby pro-logic audio system is provided to improve the sound quality and reduce the manufacturing cost by dividing a sound source into 5.1 and more channel signals. CONSTITUTION: A Dolby pro-logic audio system includes a first IC, a second IC, and a third IC. The first IC(100) is used for receiving a compressed digital signal from a predetermined device connected to a digital input terminal and compressing and decoding an external input signal, a stereo signal, and a mono signal of the third IC. The second IC(200) is used for processing a left surround signal, a right surround signal, and a center signal and transmitting a main left signal, a main right signal, and a woofer signal. The third IC(300) is used for processing the main left signal, the main right signals, and the woofer signal and receiving the stereo signal, the mono signal, and the external input signal.

Description

Dolby Pro Logic Audio Device {DOLBY PROLOGIC AUDIO APPARATUS}

The present invention relates to a Dolby Pro Logic audio device, and more particularly, to a Dolby Pro Logic audio device capable of outputting an analog or digital signal of 5.1 channels or more.

In general, the pursuit of sound quality and sound field faithful to the original sound in an AV (audio-visual) device that plays music and movies is an eternal purpose in sound reproduction. Sound quality has already been greatly improved due to advances in digital signal recording and transmission technologies. In addition, in terms of sound field reproduction, reproduction by multi-channels seen in movie theaters has been pointed out as the answer.

Four-channel playback was proposed and released by each set maker in 1970 for general household use, but it disappeared from the market due to the troublesome arrangement and high price of four speakers.

The idea of creating a sound image in any direction around the listener using two front speakers has been around for a while. The principle was first published in 1963 by Dr. Schrader of the Bell Institute. The method using two speakers is realized by measuring the transmission characteristics of the listener's ears in an arbitrary direction and reproducing the aforementioned transmission characteristics by the two front speakers.

In the mid 70's, a product was introduced based on this principle of using two speakers to create sound in any direction around the listener. At the time, this product was made by analog technology, so complex reflections could not be realized, and thus could not achieve the required performance.

In the current technology, many standards have been proposed to overcome the problems of these functions, the most widely used among them, the Dolby AC-3 method is recognized for the excellent sound quality. For example, sound processing by the Dolby AC-3 system is performed in movie theaters. It encodes and records movie 5.1-channel soundtracks, also called Dolby Stereo, into tracks on film and plays them back.

The above-mentioned Dolby Surround is a multi-channel method originally made for reproduction in a movie theater. The theater is arranged to connect the front left and front right channels and the front center channel centered on the dialogue, the rear left and right channels and the surround channels to a plurality of speakers arranged on the wall. It is Dolby Surround (or Dolby Stereo) that stores this in the track of the film.

Software created for home use based on AC-3 recorded film has a soundtrack that is encoded as is, allowing playback on playback devices that support AC-3.

In addition, a system suitable for outputting the same after the playback is required. For this purpose, in order to play AC-3 encoded video or audio software at home, it is necessary to perform decoding processing and then install 6 or more speakers. After decoding, it should be output through each speaker.

Dolby's AC-3 surround described above is a multi-channel method originally created for cinema. Decode the encoded 5.1 channels by encoding audio signals in the form of 5.1-bit bitstreams, and output the decoded signals through the front left, front right, center and rear speakers and through multiple speakers on the left and right walls. This is Dolby's AC-3 surround (or Dolby AC-3 stereo).

However, since Dolby AC-3 stereo decodes only 5.1-encoded media into 5.1-channels and outputs them to multiple speakers, these Dolby AC-3 stereos are generally 2-channel-encoded signals such as video tapes, LDs, and satellites. Alternatively, a signal transmitted in stereo television broadcasting may not be decoded into 5.1 channels using Dolby AC-3 stereo.

To solve this problem, Dolby Pro Logic has emerged, and Dolby Pro Logic implements a 2-channel encoded signal as a front channel left, right, center, and surround mono 5.1 channels. In other words, this method decodes two-channel encoded signals into left and right signals of the front channel and mono signals of the center and surround and outputs them to the respective speakers.

However, since Dolby Pro Logic can separate only a signal encoded in two-channel stereo, a signal encoded in a mono signal cannot be separated.

An object of the present invention is to solve the problems of the prior art, and to provide a Dolby Pro Logic audio device capable of separating and outputting digital signals, stereo, mono and external input signals into 5.1 channels.

In order to achieve the above object, the present invention receives a compressed digital signal from a device connected to the digital input terminal and receives an external input signal, stereo or mono signal from the IC 3, the digital signal, external input signal, stereo mono IC 1, which compresses and decodes the signal and sends it out through one serial data line; IC 2 which processes the left and right surround and center signals from the signals output from the IC 1 and outputs them to the left and right surround and center speakers, and transmits the main left and right signals and the woofer signal; And an IC 3 which processes the main left and right signals and the woofer signal output from the IC 2 and outputs them to the main left and right and woofer speakers, and receives the stereo, mono or external input signal.

1 is a block diagram illustrating a Dolby Pro Logic audio device according to the present invention.

<Description of the code | symbol about the principal part of drawing>

100: IC 1 200: IC 2

300: IC 3

There may be a plurality of embodiments of the present invention, and a preferred embodiment will be described in detail below with reference to the accompanying drawings. Those skilled in the art will be able to better understand the objects, features and advantages of the present invention through this embodiment.

1 is a block diagram illustrating a Dolby Pro Logic audio device according to the present invention.

As shown therein, the Dolby Pro Logic audio device includes IC 1 (100), IC 2 (200), and IC 3 (300), wherein IC 1 (100), IC 2 (200) and IC 3 ( 300 is connected to the I2S, I2C interface.

IC 1 (100) has a built-in Pulse Code Modulation (PCM) / Moving Pictures Experts Group (MPEG) / Dolby Digital Audio Compression (AC-3) decoder and is input to the Sony / Philips Digital Interface (S / PDIF) terminal. Any one of the decoders is selected according to the sound source to compress and decode the input sound source, and the decoded sound source is provided to the IC 2 200 through I2S communication. Here, the decoded sound source is output as one SOD (Serial Output Data).

The IC 2 200 receives the SOD provided from the IC 1 100, and the input SOD converts the digital signal into an analog signal through prescale, source, and switching, and outputs it to the left and right surround and center speaker stages. do. Here, the IC 2 200 processes only the surround left and right signals and the center signal among the digital signals input to the IC 1 100, and outputs them to the left and right surround and center speaker stages, and the rest of the signals are connected to the IC using the I2S interface. Provided at 3 (300).

IC 3 (300) processes the signals output from IC 2 (200), that is, the main left and right and woofer signals, and outputs them through the source and switching to the main left and right and woofer speakers, and the SIF signal is a SIF signal (stereo, mono signal). Or receives an external input signal from the Scart 1-4 terminals and provides it to the IC 1 (100) using the I2S interface. At this time, the IC 1 100 compresses and decodes the signal provided from the IC 3 300 to expand the two channel signal to six channels, and provides the processed signal to the IC 2 200 connected to the I2S interface. do.

In addition, the IC 3 300 analog-processes an external input signal, a stereo or a mono signal, and outputs it to headphones.

A Dolby Digital implementation process using the Dolby Pro Logic audio device having such a structure will be described below.

First, IC 1 (100) receives a digital signal source compressed with AC-3, PCM, MPEG from a device connected to the S / PDIF (?) Input terminal, for example, DVD player, set-top box, etc. It decodes it and outputs it to the IC 2 200 connected to the I2S interface.

The IC 2 200 converts the digital signal decoded by the IC 1 100 into an analog signal, and the analog converted signal is subjected to a source and a switching process. The left and right surround and center signals are output to the left and right surround and center speakers after a source and switching process, and the rest of the signals are output to the IC 3 (300) connected to the IC 2 (200) and the I2S interface.

The IC 3 300 processes the signal provided from the IC 2 200 as an analog signal, and outputs the signal to the main left and right and the woofer speaker through a source and switching process.

Dolby Pro Logic audio apparatus according to the present invention to process a stereo or mono signal, Dolby Pro Logic processing will be described as follows.

The IC 3 300 receives a stereo or mono signal through a sound inter frequency (SIF) input terminal or outputs an external input signal received from the scat 1 to 4, which are external input terminals, to the IC 1 100 connected to the I2S interface.

IC 1 100 outputs an external input signal, stereo or mono signal output from IC 3 300 to IC 2 200 through a compression process and a switching process.

The IC 2 200 converts the left and right surround and center signals from the signals output from the IC 1 100 into analog signals and outputs them to the surround left and right and center speakers, and the main left and right and woofer signals are output to the IC 3 300. do.

IC 3 300 converts the main left and right and woofer signals into analog signals and outputs them to the main left and right speakers and woofer speakers.

As described above, the present invention can reduce the manufacturing cost in the development of high-quality TV and audio amplifier by separating and outputting any sound source into a 5.1 channel or more signal.

In addition, the present invention can separate and output the mono signal input to the SIF stage into more than 5.1 channels.

Claims (4)

Receives a compressed digital signal from a device connected to a digital input terminal, receives an external input signal, a stereo or mono signal from IC 3, compresses and decodes the digital signal, the external input signal, and a stereo mono signal to generate one serial data line. IC 1 transmitted through; IC 2 which processes the left and right surround and center signals from the signals output from the IC 1 and outputs them to the left and right surround and center speakers, and transmits the main left and right signals and the woofer signal; And Dolby Pro Logic audio device comprising an IC 3 processing the main left and right signals and the woofer signal output from the IC 2 to the main left and right and woofer speakers, and receives the stereo, mono or external input signal. The Dolby Pro Logic audio device of claim 1, wherein the IC 1, the IC 2, and the IC 3 are respectively connected to an I 2 S interface to transmit and receive data. The Dolby ProLogic audio device of claim 1, wherein the IC 1 receives a digital signal compressed with AC-3, MPEG-2, or PCM through an S / PDIF stage. The Dolby Pro Logic audio device of claim 1, wherein the IC 3 outputs an external input signal, a stereo, or a mono signal to a headphone.