JPH0397306A - Digital audio equipment - Google Patents

Abstract

PURPOSE:To adjust the signal level with simple constitution by providing a transmission means sending a digital data having an attenuate data and a decode means detecting the attenuate data from the said digital data so as to decide the signal level adjustment quantity of the digital audio equipment with the attenuate data. CONSTITUTION:Digital data provided with attenuate data is outputted from a digital audio disk player 5 through a digital audio interface section 5c and fed to a power amplifier 6. The digital data from the digital audio disk player 5 is fed to a decode circuit section 6 through a digital audio data interface section 6a. The audio data is adjusted by the signal level corresponding to the attenuate data at a A/D converter section/attenuate section 6c and the data is demodulated into an analog signal (audio signal) with D/A conversion.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital audio device featuring a signal level adjustment system in a digital audio system.

[Prior Art] Recently, with the spread of digital technology, audio equipment that outputs audio signals or video signals as digital data, such as digital audio disc players, digital audio tape players, digital video disc players, digital video tape players, PCM digital tuners, etc. Video equipment is emerging.

This type of audio equipment or video equipment, such as audio equipment, supplies the output of a digital audio disc player 1 to a digital preamplifier 2, and the output thereof to a power amplifier 3, as shown in FIG.

The configuration is such that the output of the power amplifier 3 is supplied to the speaker 4.

The power amplifier 3 includes a digital-to-analog conversion section 3a that converts input digital data into an analog signal (audio signal), a volume adjustment volume 3b that adjusts the level of the audio signal, and a volume adjustment volume 3b that adjusts the level of the audio signal. and a power amplifier section 3C that amplifies the audio signal adjusted by.

Furthermore, as shown in FIG. 4, it is also possible to directly supply the output of the digital audio disc player 1 to the power amplifier 3.

[Problems to be Solved by the Invention] Volume adjustment in such audio equipment is a method of adjusting the signal level in an analog manner, and a volume adjustment unit (volume adjustment unit) is installed after the digital-to-analog conversion unit 3a of the power amplifier 3. An adjustment volume 3b) is configured.

On the other hand, in the digital audio disc player 1,
It is configured to take advantage of the features of digital equipment to control various operating modes such as disc exchange, disc loading, disc unloading, song selection (search), and fast forwarding.

For this reason, these types of operations are controlled on the digital audio disc player 1 side, but the volume adjustment of the audio signal must be done on the amplifier 3 side, and centralized control on the digital audio disc player 1 side is not possible. There is a problem.

In addition, if volume adjustment is to be performed on the digital audio disc player 1 side, a separate control signal line is provided between these and the power amplifier 3, and the volume adjustment control data or volume adjustment control signal is transmitted. Therefore, there are problems in that not only the connection of the control signal lines but also the circuit configuration becomes complicated.

[Means for Solving the Problems] To explain with reference to FIG. A digital audio system that is equipped with a digital audio device that outputs digital data having a format, and that converts the digital data output from the digital audio device into an analog signal and plays it back, wherein the audio data of the digital data is encoding means for inputting predetermined bits of attenuated data corresponding to the amount of signal level adjustment into empty bits of the part; transmission means for transmitting digital data having the attenuated data; and detecting the attenuated data from the digital data. The apparatus is characterized in that the signal level adjustment amount of the digital audio equipment is determined by the attenuated data.

[Operation] Predetermined bits of attenuated data corresponding to the amount of signal level adjustment are input to empty bits of the audio data portion of the digital data of the digital audio device. That is, control information corresponding to the signal level adjustment amount is added to this digital data.

Therefore, attenuated data corresponding to the signal level adjustment amount can be detected from the digital data and output.

Then, the signal level adjustment amount of the digital audio equipment can be adjusted using this attenuated data.

[Example] The present invention will be explained with reference to FIG. 1, which is representative of the present invention. In the figure, the third
The same reference numerals are given to the same parts as those of the conventional example shown in FIGS.

First, the format of digital data of a digital audio device will be explained with reference to FIG.

Two words per sample (Dals-L, Dija
-R) and are assigned to left and right channel data, respectively.

One word consists of 4-bit brainstorm data (Preamble Datx) indicating the beginning of the word and 16-bit or 24-bit audio data (D
digital^audio Data), and each t
Bit Validity Flag (Validil7)
Flag ), user day final data (
UserDelinable Data), channel status data (Channel Stsl)
us Dalg), t<Retei bit(Pxri
17 Bit).

Generally, actual audio data is given in 16 bits, so in type A in Figure 2, 8 bits of space are provided before the 16-bit audio data section [DO DI D2...D 14D +5]. For example, in the type B of FIG. D.I.
O...D22D23] is allocated as audio data, and there is an 8-bit empty part [DO DI D2...D7] in front of it.

The present embodiment will be described below with reference to the case where the format is of type B in FIG.

That is, in this embodiment, the MSB of the 24-bit audio data section [DQ Di D2...D22D23]
8 bits [DO DI D2...D7] are assigned to attenuated data, and the remaining 16 bits [D8 D9 DIG...D23] are assigned to audio data.

Reference numeral 5 denotes a digital audio disc player, a digital audio tape player, a PCM digital tuner, etc. For example, the digital audio disc player 5 includes attenuated data [AO AI A2... . . . A7], and this attenuated data is converted into an empty bit (attenuated data section) of the audio data section [DO Di D2 . ) [DO DI D2
...D? ] is input as attenuated data corresponding to the signal level adjustment amount.

Note that, as shown in FIG. 2, this attenuated data is generated as data of 8 bits or less in relation to the free bits of the audio data.

Then, the digital data to which this attenuated data has been added is sent to the digital audio interface section 5.
The signal is output from the digital audio disc player 5 through C and supplied to the power amplifier 6.

The power amplifier 6 is composed of a digital audio interface section 6as, a decoding circuit section 6b, a digital-to-analog conversion section/attenuation section 6C, and a power amplifier section 6d, and the digital data from the digital audio disc player 5 is transmitted through the digital audio interface section 6a. The signal is supplied to the decoding circuit section 6b.

In this decoding circuit section 6b, 8 bits [DQ Di D2...D? ] is detected and converted into attenuated data [AO AI
A2...A7].

On the other hand, the audio data [D8 D9 DIG...D22D23] is supplied to the digital-to-analog converter/attenuator 6C.

In this digital-to-analog conversion section/attenuation section 6C, the audio data is adjusted by the signal level adjustment amount corresponding to the attenuated data using the attenuated data, and is digital-to-analog converted into an analog signal (audio signal). demodulated.

Thereafter, this analog signal (audio signal) is audio amplified by the power amplifier section 6d and reproduced from the speaker.

[Effect of the Invention 1] The present invention provides the above signal level adjustment for this digital data by inputting predetermined bits of attenuated data corresponding to the signal level adjustment amount into empty bits of the audio data portion of the digital data. Since the configuration is configured such that control information corresponding to the volume is added and transmitted, and then the signal level adjustment amount of the digital audio device is adjusted based on the attenuated data detected from the digital data. The operation mode can be centrally controlled on the digital audio disc player 1 side, and there is no need for a separate control signal line as in the past.
Its circuit configuration is also extremely simple.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a typical embodiment of the digital audio device of the present invention, FIG. 2 is a diagram showing the format of digital data, and FIGS. FIG. 3 is a diagram showing the configuration. 4...Speaker, 5...Digital audio disc player, 5a...Volume operation section, 5b...Encoding circuit section,
5c...Digital audio interface section, 6...Power amplifier, 6a...Digital audio interface section, 6b...
- Decode circuit section, 6C...Digital-to-analog conversion section/attenuator section, 6d...Power amplifier section.

Claims (1)

[Scope of Claims] A digital audio device that outputs digital data having a format consisting of brainwave data indicating the beginning of one word, audio data, and a plurality of control data, and output from the digital audio device. A digital audio system configured to convert digital data into an analog signal and play it back, wherein predetermined bits of attenuated data corresponding to a signal level adjustment amount are input into empty bits of an audio data portion of the digital data. The apparatus comprises an encoding means, a transmission means for transmitting digital data having the attenuated data, and a decoding means for detecting the attenuated data from the digital data, and uses the attenuated data to adjust the signal level adjustment amount of the digital audio equipment. A digital audio device characterized by: