JP2001338473A - Audio data processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an audio data processor in which circuit constitution is made small and the cost is reduced by commonly using a reference clock generating section while reproducing audio data from a tape and a memory card. SOLUTION: A detecting section 15 detects the fact that a tape 11 and a memory card 12 are mounted. A frequency detecting section 17 detects the sampling frequencies of the tape 11 and the card 12 and transmits the sampling frequency data to a reference clock generating section 16. The section 16 outputs a reference clock synchronized with audio data to first and second audio data processing sections 13 and 14 in the case of the tape 11. In the case of the card 12, the section 16 sends a reference clock, which is asynchronous to the audio data, to the sections 13 and 14. The sections 13 and 14 conducts various signal processes of the audio data for the tape 11 and the card 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio data processing device effective for use in a video camera supporting various multimedia.

[0002]

2. Description of the Related Art In recent years, digital video cameras have become smaller and lighter and have improved portability. Under such circumstances,
There are demands from the market for various additional functions and usage methods using the portability inherent to video cameras. For example, it is known that a video camera is provided with a slot in which a memory card can be inserted, a rewritable memory card can be attached and detached, and the memory card can record video and audio shot by the video camera, You can see the video taken anywhere. As such a configuration, for example, Japanese Patent Application Laid-Open No.
For example, Japanese Patent Application Laid-Open No. 331656 discloses an example.

Hereinafter, a conventional audio data processing apparatus will be described with reference to the drawings.

FIG. 3 is a block diagram showing a configuration of a conventional audio data processing device. In FIG. 1, reference numeral 1 denotes a tape as a recording medium on which video / audio data is recorded, on which digital video / audio data is recorded. Reference numeral 2 denotes a memory card which is a recording medium typified by a semiconductor memory such as a flash memory in which audio data is recorded, in which digital audio data is recorded. Reference numeral 3 denotes a first audio data processing unit for performing various signal processing on audio data reproduced on the tape 1, and reference numeral 4 denotes a second audio data processing unit for performing various signal processing on audio data reproduced by the memory card 2. A first reference clock generator for generating a reference clock for audio data reproduced from the tape 1 and outputting the reference clock to the first audio data processor; 6 generates a reference clock for audio data reproduced from the memory card 2 A second reference clock generator for outputting to the second audio data processor, 7 is a switch for selecting one of the output signals of the first and second audio data processors 3 and 4, and 8 is a switch from A digital-to-analog converter (hereinafter, referred to as a DA converter) for converting the digital audio data of FIG.
This is an audio output unit that outputs an audio signal from the external device.

[0005] The operation of the conventional audio data processing device configured as described above will be described below.

First, digital audio data reproduced from the tape 1 is input to a first audio data processing unit 3 and performs various audio data processing such as signal decoding. Here, in order to reproduce the digital audio data, a clock serving as a reference is required. This reference clock is generated by the first reference clock generator 5 and input to the first audio data processor 3. . The digital audio data output from the first audio data processing unit 3 is input to the DA converter 8 via the switch 7 connected to the terminal A. The digital audio data is converted into an analog audio signal by the DA converter 8 and output from the audio output unit 9 to the outside.

Next, the digital audio data reproduced from the memory card 2 is input to a second audio data processing section 4 and performs various audio data processing such as signal decoding. Here, in order to reproduce the digital audio data, a reference clock is required. This reference clock is generated by the second reference clock generator 6 and input to the second audio data processor 4. . Second audio data processing unit 4
Is output to the DA converter 8 via the switch 7 connected to the terminal B side.
The digital audio data is converted into an analog audio signal by the DA converter 8 and output from the audio output unit 9 to the outside.

[0008]

However, in the above-mentioned conventional configuration, the first reference clock generator 5 for generating the reference clock required for reproducing the digital audio data from the tape 1 and the memory card 2 from the memory card 2 are provided. Since two reference clock generating means of the second reference clock generating unit 6 for generating a reference clock necessary for reproducing digital audio data are provided, the circuit configuration becomes large and the cost is greatly increased. There is a problem that they are connected.

In view of the above-mentioned conventional problems, the present invention shares a reference clock generating means for audio data reproduced from a tape and audio data reproduced from a memory card, thereby reducing the circuit configuration and cost. It is an object of the present invention to provide an audio data processing device that can be down.

[0010]

In order to achieve the above object, an audio data processing apparatus according to the present invention has first and second recording media and can reproduce a plurality of digital audio data having different sampling frequencies. A first audio data processing unit for processing first digital audio data reproduced from the first recording medium;
Second audio data processing means for processing second digital audio data reproduced from the second recording medium;
Generating a reference clock corresponding to the sampling frequency of each of the first and second digital audio data;
And a reference clock generating means for supplying the reference clock to the audio data processing means.

With this configuration, the audio data reproduced from the tape and the audio data reproduced from the memory card share the reference clock generating means, so that the circuit configuration can be made smaller and the cost can be reduced. It is an object to provide an audio data processing device.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The first aspect of the present invention is an audio data processing apparatus having first and second recording media and capable of reproducing a plurality of digital audio data having different sampling frequencies. A first audio data processing means for processing first digital audio data reproduced from the first recording medium; and a second digital audio data reproduced from the second recording medium. Second audio data processing means, and a reference clock corresponding to a sampling frequency of each of the first and second digital audio data is generated, and the reference clock is supplied to the first and second audio data processing means. With this configuration, the circuit configuration can be simplified by sharing the reference clock generation unit between tape playback and memory card playback. Can, cost reduction can be realized.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of an audio data processing apparatus according to an embodiment of the present invention. In the figure, reference numeral 11 denotes a tape as a first recording medium on which video / audio data is recorded, and in this embodiment, a digital signal is recorded. Reference numeral 12 denotes a memory card, which is a second recording medium made of a semiconductor memory such as a flash memory, and in this embodiment, a digital signal is recorded. A first audio signal 13 performs various signal processing such as decoding digital audio data reproduced from the tape 11, counts the number of audio data samples in a predetermined period, and sends the counted data to the reference clock generator 16. A first audio data processing unit serving as a data processing unit;

A second audio data processing unit 14 is a second audio data processing means for performing various signal processing such as decoding digital audio data reproduced from the memory card 12.

Reference numeral 15 denotes a tape 11 and a memory card 1
Reference numeral 2 denotes a detection unit serving as a detection unit for detecting that the tape 11 or the memory card 12 has been mounted.
Alternatively, signals recorded on the tape 11 and the memory card 12 may be detected. Reference numeral 16 denotes a reference clock generation unit which is a reference clock generation unit that outputs to the first or second audio data processing units 13 and 14 according to the detection result of the detection unit 15, and is configured by a PLL circuit or the like. 17 is the tape 11
A frequency detecting unit for detecting the recording sampling frequency of each audio data of the memory card 12;
Is a switch for selecting either the first audio data processing unit 13 or the second audio data processing unit 14 according to the detection result of the above. 19 is a DA converter for converting digital audio data output from the switch 18 into an analog audio signal Reference numeral 20 denotes an audio output unit that is an audio output unit that outputs an analog audio signal output from the DA converter 19 to the outside.

The operation of the audio data processing apparatus according to the present embodiment configured as described above will be described below.

First, when the tape 11 is mounted on an electronic device in which the present apparatus is used, the detecting unit 15 detects the mounting of the tape, and sends the tape to the reference clock generating unit 16, the frequency detecting unit 17 and the switch 18. 11 is transmitted. The frequency detector 17 detects a sampling frequency in the audio AUX recorded on the tape, and sends out sampling frequency data to the reference clock generator 16. The reference clock generator 16 synchronizes with the audio data on the tape 11 based on the tape detection information from the detector 15, the sampling frequency data from the frequency detector 17, and the number of samples sent from the first audio data processor 13. A reference clock is generated and output to the first audio data processing unit 13. The first audio data processing unit 13 performs various signal processing of the audio data reproduced on the tape 11 based on a reference clock synchronized with the audio data from the reference clock generation unit 16. Digital audio data output from the first audio data processing unit 13 is input to the switch 18. The switch 18 is connected to the terminal A according to the detection result of the detection unit 15, and inputs the digital audio data from the first audio data processing unit 13 to the DA converter 19. The DA converter 19 converts the input digital audio data into an analog audio signal, outputs the analog audio signal to the audio output unit 20, and outputs the audio output unit 20 to the outside.

Next, when the memory card 12 is inserted into an electronic device in which the present apparatus is used, the detecting unit 15 detects the mounting of the memory card 12 and sends a signal to the reference clock generating unit 16, the frequency detecting unit 17 and the switch 18. Then, the fact that the memory card 12 is mounted is transmitted. Frequency detector 1
7 detects the sampling frequency described in the data of the music file in the memory card. The reference clock generator 16 generates a reference clock for reproducing the audio data of the memory card 12 based on the detection results of the detector 15 and the frequency detector 17, and outputs the reference clock to the second audio data processor 14. I do. The second audio data processing unit 14 performs various signal processing of the audio data reproduced by the memory card 12 based on the reference clock from the reference clock generation unit 16. The digital audio data output from the second audio data processing unit 14 is
8 is input. The switch 18 is connected to the terminal B side according to the detection result of the detection unit 15, and converts the digital audio data from the second audio data processing unit 14 into the DA converter 1.
Enter 9 The D / A converter 19 converts the input digital audio data into an analog audio signal, and
0 and output from the audio output unit 20 to the outside.

Next, the detailed configuration of the reference clock generator 16 will be described with reference to FIG.

FIG. 2 is a block diagram showing the internal configuration of the reference clock generator 16. Reference numeral 21 denotes a sampling frequency to which sampling frequency data of audio data recorded on the tape 11 and the memory card 12 from the frequency detector 17 is input. A data input terminal 22 is a tape sample generator, which is a tape sample generator for generating a sample signal for a predetermined period based on the count data from the first audio data processor 13, and 23 is a memory card sample. The memory card sample generation unit that generates a signal includes a fixed value unit 24 that holds a fixed value, and an average value unit 25 that calculates the average value of the sample signals output from the tape sample generation unit 22. 26 is a fixed value part 24
And a first switch for selecting one of the averaging unit 25,
29 is a detection signal input terminal to which the detection result from the detection unit 15 is input, and 27 is one of the tape sample generation unit 22 and the memory card sample generation unit 23 according to the detection result from the detection signal input terminal 29. A second switch 28 is a reference clock generation circuit for generating a reference clock from a sample signal input from the second switch 27, and a reference numeral 30 is for processing the reference clock from the reference clock generation circuit 28 into first and second audio data processing. Output terminals for outputting to the units 13 and 14 (FIG. 1).

Here, the reference clock generator as described above generates a reference clock synchronized with a reproduced data signal during tape reproduction. At the time of memory card reproduction, a reference clock that is asynchronous with respect to input audio data, such as a fixed value from the fixed value section 24 and an average value from the average value section 25, is generated.

The operation of the reference clock generator configured as described above will be described below.

At the time of tape reproduction, the reference clock generation circuit 28 outputs a sample signal from the tape sample generation section 22 through the A of the second switch 27 according to a detection signal (detection of the tape 11) from the detection signal input terminal 29. Is entered. Also, by inputting sampling frequency data from the sampling frequency data input terminal 21, a reference clock that is a predetermined clock of the sampling frequency and synchronized with the audio data is generated, and the audio data processing unit is output from the output terminal 30. 13 (see FIG. 1). The sample signal from the tape sample generation unit 22 is also input to the average value unit 25 of the memory card sample generation unit 23, averaged, and used as a sample signal for a memory card.

At the time of reproducing the memory card, the reference clock generation circuit 28 uses the detection signal from the detection signal input terminal 29 (detection of the memory card 12) to change the sample signal from the memory card sample generation section 23 to the second switch 27. Input via B. The memory card sample generator 23 holds the averaged data of the sample signal at the time of tape reproduction or the fixed value at the time of tape reproduction for each sampling frequency. Accordingly, when the memory card 12 is detected, the reference clock generation circuit 28 generates a reference clock based on the sample signal at the time of tape reproduction, and outputs the reference clock from the output terminal 30 to the audio data processing unit 14 (see FIG. 1). I do. here,
The sample signal for the memory card may be performed using either the fixed value from the fixed value section 24 or the sample signal from the average value section 25.

As described above, according to the present embodiment, the means for generating the reference clock is shared between the tape reproduction and the memory card reproduction, thereby simplifying the circuit configuration and generating the reference clock. it can.

[0027]

As described above, according to the present invention, the circuit configuration can be simplified and the cost can be reduced by sharing the reference clock generating means during tape playback and memory card playback. The effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an audio data processing device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a reference clock generator according to the embodiment;

FIG. 3 is a block diagram showing a configuration of a conventional audio data processing device.

[Explanation of symbols]

 Reference Signs List 11 tape 12 memory card 13 first audio data processing unit 14 second audio data processing unit 15 detection unit 16 reference clock generation unit 17 frequency detection unit 18 switch

Claims (2)

[Claims] 1. An audio data processing device having a first and a second recording medium and capable of reproducing a plurality of digital audio data having different sampling frequencies, wherein the audio data processing device reproduces a plurality of digital audio data from the first recording medium. First audio data processing means for processing one digital audio data; second audio data processing means for processing second digital audio data reproduced from the second recording medium; And a reference clock generating means for generating a reference clock corresponding to a sampling frequency of each digital audio data of 2 and supplying the reference clock to the first and second audio data processing means. Data processing device. 2. The reference clock generating means, when the first audio data processing means is selected, generates a reference clock synchronized with the number of samples of the first digital audio data in a predetermined period, and selects the second audio data processing means. 2. The audio data processing device according to claim 1, wherein the time is such that a reference clock synchronized with an average value of the number of samples of the first digital audio data in a predetermined period or a fixed value of the predetermined period is generated. .