JPH0528635A - Sound recording camera - Google Patents

Abstract

PURPOSE:To enable a natural sound recording without an interruption during the sound signal recording in a photographying by repeatedly overwriting the sound signals in a buffer memory prior to inputting a recording start signal. CONSTITUTION:During the recording of a sound in a photographying, a sound detecting means 4 detects no sound sections and the signals without surrounding noise are repeatedly overwritten in a portion of a buffer memory 6 constantly prior to the time at which the shutter is pushed to photograph an optical image. And after the shutter is pushed, a memory control means 7 sends the sound data from a digital signal processor DSP3 to the memory 6 and simultaneously controls the addresses of the memory 6 so that the sound data from the memory 6 are sent to a sound memory 15. Thus, a natural sound recording is realized without an interruption.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voice recording camera having a function of capturing an optical image of a subject and recording voice.

[0002]

2. Description of the Related Art A conventional electronic camera has a function of recording an optical image of a subject and a sound at the time of photographing,
Video and audio were recorded on a floppy disk.

When recording the sound at the time of photographing, when recording the sound after pressing the shutter for photographing the optical image, it takes time from the time when the operator tries to record the sound until the shutter is actually pressed, so that the sound is interrupted. It becomes voice and becomes unnatural voice.

Therefore, there is a demand for a technique for recording from a voice a few seconds before the shutter is pressed, and a recording time before the shutter is pressed is set in advance, and the shutter is opened after the set time has elapsed since the shutter switch was pressed. Therefore, the operator is forced to perform a troublesome operation.

Further, a large capacity memory is required in order to record a non-voice section such as an unnecessary silent portion or ambient noise within the time set by the operator.

Further, as disclosed in Japanese Patent Laid-Open No. 2-297535, a voice recording camera having a function of photographing an optical image of a subject and recording it on a photographic film or another recording medium and recording a voice. As a memory, there is a technology in which voice is temporarily recorded in a semiconductor memory built in the camera body and then recorded in a removable IC memory card.

Even in this method, in order to eliminate the interruption of the recorded voice, the voice for a few seconds before the shutter for photographing the optical image is recorded, so that the camera user manually operates the time before pushing the shutter. Recording must be performed automatically with a complicated circuit configuration while setting or increasing the capacity of the built-in buffer memory. Even if the interruption of the voice is eliminated by these methods, there is a problem that the removable IC memory card records unnecessary silent portions, non-voice sections, etc., and wastes the memory.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and when recording the sound at the time of shooting, it is necessary not to interrupt the recorded sound or record unnatural sound. Furthermore, it is a technical object to reduce the use of a magnetic memory or a semiconductor memory, simplify the operation of an operator, and record voice with a simple configuration and low power consumption.

[0009]

In order to solve the above-mentioned problems, the present invention provides an audio recording camera having a function of recording an optical image and recording audio information, and an audio input means for inputting an audio signal. , A / D conversion means for converting a signal input from the voice input means into a digital signal, and only a voice section is detected from an output signal of the A / D conversion means, and a signal in the voice section is a voice section. A voice section detection unit that outputs a voice section detection signal indicating that there is a shutter switch that generates a recording start signal, and a digital signal by the A / D conversion unit while being output from the voice section detection signal A first buffer memory that constantly stores signals in duplicate, and a second buffer memory that records an audio signal for a certain period of time after the recording start signal is output,
And before the recording start signal is input,
When the recording start signal is input by repeatedly overwriting the voice information in the buffer memory of, the voice information is recorded in the second buffer memory and the signal recorded in the first buffer memory is held. However, the contents of the first buffer memory and the contents of the second buffer memory are connected and recorded.

Further, in a voice recording camera having a function of recording an optical image and recording voice information, a voice input means for inputting a voice signal and a signal inputted from the voice input means are converted into a digital signal. A / D conversion means, and a voice section detection means for detecting only a voice section from an output signal of the A / D conversion means and outputting a voice section detection signal indicating that a signal in the voice section is a voice section. ,
A shutter switch that generates a recording start signal, a buffer memory that constantly stores the signal digitized by the A / D conversion means while the audio section detection signal is being output, and a recording that records audio information. Before the recording start signal is input, the audio information is repeatedly overwritten in the buffer memory, and when the recording start signal is input, the audio information is recorded in the recording medium for a certain period of time. At the same time, the signal recorded in the buffer memory is held, and the contents of the buffer memory and the contents of the recording medium are connected and recorded.

[0011]

[Operation] When recording the sound at the time of shooting, the sound detection means detects a signal excluding silent parts and surrounding noise,
Before the shutter for taking an optical image was pressed, a part of the buffer memory was always recorded in duplicate, and after the shutter for taking an optical image was pressed, it was recorded at the moment the shutter was pressed. By recording both the voice signal of the buffer memory of the section and the voice signal after the shutter is pressed in the voice recording means, it is possible to record a natural voice without interruption of the recorded voice, and moreover, the final voice. It is possible to record only voice data by removing silent portions and ambient noise that are unnecessary for magnetic memory and semiconductor memory that record voice.

[0012]

Embodiments of the audio recording camera of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a block diagram of a voice recording camera according to the present invention.

In the figure, (1) is a microphone for inputting a voice signal. (2) is an A / D converter, which converts an analog input signal into a digital signal and outputs it. (3)
Is a DSP (digital signal processor), which is composed of a voice detecting means (4) and a voice section detecting means and performs voice signal processing. (6) is a buffer memory,
The memory control means (7) controls division.

(7) is a memory control means, which is a memory address generation means (8), an address set memory (9), a comparator 1 (10), and a comparator 2 (1
1), address storage buffer 1 (12), address storage buffer 2 (13), buffer memory section dividing means (1
4) and controls the address of the buffer memory (6).

Reference numeral (15) is a voice memory for recording digital signals using an IC card, floppy disk, IC memory or the like. (16) is a D / A converter,
Converts a digital signal to an analog signal and outputs it. (1
Reference numeral 7) is a speaker, which reproduces an analog signal and outputs a sound.

Thus, when recording a voice at the time of taking an optical image, the analog input signal from the microphone (1) is converted to an 8-bit digital signal by the A / D converter (2) at 8 KHz sampling. Then, a digital signal is sent to the DSP (5).

As a voice detecting method for detecting a voice section from a voice feature amount, a method of detecting a pitch period by using a well-known autocorrelation method and extracting a voice band signal is used.
This makes it possible to remove aperiodic noise and unnecessary noise in silent parts.

The voice detecting means (4) removes unnecessary noise by the above method and outputs only voice data from the terminal of the DSP (3). During the output of the voice data, the voice section detection means (5) also outputs a voice section detection signal indicating the voice section from the other terminal of the DSP (3). Also, the voice detection function is not activated when only the optical image is captured.

The recording time of the audio signal is determined by the memory capacity of the buffer memory (6), and the A / D
A converter (2) with a sampling frequency of 8 KHz and a data length of 8 bits is used, and the minimum practical level is 10 frames.
The memory capacity of the buffer memory (6) is set to 80 KB so that the second recording can be performed.

When recording voice, the voice before the shutter signal is input to the first half of the buffer memory (6) is divided and used in the latter half so that the voice after the shutter signal is input is recorded.

That is, in order to set the voice storage area before and after the shutter signal generated by pressing the shutter is input to the memory control means (7), the section address is set in the buffer memory section setting means, The reference value of the division address of the buffer memory section division means (14) is used.

In this embodiment, the buffer memory (6) is divided by 40 KB, which is half the capacity, and the absolute address A000 is used.
By setting H, 5 before the shutter signal is input
Seconds and 5 seconds after input shall be recorded.

Further, in order to determine the data writing state to the buffer memory (6), the address storage buffer 1
(12) The final addresses of the first half and the second half are set in the address storage buffer 2 (13), respectively. Comparator 1 compares the set value with the written address value.
(10) The write state is recognized by comparing with the comparator 2 (11).

The memory control means (7) sends the voice data from the DSP (3) to the buffer memory (6), and removes the unnecessary noise from the buffer memory (6) to the voice memory (15). The address of the buffer memory (6) is controlled so that the data is sent to.

Only while the voice section output signal from the voice section detecting means (5) is being output, the DSP (3) is stored in the buffer memory (6) by the memory address generating means (9) in the memory control means (14). The address of the buffer memory (6) is generated so as to send the audio data from.

When reproducing the captured video and audio,
The audio signal recorded in the audio memory (15) is converted into an analog signal via the D / A converter (16) and then reproduced by the speaker (17).

Next, the control flow of the voice recording camera of the present invention will be described.

FIG. 2 shows a flowchart of the voice recording processing routine.

According to this flowchart, the microcomputer issues an operation instruction to the memory control means (7) and the DSP (3).

When the voice recording mode is set, control is transferred to this voice recording processing routine, and first, in step 1, it is determined whether or not the shutter is pressed by the shutter signal.

If it is determined that the shutter has not been pressed, then in step 2, the DSP (3) determines whether the input voice is unnecessary noise or a voice signal. If it is unnecessary noise, the process returns to step 1 without outputting the data to the buffer memory (6), and the next data is analyzed.

In the case of audio data, in step 3, the audio interval signal from the audio interval detector and the digital audio signal are sent to the first half (memory address 0000H to BFFFH) of the buffer memory (6).

Further, while the voice section signal is being output, the write address is sequentially compared with the final address value of the preset first half area of the buffer in step 4, and when the final address is reached, the write address is reached. Reset the counter and write.

After that, the process returns to step 1 and the repetitive processing is continued.

By doing so, while the voice section signal is being output, the first half of the buffer memory is repeatedly overwritten and recorded.

When it is determined in step 1 that the shutter has been pressed, in step 7 the DSP (3) determines whether the input voice is unnecessary noise or a voice signal. If it is unnecessary noise, the data is not output to the buffer memory (6) and the process returns to step 7 to analyze the next data.

In the case of voice data, in step 8, the voice section signal from the voice section detector and the digital signal of the voice are sent to the latter half portion (memory address A000H to 13FFFH) of the buffer memory (6).

Further, during the period during which the voice section signal is being output, the write address is sequentially compared with the final address value of the preset area in the latter half of the buffer in step 9, and writing is performed when the final address is reached. finish.

As a result, the audio data after the shutter is pressed is recorded only once in the latter half of the buffer area.

Thereafter, in step 11, the contents of the buffer memory (6) are transferred to the voice memory (15), and the data is located at the position next to the last address where the voice recording was performed (the position where the final address is incremented). Transfer is performed in the order of the first half last address, first half start address to recording last address, second half start address to second half last address.

By doing so, unnecessary noise and silent portions can be removed from the voice memory (15) such as the IC card, floppy disk, magnetic tape, MO disk, etc., and continuous recording can be performed.

Further, in the above embodiment, the voice data after the shutter is pressed is temporarily stored in the buffer memory. However, when the voice memory (15) is capable of high speed access such as an IC card, the voice It may be recorded directly in the memory (15).

In this case, the capacity of the buffer memory (6) can be halved as compared with the above embodiment, and the capacity of the memory can be further reduced.

[0045]

As described above, according to the present invention, when recording a voice at the time of shooting, a natural voice can be recorded without interruption of the recorded voice, and finally, a magnetic memory for recording the voice. It is possible to eliminate unnecessary silent parts and surrounding noise in the semiconductor memory and record only voice data, thus eliminating waste of semiconductor memory such as magnetic memory and IC card, simplifying operation and simplifying operation. The circuit can reduce power consumption.

[Brief description of drawings]

FIG. 1 is a block diagram of a voice recording camera of the present invention.

FIG. 2 is a flowchart of audio data processing of the audio recording camera of the present invention.

[Explanation of symbols]

1. microphone 2. A / D converter 3. DSP 4. Voice detection means 5. Voice section detection means 6. Buffer memory 7. Memory control means 8. Memory address generation means 9. Address set memory 10. Comparator 1 11. Comparator 2 12. Address storage buffer 1 13. Address storage buffer 2 14. Buffer memory section dividing means 15. Voice memory 16. D / A converter 17. Speaker

Claims (2)

[Claims] 1. An audio recording camera having a function of recording an optical image and recording audio information, and audio input means for inputting an audio signal, and converting a signal input from the audio input means into a digital signal. A / D conversion means, and a voice section detection means for detecting only a voice section from an output signal of the A / D conversion means and outputting a voice section detection signal indicating that a signal in the voice section is a voice section. A shutter switch for generating a recording start signal, a first buffer memory for constantly storing a signal digitized by the A / D conversion means in duplicate while being output from the voice section detection signal, and the recording start A second buffer memory for recording a voice signal for a fixed time after the signal is output,
And before the recording start signal is input,
Voice information is repeatedly overwritten in the buffer memory and the voice information is recorded in the second buffer memory and the signal recorded in the first buffer memory is held when the recording start signal is input. An audio recording camera, wherein the contents of the first buffer memory and the contents of the second buffer memory are connected and recorded. 2. An audio recording camera having a function of recording an optical image and recording audio information, and audio input means for inputting an audio signal, and converting a signal input from the audio input means into a digital signal. A / D conversion means, and a voice section detection means for detecting only a voice section from an output signal of the A / D conversion means and outputting a voice section detection signal indicating that a signal in the voice section is a voice section. , A shutter switch for generating a recording start signal, a buffer memory for constantly storing the signal digitized by the A / D conversion means in duplicate while outputting the voice section detection signal, and recording of voice information A recording medium is provided, and audio information is repeatedly overwritten in the buffer memory before the recording start signal is input, and when the recording start signal is input, the audio information is overwritten repeatedly. An audio recording camera characterized by recording audio information on a recording medium for a certain period of time, holding a signal recorded on the buffer memory, and connecting and recording the contents of the buffer memory and the contents of the recording medium. .