JP4240805B2 - Video camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a video camera that records video and audio, and more particularly to a camera that records a photographer's narration.
[0002]
[Prior art]
As an example of a technique for clearly recording a photographer's narration, Japanese Patent Application Laid-Open No. Hei 6-245119 selects a microphone that has a good sound collection state with respect to the sound emitted by the photographer from the right and left microphones. An audio signal recording device for deriving and recording an audio signal is described.
[0003]
[Problems to be solved by the invention]
However, once recorded in the narration recording mode, the audio signal recording apparatus has a problem that it is impossible to control the presence of narration and the volume during reproduction. In addition, there is a problem that narration unintended by the photographer and voices of people near the photographer are recorded. Furthermore, since the photographer is close to the sound collecting microphone, there is a possibility that the narration is recorded at a louder volume than the sound near the photographing target.
[0004]
In view of the above problems, the present invention aims to provide a video camera capable of volume control independently be an audio near photographing target at the time of reproducing the voice of the near photographer.
[0005]
In order to improve the above problems, the present invention uses, as an example, the configurations described in the claims.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0008]
First, a first embodiment of the present invention will be described.
FIG. 1 is a diagram showing a first video camera of the present invention. As shown in the figure, this video camera has a recording medium 10, a multiplexer 20, a video encoder 30, an audio encoder 40, a camera 50, and an Lch that circulates the left audio of the shooting target and converts it into a digital signal. A recording microphone 60, an Rch recording microphone 70 for collecting right-side sound of a shooting target and converting it into a digital signal, and a narration microphone 80 are provided.
[0009]
The video imaged by the camera 50 is converted into a digital signal. The video encoder 30 encodes the digital signal obtained from the camera 50 to generate a video stream. The Lch recording microphone 60 collects the shooting target Lch sound and converts it into a digital signal. The Rch recording microphone 70 collects Rch sound to be photographed and converts it into a digital signal. The narration microphone 80 converts the sound produced by the photographer into a digital signal. The audio encoder 40 independently encodes a total of three channels of audio obtained from the Lch recording microphone 60, the Rch recording microphone 70, and the narration microphone 80 for each channel to generate an audio stream. The multiplexer 20 receives the encoded streams from the video encoder 30 and the audio encoder 40, and performs audio and video synchronization processing. Then, the generated AV stream is written to a recording medium 10 such as a magnetic tape, a semiconductor memory, or an optical disk.
[0010]
In the present invention, a clear narration can be obtained by placing a microphone near the photographer and recording in an independent channel by adopting the configuration as described above. In addition, since the Lch recording microphone 60 and the Rch recording microphone 70 do not need to collect the sound in the vicinity of the photographer, the directivity to the shooting target can be greatly improved, and the sound near the shooting target can be clearly displayed. Can record.
As described above, the narration can be determined by recording the photographer's narration in an independent channel.
[0011]
Next, a second embodiment of the present invention will be described.
FIG. 2 is a diagram showing a second video camera of the present invention. In the figure, the same parts as those in FIG. The encoding / decoding changeover switch 140 is connected to the writing side to the recording medium 10 at the time of encoding and to the reading side from the recording medium 10 at the time of decoding, and distinguishes between the encoding process and the decoding process. The demultiplexer 90 reads the AV stream via the encode / decode changeover switch 140, separates the video stream and the audio stream, and outputs them so that the audio and video are synchronized. The video decoder 100 reads the video stream from the demultiplexer 90 and performs a decoding process to obtain a video signal. The monitor 130 displays the video signal output from the video decoder 100. The audio decoder 110 reads the audio stream from the demultiplexer 90, performs decoding processing, and outputs a total of 3ch audio signals of Lch, Rch, and narration. The downmix circuit 120 reads out the 3ch audio signal from the audio decoder 110 and downmixes it to 2ch using a fixed value or a downmix coefficient set by the user. The Lch recording microphone / playback speaker 61 collects Lch sound as a shooting target during recording, and outputs Lch sound during playback. The Rch recording microphone / playback speaker 71 collects Rch sound as a shooting target during recording and outputs Rch sound during playback.
[0012]
In this embodiment, it is possible to adjust the volume of the sound near the shooting target and the voice of the narration by performing a downmix process from 3ch to 2ch when playing an AV stream in which narration is recorded on an independent channel Become.
[0013]
As the downmix coefficient of the sound near the shooting target and the voice of the narration, a coefficient value prepared in advance may be used, or the user may adjust it during reproduction. In addition, when the narration sound is muted during playback, the sound near the photographer can be almost cut off, so that the sound near the shooting target can be clearly reproduced even when the surroundings of the photographer are noisy. Similarly, when the sound near the shooting target is muted during playback, the narration can be clearly reproduced even when shooting a noisy scene.
As described above, in the second embodiment, the narration volume can be controlled by changing the downmix coefficient during reproduction.
[0014]
Next, a third embodiment of the present invention will be described.
FIG. 3 shows a third video camera of the present invention. In the figure, the same parts as those in FIG. The narration volume adjustment circuit 150 adjusts the volume of the digital signal input from the narration microphone 80 and then outputs it to the audio encoder 40. The volume adjustment circuit 151 adjusts the volume of the digital signals input from the Lch recording microphone 60 and the Rch recording microphone 70 and then outputs them to the audio encoder 40.
[0015]
In the present embodiment, the volume of the voice of the narration and the sound near the shooting target is relatively adjusted and recorded, thereby reducing the trouble of downmix during reproduction. The volume value to be adjusted may be a value prepared in advance or a value set by the photographer during recording. Thus, by adjusting the volume during recording, the volume of the narration can be controlled.
In addition, the audio near the shooting target or narration is muted and the muted channel is not encoded by the audio encoder 40, thereby reducing the bit rate of the audio stream and extending the recording time of the video camera.
[0016]
Next, a fourth embodiment of the present invention will be described.
FIG. 4 is a diagram showing a fourth video camera of the present invention. In this figure, the same parts as those in FIG. The downmix circuit 230 downmixes the digital signal obtained from the Lch recording microphone 60 and the digital signal obtained from the Rch recording microphone 70 and outputs a monaural digital signal. The selector 240 is a digital signal obtained from the Lch recording microphone 60, a digital signal obtained from the Rch recording microphone 70, a monaural digital signal obtained from the downmix circuit 230, or a digital signal obtained from the narration microphone 80. Select one channel and output.
[0017]
In the present embodiment, by selecting two channels by the selector 240 and performing audio encoding processing, the narration can be clearly recorded even with an audio encoder limited to the conventional two channels. By limiting the number of channels to be encoded to two, the bit rate of the generated bit stream can be reduced and the recording time can be extended.
As described above, there is an effect that the present technology can be used even in a conventional audio encoder by limiting to two channels.
[0018]
Next, a fifth embodiment of the present invention will be described.
FIG. 5 shows a fifth video camera of the present invention. In this figure, the same parts as those in FIG. The zoom controller 160 controls the movement of the zoom lens of the camera 50 based on the photographer's operation.
[0019]
In the present embodiment, the sound intended by the photographer is recorded by linking the volume adjustment of the narration volume adjustment circuit 150 and the volume adjustment circuit 151 with the control signal of the zoom controller 160. In other words, when zoomed in, the photographer wants to record around the shooting target at a distance, sharpens the directivity of the camera, and plays around the shooting target near the shooting target for the narration. Increase the volume of the sound of. On the other hand, when zoomed out, the user wants to record the sound of the shooting target and the entire vicinity, so that the video intended by the photographer can be shot by performing control such as lowering the volume relative to the narration. .
[0020]
Thus, by linking the narration to the zoom, there is an effect that the volume of the narration can be adjusted in accordance with the photographed image.
[0021]
Next, a sixth embodiment of the present invention will be described.
FIG. 6 shows a sixth video camera of the present invention. In the figure, the same parts as those in FIG. The narration adjustment circuit 170 receives a digital signal from the narration microphone, and outputs a narration digital signal to the audio encoder when a sound having a predetermined volume or more is input.
[0022]
In this embodiment, considering that the photographer records narration, recording is performed only when speaking at a certain volume level, and in other cases, muting is performed to lower the bit rate and extend the recording time. . Also, voices other than the narration near the photographer are blocked during recording, so that the narration can be reproduced more clearly.
Thus, only the narration intended by the photographer is discriminated and recorded, so that there is an effect of clearly recording the narration.
[0023]
Next, a seventh embodiment of the present invention will be described.
FIG. 7 shows a seventh video camera of the present invention. In the figure, the same parts as those in FIG. The changeover switch 180 switches the audio signal output from the narration microphone 80 according to the photographer's selection. The voice recognition circuit 190 receives the digital signal of the voice collected by the narration microphone 80 from the changeover switch 180, recognizes the input voice, and outputs a corresponding control signal. The system controller 200 controls the operation of each part of the video camera, and when there is a control signal output from the voice recognition circuit 190, controls the entire system according to the content of the control signal.
[0024]
In the present embodiment, the photographer can not only record the narration using the narration microphone 80 but also control the video camera with the words uttered. In the conventional video camera operation during shooting by button operation, the types of contents to be operated are limited. However, operations such as fade-in at the time of switching screens, effects such as mosaic, and color tone changes such as color and black and white can be easily performed during shooting by control based on voice recognition. Thus, having the voice recognition circuit has an effect of enabling control of each part of the video camera.
[0025]
Next, an eighth embodiment of the present invention will be described.
FIG. 8 is a diagram showing an eighth video camera of the present invention. In the figure, the same parts as those in FIG. The headphone type narration microphone 220 can be detached from the video camera body, and is attached to the photographer's head to convert the narration emitted by the photographer into a digital signal. The reception circuit 210 receives a narration digital signal output from the headphone narration microphone 220 and outputs the narration digital signal to the audio encoder.
[0026]
In this embodiment, the narration microphone can be removed from the video camera body, and the directivity of the narration microphone can be improved by recording the narration close to the photographer's mouth. Even when the video camera is taken away from the eyes, the narration microphone is the photographer's mouth, so that clear narration can be recorded. The photographer can listen to the output of the Lch and Rch recording microphones being recorded from the headphones, and can also narrate while checking the recorded audio. The eighth embodiment has the effect of blocking noise around the photographer by clearly collecting the photographer's narration using headphones.
[0027]
According to the present invention, it is possible to clearly reproducing sound around the voice and photographer near shadow target shooting.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a first embodiment of the present invention.
FIG. 2 is a block diagram showing a second embodiment of the present invention.
FIG. 3 is a block diagram showing a third embodiment of the present invention.
FIG. 4 is a block diagram showing a fourth embodiment of the present invention.
FIG. 5 is a block diagram showing a fifth embodiment of the present invention.
FIG. 6 is a block diagram showing a sixth embodiment of the present invention.
FIG. 7 is a block diagram showing a seventh embodiment of the present invention.
FIG. 8 is a block diagram showing an eighth embodiment of the present invention.
[Explanation of symbols]
10 recording medium 20 multiplexer 30 video encoder 40 audio encoder s
50 camera 60 Lch recording microphone 61 Lch recording microphone / playback speaker 70 Rch recording microphone 71 Rch recording microphone / playback speaker 80 narration microphone 90 demultiplexer 100 video decoder 110 audio decoder 120 downmix circuit 130 monitor 140 encoding / Decode changeover switch 150 narration volume adjustment circuit 151 volume adjustment circuit 160 zoom controller 170 narration adjustment circuit 180 changeover switch 190 voice recognition circuit 200 system controller 210 reception circuit 220 headphone narration microphone 230 downmix circuit 240 selector

Claims (14)

Lch recording microphone that collects the Lch sound of the shooting target and converts it to a digital signal,
Rch recording microphone that collects the Rch sound of the shooting target and converts it to a digital signal;
A narration microphone that collects the voice of the photographer and converts it into a digital signal;
An audio encoder that compresses information and generates an audio stream for the digital signal obtained from the Lch recording microphone, the Rch recording microphone, and the narration microphone;
A camera that converts the target video to a digital signal;
A video encoder for generating a video stream subjected to information compression to said digital signal obtained from said camera,
A multiplexer for generating an AV stream performs synchronous processing to said audio stream and the video stream obtained from the video encoder obtained from the audio encoder is reproduced in synchronization,
Recording means for recording the AV stream output from the multiplexer to a recording medium,
A switch for switching input / output to write to the recording medium at the time of recording and to read out the stored AV stream at the time of reproduction,
To said AV stream read from the recording medium, and a demultiplexer for outputting audio, a video stream as video sync, the audio stream,
A video decoder that decodes the video stream obtained from the demultiplexer to obtain a video signal;
A monitor for outputting said video signal obtained from said video decoder,
An audio decoder to obtain decoded Lch and Rch and narration audio signal the audio stream obtained from the demultiplexer,
And a downmix circuit and outputting the downmixing the audio signal obtained from the audio decoder,
The audio encoder encodes the digital signal obtained from the Lch recording microphone, the Rch recording microphone, and the narration microphone as an independent channel,
The video camera characterized in that the downmix circuit changes the volume of the voice of the narration obtained from the audio decoder at the time of reproduction, and downmixes it to Lch and Rch for output. A narration volume adjustment circuit for adjusting the volume of the digital signal obtained from the narration microphone;
A volume adjustment circuit for adjusting the volume of the digital signal obtained from the Lch recording microphone and the Rch recording microphone;
2. The video camera according to claim 1, wherein both volumes are relatively adjusted during recording of audio.   3. The video camera according to claim 2, wherein the audio decoder does not encode the channel when any one of the channels is muted by the narration volume adjustment circuit or the volume adjustment circuit.   3. The video camera according to claim 2, wherein the narration volume adjustment circuit and the volume adjustment circuit perform different volume adjustments according to the zoom operation of the camera. With narration adjusting circuit for transmitting only the digital signal when the digital signal obtained from the narration microphone is equal to or larger than a predetermined volume,
2. A video camera according to claim 1, wherein words recorded by the photographer are selected and recorded. A speech recognition circuit that performs speech recognition processing on the digital signal obtained from the narration microphone;
The video camera according to claim 1, wherein the video camera being photographed can be controlled by sound produced by the photographer. The narration microphone can be arranged at a position outside the video camera body,
A receiving circuit for receiving an audio signal from the narration microphone,
The receiving circuit inputs the digital audio obtained from the narration microphone from the outside of the video camera body, and outputs it to the audio encoder,
The audio encoder to said digital audio output from the receiver circuit, a video camera according to any one of claims 1 to 6, characterized in that to generate the audio stream subjected to information compression. Lch recording microphone that collects the Lch sound of the shooting target and converts it to an audio signal ;
Rch recording microphone that collects the Rch sound of the shooting target and converts it to an audio signal ;
A third microphone that is disposed closer to the photographer than the Lch recording microphone and the Rch recording microphone and collects a third sound and converts it into an audio signal ;
An audio encoder that compresses information and generates an audio stream for the audio signal obtained from the Lch recording microphone, the Rch recording microphone, and the third microphone;
A camera that converts the target video to a video signal;
A video encoder for generating a video stream subjected to information compression to the video signal obtained from said camera,
A multiplexer for generating an AV stream performs synchronous processing to said audio stream and the video stream obtained from the video encoder obtained from the audio encoder is reproduced in synchronization,
Recording means for recording the AV stream output from the multiplexer to a recording medium,
Switching means for switching input / output to write to the recording medium at the time of recording and to read out the stored AV stream at the time of reproduction,
To said AV stream read from the recording medium, and a demultiplexer for outputting audio, a video stream as video sync, the audio stream,
A video decoder that decodes the video stream obtained from the demultiplexer to obtain a video signal;
A monitor for outputting said video signal obtained from said video decoder,
An audio decoder to obtain decoded Lch and Rch and third audio signals to the audio stream obtained from the demultiplexer,
And a downmix circuit and outputting the downmixing the audio signal obtained from the audio decoder,
The audio encoder encodes the Lch recording microphone, the Rch recording microphone, as the third independent channels audio signals obtained from the microphone,
The video camera characterized in that the downmix circuit changes the volume of the third audio signal obtained from the audio decoder at the time of reproduction, downmixes it to Lch and Rch, and outputs it. A first volume adjustment circuit for adjusting the volume of an audio signal obtained from the third microphone;
A second volume adjustment circuit for adjusting the volume of the audio signal obtained from the Lch recording microphone and the Rch recording microphone;
9. The video camera according to claim 8, wherein both volumes are relatively adjusted during recording of audio.   10. The video camera according to claim 9, wherein the audio decoder does not encode the channel when any channel is muted by the first volume adjustment circuit or the second volume adjustment circuit.   10. The video camera according to claim 9, wherein the first volume adjustment circuit and the second volume adjustment circuit perform different volume adjustments according to a zoom operation of the camera. It said third video camera according to claim 8, wherein the further comprising a speech signal transmission control circuit which transmits only audio signals when the audio signals obtained is equal to or larger than a predetermined volume from the microphone. A speech recognition circuit for performing speech recognition processing on the speech signal obtained from the third microphone;
9. The video camera according to claim 8, wherein the video camera being photographed can be controlled by the third audio signal. The third microphone can be arranged at a position outside the video camera body,
A receiving circuit for receiving an audio signal from the third microphone,
The receiving circuit inputs an audio signal obtained from the third microphone from the outside of the video camera body, and outputs the audio signal to the audio encoder.
The audio encoder to the audio signal output from the reception circuit, a video camera according to any one of claims 8 to 13, characterized in that to generate the audio stream subjected to information compression.

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