JP2001313930A - Video transmission system and video transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control connection with a remote video storing device, and a video recording start by operation of a video camera. SOLUTION: When an operator changes a video recording button 28 into a half push state pushed in lightly, one communication channel ch1 is established between the video camera 10 and the video storing device 12. The video camera 10 transmits a capacity inquiry command via the communication channel ch1 to the video storing device 12. Image quality and video recording time to which the video storing device 12 can deal with are displayed in an information display device 26 from contents of response from the video storing device 12. When the video recording button 28 is in a fully pushed state, the video camera 10 encodes and multiplexes video data of a video input device 14, and voice data of a voice input system 16 to convert them into a data stream and to transmit them to the video storing device 12. A control circuit 30 increases or decreases the number of channels of radio communication in compliance with the quantity of stored data of a buffer 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video transmission system and a video transmission device, and more specifically, to a video reception device at a remote place via a communication line whose data transmission rate changes like a wireless communication path. For example, the present invention relates to a video transmission system and a video transmission device for transmitting video information to a video storage device.

[0002]

2. Description of the Related Art Conventionally, there has been known a video camera which transmits a photographed image to a remote image storage device by wireless communication. FIG. 9 shows a schematic block diagram of a conventional example.

[0003] Reference numeral 110 denotes a video input device for outputting video data of a photographed video, 112 denotes an audio input device for capturing and digitizing surrounding audio, and 114 denotes video data from the video input device 110 and audio input device 112. An encoding and multiplexing apparatus 116 for compressing and encoding the audio data according to the MPEG system,
An RF modulation circuit that modulates the output of the video signal at a wireless carrier frequency and wirelessly transmits the output from an antenna 118;
0, a recording button for instructing wireless transmission of the captured video (and input audio); 124, an encoding and multiplexing device 114 and other parts according to the operation of the recording button 122 Control circuit.

When the operator fully presses the recording button 122, the encoding and multiplexing device 114 compresses and encodes the video data from the video input device 110 and the audio data from the audio input device 112, 116. The RF modulation circuit 116 controls the encoding and multiplexing device 11
4 is modulated by the radio carrier frequency and transmitted wirelessly from the antenna 118.

[0005] The wirelessly transmitted data is received by a wireless receiver (not shown) and stored in a video storage device. The video storage device is, for example, a digital video recording device that digitally records video / audio information on a recording medium such as a magneto-optical disk and a hard disk.

[0006]

In the prior art, it is necessary to independently perform the shooting operation of the video camera and the recording operation of the video storage device. That is, at the start of shooting, the operator must perform the shooting operation of the video camera after performing the recording operation of the video storage device. At the end of shooting, it is necessary to operate the video recording device to stop the recording operation and then to stop the video camera. Therefore, in the conventional example, not only the operation is complicated, but also both the video camera and the video storage device must be installed within a distance range where the operator can operate simultaneously.

In the conventional example, the transmission rate of wireless communication is constant during communication. The coding and multiplexing device 114
Even if the coding rate is adaptively changed in accordance with the amount of video information, the image quality may need to be reduced more than necessary depending on the transmission rate of wireless communication.

If the video storage device is far from the video camera, the operator of the video camera cannot immediately know the recordable time of the video storage device. This means that the recording may end unintentionally.

[0009] It is an object of the present invention to provide a video transmission system and a video transmission device which solve such inconveniences.

[0010]

A video transmission system according to the present invention is a video transmission system comprising a video transmission device and a video storage device for storing video information transmitted from the video transmission device. The video transmitting device detects a video source, a video output unit that outputs video information output from the video source to a communication line connected to the video storage device, an operation unit, and an operation state of the operation unit. ,
When the operating means is in the first state, the communication line with the video storage device is disconnected; when in the second operation state, the communication line with the video storage device is established; 3
And control means for causing the video output means to output video information from the video source to the communication line when in the state described above.

[0011] A video transmitting apparatus according to the present invention is a video transmitting apparatus for transmitting video information to a video storage device via a communication line, and includes a video source and video information output from the video source. Video output means for outputting to
Operating means, detecting the operating state of the operating means, when the operating means is in the first state, disconnecting the communication line with the video storage device, when in the second operating state, Establish the communication line with the video storage device,
A control unit for causing the video output unit to output video information from the video source to the communication line when in the third state.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic block diagram showing an embodiment of the present invention. Reference numeral 10 denotes a video camera, and 12 denotes a video storage device that stores video / audio information wirelessly transmitted from the video camera 10.

Reference numeral 14 denotes a video input device for outputting video data of a photographed video, 16 denotes an audio input device for taking in surrounding sounds, digitizing and outputting, and 18 denotes a video input device 1
The encoding and multiplexing device 20 for compressing and encoding the video data from the audio input device 4 and the audio data from the audio input device 16 according to the MPEG system, and temporarily stores the output data stream of the encoding and multiplexing device 18; This is a buffer distributed to a plurality of communication channels. Reference numeral 22 denotes a wireless communication device capable of selecting the number of communication channels, reads a data stream of one or a plurality of communication channels stored in the buffer 20, converts the data stream into a wireless signal, and wirelessly outputs the wireless signal from the antenna 24.

Reference numeral 26 denotes an information display device for displaying a video captured by the video input device 12 and information indicating an operation state; 28, a recording button for instructing wireless transmission and recording of the captured video (and input audio); And the encoding and multiplexing device 1 according to the operation of
8, a control circuit for controlling the wireless communication device 22 and other parts.

The recording button 28 has three states: an open state, a half-press state, and a full-press state, and the control circuit 26 can detect each state. Although the details will be described later, the video camera 10 of the present embodiment stops the operation when the recording button 28 is open, and when the recording button 28 is half-pressed, the video camera 10 waits for the transmission of the video / audio and the video storage device. When the recording button 28 is fully pressed when the connection with the video recording device 28 is established, the video / audio information is transmitted and the video storage device 12 is instructed to start recording.

FIG. 2 is a schematic diagram showing a connection form between the video camera 10 and the video storage device 12. Base station 3 of network 32
4 establishes a wireless communication path with the video camera 10, and the base station 36 establishes a wireless communication path with the video storage device 12. Base stations 34 and 36 are wireless terminals (video camera 1).
0 and the video storage device 12) and a connection protocol between the network 32 and data transfer between wireless terminals via the network 32. The information transferred from the video camera 10 to the video storage device 12 is video and audio, but most of the data amount is video. Therefore, in the following description, for convenience, the video camera 10 is connected to the video storage device 12.
Although the information transferred to is described as video, it should be understood that it naturally includes audio.

Video data output from the video camera 10 is transmitted to and stored in the video storage device 12 via the base station 34, the network 32, and the base station 36. The wireless communication path between the video camera 10 and the base station 34 and the wireless communication path between the video storage device 12 and the base station 36 are provided with a plurality of communication channels. Communication channels are used for data transmission.

Although various types of systems having a plurality of communication channels in a wireless communication path are known, in the present embodiment, TDD (TDD) occupying one or a plurality of time-division time slots is used.
An image division duplex (X) method is employed.

FIGS. 3, 4 and 5 are conceptual diagrams of a method in which the video camera 10 transmits video data using one or a plurality of communication channels. 3 shows a case where one communication channel is used, FIG. 4 shows a case where two communication channels are used, and FIG. 5 shows a case where three communication channels are used.

The buffer 20 includes a FIFO memory 40, a switch 42, and data buffers 44, 46, 48. The FIFO memory 40 temporarily stores the data stream output from the encoding and multiplexing device 18. The switch 42 distributes data output from the FIFO memory 40 to data buffers 44, 46, 48 corresponding to three communication channels ch1, ch2, ch3.

When only one communication channel ch1 is used (FIG. 3), the packets p1, p2, p3... Of the FIFO buffer 40 are distributed only to the data buffer 44 by the switch 42, and the communication from the data buffer 44 is performed. It is output to channel ch1.

When two communication channels ch1 and ch2 are used (FIG. 4), the switch 42 converts the packets p1, p2, p3...
The data is allocated to the data buffers 44 and 46 in order. As a result, odd-numbered packets are output to the communication channel ch1, and even-numbered packets are output to the communication channel ch1.

Three communication channels ch1, ch2, c
When h3 is used (FIG. 5), the switch 42
Packets p1, p2, p3,... From the O buffer 40
Are sequentially allocated to the data buffers 44, 46, and 48. Are output to the communication channel ch1 via the data buffer 44, and the 3n + 2th packets p2, p5,. ., P3, p6,... Which are 3n + 3rd packets are output to the data buffer
8 to the communication channel ch3.

FIG. 6 shows a sequence in which the video camera 10 is connected to the video storage device 12 to transfer video data, and FIG. 7 shows a change in the amount of data in the FIFO buffer 40 at that time.

In the standby state, the recording button 28 is open, and at this time, the video camera 10 is not communicating with the video storage device 12.

When the operator presses the recording button 28 halfway down (S1), the video camera 10 calls the network 32 (S2) and requests connection to the video storage device 12. Upon receiving the incoming call from the network 32 (S3), the video storage device 12 returns a connection response to the network 32 (S3).
4). A connection response is returned from the network 32 to the video camera 10 (S5), and one communication channel ch1 is established between the video camera 10 and the video storage device 12.

When the communication channel ch1 is established, the video camera 10 transmits a capability inquiry command to the video storage device 12 via the communication channel ch1 (S
6). The content of the capability inquiry is necessary to connect the video camera 10 and the video storage device 12 with each other, including the maximum transfer rate at which the video storage device 12 can receive video data, information indicating the amount of video data that can be stored, and the video camera 10. And other various set values. In response to the capability inquiry (S6), the video storage device 12 notifies the video camera 10 of the information indicating its own capability as a capability response via the communication channel ch1 (S7). The video camera 10 displays the image quality and the recording time that the video storage device 12 can support on the information display device 26 according to the received capability response information (S
8).

When the communication channel ch1 is established and the recording button 28 is fully depressed by the operator (S9), the video camera device 10 transmits the video data of the video input device 14 and the audio input device. The 16 audio data are encoded and multiplexed, converted into a data stream, transmitted from the wireless communication device 22 to the line network 32 via the buffer 20 (S10), and the video storage device 12 is transmitted via the communication channel ch1. To receive video data (S
11). At this time, the buffer 20 is processing the data stream in the state shown in FIG. The time when the recording button 28 is fully pressed and transmission and recording of video data is started is defined as t0.

The encoding and multiplexing device 18 of the video camera 10
Encodes video data in the MPEG4 format, so that the amount of data output from the coding and multiplexing device 18 varies depending on the video. Accordingly, the amount of data stored in the FIFO buffer 40 changes from t0 as illustrated in FIG.
Usually, in data transmission of only one channel, the transmission rate is smaller than the coding rate. Therefore, after starting transmission,
After the start of data transmission, the data amount of the FIFO buffer 40 increases by the difference between the data transmission rate and the data stream generation amount.

When the video camera apparatus 10 transmits video data on one communication channel ch1, it transmits a message (S1).
1) The amount of data in the FIFO buffer 40 of the buffer 20 is monitored. As the change of the video becomes large, the generated code amount increases, and as shown in FIG.
When the data amount exceeds the value of the first threshold L1, the video camera 10 outputs a command requesting addition of a communication channel to the line network 32 (S12). The network 32 is
This command is transferred to the video storage device 12 (S1
3).

When it is possible to add a communication channel, the video storage device 12 returns a connection response indicating that an additional channel is possible to the network 32 (S14), and the network 32 transmits this connection response. The data is transferred to the video camera 10 (S15). The video camera 10 that has received the connection response of the additional channel (S15) updates the display content of the information display device 26 to one corresponding to the case where the communication channel is added (S16).

When a second communication channel is established between the video camera 10 and the video storage device 12, the buffer 20 of the video camera 10 is in the state shown in FIG. 4, and the data stream is transferred to the two data buffers 44 and 46. The video data is transmitted using the communication channels ch1 and ch2 (S18). In FIG. 7, data transmission using two communication channels ch1 and ch2 (S18).
Is started at time t1.

When the data transmission on the two communication channels ch1 and h2 starts, the data transfer rate increases and the difference from the amount of data stream generated changes. Therefore, the data amount of the FIFO buffer 40 is, for example, as shown in FIG.
Changes as shown in FIG.

When the amount of data generated by the encoding and multiplexing device 18 further increases and the amount of data in the FIFO buffer 40 exceeds the second threshold L2 as shown in FIG.
0 sends a command requesting the addition of another communication channel to the network 32 (S19). Network 32
Transmits the channel addition request to the video storage device 12 (S20).

When it is possible to add a communication channel, the video storage device 12 returns a connection response indicating that an additional channel is possible to the network 32 (S 21). The data is transferred to the video camera 10 (S22). The video camera 10 that has received the connection response of the additional channel (S22) updates the display content of the information display device 26 to one corresponding to the case where the communication channel is added (S23).

When a third communication channel is established between the video camera 10 and the video storage device 12, the buffer 20 of the video camera 10 changes to the state shown in FIG. 5, and the data stream is transferred to the three data buffers 44 and 46. , 48
And video data is transmitted using the communication channels ch1, ch2 and ch3 (S25). In FIG.
Data transmission using the three communication channels ch1 and ch2 (S25) is started at time t2.

After the data transmission using the three communication channels, for a while, the motion of the video being shot is reduced, the code generation amount of the coding multiplexing device 18 is reduced, and the data transmission amount is reduced. Then, as shown in FIG.
The data amount of the FO buffer 40 starts to decrease. And
When the data amount of the FIFO buffer 40 becomes smaller than the threshold L2 as shown in FIG.
A channel disconnection request command for disconnecting the last added communication channel is transmitted to the line network 32 (S26).
The network 32 transmits this channel disconnection request command to the video storage device 12 (S27). Video storage device 12
Returns a disconnection response indicating that the last added communication channel can be disconnected to the network 32 (S28), and the network 32 transmits the disconnection response to the video camera 10 (S29).

Upon receiving the disconnection response (S29), the video camera 10 updates the display contents of the information display device 26 (S3).
0), and thereafter, the video data is transmitted through the two communication channels ch1 and ch2 (S31, S32). That is, the buffer 20 of the video camera 10 converts the data stream into two data buffers 44, as shown in FIG.
Assign to 46. In FIG. 7, two communication channels ch
The transmission of video data using S1 and ch2 (S32)
It has started at time t3.

After the data transmission using the two communication channels, for a while, the motion of the video being shot is further reduced, and the amount of codes generated by the coding and multiplexing device 18 is reduced.
When it becomes less than the data transmission amount, as shown in FIG.
The data amount of the FlFO buffer 40 starts to decrease. When the data amount of the FIFO buffer 40 becomes smaller than the threshold value L1 as shown in FIG.
Transmits a command of a channel disconnection request for disconnecting the last added communication channel to the line network 32 (S3).
3). The network 32 transmits the channel disconnection request command to the video storage device 12 (S34). The video storage device 12 returns a disconnection response indicating that disconnection of the last added communication channel is possible to the line network 32 (S3).
5) The line network 32 sends the disconnection response to the video camera 10
(S36).

The video camera 10 receiving the disconnection response (S36) updates the display contents of the information display device 26 (S3).
7) Thereafter, the video data is transmitted through one communication channel ch1 (S38, S39). That is, the buffer 20 of the video camera 10 transfers the data stream to the data buffer 44 as shown in FIG. In FIG. 7, transmission of video data using one communication channel ch1 and ch2 (S32) is started at time t4.

When the operator half-presses the recording button 28 at time t5 (S40), the encoding and multiplexing device 18 stops, the wireless communication circuit 22 also stops transmitting video data, and the video camera 10 It becomes a waiting state.

When the recording button 28 is released by the operator (S41), the video camera 10 determines that the recording operation has ended, and outputs a command for requesting disconnection of the communication line to the line network 32 (S42). . This line disconnection request command is a command for requesting disconnection of all connected communication channels. The line network 32 transmits this line disconnection request command to the video storage device 12 (S43). The video storage device 12 outputs a disconnection response indicating that all communication channels can be disconnected to the network 32 (S4).
4) Disconnect the connection with the line network 32. The network 32 is
A disconnection response is transmitted to the video camera 10 and the video camera 1
0 disconnects the connection with the line network 32 accordingly.

In this embodiment, in addition to the above-mentioned L1 and L2, L3 which is larger than L2 is set as the data amount threshold of the FIFO buffer 40. L3 is a value obtained by subtracting a predetermined margin value from the upper limit value of the storage capacity of the FIFO buffer 40. When the data amount of the FIFO buffer 40 exceeds the threshold L3, the video camera 10 encodes the image to be MPEG4 encoded with a low image quality by the encoding and multiplexing device 18 (that is, encodes the image with a higher compression rate). Reduce the amount of generated data.

FIG. 8 is a flowchart showing the operation of the control circuit 30 for determining the amount of data in the FIFO buffer 40. Referring to FIG. 8, control circuit 3 at the time of the above communication
The operation of 0 will be described in detail.

When the recording button 28 is fully pressed, the flow shown in FIG. 8 starts, and when the recording operation is terminated, that is, when the recording button 28 is half-pressed or released, any state is determined. Even if forced to end.

When the control circuit 30 starts, first, the control circuit 30
It is determined whether the data amount Lb of the IFO buffer 40 is 0 (S51). When Lb is 0 (S51), ie, F
If the IFO buffer 40 is empty, the process waits until data is written to the FIFO buffer 40 (S51). Lb
Is not 0 (S51), that is, the FIFO buffer 4
When not a little data is written to 0, data transfer to the wireless communication circuit 22 is started (S52), and the data is transferred to the video storage device 12 via one channel of the wireless communication line.

The control circuit 30 monitors whether the data amount Lb of the FIFO buffer 40 has become 0 (S5).
3) If Lb is 0 (S53), the wireless communication circuit 22
The data transfer to S51 is stopped (S54), and the process returns to S51.
If Lb is not 0 (S53) and is smaller than the threshold L1, (S53)
55) Until Lb becomes 0 (S53), data transmission by one channel is continued.

When the data amount Lb of the FIFO buffer 40 is L
When the number becomes 1 or more (S55), the control circuit 30 adds the channel ch2 (S56). It is monitored whether the data amount Lb of the FIFO buffer 40 has become smaller than L1 (S57), and if Lb becomes smaller than L1 (S57),
The channel ch2 is deleted (S58), and the process returns to S53. If Lb is equal to or greater than L1 (S57), it is checked whether Lb is equal to or greater than the second threshold L2 (S59), and while less than L2, data transmission by two channels is continued.

The data amount Lb of the FIFO buffer 40 is L
When the number becomes 2 or more (S59), the control circuit 30 adds the channel ch3 (S60). It is monitored whether the data amount Lb of the FIFO buffer 40 has become smaller than L2 (S61), and if Lb becomes smaller than L1 (S61),
The channel ch3 is deleted (S62), and the process returns to S57. If Lb is equal to or greater than L2 (S61), it is checked whether Lb is equal to or greater than a third threshold L3 (S63). If Lb is equal to or greater than L3, the control circuit 30 controls the coding and multiplexing device 18 to increase or decrease the compression ratio. The encoding at the resolution is instructed (S64). Until the data amount of the FIFO buffer 40 becomes less than L3 (S63), the image quality or the compression ratio is sequentially adjusted (S64).

Although the TDD system has been exemplified as the wireless communication system, the FDD (Frequency Division D) is used.
CDMA (Code Di).
Vision Multiple Access). Furthermore, other communication methods having a plurality of communication channels can be applied. It goes without saying that the transmission medium may be not only a public line but also a dedicated line.

The recording button 28 may be any of a dial type and a menu selection type other than the push button type, and may be a means capable of setting three or more states.

As long as the coding rate can be freely changed, the video coding method is the MPEG method, the JPEG method, or the H.264 method. 26
1 system and H.264. 263 system or the like.

The FIFO buffer 40 may be any one that physically or logically realizes a FIFO (first-in first-out) operation, and may be a so-called ring buffer, hardware, or software. May be either.

Threshold L of data amount of FIFO buffer 40
1, L2, and L3 may be different values when the data amount of the FIFO buffer 40 increases and decreases. That is,
A hysteresis characteristic may be provided between the data amount of the FIFO buffer 40 and the number of communication channels, that is, the transmission rate.

The means for notifying the operator of the operation status may be provided in the finder or in an image display device using a liquid crystal display device. Of course, various kinds of information may be displayed by combining optical display means such as a plurality of LEDs. Further, a method of notifying the operator of information by acoustic means such as synthetic voice may be used.

Although the embodiment of the connection type communication line has been described, the present invention is also applicable to a connectionless type communication line or a data transmission line.

[0058]

As can be easily understood from the above description, according to the present invention, in the first operation state, the communication line with the remote video storage device is disconnected, and in the second operation state, the communication line is disconnected. Establishing a communication line with the video storage device,
Since the video is transmitted to the video storage device in the third operation state, even if the video storage device is at a remote place, the operator of the video camera can start the video storage by operating the video camera. Stop can be easily operated.

Further, by adaptively adjusting the data transmission rate according to the generated code amount, it is possible to efficiently transmit video information of the highest possible quality.

Since the recordable time is calculated from the recordable amount of the video storage device and the data transmission rate and notified to the operator, it is possible to prevent the recording from being stopped at a time not intended by the photographer.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an embodiment of the present invention.

FIG. 2 is a schematic diagram of a connection configuration between a video camera 10 and a video storage device 12.

FIG. 3 is a configuration diagram in a buffer 20 in the case of video transmission by one channel.

FIG. 4 is a configuration diagram in a buffer 20 in the case of video transmission by two channels.

FIG. 5 is a configuration diagram of a buffer 20 in the case of video transmission by three channels.

FIG. 6 is a schematic diagram of a video transmission sequence according to the present embodiment.

FIG. 7 is a schematic diagram showing a change in a data amount of a FIFO buffer 40;

FIG. 8 is a flowchart of a process for determining a data amount of a FIFO buffer 40;

FIG. 9 is a schematic configuration block diagram of a conventional video camera.

[Explanation of symbols]

 10: Video camera 12: Video storage device 14: Video input device 16: Audio input device 18: Coding multiplex device 20: Buffer 22: Wireless communication device 24: Antenna 26: Information display device 28: Record button 30: Control circuit 32: circuit network 34, 36: base station 40: FIFO memory 42: switch 44, 46, 48: data buffer 110: video input device 112: audio input device 114: coding multiplexer 116: RF modulation circuit 118: antenna 120: video display device 122: recording button 124: control circuit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G11B 27/02 A F term (reference) 5C053 GB11 GB17 GB28 GB37 JA07 KA02 KA08 KA24 LA01 LA15 5C054 AA01 AA05 CC05 DA07 DA08 EA01 EA03 EA07 EG01 EG09 GB01 GD07 HA17 5C059 KK34 MA00 PP04 RA04 RA06 RA08 SS06 SS12 TA00 TA72 TB01 TC15 TC20 TC37 UA02 UA32 5D044 AB07 EF03 EF06 GK03 GK08 HL11 5D110 AA29 CB08 CL02 FA07

Claims (10)

[Claims] 1. A video transmission system comprising a video transmission device and a video storage device for storing video information transmitted from the video transmission device, wherein the video transmission device includes a video source and a video source. Video output means for outputting the video information to be output to a communication line connected to the video storage device, an operation means, and detecting an operation state of the operation means, and when the operation means is in the first state, When the communication line with the video storage device is disconnected and in the second operation state, the communication line with the video storage device is established, and in the third state, the video output means is disconnected. And a control unit for outputting video information from the video source to the communication line. 2. The communication line according to claim 1, wherein the communication line is a communication line capable of changing a data transmission rate, and the video output unit includes: an encoding unit; a buffer for temporarily storing output data of the encoding unit; 2. The video transmission system according to claim 1, further comprising communication means for outputting said data to said communication line, wherein said communication means adjusts a data transmission rate according to the amount of data stored in said buffer. 3. The video transmission system according to claim 2, wherein said communication line is a wireless communication line having a plurality of communication channels. 4. The video transmission system according to claim 2, wherein said encoding means is capable of changing a compression ratio, and increases the compression ratio at a data transmission rate less than a predetermined value. 5. The video transmitting apparatus further comprises: receiving means for receiving a free capacity of the video storage device; calculating means for calculating a recordable time from the free capacity and a data transmission rate of the communication line; 2. The video transmission system according to claim 1, further comprising: a notification unit configured to notify a user of a calculation result of the unit. 6. A video transmission device for transmitting video information to a video storage device via a communication line, comprising: a video source; and video output means for outputting video information output from the video source to the communication line. Operating means for detecting an operating state of the operating means, and
When in the state, the communication line with the video storage device is disconnected, and when in the second operation state, the communication line with the video storage device is established, and in the third state, A video transmission device comprising: a control unit that causes the video output unit to output video information from the video source to the communication line at a certain time. 7. The communication line is a communication line capable of changing a data transmission rate, wherein the video output means comprises: an encoding means; a buffer for temporarily storing output data of the encoding means; 7. The video transmitting apparatus according to claim 6, further comprising communication means for outputting said data to said communication line, wherein said communication means adjusts a data transmission rate according to the amount of data stored in said buffer. 8. The video transmission system according to claim 7, wherein said communication line is a wireless communication line having a plurality of communication channels. 9. The video transmitting apparatus according to claim 7, wherein said encoding means is capable of changing a compression ratio, and increases the compression ratio at a data transmission rate less than a predetermined value. 10. A receiving means for receiving a free capacity of the video storage device, a calculating means for calculating a recordable time from the free capacity and a data transmission rate of the communication line, and a calculating result of the calculating means. The video transmitting apparatus according to claim 6, further comprising a notification unit configured to notify a user.