Video transmission apparatus, video transmission method, program, and recording medium

Abstract

To provide a video transmission device, a video transmission method, and a program capable of transmitting a video of the outside of a car to an operator of a car exterior terminal in an appropriate mode according to a situation while lowering traffic during communication.SOLUTION: In a video distribution system 100 in which an in-vehicle device, a terminal device, and a server can transmit and receive data to and from each other via a network, the in-vehicle device 10 is a video transmission device that moves together with a moving object and transmits a video to a terminal outside the moving object, and includes a video acquisition unit that sequentially acquires a video around the moving object, a speed information acquisition unit that sequentially acquires a speed of the moving object, and a video transmission unit that transmits a video with a frame rate corresponding to the speed of the moving object, and the video transmission unit transmits a video with a higher frame rate as the speed of the moving object is lower.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a video transmission device, a video transmission method, a program, and a recording medium. [Background technology]

[0002] There is a communication system that performs communication between an onboard device mounted in a vehicle and an external terminal located outside the vehicle. For example, Patent Document 1 discloses a system in which a voice call is performed between a driver of the vehicle and an operator of the external terminal, and video data showing an image of the area in front of the vehicle is transmitted from the onboard device to the external terminal while the voice call is being performed, and the video is displayed on the external terminal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-213791 Summary of the Invention [Problem to be solved by the invention]

[0004] In a system such as that described in Patent Document 1, for example, in order to avoid unnecessary increases in the amount of communication traffic during video transmission, the video may be transmitted to the external terminal in a mode that minimizes the amount of communication traffic. Even in such a case, it is preferable not to cause discomfort to the operator of the external terminal who is watching the video.

[0005] The present invention has been made in consideration of the above points, and aims to provide a video transmission device, a video transmission method, a program, and a recording medium that can transmit video of the outside of the vehicle in an appropriate manner depending on the situation to the operator of the external terminal while reducing the amount of communication during communication. [Means for solving the problem]

[0006] The video transmission device described in claim 1 is a video transmission device that moves with a moving body and transmits video to a terminal outside the moving body, and has a video acquisition unit that sequentially acquires video around the moving body, a speed information acquisition unit that sequentially acquires the speed of the moving body, and a video transmission unit that transmits video at a frame rate according to the speed of the moving body, characterized in that the video transmission unit transmits video at a higher frame rate the slower the speed of the moving body.

[0007] The video transmission method described in claim 5 is a video transmission method executed by a video transmission device that moves with a moving body and transmits video to a terminal outside the moving body, and includes a video acquisition step of sequentially acquiring video around the moving body, a speed information acquisition step of sequentially acquiring the speed of the moving body, and a video transmission step of transmitting video at a frame rate according to the speed of the moving body, characterized in that in the video transmission step, the lower the speed of the moving body, the higher the frame rate of the video transmitted.

[0008] The program described in claim 6 is a program to be executed by a computer, and is a video transmission method to be executed by a video transmission device that moves with a moving body and transmits video to a terminal outside the moving body, and includes a video acquisition step of sequentially acquiring video around the moving body, a speed information acquisition step of sequentially acquiring the speed of the moving body, and a video transmission step of transmitting video at a frame rate according to the speed of the moving body, characterized in that in the video transmission step, the lower the speed of the moving body, the higher the frame rate of the video transmitted.

[0009] A recording medium according to a seventh aspect of the present invention is a recording medium on which the program according to the sixth aspect of the present invention is stored. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a configuration of a video distribution system according to a first embodiment. [Figure 2] 1 is a diagram showing a configuration of a front seat portion of a vehicle according to a first embodiment. [Figure 3]FIG. 2 is a diagram illustrating an example of a configuration of a terminal device T according to a first embodiment. [Figure 4] 1 is a block diagram illustrating an example of a configuration of a video transmitting device according to a first embodiment. [Figure 5] FIG. 2 is a block diagram illustrating an example of a configuration of a server according to the first embodiment. [Figure 6] FIG. 2 is a block diagram illustrating an example of a configuration of a terminal device according to the first embodiment. [Figure 7] 4 is a flowchart showing a control routine of the video transmission device according to the first embodiment. [Figure 8] 4 is a flowchart showing a control routine of the video transmission device according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same components are designated by the same reference numerals, and the description of the same components will be omitted. [Example]

[0012] Fig. 1 is a diagram illustrating a configuration of a video distribution system 100 according to Example 1. As illustrated in Fig. 1, the video distribution system 100 enables an in-vehicle device 10 mounted on a vehicle M as a mobile body, a terminal device T, and a server S to transmit and receive data to and from each other via a network NW using a communication protocol such as TCP / IP or UDP / IP.

[0013] The network NW can be constructed, for example, by a mobile communication network such as LTE (Long Term Evolution), 4G (4th Generation) or 5G (5th Generation: 5th generation mobile communication system), wireless communication such as Wi-Fi (registered trademark), and Internet communication including wired communication.

[0014] 2 is a perspective view showing a front seat area of ​​a vehicle M equipped with an in-vehicle device 10 according to the first embodiment. The in-vehicle device 10 is connected to an exterior camera 12, an interior camera 13, a GPS receiver 14, a microphone 15, a touch panel display 16, and a speaker 17, which are installed in the vehicle M, and includes a control unit that controls these. The in-vehicle device 10 is disposed, for example, in the center of a dashboard DB in the front seat of the vehicle M.

[0015] The exterior camera 12 is an imaging device that captures images of the situation outside the vehicle M. In this embodiment, the exterior camera 12 is a wide-angle camera that captures an image of a wide area in front of the vehicle M through the windshield FG. In this embodiment, the exterior camera 12 is disposed on the dashboard DB.

[0016] The interior camera 13 is an imaging device that captures images of the interior of the vehicle M. In this embodiment, the interior camera 13 is a camera that captures images of the driver of the vehicle M. In this embodiment, the interior camera 13 is provided on the upper end of the windshield FG or on the ceiling near the upper end.

[0017] The GPS receiver 14 is a receiver that receives signals (GPS signals) from GPS (Global Positioning System) satellites. In this embodiment, the GPS receiver 14 is arranged on the dashboard DB.

[0018] The microphone 15 is a voice input device that receives sounds inside the vehicle, such as the voice of the driver, and converts the sounds into electrical signals. In this embodiment, the microphone 15 is disposed on the dashboard DB.

[0019] The touch panel display 16 is a display device that combines a display that displays a screen based on the control of the in-vehicle device 10 and a touch panel that accepts input operations from a passenger (e.g., the driver) of the vehicle M. In this embodiment, the touch panel display 16 is disposed in the center of the dashboard DB.

[0020] The touch panel display 16 may display, for example, a car navigation image in which the current position of the vehicle M and the planned travel route are superimposed on a map. In addition, operations related to the car navigation function, such as setting a destination, may be possible via the touch panel display 16.

[0021] The speaker 17 is an audio output device that outputs audio based on an electrical signal transmitted from the outside. In this embodiment, the speaker 17 is provided on each of the two A-pillars AP.

[0022] In this embodiment, the driver of the vehicle M can make a voice call with the operator of the terminal device T (hereinafter also referred to as a user) via the microphone 15 and speaker 17 connected to the in-vehicle device 10.

[0023] The positions of the on-board device 10, exterior camera 12, interior camera 13, GPS receiver 14, microphone 15, touch panel display 16 and speaker 17 in the front seat area of ​​the vehicle M described above are merely examples, and these may be arranged in other positions.

[0024] For example, the exterior vehicle camera 12 may be installed anywhere as long as it can capture an image of the situation ahead of the vehicle M, and may be installed at the top edge of the windshield FG or on the ceiling near the top edge.

[0025] In this embodiment, the in-vehicle device 10 sequentially transmits video information showing the video of the outside (forward) of the vehicle M captured by the exterior camera 12 to the terminal device T via the server S.

[0026] 3 is a diagram showing the configuration of the terminal device T and the display mode of the video and images displayed on the terminal device T. The terminal device T is a communication device including a frame F and a microphone 21, a speaker 22, and a touch panel display 23 housed in the frame F. In this embodiment, the terminal device T is a smartphone capable of communicating with others via communication.

[0027] The microphone 21 is a voice input device that receives voice uttered by the user of the terminal device T and converts it into an electrical signal. The microphone 21 is provided on one end side of the terminal device T.

[0028] The speaker 22 is an audio output device that outputs audio based on an electrical signal transmitted from the outside. The speaker 22 is provided on the other end side of the terminal device T.

[0029] The touch panel display 23 is a display device that combines a display that displays a screen based on the control of the terminal device T and a touch panel that accepts input operations from the user of the terminal device T. The touch panel display 23 is provided in the center of the terminal device T.

[0030] In this embodiment, the operator of the terminal device T is configured to be able to communicate by voice with the driver of the vehicle M in which the in-vehicle device 10 is installed via the microphone 21 and speaker 22 described above.

[0031] In this embodiment, the terminal device T sequentially receives, via the server S, video information showing an image of the outside of the vehicle M, which is sequentially transmitted from the in-vehicle device 10 of the vehicle M. Specifically, the terminal device T sequentially receives, via the server S, video information showing an image of the area ahead of the vehicle M captured by the exterior camera 12.

[0032] As described above, in this embodiment, the video distribution system 100 is configured to enable voice communication between the driver of the vehicle M equipped with the in-vehicle device 10 and the operator of the terminal device T. Furthermore, in this embodiment, the video distribution system 100 is configured to enable real-time display of video of the outside of the vehicle M captured by the exterior camera 12 on the touch panel display 23 of the terminal device T. In other words, the video distribution system 100 is configured to enable the in-vehicle device 10 to perform live streaming to the terminal device T.

[0033] This communication mode in which, while establishing voice communication between the in-vehicle device 10 and the terminal device T, the in-vehicle device 10 transmits in real time images of the outside of the vehicle M, the current position of the vehicle M, and the travel route of the vehicle M to the terminal device T is called video communication. In this embodiment, the in-vehicle device 10 and the terminal device T perform video communication via the server S.

[0034] By performing such video communication, the user of the terminal device T watching the video transmitted from the in-vehicle device 10 can feel as if he or she is riding in the vehicle M with the driver of the vehicle M. In other words, the video communication makes it possible to realize a virtual ride-along of the user of the terminal device T in the vehicle M. A system configured using such video communication is called a virtual ride-along system.

[0035] The configurations of the in-vehicle device 10, the server S, and the terminal device T that make up the video distribution system 100 will be described below with reference to FIGS.

[0036] 4 is a block diagram showing the configuration of the in-vehicle device 10. The in-vehicle device 10 is connected to an acceleration sensor 24 that measures the acceleration of the vehicle M, in addition to the various devices provided in the front seat of the vehicle M shown in FIG.

[0037] The control unit 25 is a processing device including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). In this embodiment, the control unit 25 functions as a computer, and performs a video transmission function during video communication.

[0038] The encoding unit 26 is a part that encodes the video (also referred to as captured video) captured by the exterior camera 12 or the interior camera 13 based on commands from the control unit 25. The encoding unit 26 has a CPU for video encoding, a so-called GPU, and encoding may be performed by the GPU.

[0039] The encoding unit 26 generates encoded data as video data by encoding the captured video using, for example, an encoding method conforming to the MPEG-4 standard. For example, the encoding unit 26 generates encoded data from the captured video using a codec such as H.264, Xvid, DivX, VP8, or VP9.

[0040] The communication unit 27 is a communication device that transmits and receives data to and from external devices in accordance with instructions from the control unit 25. The communication unit 27 is, for example, a network interface card (NIC) for connecting to the network NW.

[0041] The communication unit 27 may be, for example, a video transmission unit that transmits encoded data of the captured video generated by the encoding unit 26 to the terminal device T via the server S. The communication unit 27 is connected to the above-mentioned network NW, and transmits and receives various data between the in-vehicle device 10 and the terminal device T.

[0042] The storage unit 28 is a storage device that stores and manages data necessary for processing by the control unit 25. The storage unit 28 is, for example, a storage device such as a hard disk, a flash memory, or an SSD (Solid State Drive). The storage unit 28 stores, for example, contact information for the terminal device T as the other party in video communication. The storage unit 28 also stores, for example, map data to be displayed on the touch panel display 16.

[0043] The functional blocks of the control unit 25 will be described below.

[0044] The video acquisition unit 31 is a part that acquires the captured video captured by the above-mentioned exterior vehicle camera 12 or interior vehicle camera 13. The control unit 25 encodes the captured video acquired by the video acquisition unit 31 via the encoding unit 26 and transmits the encoded captured video to the server S via the communication unit 27.

[0045] The speed information acquisition unit 32 is a part that acquires speed information indicating the speed of the vehicle M based on the acceleration data of the vehicle M measured by the acceleration sensor 24. The control unit 25 changes the manner in which the encoding unit 26 encodes the captured video based on the speed of the vehicle M acquired by the speed information acquisition unit 32.

[0046] Here, in this embodiment, a description will be given of the encoding performed by the encoding unit 26 when transmitting captured video. In the following description, it is assumed that the exterior vehicle camera 12 always captures video at a frame rate, such as 27.5 fps, which is sufficiently higher than the frame rate of the video data after the encoding process described below, and that the encoding process reduces the frame rate to generate encoded data with a variable frame rate.

[0047] The encoding unit 26 encodes the captured video in a plurality of different encoding modes based on instructions from the control unit 25. Specifically, the encoding unit 26 has, as operation modes during encoding, a normal mode as a first encoding mode and a high frame rate mode as a second encoding mode.

[0048] The normal mode as the first encoding mode is an encoding mode that encodes captured video at a frame rate lower than that of the second encoding mode. In this embodiment, the normal mode is applied, for example, when the vehicle M is traveling at a speed exceeding a predetermined speed.

[0049] The high frame rate mode as the second encoding mode is an encoding mode in which the captured video is encoded at a frame rate higher than that of the first encoding mode. In this embodiment, the high frame rate mode is applied, for example, when the speed of the vehicle M is lower than a predetermined speed.

[0050] For example, when the predetermined speed is set to 30 km / h, the encoding unit 26 encodes the captured video at a frame rate of 10 fps in normal mode when the vehicle M is traveling at 60 km / h. When the vehicle M slows down to 20 km / h, for example, the encoding unit 26 switches from normal mode to high frame rate mode and encodes the captured video at a frame rate of 24 fps.

[0051] In this embodiment, when video communication is established between the in-vehicle device 10 and the terminal device T, the encoding mode of the video of the outside of the vehicle M transmitted from the in-vehicle device 10 is automatically changed when the speed of the vehicle M drops below a predetermined speed.

[0052] For example, if the encoding unit 26 of the in-vehicle device 10 encodes and transmits all images of the exterior of the vehicle M in normal mode, the operator of the terminal device T receiving the images may feel uncomfortable when watching them due to changes in the speed of the vehicle M.

[0053] Specifically, when the speed of the vehicle M is relatively slow, and the operator of the terminal device T receives video encoded in the normal mode described above, the operator may feel that the sense of speed visually obtained from the video, that is, the perceived speed, is faster than the actual speed of the vehicle M. This may cause the operator of the terminal device T watching the video to feel uncomfortable.

[0054] Furthermore, due to a difference between the speed of the vehicle M or the actual speed perceived by the driver of the vehicle M and the speed perceived by the operator of the terminal device T, there is a risk that the sense of sharing the image between the driver of the vehicle M and the operator of the terminal device T will be weakened. Also, for example, there is a possibility that the operator of the terminal device T will feel frightened.

[0055] According to this embodiment, the encoding unit 26 encodes video at a low frame rate in the normal mode to reduce the amount of communication traffic during video communication, and then encodes video in the high frame rate mode when the speed of the vehicle M drops below a predetermined speed. This allows the in-vehicle device 10 to transmit video of the outside of the vehicle M to the terminal device T in an appropriate manner depending on the situation while reducing the amount of communication traffic during communication.

[0056] Therefore, the operator of the terminal device T who receives the video of the outside of the vehicle M can view the video without feeling uncomfortable. This enhances the sense of sharing the video between the driver of the vehicle M and the operator of the terminal device T, enabling smooth information sharing.

[0057] 5 is a block diagram showing the configuration of the server S. The server S has a function similar to that of a SIP server that establishes a voice call between the in-car device 10 and the terminal device T during video communication and transfers data of the voice call.

[0058] The control unit 35 is a processing unit including a CPU, a ROM, and a RAM. In this embodiment, the control unit 35 transfers the captured video transmitted from the in-car device 10 to the terminal device T during video communication.

[0059] The communication unit 36 ​​is a communication device that transmits and receives data to and from external devices in accordance with instructions from the control unit 25. The communication unit 36 ​​is, for example, a NIC for connecting to the network NW. In this embodiment, the communication unit 36 ​​may be a receiving unit that receives the encoded video of the outside of the vehicle M from the in-vehicle device 10. Furthermore, the communication unit 36 ​​may be a transmitting unit that transmits the encoded video of the outside of the vehicle M to the terminal device T.

[0060] 6 is a block diagram showing the configuration of the terminal device T. The control unit 37 is a processing device including a CPU, a ROM, and a RAM.

[0061] The communication unit 38 is a communication device that transmits and receives data to and from external devices in accordance with instructions from the control unit 37. The communication unit 38 is, for example, a NIC for connecting to the network NW. In this embodiment, the communication unit 38 may be a receiving unit that receives encoded video of the outside of the vehicle M transferred from the server S.

[0062] The decoding unit 39 is a part that decodes the encoded video of the outside of the vehicle M received from the in-vehicle device 10 via the server S based on an instruction from the control unit 37, plays it back, and outputs it.

[0063] The decoding unit 39 decodes the encoded data using the codec used when encoding the encoded data, for example, the MPEG-4 encoding method, and plays back and outputs the video. The played-back video is displayed on the touch panel display 23 by the control unit 37.

[0064] In this way, the terminal device T can receive and decode the video (encoded data) of the outside of the vehicle M transmitted from the in-vehicle device 10 in video communication, thereby displaying the video on the touch panel display 23. Furthermore, the terminal device T can display video at different frame rates depending on the speed of the vehicle M by using the different encoding modes used by the in-vehicle device 10 during decoding.

[0065] The specific operation of the in-vehicle device 10 in this embodiment will be described below.

[0066] 7 is a flowchart showing a video distribution routine RT1 executed by the control unit 25 of the in-vehicle device 10. The control unit 25 starts the video distribution routine RT1 when a connection for video communication (hereinafter referred to as a video connection) is established between the in-vehicle device 10 and the terminal device T via the server S, for example.

[0067] Specifically, for example, when the driver of the vehicle M turns on the touch panel display 16 of the in-vehicle device 10, a video call acceptance screen is displayed on the touch panel display 16. Then, when the terminal device T is selected as the other party of the video connection on the screen, a video connection is established between the in-vehicle device 10 and the terminal device T. This causes the control unit 25 to start a video distribution routine RT1.

[0068] The control unit 25 determines whether or not video communication has started by determining that a video connection has been established (step S101). If the control unit 25 determines that video communication has not started (step S101: NO), the control unit 25 ends the video distribution routine RT1.

[0069] When the control unit 25 determines that video communication has started (step S101: YES), it acquires the captured image and the speed of the vehicle M, encodes the image, and starts a video distribution operation to transmit it to the terminal device T via the server S (step S102).

[0070] Specifically, in step S102, the image acquisition unit 31 of the control unit 25 acquires captured image of the outside of the vehicle M from the exterior shooting camera 12, and the speed information acquisition unit 32 of the control unit 25 acquires acceleration from the acceleration sensor 24 to acquire speed information indicating the speed of the vehicle M. Then, the control unit 25 instructs the encoding unit 26 and the communication unit 27 to encode the captured image and transmit the encoded data obtained by encoding the captured image to the terminal device T via the server S.

[0071] After step S102, the control unit 25 determines whether the video communication has ended (step S103). If the control unit 25 determines that the video communication has ended (step S103: YES), the control unit 25 ends the video distribution operation (step S104). In other words, if the control unit 25 determines that the video communication with the external device 70 has ended, the control unit 25 ends the acquisition of speed information, the acquisition of captured video, and the encoding and transmission of the captured video.

[0072] If the control unit 25 determines that the video communication has not ended (step S103: NO), it repeats step S103.

[0073] The control unit 25 of the in-vehicle device 10 continues to encode video outside the vehicle M and transmit it to the terminal device T via the server S as long as video communication between the in-vehicle device 10 and the terminal device T continues, using the video distribution routine RT1 described above.

[0074] 8 is a flowchart showing a frame rate control routine RT2 executed by the control unit 25 of the in-vehicle device 10. The control unit 25 starts the frame rate control routine RT2 using, as a start trigger, for example, the start of the above-described video distribution operation in the in-vehicle device 10 via video communication.

[0075] First, the control unit 25 determines whether the speed of the vehicle M is equal to or lower than a predetermined speed based on the speed information indicating the speed of the vehicle M (step S201). This determination is made, for example, when the vehicle M approaches an intersection with many branches, a narrow road, or the like and reduces its speed from the speed it has been traveling up until then (a speed exceeding the predetermined speed).

[0076] When the control unit 25 determines that the speed of the vehicle M is not equal to or less than the predetermined speed, that is, the speed of the vehicle M exceeds the predetermined speed (step S201: NO), the control unit 25 ends the frame rate control routine RT2.

[0077] When the control unit 25 determines that the speed of the vehicle M is equal to or lower than a predetermined speed (step S201: YES), the control unit 25 changes the encoding mode of the encoding unit 26 to a high frame rate mode (step S202). Specifically, the control unit 25 changes the encoding mode of the encoding unit 26 to a high frame rate mode, which is a mode in which the frame rate of the captured video during encoding is higher than that in the normal mode.

[0078] After step S202, the control unit 25 determines whether the speed of the vehicle M has exceeded a predetermined speed (step S203). If the control unit 25 determines that the speed of the vehicle M has exceeded the predetermined speed (step S203: YES), the control unit 25 changes the encoding mode of the encoding unit 26 to the normal mode (step S204).

[0079] When the control unit 25 determines that the speed of the vehicle M does not exceed the predetermined speed (step S203: NO), it repeatedly executes step S203.

[0080] In addition, in the frame rate control routine RT2, when changing from normal mode to high frame rate mode, and when changing from high frame rate mode to normal mode, the control unit 25 may send a mode change signal to the terminal device T notifying that the encoding mode during encoding by the encoding unit 26 has been changed.

[0081] According to this embodiment, as described above, during video communication between the in-vehicle device 10 and the terminal device T, the encoding mode of the video of the outside of the vehicle M transmitted from the in-vehicle device 10 is automatically changed when the speed of the vehicle M drops below a predetermined speed.

[0082] Therefore, according to this embodiment, the in-vehicle device 10 can transmit an image of the outside of the vehicle M in an appropriate manner depending on the situation while reducing the communication volume during communication. Therefore, according to this embodiment, information can be smoothly shared between the driver of the vehicle M and the operator of the terminal device T while reducing the communication volume during communication.

[0083] In this embodiment, the control unit 25 of the in-vehicle device 10 changes the encoding mode of the encoding unit 26 when the speed of the vehicle M is equal to or lower than a predetermined speed, i.e., the frame rate is changed in two stages. However, this change may be made in three or more stages. In other words, there may be three or more encoding modes for changing the video frame rate.

[0084] For example, the control unit 25 of the in-vehicle device 10 may perform encoding in a first high frame rate mode when the speed of the vehicle M is equal to or less than a first speed, and may change to a second high frame rate mode, which is a mode in which the frame rate mode is higher than the first high frame rate mode, when the speed of the vehicle M is equal to or less than a second speed that is smaller than the first speed.

[0085] In this way, in the high frame rate mode, the frame rate of the video during encoding may be increased as the speed of the vehicle M decreases. This allows the operator of the terminal device T to view the video without perceiving any difference between the actual speed of the vehicle M and the perceived speed of the vehicle M in the video. In other words, the sense of sharing information between the operator of the terminal device T and the driver of the vehicle M can be further enhanced.

[0086] As in the case of the high frame rate mode described above, for example, the control unit 25 of the in-vehicle device 10 may switch to the normal mode when the speed of the vehicle M exceeds a first speed, and may switch to the low frame rate mode, which is a mode in which the frame rate mode is lower than the normal mode, when the speed of the vehicle M exceeds a second speed that is greater than the first speed.

[0087] This allows, for example, when vehicle M is traveling on a highway where high speeds are possible and the image outside vehicle M does not show much change, to reduce the amount of communication during video communication by lowering the frame rate mode below normal mode.

[0088] Contrary to the above explanation, depending on the shooting environment, shooting subject, or type or specification of the shooting equipment in the vehicle M, or depending on the type or specification of the terminal device T, when the speed of the vehicle M is fast in normal mode, the speed perceived by the operator of the terminal device T may feel faster than the speed of the vehicle M or the actual speed perceived by the driver of the vehicle M. In such cases, the encoding mode described above is reversed.

[0089] For example, the control unit 25 of the in-vehicle device 10 may perform encoding in normal mode when the speed of the vehicle M is below a predetermined speed, and may change to a high frame rate mode, which is a mode in which the frame rate is higher than in normal mode, when the speed of the vehicle M exceeds the predetermined speed.

[0090] In this embodiment, the resolution of the video during encoding by the encoding unit 26 may be changed depending on the encoding mode. For example, the control unit 25 may be configured to lower the resolution of the video when encoding in the high frame rate mode when the speed of the vehicle M is equal to or lower than a predetermined speed. This makes it possible to suppress an increase in communication volume caused by an increase in the frame rate of the video when switching from the normal mode to the high frame rate mode, for example.

[0091] In this embodiment, the control unit 25 of the in-vehicle device 10 may change the encoding mode of the encoding unit 26 according to the speed of the vehicle M, and may also change the encoding mode based on the current position of the vehicle M.

[0092] Specifically, the control unit 25 of the in-vehicle device 10 may have a location information acquisition unit, and, for example, when the current position of the vehicle M on the map approaches a guidance point to which the driver of the vehicle M should be guided, the encoding mode of the encoding unit 26 may be changed from a normal mode to a high frame rate mode.

[0093] For example, the memory unit 28 may store information regarding the route of travel of the vehicle M, and the control unit 25 may determine whether the vehicle M is approaching a guidance point based on the current position and route of travel of the vehicle M.

[0094] As a result, for example, when the operator of terminal device T wants to get a good view of the exterior of vehicle M while guiding the driver of vehicle M to a guidance point, the encoding mode described above becomes high frame rate mode, allowing information to be shared smoothly between the driver of vehicle M and the operator of terminal device T.

[0095] In this embodiment, the in-vehicle device 10 and the terminal device T perform video communication via the server S, but the video communication may also be performed directly between the in-vehicle device 10 and the terminal device T by P2P (Peer to Peer) communication or the like.

[0096] In this embodiment, the case where the in-vehicle device 10 is connected to the touch panel display 16 has been described, but the present invention is not limited to this. For example, the in-vehicle device 10 may communicate with a smartphone carried by the driver of the vehicle M, and display a screen related to video communication or the like on the display of the smartphone instead of the touch panel display 16.

[0097] Furthermore, the in-vehicle device 10 may be configured not to display a screen to be presented to the driver of the vehicle M. For example, the in-vehicle device 10 may have a configuration similar to that of a drive recorder, and may be a device integrated with the exterior camera 12. Specifically, the in-vehicle device 10 may be a device in which hardware that performs the functions of the in-vehicle device 10 described above is built into the housing of the exterior camera 12. In this case, the in-vehicle device 10 may not perform the various display outputs described above.

[0098] Furthermore, the video transmission device of the present application may be configured by integrating a terminal device (for example, FIG. 4) having a configuration similar to that of the in-vehicle device 10 of this embodiment, the outside-vehicle camera 12, and the touch panel display 16.

[0099] In this embodiment, a case has been described in which an image of the outside of the vehicle M is transmitted from the in-vehicle device 10 to the terminal device T, but the image transmitted from the in-vehicle device 10 to the terminal device T may be switched from an image of the outside of the vehicle M to an image of the inside of the vehicle M captured by the in-vehicle camera 13. When an image of the inside of the vehicle M is being transmitted, the user of the terminal device T can, for example, communicate with the driver of the vehicle M while viewing the state of the interior of the vehicle M.

[0100] The switching operation for switching the video to be transmitted to the terminal device T between the video from the exterior camera 12 and the video from the interior camera 13 may be performed by the in-vehicle device 10. The switching operation may also be performed remotely by the user of the terminal device T operating the terminal device T.

[0101] In this embodiment, the control unit 37 of the terminal device T receives the image of the outside of the vehicle M transmitted from the in-vehicle device 10 via the server S, but in addition to the image, it may also receive a map image showing the current location of the vehicle M and the planned route of travel, the name of the driver of the vehicle M, the driving speed of the vehicle M, etc.

[0102] For example, the control unit 37 of the terminal device T may display on the touch panel display 23 the map image, the name of the driver of the vehicle M, and the traveling speed of the vehicle M received from the in-vehicle device 10 on top of the video of the outside of the vehicle M, or may display them in a display area different from the video of the outside of the vehicle M. In this case, the operator of the terminal device T may be able to freely switch between displaying and hiding the map image, the name of the driver of the vehicle M, and the traveling speed of the vehicle M.

[0103] In this embodiment, the speed information acquisition unit 32 of the in-vehicle device 10 acquires speed information indicating the speed of the vehicle M based on the acceleration of the vehicle M measured by the acceleration sensor 24, but the method of acquiring the speed of the vehicle M is not limited to this. For example, the speed information acquisition unit 32 may acquire a speed calculated from the travel distance and time of the vehicle M, or may acquire the speed of the vehicle M by receiving a vehicle speed signal (vehicle speed pulse).

[0104] In this embodiment, an example has been described in which the in-vehicle device 10 is mounted on a vehicle M, but the in-vehicle device 10 may be mounted on other moving objects such as a bicycle, a motorcycle, etc. Also, the in-vehicle device 10 may be held by a person, and video communication may be performed while the person is walking, for example, to distribute video.

[0105] In this embodiment, the terminal device T is a smartphone, but the present invention is not limited to this. For example, the terminal device T may be a tablet terminal capable of video communication with the in-car device 10.

[0106] In the present embodiment, the control unit 25 of the in-vehicle device 10 starts the video distribution operation after video communication between the in-vehicle device 10 and the terminal device T is established. However, the control unit 25 may perform video distribution in a manner similar to video distribution on YouTube (registered trademark) or Niconico Live Broadcast (registered trademark). That is, the video distribution operation may be started even if communication with the terminal of the operator of the terminal device T is not established. Specifically, the in-vehicle device 10 may start uploading video data to the server S even if communication between the in-vehicle device 10 and the terminal of the operator of the terminal device T is not established.

[0107] For example, the video distribution operation by the in-vehicle device 10 may be started after communication between the in-vehicle device 10 and the server S is established, without establishing a communication connection with the terminal device T. In this case, an unspecified or authorized specific terminal device T connects to the server S, thereby receiving the video distributed from the in-vehicle device 10, and the operator of the terminal device T can view the video.

[0108] The series of processes performed by the control unit 25 of the in-vehicle device 10 described in the first embodiment may be a program executed by a computer. The program may be recorded on a computer-readable recording medium. The type of recording medium is not particularly limited, and may be, for example, an optical disk, a hard disk, or a semiconductor memory such as a flash memory or an SSD. The program may also be downloaded and installed in the in-vehicle device 10, the server S, and the terminal device T via communication.

[0109] The control routine shown in the first embodiment is merely an example, and can be appropriately selected and changed depending on the application or conditions of use. [Explanation of symbols]

[0110] 100 Information Processing Systems M vehicle 10 Onboard equipment S Server T terminal device 12. Exterior camera 13 In-car camera 14 GPS receiver 15, 21 Mike 16, 23 Touch panel display 17, 22 speakers 24 Acceleration sensor 25, 35, 37 Control section 26 Encoding section 27, 36, 38 Communications Department 28 Memory section 31 Video acquisition unit 32 Speed ​​information acquisition section 39 Decoding section

Claims

1. A video transmission device that moves with a moving object and transmits video to a terminal outside the moving object, an image acquisition unit that sequentially acquires images of the surroundings of the moving object; a speed information acquisition unit that sequentially acquires the speed of the moving object; a video transmission unit that transmits the video at a frame rate according to the speed of the moving object, The video transmitting device is characterized in that the video transmitting unit transmits the video at a higher frame rate as the speed of the moving object decreases.

2. an encoding unit having a first encoding mode and a second encoding mode for encoding the video in a manner that increases the frame rate compared to the first encoding mode as operation modes when encoding the video; 2. The video transmission device according to claim 1, wherein the encoding unit operates in the second encoding mode when the speed of the moving object is equal to or lower than a predetermined speed.

3. a location information acquisition unit for acquiring a location of the moving object; The video transmission device according to claim 2, wherein the video transmission unit operates in the second encoding mode when the position of the moving body approaches a guidance point to which a route should be provided to a passenger of the moving body.

4. 4. The video transmission device according to claim 2, wherein the resolution of the video in the second encoding mode is smaller than the resolution of the video in the first encoding mode.

5. A video transmission method executed by a video transmission device that moves with a moving object and transmits video to a terminal outside the moving object, comprising: an image acquisition step of sequentially acquiring images of the surroundings of the moving object; a speed information acquisition step of sequentially acquiring the speed of the moving body; a video transmission step of transmitting the video at a frame rate according to the speed of the moving object, A video transmission method, wherein in the video transmission step, the video is transmitted at a higher frame rate as the speed of the moving object decreases.

6. A program to be executed by a computer, an image acquisition step of sequentially acquiring images of the surroundings of the moving object; a speed information acquisition step of sequentially acquiring the speed of the moving body; a video transmission step of transmitting the video at a frame rate according to the speed of the moving object, The program, wherein in the video transmission step, the video is transmitted at a higher frame rate as the speed of the moving object decreases.

7. A recording medium storing the program according to claim 6.

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