JP2008199677A - Video distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video image more detailed than a first distributed video image, without constantly increasing the amount of bits to be obtained, when retransmitting the distributed video image. <P>SOLUTION: In a camera terminal 10, a video signal A from a camera 11 is encoded at a high compression rate by an encoder 12a to produce a bit stream B<SB>L</SB>with low image quality and to supply it to a changeover switch 14, and encoded at a low compression rate by an encoder 12a to produce a bit stream B<SB>H</SB>with high image quality and to supply it to the changeover switch 14 as a high image quality bit stream B<SB>H</SB>' delayed via a recording medium 13. Ordinarily, the bit stream B<SB>L</SB>of low image quality is distributed to a receiving terminal 20 via a network 30 but if there is a retransmission request of a distributed video image from the receiving terminal 20, the high image quality bit stream B<SB>H</SB>' from the recording medium 13 is distributed to the receiving terminal 20 by changing over the changeover switch 14 by a system controller 23. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a video distribution system, a camera terminal, and a receiving terminal including a camera device that distributes photographed video information to a network and a receiver that displays video information obtained from the network.

  Conventionally, a system that receives video information obtained from a plurality of cameras via a network and displays it on a display screen of a receiver, such as a surveillance camera system, is known. As video information compression technology advances and network infrastructure speeds up, it is also possible to build a video distribution system in which the camera unit of such a system is a broadcasting station and the screen display unit is a home terminal. .

  FIG. 15 is a block diagram showing a conventional example of such a video distribution system, where 10 is a camera terminal, 11 is a camera, 12 is an encoder, 20 is a receiving terminal, 21 is a decoder, 22 is a display, and 23 is a system controller. , 24 is a changeover switch, 25 is a recording medium (recording / reproducing apparatus), and 30 is a network.

  In the figure, in this conventional video distribution system, a camera terminal 10 and a receiving terminal 20 are connected via a network 30. The camera terminal 10 includes a camera 11 and an encoder 12, and the reception terminal 20 includes a decoder 21, a display 22, a system controller 23, a changeover switch 24, and a recording medium 25.

  Next, the operation of this conventional example will be described.

  In the camera terminal 10, the camera 11 takes a picture and generates a video signal. This video signal is subjected to information compression processing by the encoder 12 to generate a bit stream, and this bit stream is supplied to the receiving terminal 20 via the network 30. As described above, the camera terminal 10 is a minimum unit for distributing a bit stream, and one or more camera terminals 10 are connected to the network 30 and a bit stream is distributed from each of them.

  In the receiving terminal 20, each part is controlled by the system controller 23. Under this control, a bit stream from a predetermined camera terminal 10 transmitted via the network 30 is selected and decoded by the decoder 21 into a video signal. The decoded video signal is recorded and stored in the recording medium 25 and is supplied to the display 22 by the system controller 23 via the changeover switch 24 closed to the a contact side, where video display is performed.

  When the viewer of the receiving terminal 20 wants to view the distributed video again, the system controller 23 switches the changeover switch 24 to the b-contact side and the recording medium by the viewer performing a predetermined operation for that purpose. The video signal is read by operating 25 and supplied to the display 22 via the changeover switch 24. As a result, past video signals stored in the recording medium 25 can be reproduced on the display 22.

  In the above-described conventional example, the viewer needs rewind playback because the video displayed on the display 22 is alerted, and he wants to see the video of the part that has been alerted in detail. Because it is. For this purpose, it is necessary to distribute a detailed video from the camera terminal 10. However, for this purpose, it is necessary to decrease the compression rate and increase the bit amount on the encoder 12 side.

  By the way, in a video distribution system using a surveillance camera system as a representative example, it is necessary to constantly distribute video, and a large number of camera terminals 10 are connected to the network 30 and video signals from them are connected. The bitstream is always transmitted. For this reason, when the bit amount of the bit stream output from each camera terminal 10 is increased, the bit amount transmitted through the network 30 is increased according to the number of camera terminals 10 connected thereto.

  On the other hand, the network 30 also has a transmittable capacity, and the amount of bits that can be transmitted is limited. For this reason, if a detailed (high-quality) video bitstream compressed at a low compression rate is constantly transmitted from each camera terminal 10 via the network 30, the camera terminal 10 connected to the network 30 is naturally connected. The number of units is limited, and if a large number of camera terminals 10 are to be connected to the same network 30, the video signal compression rate of each camera terminal 10 must be increased, and a portion for monitoring cautions. You can't watch it again with high-quality video.

  The present invention has been made in view of such a problem, and an object of the present invention is to obtain a high-quality image of the same portion to be viewed again without constantly increasing the transmission bit amount in the network. Another object is to provide a video distribution system, a camera terminal, and a receiving terminal.

  In order to achieve the above object, the present invention provides a video distribution system in which a camera terminal and a receiving terminal are connected via a network, and a bit stream generated from a captured video by the camera terminal is distributed to the receiving terminal. The terminal encodes the captured video signal to generate a first bit stream and a second bit stream that forms a higher quality video than the first bit stream, and usually receives the first bit stream from the receiving terminal. One bit stream is distributed, and in response to a retransmission request from the receiving terminal, a second bit stream from a video that is a predetermined time before the time when the retransmission request is made is distributed.

  The present invention is also a video distribution system, and the network includes an upper layer network connecting the camera terminal and the local server, and a lower layer network connecting the local server and the receiving terminal. The camera terminal encodes the captured video signal, and a first bit stream and a second bit stream that forms a higher quality video than the first bit stream, And the first and second bit streams are simultaneously transmitted to the upper layer network, and the receiving terminal selects one of the first and second bit streams from the local server via the lower layer network. The system is configured to be distributed in an automated manner.

  Furthermore, the present invention is a video distribution system in which a plurality of camera terminals are connected to a receiving terminal via a network, and a bit stream generated from a captured video by these camera terminals is distributed to the receiving terminal. Encodes the captured video signal to generate a first bit stream and a second bit stream having a higher image quality than the first bit stream. When the generated first bit stream is simultaneously distributed to the receiving terminal and one of the plurality of camera terminals is designated from the receiving terminal and a retransmission request is made, only the designated camera terminal receives the second bit stream. Is distributed to the receiving terminal.

  Furthermore, the present invention is a video distribution system in which a camera terminal and a receiving terminal are connected via a network, and a bit stream generated from a captured video by the camera terminal is distributed to the receiving terminal. N bit streams (where n is an integer of 3 or more) encoded by different processing methods according to the video playback mode are generated, and the playback specified by the request specifying the playback mode from the receiving terminal The bit stream corresponding to the form is distributed to the receiving terminal.

  In order to achieve the above object, the present invention provides a camera terminal that distributes video information via a network, a camera that outputs a video signal of a photographed subject, and a first signal obtained by encoding the video signal. A first encoder that generates a bit stream; a second encoder that encodes the video signal to generate a second bit stream of a higher quality video than the first bit stream; and a second bit And a recording medium for recording and reproducing the stream, and the first and second bit streams are used as video information for distribution.

  The present invention is also a camera terminal, which is a camera that outputs a video signal of a photographed subject, and performs a first encoding process and a second encoding process on the video signal in a time-sharing manner, and a first bit stream. And a processor for generating a second bit stream of video having a higher image quality than the first bit stream, and a recording medium for recording and reproducing the second bit stream, the first and second The bit stream is used as video information to be distributed.

  Furthermore, the present invention is also a camera terminal that outputs a video signal of a photographed subject, and extracts the video portion within the extraction range set for each frame from the video signal and extracts the video A signal processing unit that expands a portion to one whole frame, a first encoder that encodes an output video signal of the signal processing unit to generate a first bit stream, and a video signal output from the camera, A first encoder that generates a second bit stream of a higher quality video than the first bit stream; and a recording medium that records and reproduces the second bit stream; The bit stream is used as video information to be distributed.

  Furthermore, the present invention is also a camera terminal, which outputs a video signal of a photographed subject, a first encoder that encodes the video signal to generate a first bit stream, and the video signal And a second encoder for generating a second bit stream of video with higher image quality than the first bit stream by encoding the image, image recognition based on the video signal output from the camera, and a camera An image / voice recognition circuit that performs at least one of voice recognition based on a voice signal output from the microphone, and a recording that records and reproduces the second bit stream based on the recognition result of the image / voice recognition circuit And video information for distributing the first and second bit streams.

  Furthermore, the present invention is also a camera terminal, which is a camera that outputs a video signal of a photographed subject, and n (which encodes the video signal by different processing methods to generate bit streams having different image quality). However, n is an integer of 3 or more) and a recording medium that records and reproduces a bit stream other than the lowest image quality bit stream, and uses the n bit streams as video information. is there.

  Further, the above camera terminal is provided with a selector switch that selects and distributes any one of the generated bitstreams, and switches the selector switch in response to a request from the distribution destination. It is.

  To achieve the above object, the present invention provides a receiving terminal for receiving a bit stream of a video distributed via a network, a decoder for decoding the received bit stream into a video signal, and the decoded video. The display is configured to include a display that displays a video by supplying a signal, and a system controller that requests retransmission of the video displayed on the display as a high-quality video for the video distribution source.

  According to the video distribution system of the present invention, a camera terminal and a reception terminal are connected via a network, and the video distribution system distributes a bit stream generated from a captured video by the camera terminal to the reception terminal, the camera The terminal encodes the captured video signal to generate a first bit stream and a second bit stream that forms a higher quality video than the first bit stream. The first bit stream is distributed, and in response to a retransmission request from the receiving terminal, the second bit stream from a video that is a predetermined time before the time when the retransmission request is made is distributed. Therefore, it is possible to reduce the amount of bits by receiving with the minimum necessary image quality in normal times, and when requesting retransmission, the amount of bits increases, but it is up to the required time. Going back and rewinding playback, high-quality video is displayed and a clear image can be obtained, and the amount of bits that can be obtained steadily only increases when retransmitting. And a clear image can be obtained from a necessary part.

  According to the video distribution system of the present invention, the network includes a higher layer network connecting the camera terminal and the local server, and a lower layer network connecting the local server and the receiving terminal. The camera terminal encodes the captured video signal to generate a first bit stream and a second bit stream that forms a higher quality video than the first bit stream. The first and second bitstreams are simultaneously transmitted to the local server via the upper layer network, and the receiving terminal transmits either the first or second bitstream from the local server via the lower layer network. Therefore, the load of resending requests for high-quality video bitstreams is Distributed Karusaba, it becomes possible to deliver high-quality video without stagnation.

  Furthermore, according to the video distribution system of the present invention, the plurality of camera terminals encodes the captured video signal to form the first bit stream and the second bit stream having higher image quality than the first bit stream. A first bit stream generated by a plurality of camera terminals is simultaneously distributed to a receiving terminal, and one of the plurality of camera terminals is designated by the receiving terminal and a retransmission request is made. Since only the designated camera terminal delivers the second bit stream to the receiving terminal, the viewer views the video from a plurality of cameras in parallel, and selects the video of one of the cameras. The high-quality bitstream can be received, and a desired video can be easily selected and viewed with high quality.

  Further, according to the video distribution system of the present invention, the camera terminal generates n bit streams (where n is an integer of 3 or more) encoded by different processing methods according to the video playback mode at the receiving terminal. Since the bit stream corresponding to the designated reproduction format is distributed to the receiving terminal in response to the request designating the reproduction format from the receiving terminal, the optimum encoding process is performed for the retransmission request on the receiving terminal side. Therefore, a clear and high-quality image reproduction can be obtained in any image reproduction mode.

  According to the camera terminal of the present invention, a camera terminal that distributes video information via a network, which outputs a video signal of a photographed subject, encodes the video signal, and outputs a first bit stream. A first encoder for generating, a second encoder for encoding the video signal to generate a second bit stream of video having higher image quality than the first bit stream, and the second bit stream A recording medium for recording and reproduction, and the first and second bitstreams are used as video information to be distributed, so that any image quality video can be distributed in response to a request from a distribution destination. And the amount of bits obtained from the network on a regular basis is not increased.

  According to the camera terminal of the present invention, the camera that outputs the video signal of the photographed subject, the first encoding process and the second encoding process of the video signal in a time division manner, the first bit stream, A processor that generates a second bit stream of video with higher image quality than the first bit stream, and a recording medium that records and reproduces the second bit stream, the first and second bit streams being Since the video information is distributed, it is possible to reduce the number of camera terminal parts and reduce the manufacturing cost.

  Furthermore, according to the camera terminal of the present invention, a camera that outputs a video signal of a photographed subject, a video portion within an extraction range set for each frame is extracted from the video signal, and the extracted video portion is 1 A signal processing unit that extends to the entire frame; a first encoder that encodes the output video signal of the signal processing unit to generate a first bit stream; and the video signal output from the camera is encoded, A first encoder that generates a second bit stream of video with higher image quality than the bit stream of the first bit stream; and a recording medium that records and reproduces the second bit stream. Therefore, the amount of bits to be transmitted can be reduced, and the captured video can be viewed with high image quality when necessary.

  Furthermore, according to the camera terminal of the present invention, a camera that outputs a video signal of a photographed subject, a first encoder that encodes the video signal to generate a first bit stream, and encodes the video signal And a second encoder that generates a second bit stream of video with higher image quality than the first bit stream, an image recognition based on a video signal output from the camera, and a microphone provided in the camera. An image / speech recognition circuit that performs at least one of speech recognition based on a sound signal, and a recording medium that records and reproduces the second bitstream based on the recognition result of the image / speech recognition circuit. Since the first and second bit streams are used as video information to be distributed, recording on the recording medium can be performed only when necessary. Since the ropes to be reduced recording capacity of the recording medium, or alternatively, it is possible to lengthen the recording time of the recording medium.

  Further, according to the camera terminal of the present invention, the camera that outputs the video signal of the photographed subject, and n (however, n) that encode the video signal by different processing methods and generate bit streams of different image quality. Is an integer of 3 or more) and a recording medium that records and reproduces the bitstream other than the bitstream with the lowest image quality, and provides video information for distributing n bitstreams. The bit stream encoded by the processing method most suitable for the video playback mode requested by the distribution source can be distributed, and a good video can be provided regardless of the playback mode.

  Furthermore, according to the receiving terminal according to the present invention, the receiving terminal receives a bit stream of a video distributed via a network, the decoder for decoding the received bit stream into a video signal, and the decoded video signal It is equipped with a display that displays the supplied video and a system controller that requests retransmission of the video displayed on the display from the video distribution source as high-quality video. It is possible to receive a re-transmission of high-quality video and view the same video again with high image quality.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a first embodiment of a video distribution system, a camera terminal and a receiving terminal according to the present invention, wherein 10 is a camera terminal, 11 is a camera, 12a and 12b are encoders, and 13 is a recording medium (or Recording / reproducing apparatus: However, although described below as a recording medium, it may be a recording / reproducing apparatus), 14 is a changeover switch, 20 is a receiving terminal, 21 is a decoder, 22 is a display, 23 is a system controller, 30 Is a network.

  In the figure, a camera terminal 10 and a receiving terminal 20 are connected via a network 30 to constitute a video distribution system. Here, one camera terminal 10 and one reception terminal 20 are shown, but two or more camera terminals 10 and two reception terminals 20 may be connected to the network 30. The camera terminal 10 includes a camera 11, encoders 12 a and 12 b, a changeover switch 14, and a recording medium 13, and the reception terminal 20 includes a decoder 21, a system controller 23, and a display 22.

  Next, the operation of the first embodiment will be described.

In the camera terminal 10, the camera 11 shoots and generates a video signal A. This video signal A is subjected to information compression (encoding) processing based on a high compression rate, for example, a method conforming to the international standard MPEG (Moving Picture Expert Group), and the like, and the video signal A has a low bit rate and therefore low image quality. Bit stream (hereinafter referred to as a low-quality bit stream) _BL is generated. The video signal A generated by the camera 11 is subjected to information compression processing by an encoder 12b based on a low compression rate, for example, a method compliant with MPEG, and the like. _BH ) (referred to as a high-quality bitstream). The changeover switch 14 is controlled to be switched by the system controller 23 of the receiving terminal 20, but is normally closed to the a contact side. For this reason, the low image quality bit stream _BL output from the normal encoder 12 a is transmitted over the network 30 via the changeover switch 14.

The high-quality bit stream B _H output from the encoder 12b is always supplied to the recording medium 13 and recorded. The recording medium 13 is, for example, a semiconductor memory, and can be reproduced simultaneously with recording. That is, the high-quality bit stream B _H supplied from the encoder 12b is sequentially recorded, and a portion recorded a predetermined time T before the recording time is reproduced. Therefore, the high-quality bit stream B _H is reproduced from the recording medium 13 after being delayed by a predetermined time T. Play quality bitstream B _H from the recording medium 13 'but is supplied to a contact b of the changeover switch 14, since the normal changeover switch 14 is closed to a contact side, the reproduction quality bitstream B _H' is Not supplied to the network 30.

  In the case where the recording medium 13 is a semiconductor memory, recording is performed from the head address. However, when recording for a predetermined time T is performed, recording for the recording capacity is performed, and the head address is recorded. Recording will be performed again, and the already recorded content will be rewritten. Further, reproduction is performed with a delay of a predetermined time T from this recording. In this way, recording and reproduction are performed at the same time, whereby a high-quality bit stream that is always recorded and delayed by a predetermined time T is reproduced. In this case, the recording medium 13 may be a memory having a capacity capable of recording a high-quality bit stream for a time slightly longer than the predetermined time T. The predetermined time T can be arbitrarily set as appropriate. However, when this embodiment is applied to a surveillance camera system, a high-quality video is obtained from a scene that goes back to some extent before a scene that calls attention. It needs to be time that can be seen. The same applies to other embodiments described later.

In addition, when the bit streams B _L and B _H are encoded by a method compliant with MPEG, the delivery of the high-quality bit stream B _H ′ in response to the retransmission request is performed from the frame after the intra-frame encoding or from immediately before. Will be started.

In this way, the video signal A output from the camera 11 is distributed from the network 30 to the receiving terminal 20 as a low image quality bit stream _BL .

  In the receiving terminal 20, a bit stream distributed via the network 30 is received, decoded into an original video signal by the decoder 21, and supplied to the display 22. As a result, the distributed video is displayed on the display 22.

In such a display state, a scene that alerts the viewer is displayed, and when the viewer wants to view this scene again, the viewer performs a predetermined operation (hereinafter referred to as retransmission) with the remote control or operation unit on the receiving terminal 20 side. The system controller 23 generates a switching control signal C and transmits it to the camera terminal 10 via the network 30. In the camera terminal 10 that has received this, the changeover switch 14 is controlled by this changeover control signal C, and the contact is switched from the a contact to the b contact. As a result, the reproduced high-quality bit stream B _H ′ of the recording medium 13 is distributed (retransmitted) to the receiving terminal 20 via the changeover switch 14 and the network 30. As a result, the reproduced high-quality bit stream B _H ′ is decoded into a high-quality video signal by the decoder 21 and supplied to the display 22 to display a high-quality video.

Here, the reproduction high-quality bit stream B _H ′ of the recording medium 13 is a bit stream delayed by the predetermined time T from the low-quality bit stream _BL output from the encoder 12a and distributed. The display 22 at the receiving terminal 20 starts to display a high-quality video from a point that is a predetermined time T earlier than the current point. That is, the same effect as the rewind reproduction from the recording / reproducing apparatus can be obtained with the high-quality video, so that the above-mentioned scene that has attracted the viewer's attention can be seen again with the high quality. . At this time, since the changeover switch 14 is switched to the b contact side, the low image quality bit stream _BL from the encoder 12a is not transmitted over the network 30.

(A) When the bit stream B _H ′ is delivered to the receiving terminal 20 only for a certain set time T ′ that is equal to or greater than the predetermined time T, the changeover switch 14 is automatically switched to the a contact side, resulting in low image quality. You may make it return to delivery of bit stream _BL , or (b) Unless the receiving terminal 20 side requests | requires delivery of the low image quality bit stream _BL (that is, unless a switching control signal is transmitted from the system controller 23). Alternatively, the high-quality bit stream B _H ′ may continue to be delivered as it is.

When a video with low-quality bitstream _BL is displayed and a scene (scene) that calls attention is displayed, the normal viewer wants to see this scene again after looking through this scene. It is what you think. In such a case, the camera terminal is requested to retransmit after viewing this scene. In response to such a re-transmission request, in any of the cases (a) and (b), the display of the high-quality video by the re-transmitted high-quality bit stream B _H ′ is at least one of the above scenes viewed at least. It must be started from the beginning, and the predetermined time T must be set to be longer than the time that can be traced back to the beginning of this scene. For example, if the time for which the viewer recognizes such a scene as a whole is about 2 to 3 minutes, the predetermined time T may be set longer than the time required.

Further, the display period (the set time T ′) of the high-quality video by the high-quality bitstream B _H ′ in the case (b) can be appropriately set to an arbitrary time required by the normal viewer. In the case of (b) above, the viewer can continue to watch high-quality video until they are satisfied.

  The same applies to the embodiments described later.

Figure 2 is a timing diagram illustrating the above operations, the (a) shows the timing of the low quality bitstream B _L and quality bitstream B _L in the camera terminal 10, FIG. (B) receiving The display timing of the low quality video by the low quality bit stream _{BL on the} terminal 20 and the display timing of the high quality video by the high quality bit stream B _H are shown.

In the figure, when the time at which the receiving terminal 20 is operated to receive distribution from the camera terminal 10 is t ₁ , the receiving terminal 20 receives the low-quality stream _BL and decodes it into a video signal by the decoder 21. from the time t ₂ begins to display the low quality of the video is on the display 22. Thereafter, there is a scene in which the viewer is alerted at time t ′ in this video, and when the viewer performs an operation for reproducing high-quality video at time t ₃ in order to see this again, the system controller 23 A switch control signal is sent to the camera terminal 10 from the network 30 to the camera terminal 10, and in the camera terminal 10, the changeover switch 14 is switched to the b contact side, and the high-quality bit stream B _H recorded from the recording medium 13 at time t ₁ is received. It is reproduced and distributed to the receiving terminal 20 via the changeover switch 14 and the network 30. In the receiving terminal 20, the high-quality bit stream B _H is decoded into a high-quality video signal by the decoder 21, and the high-quality video signal from the time t ₁ is supplied to the display 22 from the time t ₄ to reproduce the video. It is.

The portion to be recorded on the recording medium 13 is output from the encoder 12b at time t _1, this than is reproduced from the later recording medium 13 by a predetermined time T of the. Therefore, the quality bitstream B _H shown in FIG. 2 there is shown a high-quality bit stream B _H output from the encoder 12b, part of that time t _1, this than a predetermined time T delay It is distributed to the receiving terminal 20.

The time until time t ₁ of the portion of the low-quality bit stream B _L is initiated displayed on the display _{22 t 12 (= t 2 -t} 1) is the time t ₁ of a portion of the high quality bit stream B _H The time t ₃₄ (= t ₄ −t ₃ ) from the start of distribution (time t ₃ ) to the start of display on the display 22 (time t ₄ ) is longer for the low-quality bitstream _BL . This is because since the information is further compressed, it takes time to decode the original video signal.

As described above, according to the first embodiment, the camera terminal 10 delivers a high-quality video only when the viewer is alerted to the delivered video and wants to review it again. Normally, the network 30 is steadily transmitted by transmitting a low-quality bit stream _BL having a necessary minimum image quality bit rate and transmitting the high-quality bit stream B _H only when requested by the system controller 23. The amount of bits to be transmitted can be reduced. Further, when the high-quality bit stream B _H is retransmitted, it is possible to obtain a detailed (that is, high-quality) video signal as compared with the conventional technique shown in FIG.

  In the first embodiment, for simplicity of explanation, one camera terminal is connected to the network 30. However, the number of camera terminals is increased within a range in which the network 30 can transmit a bit stream, and a plurality of receiving terminals are used. You may be able to view the screen. For example, for the purpose of monitoring with a large number of cameras, the bit rate transmitted by the network 30 is suppressed by connecting a large number of camera terminals and reducing the image quality output by each camera terminal during normal times. However, in the event of an anomaly that alerts the viewer, the low-quality bitstreams of other camera terminals are suppressed or eliminated, and only the video of the camera terminal of interest is delivered as a high-quality bitstream. It becomes possible to view the details again. In normal times, the minimum necessary low image quality bit rate is sufficient, so it is possible to increase the number of camera terminals without changing the maximum transmission capacity of the network 30, and when an abnormality occurs, more camera terminals are generated. Detailed video can be obtained by viewing the video only.

  Further, for example, when the first embodiment is intended for television broadcasting, the amount of data per unit time that can be transmitted through the network 30 is finite, so the broadcasting station charges according to the amount of data viewed. It is envisaged to insert a CM or insert a CM. A viewer can normally view a television broadcast by performing viewing with a low-quality bitstream and requesting a high-quality bitstream as necessary during viewing.

  In the above description, the high-quality video reproduced and distributed from the recording medium 13 can be viewed only once on the display 22, but the conventional receiving terminal 20 shown in FIG. As described above, the recording medium 25 controlled by the system controller 23 and the changeover switch 24 are provided, and the high-quality video signal decoded by the decoder 21 is displayed on the display 22 and recorded on the recording medium 25 when necessary. Alternatively, the high-quality video signal may be reproduced from the recording medium 25 and supplied to the display 22 via the changeover switch 24. The same applies to other embodiments described later.

Further, although the recording medium 13 in FIG. 1 is a semiconductor memory, it may be a recording medium such as a recordable / reproducible disk or a magnetic tape. In this case, when the switching control signal C is supplied from the system controller 23, the recording medium is also controlled to switch from the recording mode to the reproduction mode, and the recording is performed a predetermined time T before the switching point. The reproduction of the high-quality bit stream B _H is started. The same applies to other embodiments described later.

  FIG. 3 is a block diagram showing a second embodiment of the video distribution system, camera terminal and receiving terminal according to the present invention, wherein 10a and 10b are camera terminals, 20a, 20b and 20c are receiving terminals, and 30 to 32 are networks. , 40 and 41 are local servers, and parts corresponding to those in FIG.

  In this figure, in this embodiment, the network 30 is hierarchically configured with the network 30 as an upper layer and the networks 31 and 32 as lower layers, and the network 30 is a high-capacity network of the upper layer. The plurality of camera terminals 10 a and 10 b are connected to a plurality of local servers 40 and 41 via the upper layer network 30. The lower layer network 31 connects the local server 40 and the receiving terminal 20a, and the lower layer network 32 connects the local server 41 and the receiving terminals 20b and 20c.

The camera terminals 10 a and 10 b are different from the camera terminal 10 in FIG. 1 only in that the changeover switch 14 is not provided. Therefore, any of the camera terminals 10 a and 10 b is output from the encoder 12. The low-quality bit stream B _L and the high-quality bit stream B _H ′ delayed by the recording medium 13 are always transmitted to the local servers 40 and 41 via the network 30. Therefore, the local servers 40 and 41 store the low image quality bit streams and the delayed high image quality bit streams from all the camera terminals connected to the network 30.

  On the other hand, the receiving terminal 20a connected to the local server 31 and the receiving terminals 20b and 20c connected to the local server 32 have the same configuration as the receiving terminal 20 shown in FIG. The low-quality bitstream is distributed from the local servers 40 and 41 via the networks 31 and 32, and there is a scene that draws attention to the viewer by watching the video by the low-quality bitstream displayed on the display 22, When a predetermined operation for requesting retransmission of a scene is performed by the viewer, a retransmission request signal is formed and output from the system controller 23 and transmitted to the local servers 40 and 41 via the networks 31 and 32. When receiving the retransmission request signal, the local servers 40 and 41 replace the delayed high-quality bit stream corresponding to the low-quality bit stream that has been transmitted so far with the low-quality bit stream, and send the networks 31 and 32. To the receiving terminal 20a and the receiving terminals 20b and 20c.

In this way, in the upper layer network 30, the low image quality bit stream _BL and the high image quality bit stream B _H ′ from each camera terminal are transmitted simultaneously, but in the lower layer networks 31 and 32, the low image quality bit stream B _H ′. Only one of _BL and high-quality bit stream B _H ′ is transmitted.

  In this way, in each of the receiving terminals 20a to 20c, when a re-transmission request is made, a scene to call attention can be seen again with a high-quality video, and the local servers 40 and 41 each have the same camera. Since the low-quality bit stream and the delayed high-quality bit stream from the terminals 10a and 10b are stored, when the respective receiving terminals 20a to 20c can acquire the video from the camera terminals 10a and 10b, In addition, images from the same camera terminal 10a or 10b can be acquired simultaneously.

  As described above, in the second embodiment, similarly to the first embodiment shown in FIG. 1, the low-quality bit stream with a low bit rate is normally transmitted and the same video distributed by the viewer is displayed. When viewing again, a high-quality bit stream with a high bit rate is retransmitted, so that a high-quality video can be obtained.

  In addition, even if a retransmission request for a high-quality bitstream is issued from all receiving terminals to one camera terminal, the camera terminal only needs to transmit this to each local server. The maximum transmission capacity is not exceeded.

  Also, for example, when the second embodiment is intended for television broadcasting, it is expected that viewers concentrate on one camera terminal and request a high-quality bitstream. By layering the network 30 and the lower-layer networks 31 and 32, it is possible to reduce the transmission load on the recording medium 13 in the camera terminal and to continuously transmit a high-quality bit stream to the receiving terminal. Become.

  FIG. 4 is a block diagram showing a third embodiment of a video distribution system, a camera terminal, and a receiving terminal according to the present invention, in which 15 is a processor, 16 is a memory, 16a is an encoding program, and 16b is an encoding program. Parts corresponding to 1 are assigned the same reference numerals and redundant description is omitted.

In the figure, the processor 15 executes encoding programs 16 a and 16 b stored in the memory 16 to encode the video signal A output from the camera terminal 10. Here, the encoding program 16a causes the processor 15 to perform processing equivalent to the encoder 12a in FIG. 1, and the encoding program 16b causes the processor 15 to perform processing equivalent to the encoder 12b in FIG. It is. As a result, the processor 15 generates the low image quality bit stream B _L and the high image quality bit stream B _H , the low image quality bit stream B _L is supplied to the changeover switch 14, and the high image quality bit stream B _H is supplied to the recording medium 13. Supplied and recorded.

  FIG. 5 is a timing diagram showing a specific example of the processing operation of the processor 15 in FIG. 4, where the horizontal axis is the time axis and the time ta + tb is one frame period of the camera 11.

For each period (one frame period) in which the camera 11 outputs one frame of the video signal A (FIG. 4), the processor 15 executes the encoding programs 16a and 16b in a time-sharing manner. The low-quality bitstream _BL is generated by executing the encoding program 16a in the previous period ta, and the high-quality bitstream _BH is generated by executing the encoding program 16b in the subsequent period tb after the same frame period.

Here, the processor 15 is provided with a frame memory, and the video signal A supplied from the camera 11 is temporarily stored in the frame memory, and is first read out from the frame memory at a high speed, and the period ta is set by the encoding program 16a. inner encoded processed low quality bitstream B _L are generated by, then again from the frame memory is read out at high speed, the encoding program 16b, is encoded processed within a period tb with high quality bitstream B _H Is generated. The generated low image quality bit stream B _L and high image quality bit stream B _H are once recorded in different frame memories, read out so as to have a time length of one frame period, and output from the processor 15. The

  As described above, in the third embodiment, the processor 15 performs the encoding process in a time division manner, so that the encoding process with different compression rates can be performed without increasing the number of parts constituting the camera terminal 10. In addition, a high-quality bitstream can be retransmitted in response to a request from the receiving terminal 20. Further, by reducing the number of parts, it is possible to reduce the weight of the camera terminal 10 and the manufacturing process.

  Needless to say, this third embodiment can also be applied to the second embodiment shown in FIG.

Next, a fourth embodiment of the video distribution system, camera terminal, and receiving terminal according to the present invention will be described.
The configuration of the fourth embodiment is the same as that of the previous embodiment, but will be described below with the configuration of the first embodiment shown in FIG.

  In FIG. 1, the fourth embodiment also enables retransmission of a still image from the recording device 13. For this reason, the encoder 12b performs reversible compression (for example, intraframe coding) for each frame of the video signal A from the camera 11.

When the viewer performs a retransmission operation on the receiving terminal 20 side, the changeover switch 14 is set to the b contact side on the camera terminal 10 by the switching control signal from the system controller 23, as in the first embodiment shown in FIG. The high-quality bit stream B _H ′ is retransmitted from the recording medium 13 to the receiving terminal 20 and a high-quality video is displayed on the display 22, but when the viewer performs a still image playback instruction operation, the instruction control is performed. A signal is supplied from the system controller 23 to the camera terminal 10, the recording medium 13 is controlled, and a high-quality bit stream of one frame at that time is repeatedly read and distributed to the receiving terminal 20. As a result, a still image is displayed on the display 22 of the receiving terminal 20 by repeating the high-quality bit stream of one frame.

Alternatively, the receiving terminal 20 is provided with a recording medium 25 or a recording medium such as a frame memory as shown in FIG. 15 and a changeover switch 24, and the high-quality bit stream B _H ′ is sequentially recorded on this recording medium. Along with the above-described still image reproduction instruction, the high-quality bit stream of one frame recorded at this time may be repeatedly reproduced from this recording medium and supplied to the display 22.

  By the way, since the video compression system represented by the MPEG system has a high correlation between frames before and after the video signal, interframe coding by motion compensation is performed in most frames. In general, a frame subjected to interframe coding by motion compensation has a lower image quality than a frame subjected to intraframe coding in order to improve the compression rate. For this reason, when a pause is made at a frame that has been subjected to interframe coding by motion compensation and a still image is requested, a video with poor image quality is stopped and displayed on the display 22 as it is.

However, in the fourth embodiment, since the high-quality bitstream is subjected to a reversible compression process, even when the viewer temporarily displays the delivered high-quality image, Since the decoder 21 decodes the high-quality bitstream B _H ′ into a video signal while maintaining high image quality, a high-quality still image without image quality deterioration can be obtained.

Next, a fifth embodiment of the video distribution system, camera terminal, and receiving terminal according to the present invention will be described.
The configuration of the fifth embodiment is the same as that of the previous embodiment. However, a high-quality slow motion image (hereinafter referred to as a slow image) is also obtained. The configuration shown in FIG. Will be described as an example.

  Hereinafter, the operation of the fifth embodiment will be described with reference to FIG. 6. FIG. 6A shows a frame to be encoded by the encoder 12a in FIG. 1, and FIG. 6B shows the encoder in FIG. Reference numeral 12b denotes a frame to be encoded, and FIG. 10C shows a video frame displayed on the display 22 in the receiving terminal 20.

In FIG. 1, an encoder 12a outputs a low-quality bit stream _BL in the order of frame 1, frame 2, frame 3,... Every frame period, as shown in FIG.

Further, as shown in FIG. 6B, the encoder 12b encodes a video signal with a high frame rate received from the camera so that a slow image is possible. Here, in FIG. 6B, frame 1.5 is a frame at a time intermediate between frames 1 and 2, and frame 2.5 is a frame at a time intermediate between frames 2 and 3. The same applies hereinafter. Here, each frame 1, frame 1.5, frame 2, frame 2.5,... Is a frame that is time-compressed to 1/2 frame time length so that a double slow image can be obtained. The high-quality bit stream B _H is output from the encoder 12 b and recorded on the recording medium 13.

  In general, in order to obtain n (where n is an integer of 2 or more) slow images, (n−1) one of the frames in the video signal A from the camera 11 is obtained. Frames whose contents sequentially change from one frame to the other are inserted.

From the recording medium 13, the high-quality bit stream B _H ′ of each frame is reproduced at a frame period. In the receiving terminal 20, as a retransmission from the recording medium 13, it is possible to request the reproduction of a slow image (in the case of the high-quality bitstream B _{H in} FIG. 6B, double the slow image) together with the normal image. .

Therefore, as shown in FIG. 6C, when the low-quality bit stream _BL shown in FIG. _6A is distributed and displayed on the display 22 in the “(1) normal playback” state. When there is a request for slow playback on the receiving terminal 20 side, the changeover switch 14 is switched to the b contact side as described above, and each frame is recorded at a ½ frame period as shown in FIG. 6B. The high-quality bit stream B _L recorded in the above is reproduced as a high-quality bit stream B _H ′ with each frame being one frame period, and is retransmitted from the changeover switch 14 to the receiving terminal 20 via the network 30. Thus, the display 22, as shown in FIG. 6 (c), the frame is frame 0 of 1 frame time length from the time _ts. 5 frame 1, frame _1.5, frame 2, it is displayed in the order of ...... Therefore, the state becomes “(2) Slow playback” in which the high-quality slow playback is doubled.

  Note that the receiving terminal 20 can also request retransmission of a normal high-quality bitstream. In this case, in response to this request, the high-quality bit stream of every other frame is read from the recording medium 13 in the order of frame 1, frame 2, frame 3,. be delivered.

  As described above, in the fifth embodiment, it is possible to increase the frame rate and observe the video only when the slow reproduction is selected for the distributed image. The viewer needs slow playback when the video changes quickly. Since the encoder 12b always encodes at a high frame rate, it cannot be seen from the output from the encoder 12a (frames 0.5, 1... Shown as d, e, and f in FIG. 6C). 5, the movement of the frame 2.5) can be seen in detail, and the detailed movement can be observed.

In the fifth embodiment, the high-quality bit stream B _H ′ for slow reproduction is subjected to inter-frame interpolation between frames of the input video signal A before recording on the recording medium 13. However, when the high-quality bit stream B _H from the encoder 12b is recorded on the recording medium 13 and reproduced from the recording medium 13, as in the first embodiment shown in FIG. High-quality slow reproduction may be performed by repeatedly reproducing the stream a plurality of times.

Next, a sixth embodiment of the video distribution system, camera terminal, and receiving terminal according to the present invention will be described.
In the sixth embodiment, images are distributed simultaneously from a plurality of camera terminals, and the distributed images can be simultaneously displayed on the display of the same receiving terminal. FIG. 7 is a block diagram for explaining the sixth embodiment in the case where video is simultaneously distributed from two camera terminals to the same receiving terminal. Reference numerals 10a and 10b denote camera terminals 10 in the previous embodiment. However, here, assuming that the camera terminal 10 has the same configuration as that of the camera terminal 10 shown in FIG. 1, parts corresponding to those in FIG.

  In the figure, the receiving terminal 20 can control the change-over switches 14 a and 14 b of the camera terminals 10 a and 10 b by the switching control signal C from the system controller 23, and the system controller 23 can control the receiving terminal 20. A receiving unit (not shown) can be controlled. As a result, the receiving terminal 20 can receive a video (low-quality video or high-quality video) from either one of the camera terminals 10 a and 10 b and display the received video on the display 22. It is also possible to simultaneously receive video from both the camera terminals 10a and 10b and display these videos on the display 22 at the same time.

FIG. 8 is a timing chart showing the operation of the sixth embodiment. FIG. 8A shows the timing of the low image quality bit stream B _L and the high image quality bit stream B _H in the camera terminal 10a. (B) shows the timing of the low image quality bit stream B _L and the high image quality bit stream B _H at the camera terminal 10 b, respectively. FIG. 9 (c) shows the low image quality bit stream B _L at the display 22 of the receiving terminal 20. The display timing of the low quality video and the display timing of the high quality video by the high quality bitstream _BH are shown.

In the figure, when the viewer performs an operation on the receiving terminal 20 side to simultaneously distribute video from the camera terminals 10a and 10b (time t1), the low-quality bit stream _BL from the camera terminals 10a and 10b is received simultaneously. These are simultaneously supplied to the display 22 decoded by the decoder 21 into a video signal. At this time, a screen reduction process is performed on these video signals by a processing unit (not shown). As a result, as shown in FIG. 9A, the video images 1 and 2 from the camera terminals 10a and 10b are displayed on the display 22. Thumbnails that are displayed at the same time are reduced (time t2).

After that, for example, there is a scene that alerts the viewer to the video from the camera terminal 10b, and when the viewer performs an operation for requesting retransmission of the high-quality video 2 by watching this, (time t3) The system controller 23 causes the receiving unit (not shown) to receive only the bit stream from the camera terminal 10b, and closes the changeover switch 14 in the camera terminal 10b to the b contact side by the change control signal C. Thereby, the high-quality bit stream B _H ′ is distributed from the camera terminal 10 b and received by the receiving terminal 20, which is decoded and supplied to the display 22. At this time, that is, when only the bit stream distributed from one camera terminal is received, the received video (in this case, the camera terminal 10b is controlled by the system controller 23 as shown in FIG. 9B). (High-quality video from) is displayed on the entire screen of the display 22 (time t4).

  Here, two camera terminals are targeted, but the same applies to a case where three or more arbitrary number of camera terminals are targeted.

  As described above, in the sixth embodiment, after the viewer previews the videos of the plurality of camera terminals, the viewer can view the desired video of the predetermined camera terminal again from the beginning.

  In addition, when the sixth embodiment is applied to television broadcasting, if the capacity of the recording medium 13 is a predetermined time T, the viewer can simultaneously watch the beginning portion of the program broadcast at the same time. If an interesting program is selected within the time T, it can be viewed from the broadcast start time. In this case, the recording medium 13 records the program from the start address when the program starts broadcasting. When a program for a predetermined time T is recorded, the recording capacity is recorded. Recording is performed again from the head address, and the already recorded content is rewritten. Further, when there is a read request from the recording medium 13 from the system controller 23 of the receiving terminal 20, the recording medium 13 starts reading from the head address. Thus, if there is a read request from the recording medium 13 from the system controller 23 of the receiving terminal 20 before the predetermined time T has elapsed since the start of the program reception, the program is read out and received from the beginning. It is distributed to the terminal 20. Therefore, the predetermined time T is a time that allows the viewer to sufficiently select one desired program from the plurality of thumbnail-always programs shown in FIG. 9A, for example, 1 to several minutes. Any degree is acceptable.

  In this way, the viewer can select the program after actually watching the program, and can easily and efficiently select the program as compared with a program guide such as EPG (Electoronic Program Guide). .

  FIG. 10 is a block diagram showing a seventh embodiment of the video distribution system, camera terminal and receiving terminal according to the present invention. Reference numeral 17 denotes a signal processing unit, and parts corresponding to those in FIG. A duplicate description is omitted.

In the figure, the camera terminal 10 is provided with a signal processing unit 17, and the video signal A output from the camera 11 is processed by the signal processing unit 17 and then supplied to the encoder 12 a and encoded. A low image quality bit stream _BL is generated. Other than this, the second embodiment is the same as the first embodiment shown in FIG. 1. Therefore, the encoder 12b encodes the video signal A from the camera 11 as it is to generate a high-quality bitstream _BH .

  The signal processing unit 17 extracts a part of the video signal A output from the camera 11 so that a part of the image captured by the camera 11 is extracted, and the extracted part becomes the size of one screen. The image is enlarged and supplied to the encoder 12a.

  This will be described with reference to FIG. 11. In FIG. 11A, a range 50 is a shooting range of the camera 11, and a video signal A in the shooting range 50 is output from the camera 11. The signal processing unit 17 extracts a part of a range (hereinafter referred to as an extraction range) 51 of the shooting range 50 from the video signal A of the shooting range, and the video of the extraction range 51 is extracted from the receiving terminal 20. Expansion processing is performed so that the entire screen of the display 22 is displayed. In this extension processing, line interpolation processing is performed so that one frame line matches the number of lines of the video signal A.

  In this manner, the video signal A ′ obtained by extending the video of the extraction range 51 of a part of the shooting range 50 of the camera 11 is output from the signal processing unit 17 and supplied to the encoder 12a to be encoded. Here, for example, by setting the extraction range 51 to about 1 / several times to 1/10 times the shooting range 50, the video signal A ′ is sufficiently narrower than the original video signal A. Therefore, the encoder 12a can encode at a higher information compression rate than the original video signal A is encoded.

When the low-quality bit stream _BL output from the encoder 12a is supplied from the changeover switch 14 to the receiving terminal 20 via the network 30, the display 22 shown in FIG. The video of the extraction range 51 shown in FIG.

Here, in FIG. 11A, the position of the extraction range 51 is changed so that the extraction range 51 moves within the photographing range 50 as indicated by an arrow for each frame. For this reason, the image displayed on the display 22 also changes. Then, when an image that calls attention to the viewer such as the person 52 enters the extraction range 51, the person 52 is displayed on the display screen 22 as shown in FIG. The image begins to appear. When the viewer performs a retransmission request operation on the receiving terminal 20 side after seeing this to some extent, the changeover switch 14 is closed to the b-contact side and the image quality from the recording medium 13 is the same as in the first embodiment shown in FIG. The bit stream B _H ′ is distributed, and a high-quality video in the shooting range 50 shown in FIG. In this way, in the seventh embodiment, since a limited area within the shooting range of the camera is normally viewed and the entire screen is viewed as necessary, the received bit amount in the normal state It is also possible to display an image capable of recognizing an image that needs to be retransmitted while drastically reducing. Further, since only a limited area (video in the extraction range 51) is distributed during normal times, the amount of bits that the network 30 regularly transmits can be greatly reduced.

Next, an eighth embodiment of the video distribution system, camera terminal, and receiving terminal according to the present invention will be described with reference to FIG.
The configuration of the eighth embodiment is the same as that of the first embodiment shown in FIG.

12A shows the resolution of the video obtained from the bit stream _BL output from the encoder 12a in FIG. 1, and FIG. 12B shows the resolution obtained from the bit stream B _H output from the encoder 12b in FIG. It shows the resolution of the video to be recorded. A grid surrounded by a dotted line in FIGS. 12A and 12B represents a pixel.

As is clear from FIGS. 12A and 12B, the video by the bit stream _BL output from the encoder 12a has a resolution sufficient to view it, but is output from the encoder 12b. that the bitstream B _H, therefore, the video by the bit stream B _H 'which are reproduced from the recording medium 13, as compared with the image according to the bit stream B _L output from the encoder 12a, a further high-resolution video. Therefore, it is sufficient for the viewer to view the video by the bit stream _BL from the encoder 12a at the normal time.

When a scene that calls attention during viewing of the video by the bit stream _BL appears and the viewer requests the retransmission, the bit stream B _H ′ is reproduced and received from the recording medium 13 as in the previous embodiment. The video is distributed to the terminal 20 and a high-resolution video is displayed on the display 22. The details of the part that has attracted attention from this video, for example, if this part is the face part of the person 53, the facial part has a large number of pixels, so that the facial expression can be clearly recognized.

  In the eighth embodiment, when the high-resolution video is retransmitted in this way, the video signal decoded by the decoder 21 is supplied to the display 22 via the frame memory in the receiving terminal 20. By configuring in this way, it is possible to enlarge and display the part that has received attention.

Now, there is a scene that draws attention to the viewer in the video display state shown in FIG. 12A, and when the viewer requests retransmission, the recording medium 13 in the camera terminal 10 as described above. A high-resolution video bit stream B _H ′ reproduced from the above is distributed to the receiving terminal 20, decoded by the decoder 21, and supplied to the display 22 via the frame memory. As a result, a high-resolution video as shown in FIG. 12B is displayed on the display 22. Here, when a predetermined portion is indicated by a cursor operation or the like on the high-resolution video screen, this indication portion is displayed. An area having a predetermined size is enlarged and displayed by reading control of the frame memory. The enlarged display area is displayed so as to overlap the video shown in FIG.

  Here, by setting the enlargement ratio of the video in the enlarged display area to a value in which, for example, the resolution of the video in the enlarged display area is equal to or less than the resolution of the video shown in FIG. Can be enlarged and displayed at a high resolution. Therefore, even if a part of the video is enlarged and displayed, a clear video can be obtained, and the viewer can clearly recognize the part of the video to be confirmed.

  FIG. 13 is a block diagram showing a ninth embodiment of the video distribution system and camera terminal and receiving terminal according to the present invention. Reference numeral 18 denotes an image / speech recognition circuit, and parts corresponding to those in FIG. In addition, overlapping explanation is omitted.

In the figure, the camera terminal 11 is provided with an image / sound recognition circuit 18, and a specific video is obtained from a video signal obtained from the camera 11, or alternatively, from a microphone (not shown) provided in the camera 11. When specific sound is detected by the image / speech recognition circuit 18 from the output sound signal, the image / sound recognition circuit 18 controls the recording medium 13 in response to this detection, and the high-quality bit stream from the encoder 12b. B _H is written to the recording medium 13.

Here, the specific video is, for example, a video of a moving object, and when this embodiment is applied to a monitoring system, when a person or the like enters a shooting scene, this is converted into an image / voice recognition circuit. 18 recognizes this and controls the recording medium 13 during the period in which this is recognized to record the high-quality bit stream B _H from the encoder 12b. Also, some specific videos are stored in the image / sound recognition circuit 18, and when a video other than the stored specific video is recognized from the video signal A from the camera 11, or this specific video is recognized. When the video is recognized, the recording medium 13 may be recorded. The same applies to sound, and when sound is output from the above microphone, the image / sound recognition circuit 18 may recognize this and cause the recording medium 13 to perform recording operation, or some specific sound. The pattern is stored, and when the sound of the pattern other than the specific sound pattern is output from the microphone or when the specific sound pattern is output from the microphone, the image / speech recognition circuit 18 recognizes this. Thus, the recording medium 13 may be operated for recording.

  In this way, in the ninth embodiment, since the recording medium 13 is written according to the recognition result of the image / speech recognition circuit 18, the storage capacity required for the recording medium 13 can be reduced, and A long-time video can be stored in the recording medium 13.

  Information stored in the recording medium 13 in this way is read out by a control signal from the system controller 23 and distributed to the receiving terminal 20. Therefore, the viewer can obtain information stored in the recording medium 13 and display it on the display 22 by making a distribution request when necessary.

  FIG. 14 is a block diagram showing a tenth embodiment of a video distribution system, a camera terminal and a receiving terminal according to the present invention, wherein 12c is an encoder, 13a is a recording medium, and parts corresponding to those in FIG. A duplicate description is omitted.

  In the figure, the tenth embodiment is obtained by adding an encoder 12c and a recording medium 13a to the first embodiment shown in FIG. One of the output and the output of the recording medium 13, 13a is selected.

  That is, as a method of displaying video on the display 22 of the receiving terminal 20 (image playback mode), not only normal playback (normal display) of low-quality video and high-quality video, but also slow playback as described above. Various modes such as still image playback and high-speed playback are conceivable, and in order to make these possible, the bit stream to be distributed must be encoded by a processing method suitable for such image playback mode. (For example, as described above, when a still image is reproduced from a bit stream encoded by a processing method compliant with MPEG, good still image reproduction is not always performed). In the sixth embodiment, therefore, a bit stream encoded by various processing methods can be obtained.

The encoder 12c has a performs an encoding process that is different from the encoder 12a, 12b, quality bitstream B _h generated in the encoder 12c is stored in the recording medium 13a. The changeover switch 14 normally selects and outputs the low image quality bit stream _BL of the encoder 12a, but when receiving a retransmission request from the system controller 23 of the receiving terminal 20, the high image quality stored in the recording media 13 and 13a. The bit stream that has been subjected to the optimum encoding process is selected and output from the bit stream.

  Here, two encoders that perform different encoding processes other than the low image quality encoder 12a are provided, but three or more such encoders may be provided.

  Thus, in the tenth embodiment, by performing a plurality of encodings within the camera terminal 10, it is possible to select a bitstream that has been subjected to an optimal encoding process in response to a retransmission request. The optimum encoding method differs depending on the form of image reproduction, such as slow reproduction and enlargement reproduction. In the tenth embodiment, encoding processing is performed by an optimum method for each form of image reproduction. And a recording medium for storing the bit stream output from these encoders, and these encoders simultaneously encode video signals from the same camera 11 and store them in the recording medium. In response to a re-transmission request instructing the reproduction form from the video, it is possible to receive a bitstream that has been encoded by a method that is always optimal for the designated reproduction form, and the viewer is always clear regardless of the reproduction form It is possible to receive a playback image.

It is a block diagram which shows the 1st and 4th embodiment of the video delivery system by this invention, a camera terminal, and a receiving terminal. FIG. 2 is a timing chart showing an operation in the first embodiment shown in FIG. 1. It is a block diagram which shows 2nd Embodiment of the video delivery system by this invention, a camera terminal, and a receiving terminal. It is a block diagram which shows 3rd Embodiment of the video delivery system by this invention, a camera terminal, and a receiving terminal. FIG. 5 is a timing chart showing the processing operation of the processor in FIG. 4. It is a figure which shows operation | movement of 5th Embodiment of the video delivery system by this invention, a camera terminal, and a receiving terminal. It is a block diagram which shows 6th Embodiment of the video delivery system by this invention, a camera terminal, and a receiving terminal. FIG. 8 is a timing chart showing the operation of the sixth embodiment shown in FIG. 7. It is a figure which shows one specific example of the screen displayed on the display of the receiving terminal in FIG. It is a block diagram which shows 7th Embodiment of the video delivery system by this invention, a camera terminal, and a receiving terminal. It is explanatory drawing of the display image by the bit stream obtained with the encoder for low image quality in 7th Embodiment shown in FIG. It is explanatory drawing of the image | video displayed in 8th Embodiment of the video delivery system by this invention, a camera terminal, and a receiving terminal. It is a block diagram which shows 9th Embodiment of the video delivery system by this invention, a camera terminal, and a receiving terminal. It is a block diagram which shows 10th Embodiment of the video delivery system by this invention, a camera terminal, and a receiving terminal. It is a block diagram which shows an example of the conventional video delivery system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Camera terminal 11 Camera 12a-12c Encoder 13,13a Recording medium 14 Bit stream changeover switch 15 Processor 16 Memory 16a, 16b Encoding program 17 Signal processing part 18 Image / voice recognition circuit 20 Camera terminal 21 Decoder 22 Display 23 System controller 30- 32 Network 40, 41 Local bus 50 Shooting range 51 Extraction range 52, 53 People

Claims (11)

A video distribution system in which a camera terminal and a receiving terminal are connected via a network, and a bit stream generated from a captured video by the camera terminal is distributed to the receiving terminal,
The camera terminal encodes the captured video signal to generate a first bit stream and a second bit stream that forms a higher quality video than the first bit stream, and Usually, the first bit stream is distributed, and the second bit stream from the video a predetermined time before the time when the retransmission request is made is distributed in response to the retransmission request from the receiving terminal. Video distribution system characterized by A video distribution system in which a camera terminal and a receiving terminal are connected via a network, and a bit stream generated from a captured video by the camera terminal is distributed to the receiving terminal,
The network has a hierarchical structure composed of an upper layer network connecting the camera terminal and the local server and a lower layer network connecting the local server and the receiving terminal,
The camera terminal encodes the captured video signal to generate a first bit stream and a second bit stream that forms a higher-quality video than the first bit stream. Simultaneously sending a second bitstream to the local server via the higher layer network;
The receiving terminal selectively distributes one of the first and second bit streams from the local server via the lower layer network. A video distribution system in which a plurality of camera terminals are connected to a receiving terminal via a network, and a bit stream generated from a captured video by the camera terminal is distributed to the receiving terminal,
The plurality of camera terminals encode a captured video signal to generate a first bit stream and a second bit stream that forms a higher quality video than the first bit stream,
Usually, the first bit stream generated by the plurality of camera terminals is simultaneously delivered to the receiving terminal, and when one of the plurality of camera terminals is designated by the receiving terminal and a retransmission request is made, The video distribution system, wherein only the camera terminal that has been distributed distributes the second bit stream to the receiving terminal. A video distribution system in which a camera terminal and a receiving terminal are connected via a network, and a bit stream generated from a captured video by the camera terminal is distributed to the receiving terminal,
In the camera terminal, n bitstreams (where n is an integer of 3 or more) encoded by different processing methods according to the video playback mode at the receiving terminal are generated, and the playback mode from the receiving terminal A video distribution system that distributes the bit stream corresponding to the designated reproduction mode to the receiving terminal in response to a request that designates. A camera terminal that distributes video information via a network,
A camera that outputs a video signal of the photographed subject;
A first encoder that encodes the video signal to generate a first bitstream;
A second encoder that encodes the video signal to generate a second bitstream of video with higher image quality than the first bitstream;
And a recording medium for recording and reproducing the second bit stream, wherein the first and second bit streams are used as video information for distribution. A camera terminal that distributes video information via a network,
A camera that outputs a video signal of the photographed subject;
A first encoding process and a second encoding process of the video signal in a time-sharing manner to generate a first bit stream and a second bit stream of an image with higher image quality than the first bit stream; ,
And a recording medium for recording and reproducing the second bit stream, wherein the first and second bit streams are used as video information for distribution. A camera terminal that distributes video information via a network,
A camera that outputs a video signal of the photographed subject;
A signal processing unit that extracts a video portion within an extraction range set for each frame from the video signal, and extends the extracted video portion to the entire frame;
A first encoder that encodes an output video signal of the signal processing unit to generate the first bitstream;
A second encoder that encodes the video signal output from the camera and generates a second bitstream of video with higher image quality than the first bitstream;
And a recording medium for recording and reproducing the second bit stream, wherein the first and second bit streams are used as video information for distribution. A camera terminal that distributes video information via a network,
A camera that outputs a video signal of the photographed subject;
A first encoder that encodes the video signal to generate a first bitstream;
A second encoder that encodes the video signal to generate a second bitstream of video with higher image quality than the first bitstream;
An image / speech recognition circuit that performs at least one of image recognition based on the video signal output from the camera and sound recognition based on a sound signal output from a microphone provided in the camera;
A recording medium that records and reproduces the second bit stream based on a recognition result of the image / speech recognition circuit, and uses the first and second bit streams as video information. A camera terminal. A camera terminal that distributes video information via a network,
A camera that outputs a video signal of the photographed subject;
The video signals are encoded by different processing methods to generate bit streams of different image quality (where n is an integer of 3 or more), and the bit streams other than the bit image of the lowest image quality And a recording medium that records and reproduces the video information for distributing the n bit streams. In any one of Claims 5-9,
Providing a changeover switch for selecting and distributing any one of the generated bitstreams;
A camera terminal, wherein the changeover switch is controlled to be switched in response to a request from a distribution destination. A receiving terminal for receiving a bit stream of a video distributed via a network,
A decoder that decodes the received bitstream into a video signal;
A display for displaying the video by being supplied with the decoded video signal;
A reception terminal comprising: a system controller for requesting retransmission of a video displayed on the display as a high-quality video for a video distribution source.

Images