JP2007329844A - Picture server - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To execute network output obtaining an image stream from an image server without delays, and quickly responding to a control command from an image data viewing terminal, to reduce the stress when viewing. <P>SOLUTION: A network communication unit comprises a bus interface, enabling burst transfer for transmitting picture streams and a bus interface or a target interface for the data communication, other than the picture streams, thereby carrying out the respective data transfers to actualize control data communication that has no interference to the burst transfer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a video server device, for example, a technique suitable for use in outputting a large amount of data such as a video stream constantly by network communication.

  Conventionally, as a video data network distribution method, the entire video is converted into a file, and then the entire file is transferred to a terminal for viewing the video data. After the transfer is completed, the terminal performs decoding processing to reproduce the video data. There is a file transfer type means to do this. Further, there is a streaming type means for sequentially packetizing video data on the video server side and transferring it to a terminal for viewing video data, and on the terminal side, sequentially playing back received video data packets without waiting for transfer completion.

  Among these video data network communication means, in streaming type communication, the formats are MPEG2, MPEG4, VC-1, H.264, and the like. There are various formats such as H.264. Various services have already been started for video streaming of standard (SD) video via a network such as the Internet.

  On the other hand, in the video streaming communication for high-definition images (HD) whose needs are rapidly increasing recently, MPEG2, VC-1, H. Formats such as H.264 are attracting attention. In the future, HD streaming is expected to spread in the fields of home streaming and Video On Demand.

  In order to realize HD video streaming, a higher-speed network communication environment is required than SD video streaming. Among the HD video stream formats described above, a video stream in the MPEG2 format requires a high transfer rate of about 17 Mbps to 30 Mbps as its transfer rate.

  On the other hand, network transfer performance has been improved due to the advancement of network equipment. In the wired LAN environment, gigabit support is in progress in the home LAN environment, and IEEE 802.11a / g speedup and 11n standardization are in progress in the wireless LAN environment. For this reason, a transfer rate of about 100 Mbps can be expected within a few years. Under these circumstances, a solution for transferring an HD quality video stream in the MPEG2 format via a network at home or via the Internet and viewing the video stream on various video data viewing terminals has become realistic.

  Examples of video server devices that perform HD video streaming include streaming servers such as network cameras and hard disk recorders. The network camera encodes the video data input from the imaging unit in real time by the encoder unit to generate video stream data, and the video stream data is sent to the network communication unit via a bus provided in the network camera. And send. Thereby, wired or wireless network output is performed. On the other hand, in the streaming server, the HDD controller reads the video stream data from an external storage device such as a hard disk provided in the server, and sends the stream data to the network communication unit via the bus provided in the server. . Thereby, network output is performed.

  As an internal bus used for such a purpose, a general-purpose bus such as a PCI bus is generally used. General-purpose buses such as PCI buses support burst transfer to support high-speed transfer, and the most efficient by performing burst transfer when performing bus transfer continuously between devices connected to the bus. A good transfer can be performed.

  Conversely, when the transfer direction on the bus changes or the device to transfer changes, the burst transfer is interrupted and the bus transfer efficiency decreases. 2. Description of the Related Art Conventionally, in a device such as a video server, a network communication unit or other controller obtains a bus use right by a bus master request, and then transfers a large amount of stream data between devices by burst transfer.

  If another bus master issues a bus master request during this burst transfer, the burst transfer process is resumed from the middle when the bus master authority is transferred again by setting the standby state without stopping the burst transfer process. (For example, refer to Patent Document 1). There is also a technique in which a plurality of buses including a low-speed bus and a high-speed bus are provided between devices, and data transfer is performed by selecting one of them according to the amount of transfer data (for example, see Patent Document 2).

JP 2004-25272 A JP-A 63-149755

  As described above, in a video server device such as a network camera or a streaming server, it is necessary to continuously transfer large-capacity stream data from the encoder unit or the HDD controller to the network unit. For this purpose, it is most efficient to hold the right to use the bus between the devices performing the transfer and perform burst transfer.

  On the other hand, various control commands from the video data viewing terminal side such as a camera pan / tilt / zoom request, distribution stop, and cueing are also transmitted to the video server device. In the conventional example, a general-purpose bus such as a PCI bus is used in the same manner as the video stream data for transmission related to these control commands. However, even if the network unit receives these control commands during video stream data transfer, there is no way to transfer the control commands during burst transfer. For this reason, there has been a problem that the response to the control command is delayed.

  If burst transfer is stopped with priority given to the control command and video stream data transfer is resumed after the transfer of the control command, it is necessary to make settings for burst transfer again. For this reason, there is a problem that the video stream data that must be carried out without delay in real time cannot be transferred in time and the video stream is interrupted.

  In view of the above-described problems, the present invention performs network output of a video stream from a video server device without delay and can respond quickly to a control command from the video data viewing terminal side during viewing. The purpose is to reduce stress.

  The video server apparatus according to the present invention is a video server apparatus having a network communication unit that outputs a large amount of data on a regular network, and as a connection means of the network communication unit, a bus capable of burst transfer for transmitting a video stream A bus interface or a standard interface for transmitting data other than the video stream is provided together with the interface.

  According to the present invention, when HD video streaming is performed from the video server device to the video data viewing terminal, the HD streaming output is continued without delay, and at the same time, the control command from the video data viewing terminal is promptly handled. It becomes possible to do. Thereby, a viewing environment free from stress can be provided to the user.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 is a block diagram illustrating an internal configuration example of the video server apparatus according to the present embodiment.
In FIG. 1, reference numeral 1 denotes a video server device such as a network camera, and 2 denotes a viewing terminal capable of network communication with the video server device 1 and viewing a video stream.

  Reference numeral 3 denotes a network unit provided in the video server device 1, and reference numeral 4 denotes a camera unit provided in the video server device 1. An image pickup unit 5 is provided in the camera unit 4 and shoots videos. An encoder 6 is provided in the camera unit 4 and converts video data shot by the image pickup unit 5 into a streaming format in real time.

  A camera control unit 7 is provided in the camera unit 4 and performs pan / tilt / zoom control and on / off control of the camera unit 4 by command input from the USB I / F b18. Reference numeral 8 denotes a PCI bus to which the camera unit 4, the network unit 3, and the PCI bridge 19 built in the embedded processor 9 are connected.

  Reference numeral 9 denotes an embedded processor in which peripheral functions such as the PCI Bridge 19 and the CPU 11 are integrated. Reference numeral 10 denotes a DRAM connected to the DRAM interface of the embedded processor 9. Reference numeral 11 denotes a Flash ROM connected to the expansion bus of the embedded processor 9, and reference numeral 12 denotes an interrupt controller (PIC) built in the embedded processor 9 for controlling interrupts.

  Reference numeral 13 denotes a memory controller built in the embedded processor 9, and reference numeral 14 denotes an expansion bus bridge built in the embedded processor 9. Reference numeral 15 denotes a CPU local bus that functions as a high-speed local bus for the embedded processor 9, and reference numeral 16 denotes a USB host controller built in the embedded processor 9. 17 is a USB I / F a that connects the USB host controller 16 and the network unit 3, and 18 is a USB I / F b that connects the USB host controller 16 and the camera control unit 7.

  A PCI bridge 19 bridges the CPU local bus 15 and the PCI bus 8. 20 is a DMAC such as a PCI arbiter built in the PCI Bridge 19, and 21 is a CPU built in the embedded processor 9.

  Here, using the configuration shown in FIG. 1, video data captured by the camera unit 4 of the network camera that is the video server device 1 is encoded in real time to generate stream data, and the stream data is viewed on the viewing terminal 2. Suppose you want to watch on The operations in the camera unit 4 and the network unit 3 in the video server device 1 at this time are shown in FIG.

  In the camera unit 4, first, video data captured by the imaging unit 5 is transferred to the encoder 6 as uncompressed captured video data. The encoder 6 performs compression processing on the uncompressed captured video data, and performs MPEG2-TS or H.264. Encode to H.264 format. Thereafter, the encoded data is packetized in a format such as an RTP packet, and IP header information is added.

  Thereafter, the MPEG2-TS information packetized in the RTP packet format is transferred to the network unit 3 via the PCI bus 8 and reconfigured into a frame corresponding to a wireless LAN or the like in order to perform actual network communication. Then, after a wireless header or the like is added, network communication is performed to the viewing terminal 2. At this time, packet transfer from the camera unit 4 to the network unit 3 via the PCI bus 8 is performed using a DMA bus transfer method.

  In order to carry out this transfer, the camera unit 4 transmits a bus master request to the DMA 20 which is a bus arbiter of the PCI bus 8 when encoding for a plurality of frames, which is the minimum unit of encoding, is completed. When the DMAC 20 recognizes the bus master request, the camera unit 4 starts DMA transfer (bus master transfer) of the RTP packet to the network unit 3 on the PCI bus 8.

  In the DMA transfer, the minimum encoded data prepared in the camera unit 4 needs to be transferred a plurality of times in units corresponding to the bus width, so that the transfer is continuous, and the PCI bus is transferred by burst transfer of the PCI bus 8. The utilization factor of 8 can be improved.

FIG. 3 shows a burst transfer procedure on the PCI bus 8.
As shown in FIG. 3, the camera unit 4 asserts a REQ # signal that is a bus master request. Then, the DMAC 20 which is a bus arbiter of the PCI bus 8 accepts the bus master request, asserts the GNT # signal, and notifies the camera unit 4 that the bus master request is accepted and can operate as the bus master.

  Upon receiving the GNT # signal, the camera unit 4 outputs the address information of the network unit 3 to AD [31: 0] and asserts the FRAME # signal to notify that the network unit 3 is accessed. The network unit 3 requested to write to its own address asserts the DEVSEL # signal to notify the camera unit 4 that access can be accepted. When ready to write data, assert TRDY # signal. Thereafter, the camera unit 4 as a writing base outputs write data to AD [31: 0] at a speed of one unit per clock to perform burst transfer.

  In this way, by performing burst transfer on the PCI bus 8, the address cycle required every time in normal bus transfer is omitted, and one unit (32 bits in the case of FIG. 3) of data is continuously transferred in one clock. Can do. In real-time streaming of video data from the video server device 1 such as a network camera or the like to the viewing terminal 2 as assumed in this application, video data output from the camera unit 4 is constantly performed. Therefore, burst transfer as shown in FIG. 3 is repeatedly performed on the PCI bus 8.

  Here, let us consider a case where a control command such as zoom or pan is issued from the viewing terminal 2 to the video server device 1 during such burst transfer. In this case, after the control command is received by the network unit 3, it is sent to the embedded processor 9 not via the PCI bus 8 but via the USB I / F a 17 that is another bus or I / F. .

  In the embedded processor 9, a control command transmitted from the network unit 3 is received by the USB host controller 16 incorporated in the processor. Thereafter, the control command is sent to the CPU 21 via the CPU local bus 15, and the CPU 21 analyzes the contents of the control command and transmits the result to the USB host controller 16 via the CPU local bus 15. Then, a control command is transmitted to the control unit 7 of the camera unit 4 via the USB I / F b18.

FIG. 4 shows what kind of packet transfer is performed on the USB I / F a 17, the USB I / F b 18 and the PCI bus 8 in time series.
As shown in FIG. 4, packets related to stream start / stop commands, camera zoom, and the like are transferred via USB I / F a 17 or USB I / F b 18, and video stream packets are burst transferred via the PCI bus 8. .

  Thus, by providing both the camera unit 4 and the network unit 3 with a bus capable of burst transfer of video data and a bus usable for other data transfer such as control commands and events, a response to a control command without delay And event response. In the present embodiment, a case has been described in which the camera unit 4 and the network unit 3 share a bus that can be used for other data transfer such as control commands and events. On the other hand, it goes without saying that even if each bus is different, it can be handled by the CPU 21 performing conversion.

(Second Embodiment)
Hereinafter, the present embodiment will be described with reference to FIGS.
FIG. 5 is a block diagram illustrating an internal configuration example of the video server apparatus according to the present embodiment.
In FIG. 5, 101 is a video server device such as a network camera, and 102 is a viewing terminal capable of network communication with the video server device 101 and viewing a video stream.

  Reference numeral 103 denotes a network unit provided in the video server apparatus 101. Reference numeral 104 denotes a UDP / IP-compatible Task Offload Engine (TOE) provided in the network unit 103 or in the preceding stage of the network unit 103. Reference numeral 105 denotes a camera unit provided in the video server apparatus 101.

  Reference numeral 106 denotes an imaging unit that is provided in the camera unit 105 and captures video. Reference numeral 107 denotes an encoder that converts video data captured by the imaging unit 106 provided in the camera unit 105 into a streaming format in real time. A camera control unit 108 is provided in the camera unit 105 and communicates with the UART controller 119 via the RS232C I / F 123 to perform pan / tilt / zoom control and on / off control of the camera unit 105.

  Reference numeral 109 denotes a PCI bus to which the camera unit 105, the network unit 104, and the PCI bridge 120 built in the embedded processor 110 are connected. Reference numeral 110 denotes an embedded processor in which PCI Bridge 120, CPU 113 and other peripheral functions are integrated. 111 is a DRAM connected to the DRAM interface of the embedded processor 110, and 112 is a Flash ROM connected to the expansion bus of the embedded processor 110.

  Reference numeral 113 denotes a CPU built in the embedded processor 110, and reference numeral 114 denotes an interrupt controller (PIC) built in the embedded processor 110 that performs interrupt control. Reference numeral 115 denotes a memory controller built into the embedded processor 110, and 116 denotes an expansion bus bridge built into the embedded processor 110. Reference numeral 117 denotes a CPU local bus that functions as a high-speed local bus for the embedded processor 110.

  Reference numeral 118 denotes a USB host controller built in the embedded processor 110, and reference numeral 119 denotes a UART controller built in the embedded processor 110. A PCI bridge 120 bridges the CPU local bus 117 and the PCI bus 109. Reference numeral 121 denotes a DMAC such as a PCI arbiter built in the PCI Bridge 120, and 122 denotes a USB I / F that connects the USB host controller 118 and the network unit 103. Reference numeral 123 denotes an RS232C I / F that connects the UART controller 119 and the camera control unit 108.

  Here, as in the first embodiment, video data captured by the camera unit 105 of the network camera serving as the video server apparatus 101 is encoded in real time to generate stream data, and the stream data is viewed on the viewing terminal 102. Assuming that The operations of the camera unit 105 and the network unit 103 in the video server device 101 at this time and the TOE 104 included in the network unit are shown in FIGS.

  As shown in FIG. 6, in this embodiment, unlike the first embodiment, IP header information addition processing is performed by the TOE 104 provided in the network unit 103. The TOE 104 is means for speeding up part or all of processing executed by software by hardware. However, the stream video data such as MPEG2-TS that is actually output from the camera unit 105 is generally transmitted by communication means such as RTP / UDP that does not perform retransmission. Therefore, hardware implementation is relatively easy.

  Furthermore, since it is necessary to process a large amount of packets at high speed during transmission of video data as described in this embodiment, the implementation of the TOE 104 that performs RTP / UDP protocol processing by hardware is suitable for this embodiment. Yes.

  Video data photographed by the camera unit 105 is processed according to the same procedure as in the first embodiment, using MPEG2-TS or H.264. Encoded to H.264 format. Thereafter, the data is transferred to the TOE 104 provided in the network unit 103 by burst transfer using the PCI bus 109. The transferred encoded data is added with IP header information by the TOE 104 and then sent to the wireless unit of the network unit 103.

  In the wireless unit, in order to perform actual network communication, a frame corresponding to a wireless LAN or the like is reconfigured, a wireless header or the like is added, and then network communication is performed to the viewing terminal 102. As described above, all the operations for adding the IP header to the video data output from the camera unit 105 are performed by the TOE 104, thereby enabling high-speed processing, and PCI burst transfer from the camera unit 105 to the TOE 104 is also efficiently performed. The

  On the other hand, as shown in FIG. 7, status information and control information other than video data are generated by each component of the embedded processor 110 and the camera unit 105, and then transmitted to the CPU 113 to be subjected to packetizing processing. For example, status information generated by the camera unit 105 is transmitted from the control unit 108 to the UART controller 119 built in the embedded processor 110 via the RS232C I / F 123.

  Thereafter, the data is sent to the CPU 113 via the CPU local bus 117, and the CPU 113 adds IP header information and packetizes it into a packet such as TCP / IP. The packetized status information is transmitted to the USB host controller 118 via the CPU local bus 117 and transferred from the embedded processor 110 to the network unit 103 via the USB I / F 122 which is another bus or I / F. The

  At this time, since the USB I / F 122 is directly connected to the network unit 103, processing by the TOE 104 is avoided, and the wireless unit of the network unit 103 moves to a frame corresponding to a wireless LAN or the like to perform actual network communication. Perform reconfiguration. Then, after adding a wireless header or the like, network communication is performed to the viewing terminal 102.

  Further, as in the first embodiment, a case is considered where a control command such as zoom or pan is issued from the viewing terminal 102 to the video server apparatus 101. In this case, after the control command is received by the network unit 103, the control command is sent to the embedded processor 110 via the USB I / F 122, which is another bus or I / F, without passing through the TOE 104 or the PCI bus 109. Sent.

  In the embedded processor 110, the USB host controller 118 incorporated in the processor receives the control command transmitted from the network unit 103 and then sends the control command to the CPU 113 via the CPU local bus 117. Then, after the CPU 113 performs depacketizing processing, the contents of the control command are analyzed. The result is transmitted to the UART controller 119 via the CPU local bus 117 and the control command is transmitted to the control unit 108 of the camera unit 105 via the RS232C I / F 123. This prompts the camera unit 105 to perform processing corresponding to the control command.

(Other embodiments according to the present invention)
Each means constituting the video server device and each step of the method in the embodiment of the present invention described above can be realized by operating a program stored in a RAM or ROM of a computer. This program and a computer-readable recording medium recording the program are included in the present invention.

  Further, the present invention can be implemented as, for example, a system, apparatus, method, program, or recording medium. Specifically, the present invention may be applied to a system including a plurality of devices. The present invention may be applied to an apparatus composed of a single device.

  Note that the present invention supplies a software program that implements the functions of the above-described embodiments directly or remotely to a system or apparatus. This includes the case where the system or the computer of the apparatus is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, and the like.

  Examples of the recording medium for supplying the program include a floppy (registered trademark) disk, a hard disk, an optical disk, and a magneto-optical disk. Further, there are MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card, ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, there is a method of connecting to a homepage on the Internet using a browser of a client computer. The computer program itself of the present invention or a compressed file including an automatic installation function can be downloaded from the homepage by downloading it to a recording medium such as a hard disk.

  It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  As another method, the program of the present invention is encrypted, stored in a recording medium such as a CD-ROM, distributed to users, and encrypted from a homepage via the Internet to users who have cleared predetermined conditions. Download the key information to be solved. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  Further, the functions of the above-described embodiments are realized by the computer executing the read program. Furthermore, based on the instructions of the program, an OS or the like running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments can be realized by the processing.

  As another method, the program read from the recording medium is first written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Then, based on the instructions of the program, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are also realized by the processing.

It is a block diagram which shows the example of an internal structure of the video server apparatus which concerns on the 1st Embodiment of this invention. In the 1st Embodiment of this invention, it is a figure which shows the flow of a process in a camera part and a network part. 4 is a timing chart showing PCI burst transfer in the first embodiment of the present invention. FIG. 5 is a diagram illustrating transfer timing in each I / F in the first embodiment of the present invention. It is a block diagram which shows the example of an internal structure of the video server apparatus which concerns on the 2nd Embodiment of this invention. In the 2nd Embodiment of this invention, it is a figure which shows the flow of a process in the camera part at the time of video stream transfer, and a network part. In the 2nd Embodiment of this invention, it is a figure which shows the flow of a process in CPU and the network part at the time of the other data transfer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Video server apparatus 2 Terminal for viewing 3 Network part 4 Camera part 5 Imaging part 6 Encoder 7 Control part 8 PCI bus 9 Embedded processor 10 DRAM
11 Flash ROM
12 Interrupt controller (PIC)
13 Memory controller 14 Expansion bus bridge 15 CPU local bus 16 USB controller 17 USB I / F a
18 USB I / F b
19 PCI bridge
20 DMAC
21 CPU

Claims (5)

A video server device having a network communication unit that steadily outputs a large amount of data to the network,
As a connection unit of the network communication unit, a bus interface capable of burst transfer for transmitting a video stream,
A video server device comprising a bus interface or a standard interface for transmitting data other than the video stream.   2. The video server device according to claim 1, wherein data input to two or more types of interfaces included in the network communication unit is converted into packets capable of network communication, and then mixed and output to the network.   2. The video server apparatus according to claim 1, wherein all packets input to the network are unconditionally output to a bus interface or a standard interface that transmits data other than the video stream.   2. The video data input from a bus interface capable of burst transfer for transmitting the video stream is packetized using a TOE provided in the network communication unit and output to the network. The video server device described.   2. The video server apparatus according to claim 1, wherein packetization processing or depacketization processing of data input / output from a bus interface or a standard interface for transmitting data other than the video stream is performed by a CPU provided in the apparatus. .

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