JP2007300386A - Network decoding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a network decoding apparatus which decodes and outputs an image information or a sound information to be received without oppressing a duty factor of a bus to be connected to an internal CPU, even when the number of a packet to be received increases. <P>SOLUTION: The apparatus is provided with a low-speed bus 21 and a high-speed bus 22. The low-speed bus 21 connects a data sender and receiver 13a to receive a packeted compression content data transmitted from a monitoring camera group 40; and a data extractor 16b to extract the compression content data from the packeted compression content data which has been received to an input side of a decoding means 17 to input and decode-processes the extracted compression content data, and to output the obtained content data, respectively. The high-speed bus 22 connects an output side of the decoding means 17 and a frame memory 19 to store the content data output from the output side of the decoding means 17 to a read portion 20 to read and output the stored content data, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a network decoder device for decoding and outputting video information or audio information received via a network.

  Conventionally, with the spread of network technology, transmission / reception of video or audio via an IP network has been widely performed.

  As a system using this technology, there is a monitoring system that displays video data captured by a plurality of monitoring cameras on a display device connected via an IP network.

  The configuration of a conventional monitoring system is shown in FIG.

  A conventional monitoring system 100 includes a monitoring camera group 40 having a first monitoring camera 40-1 to an n-th monitoring camera 40-n, a recorder 50 for recording video data captured by these monitoring cameras, and a monitoring camera group. A display device 110 that displays real-time video data captured by the surveillance camera 40 or video data recorded in the recorder 50 is connected via the IP network 30.

  The display device 110 includes a display control unit 111 and a display unit 112 that displays video data controlled by the display control unit 111.

  The display control unit 111 is a network interface unit 113 that transmits and receives IP packets to and from the IP network 30, a ROM 114 that stores a control program, and data of IP packets temporarily when the control program stored in the ROM 114 is executed. RAM 115 for storing the control program, CPU 116 for executing the control program stored in RAM 115, decoding unit 117 for decoding the IP packet of the image data constituting the video data received from network interface unit 113, and decoding unit The image processing unit 118 that adjusts the size and image quality of the image data decoded in 117, the frame memory 119 that stores the image data processed by the image processing unit 118, and the image data stored in the frame memory 119 are read. Having a reading unit 120 for outputting to the display unit 112, and a bus 121 that transmits data between the network interface 113 to read section 120.

  In this monitoring system 100, when shooting is performed by the first monitoring camera 40-1 to the n-th monitoring camera 40-n of the monitoring camera group 40, the captured video data is recorded in the recorder 50 via the IP network 30. In addition, the video is provided to the user by being displayed on the display device 110.

  In the display device 110, IP packets of video data taken by the first monitoring camera 40-1 to the n-th monitoring camera 40-n of the monitoring camera group 40 or image data constituting the video data recorded in the recorder 50 are received. When received via the IP network 30, it is acquired by the network interface unit 113 of the display control unit 111.

  In the display control unit 111, the control program stored in the ROM 114 is expanded in the RAM 115, and this control program is executed under the control of the CPU 116, whereby the header part is separated from the IP packet acquired by the network interface unit 113, Image data in the payload part is acquired.

  The acquired image data is decoded by the decoding unit 117, the image size and image quality are adjusted by the image processing unit 118, and then stored in the frame memory 119.

  The image data stored in the frame memory 119 is read by the reading unit 120 and displayed on the display unit 112.

  All the processes of the display control unit 111 described above are performed by transmitting information via the bus 121.

  The display device 110 not only displays the video data captured by the first monitoring camera 40-1 to the n-th camera 40-n in real time, but also displays the video data recorded in the recorder 50 according to a user request. For example, playback with time lapse is performed.

  Therefore, the display device 110 is required to have the capability of receiving video data recorded in the recorder 50 in addition to the capability of receiving video data captured by n monitoring cameras in real time.

  Furthermore, in recent surveillance systems, it is required to improve the quality of surveillance video.

  Corresponding to these requests, the bandwidth consumption of the internal bus 121 of the display control unit 111 provided in the display device 110 increases, so the display device 110 needs to be able to receive at a high bit rate.

  However, there is a problem that the display device 110 becomes expensive and a burden on the user is heavy if an attempt is made to enable reception at a high bit rate with a margin in order to perform stable reception processing.

  In order to solve this problem, there is a technique described in Patent Document 1 or Patent Document 2.

  The technique described in Patent Document 1 relates to an IP packet transmission / reception apparatus that transmits and receives a video / audio signal through an IP network.

  In the IP packet transmitting / receiving apparatus described in Patent Document 1, the received IP packet is written into an address or FIFO (First-In First-Out) type memory previously designated by the CPU on the dual port memory.

  The CPU determines whether the IP packet written in these memories is an IP packet of video / audio information by the CPU. If it is not an IP packet of video / audio information, the CPU processes the video packet. Are read from a port different from that of the CPU of the memory and decoded.

  With this IP packet processing device, the bus usage rate on the CPU side of the memory can be reduced.

  In the packet transmission / reception apparatus described in Patent Document 2, a packet analysis unit is provided in the packet reception unit of the network interface. When the packet analysis unit determines that the packet is video / audio information, the packet is transmitted to the decoder by the changeover switch. The video / audio information is not output to the CPU at all.

With this IP packet processing device, only the IP packets necessary for the CPU flow through the bus, and the IP packets of video / audio information do not flow through the CPU, so that the bus bandwidth can be greatly reduced.
JP 2004-112192 A JP-A-2005-341107

  However, when the IP packet transmitting / receiving apparatus of Patent Document 1 is used in a monitoring system, as the number of connected monitoring cameras and recorders increases, the capacity of the memory for writing IP packets must be increased in proportion to the increase. However, there is a problem that the scale of the entire system may have to be limited.

  In addition, since the CPU is notified each time an IP packet is received and written to the memory, the frequency of notification to the CPU increases as the network interface speeds up, and it is necessary to increase the processing capacity of the CPU. There was a problem.

  In addition, when the IP packet transmitting / receiving apparatus disclosed in Patent Document 2 is used in a monitoring system, the header content included in the payload of an IP packet received when a plurality of connected monitoring cameras are manufactured by different manufacturers. Since they are not necessarily the same, IP packet analysis processing corresponding to each header is required, and the processing of the packet analysis unit provided in the packet reception unit is complicated.

  In addition, when an IP packet is encrypted by, for example, IPsec (Security Architecture for Internet Protocol) or when an IP tunnel technology defined by RFC (Request For Comment) is used, it is a packet of video / audio information. There has been a problem that the process for determining whether or not the packet becomes very complicated and the packet analysis unit may not be able to handle it.

  If the packet analysis unit could not cope with it, all IP packets of video / audio information also flowed to the CPU side, and there was a problem that the effect of reducing the bandwidth used for the bus could not be obtained.

  The present invention has been made in view of the above circumstances, and when the number of content supply apparatuses connected via a network is increased, when the network interface is speeded up, or header information for each packet is different. Even when packets are encrypted or when tunnel technology is used, the received video or audio information is decoded and output without squeezing the usage rate of the bus connected to the internal CPU. It is to provide a network decoder device capable of performing the above.

  In order to achieve the above object, a network decoder device of the present invention is connected to a content supply device (40) via a network (30), and packetized compressed content data transmitted from the content supply device (40). In the network decoder device (11) that outputs the obtained content data after receiving and decoding the data, the data transfer rate is higher than that of the first internal bus (21) and the first internal bus (21). A data receiving means for receiving packetized compressed content data transmitted from the content supply device (40) on the first internal bus (21). (13) and data for extracting compressed content data from the received packetized compressed content data The extraction means (16b) is connected to the input side of the decoding means (17) for inputting and extracting the extracted compressed content data and outputting the obtained content data, and the second means The internal bus (22) has an output side of the decoding means (17), a storage means (19) for storing content data output from the output side of the decoding means (17), and the stored content data And a reading means (20) for reading out and outputting the data.

  According to the network decoder device of the present invention, when the number of content supply devices connected via a network increases, when the network interface speeds up, when the header information for each packet is different, or when the packet is encrypted The received video information or audio information can be decoded and output without squeezing the usage rate of the bus connected to the internal CPU even when the tunnel technology is used.

<Configuration of Monitoring System According to One Embodiment>
A monitoring system 1 using a display device 10 having a display control unit 11 as a network decoder device according to an embodiment of the present invention will be described with reference to FIG.

  The monitoring system 1 according to this embodiment includes a display device 10 and a monitoring camera group having a plurality of monitoring cameras 40-1 to 40-n as content supply devices connected to the display device 10 via an IP network 30. 40, a recorder 50, and a portable terminal 60.

  The display device 10 includes a display control unit 11 and a display unit 12 that displays image data that is content data controlled by the display control unit 11.

  The display control unit 11 includes a network interface 13, a ROM 14, a RAM 15, a CPU 16, a decoding unit 17, an image processing unit 18, a frame memory 19 as a storage unit, a reading unit 20, a network interface 13 to an image. A low-speed bus 21 as a first bus for transmitting data between the processing units 18 and a high-speed bus as a second bus capable of transferring data at a higher speed than the low-speed bus 21 for transmitting data between the decoding unit 17 and the reading unit 20 22.

  The network interface 13 transmits / receives an IP packet to / from the monitoring camera group 40, the recorder 50, and the portable terminal 60 via the IP network 30, and a packet for determining whether or not to pass the received IP packet by filtering. A filtering unit 13b is included.

  The network interface 13 is equipped with a PHY (physical layer) and a MAC (Media Access Control) using wired or wireless standards defined by IEEE 802.3, for example.

  The ROM 14 holds a control program for performing IP network protocol control and device control.

  The RAM 15 is a volatile memory such as an SRAM (Static Random Access Memory), an SDRAM (Synchronous Dynamic Random Access Memory), or a DDR (Double Data Rate) memory, and is used for executing a control program held in the ROM 14. .

  Based on the control program stored in the ROM 14, the CPU 16 sets a transmission source IP address or a transmission source MAC address that permits passage of an IP packet received from the IP network 30 in the packet filtering unit 13 b of the network interface 13. Passing packet setting unit 16a, data extracting unit 16b for extracting video data from IP packets permitted to pass by the packet filtering unit 13b, and image processing for controlling processing in the image processing unit 18 of image data constituting the video data The control unit 16 c includes a packetization processing unit 16 d that packetizes data to be transmitted to the IP network 30, and an image transfer unit 16 e that transfers the data packetized by the packetization processing unit 16 d to the portable terminal 60.

  These ROM 14, RAM 15, and CPU 16 are commonly used components. For example, when operating on a LINUX or UNIX (registered trademark) -based OS, a control program held in the ROM 14 is expanded in the RAM 15. Then, control is executed by the CPU 16 based on the control program developed in the RAM 15.

  The decoding unit 17 decodes the video data extracted by the data extraction unit 16b of the CPU 16.

  The image processing unit 18 adjusts each image data constituting the video data decoded by the decoding unit 17 based on the control of the image processing control unit 16c of the CPU 16, image size reduction, black and white adjustment, and image quality adjustment such as γ correction. Perform image processing.

  The frame memory 19 stores the image data processed by the image processing unit 18.

  The reading unit 20 reads the image data stored in the frame memory 19 according to the horizontal / vertical synchronization signal, and sends it to the display unit 12.

  The low-speed bus 21 has a communication speed necessary for transmitting the compressed image data received from the IP network 30 and the image data decoded by the decoding unit 17 and reduced by the image processing unit 18. For example, the operating frequency is 58 MHz and the data width is 32 bits.

  The high-speed bus 22 has a communication speed necessary for transmitting image data having a large amount of data decoded by the decoding unit 17, and has an operating frequency of 108 MHz and a data width of 32 bits, for example.

  The recorder 50 receives and records video data captured by each surveillance camera of the surveillance camera group 40 via the IP network 30 and outputs the video data to the display device 10 when a playback instruction is received from the display device 10.

  The portable terminal 60 acquires and displays the video data decoded and reduced by the display device 10 as necessary.

<Operation of Monitoring System According to One Embodiment>
The operation of the monitoring system 1 according to this embodiment will be described.

  FIG. 5 is a flowchart showing a control process of the CPU 16 provided in the display device 10 in the monitoring system 1.

  In the CPU 16 of the display device 10, a transmission source IP address and a transmission source MAC address used for filtering in a packet filtering unit 13b described later are set in advance by the passing packet setting unit 16a, and further, an image is processed by the image processing control unit 16c. An image size used for image size adjustment in the processing unit 18 is set (S1, S2).

  The source IP address and source MAC address of the IP packet that is allowed to pass during filtering are set in the packet filtering unit 13b of the network interface 13 as the source IP address table and source MAC address table.

  The setting of the transmission source IP address table and the transmission source MAC address table will be described with reference to the tables of FIGS.

  The initial values of the source IP address table and source MAC address table of IP packets that are allowed to pass are all “0”. At this time, all IP packets are prohibited from passing.

  For example, when the IP address “192.168.0.1” is set as the first source IP address that is allowed to pass, “number 1” in the source IP address table is set by the passing packet setting unit 16a of the CPU 16. It is set by storing this IP address as the value of.

  For example, when the IP address “192.168.0.46” is set as the second source IP address that is allowed to pass through, for example, the IP address “192.168.8.0” is set as the third source IP address. .100 ”is set, the passing packet setting unit 16a of the CPU 16 converts these IP addresses as the values of“ number 2 ”or“ number 3 ”in the transmission source IP address table as shown in FIG. It is set by being stored in.

  These settings are canceled by setting the value of a desired number in the source IP address table to “0”.

  Further, the setting of the source MAC address table of the IP packet that is allowed to pass is also set by the same processing. For example, as shown in FIG. 2B, the value of “number 1” in the source MAC address table Is set by storing the MAC address “00.23.45.67.89.AB”.

  Similarly to the cancellation of the setting of the transmission source IP address, the setting of the transmission permission is canceled by setting the value of the desired number in the table to “0”.

  In these settings, “*” is used to store, for example, the IP address “192.168.0.0. *”, Thereby transmitting “192.168.0.1” to “192.168.0.255”. It is also possible to set to allow passage of the original IP address.

  As an exception, when the source address is a broadcast address (“255.255.255.255” for an IP address, “FF.FF.FF.FF” for a MAC address), the setting contents of the table Passage is permitted regardless.

  Further, separately from the transmission source IP address table and the transmission source MAC address table of FIGS. 2A and 2B, as shown in FIGS. 3A and 3B, for filtering IP packets by multicast. A multicast address table may be set.

  In the multicast address table, it is possible to set IP addresses that are allowed to pass in the range of IP addresses “224.0.0.0.0” to “239.255.255.255”. In the multicast IP address table shown in FIG. 3A, “224.0.0.101” is set as the value of “number 1”, and “224.0.0.23” is set as the value of “number 2”. If the multicast address is set to these IP addresses, passage is permitted.

  In addition, in the multicast MAC address table shown in FIG. 3B, settings relating to the passage of IP packets are not performed.

  In the state where these address tables are set, first, when shooting is performed by the first monitoring camera 40-1 to the n-th monitoring camera 40-n included in the monitoring camera group 40, the captured video data The IP packet is transmitted to the recorder 50 and the display device 10 via the IP network 30.

  The recorder 50 records the received IP packet.

  In the display device 10, an IP packet of video data transmitted from the monitoring camera group 40 is received by the network interface 13 of the display control unit 11.

  The IP packet of the video data received by the network interface 13 is subjected to filtering by determining whether or not to allow the packet filtering unit 13b to pass based on the setting of the address table described above.

  The IP packet of the video data permitted to pass by the packet filtering unit 13b is sent to the data extracting unit 16b of the CPU 16 via the low speed bus 21.

  The data extraction unit 16b monitors whether or not an IP packet has been acquired (S3). When the IP packet is acquired, it is decapsulated when encapsulated by the IP tunnel technology, and IPsec When encryption by is performed, a process for releasing the encryption is performed.

  At this time, since the decryption process is complicated, an IPsec coprocessor (not shown) may be mounted so that the process can be performed at high speed.

  Next, the data extraction unit 16b determines whether or not the compressed data of the video data is included in the IP packet subjected to these processes (S4), and when it is determined that the data is included (“YES” in S4). The header portion is removed from the IP packet, and the compressed data of the video data is extracted.

  At this time, when the cameras of the first monitoring camera 40-1 to the n-th monitoring camera 40-n are different manufacturers, the control protocol, the IP packet configuration, and the like may be different. Therefore, as shown in FIG. 4, a protocol table in which the IP address and control protocol for each surveillance camera are stored in advance is stored in the ROM 14 or RAM 15 in advance, and the data extraction unit 16b uses the IP packet from the IP packet based on the setting contents of this protocol table. The header part is removed, and the compressed data that is the payload part is extracted.

  FIG. 4 shows that the first monitoring camera 40-1 having the IP address “192.168.0.1” has the A specification with a header number of 4 bytes. Similarly, the second monitoring camera 40-2 with the IP address “192.168.0.46” is shown to be B specification having a header number of 12 bytes, and the IP address “192.168.8.0. It is indicated that the third monitoring camera 40-3 of “100” has the C specification without a header.

  Compressed data extracted based on these specifications includes data compressed by the JPEG method or MPEG method. Here, the case of the JPEG method will be described.

  The extracted image data compressed by the JPEG method is sent to the decoding unit 17 via the low-speed bus 21 (S5).

  In the decoding unit 17, image data compressed by the JPEG method is decoded, and pixel data in YCbCr format is sent to the image processing unit 18.

  At this time, in the decoding unit 17, if necessary, the image data of the sampling ratio Y: Cb: Cr = 4: 2: 0 or 4: 2: 1 that is mainly used in the captured image of the monitoring camera has higher image quality. Y: Cb: Cr = 4: 2: 2 may be converted for display.

  In the image processing unit 18, the acquired image data is resized to the image size set in advance in step S <b> 2 and the image quality is adjusted under the control of the image processing control unit 16 c of the CPU 16. At this time, it may be set so that only image data of a specific surveillance camera is reduced.

  In changing the size of the image data, the original image is reduced to 1/2, 1/4, 1/8, or 1/16, for example, based on the setting in step S2, so that the VGA size is changed to the QVGA size. Or change from SXGA size to VGA size.

  In image quality adjustment, monochrome adjustment, γ correction, and the like are performed. At this time, JPEG encoding may be used.

  Image data that has undergone image processing such as size change or image quality adjustment by the image processing unit 18 is sent to the frame memory 19 via the high-speed bus 22 and stored therein.

  The image data stored in the frame memory 19 is read out by the reading unit 20 in accordance with the horizontal / vertical synchronization signal and sent to the display unit 12.

  In the display unit 12, the acquired image data in the YCbCr format is converted into the RGB format, and is displayed on a display device such as a liquid crystal panel by a video encode buffer. Alternatively, it may be converted into a television signal of the NTSC system and displayed on the television device.

  If it is determined in step S4 that the compressed data of the video data is not included in the IP packet (“NO” in S4), it is determined that the control command is used, and control according to the command is performed (S6).

  After the control according to the command is performed, if the display process is not completed (“NO” in S7), the process returns to step S3 and is repeated.

  When the image data is sent to the decoding unit 17 and decoded in step S5, it is determined in the image transfer unit 16e of the CPU 16 whether or not the transfer destination of the image processed image data is designated (S8).

  In the present embodiment, the portable terminal 60 is designated as the transfer destination of the image data subjected to the image processing (“YES” in S8), and the image data reduced by the image processing unit 18 is stored in the image transfer unit 16e of the CPU 16. Under control, the data is transferred from the network interface 13 to the portable terminal 60 via the IP network 30 (S9).

  At this time, the IP address of the portable terminal 60 as the transfer destination is set in advance in the ROM 14, and the transfer destination IP address set in the ROM 14 is acquired by the image transfer unit 16e, and the transfer process is performed.

  Since the reduced image data to be transferred has a low bit rate, it can be transmitted by the low-speed bus 21.

  If the transfer destination of the image data is not specified in step S8 (“NO” in S8) and the display process is not completed (“NO” in S7), the process returns to step S3 and is repeated.

  By transferring the image data to the mobile terminal 60, the user can check the image taken by the monitoring camera on the mobile terminal 60.

  The above process is repeated until the display device 10 receives an instruction to end the display process (S7).

  Further, when the video data recorded on the recorder 50 by the user's operation is played back in time lapse, the display device 10 performs the same processing as described above.

  According to the above-described embodiment, the display control unit transmits high-speed bus that transmits data having a large image size after decoding without being connected to the CPU, and transmits compressed data that is connected to the CPU and has a small image size. Since there is a low-speed bus, even when the number of camera devices connected via the network increases or the network interface speeds up, it does not impose the usage rate of the bus connected to the CPU. The display control process of the received IP packet can be performed.

  Also, by providing a high-speed bus and a low-speed bus in this way, decryption of encrypted IP packets, decapsulation when using tunnel technology, without reducing the usage rate of the bus connected to the CPU, Alternatively, complicated processing such as determination of header information of the IP packet can be performed by the CPU.

  In this embodiment, the case where the present invention is applied to a display control unit provided in a display device as a network decoder device has been described. It is also possible to apply to.

  Further, although the case where the portable terminal is used as the transfer destination of the reduced image data has been described, the present invention is not limited to this, and a personal computer or the like may be used.

It is a block diagram which shows the structure of the monitoring system which has a display control part as a network decoder apparatus by one Embodiment of this invention. It is the example of a setting of (a) transmission source IP address table and (b) transmission source MAC address table which are set to the display control part as a network decoder apparatus by one Embodiment of this invention. It is the example of a setting of (a) multicast IP address table and (b) multicast MAC address table which are set to the display control part as a network decoder apparatus by one Embodiment of this invention. It is a setting example of the protocol table set to the display control part as a network decoder apparatus by one Embodiment of this invention. It is a flowchart which shows operation | movement of CPU of the display control part as a network decoder apparatus by one Embodiment of this invention. It is a block diagram which shows the structure of the conventional monitoring system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Monitoring system 10 ... Display apparatus 11 ... Display control part 12 ... Display part 13 ... Network interface 13a ... Transmission / reception part 13b ... Packet filtering part 14 ... ROM
15 ... RAM
16 ... CPU
16a ... Passing packet setting unit 16b ... Data extraction unit 16c ... Image processing control unit 16d ... Packetization processing unit 16e ... Image transfer unit 17 ... Decoding unit 18 ... Image processing unit 19 ... Frame memory 20 ... Reading unit 21 ... Low speed bus 22 ... High-speed bus 30 ... IP network 40 ... Monitoring camera group 40-1 ... First surveillance camera 40-2 ... Second surveillance camera 40-3 ... Third surveillance camera 40-n ... nth surveillance camera 50 ... Recorder 60 ... Mobile Terminal

Claims (1)

In a network decoder device connected to a content supply device via a network, receiving and decoding packetized compressed content data transmitted from the content supply device, and then outputting the obtained content data.
Each having a first internal bus and a second internal bus having a higher data transfer rate than the first internal bus;
The first internal bus includes
Data receiving means for receiving packetized compressed content data transmitted from the content supply device;
Data extraction means for extracting compressed content data from the received packetized compressed content data;
The extracted compressed content data is input and decoded, and connected to the input side of the decoding means for outputting the obtained content data, respectively,
The second internal bus includes
An output side of the decoding means;
Storage means for storing content data output from the output side of the decoding means;
A network decoder device comprising: a reading means for reading and outputting the stored content data.

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