JP2008085872A - Network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a network system which can generate a PCP packet even in the network system which does not contain dedicated hardware and a sufficient software processing performance. <P>SOLUTION: The network system 0100 records PCP header information added to contents upon transmission in a recode part 0117 without being abrogated. The network system 0100 operates as the transmitter side, and when the network system 0100 transmits the received contents to another DTCP-IP responsive apparatus, it reproduces and transmits the PCP packet from the PCP header information recorded. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a network device that transmits and receives content data in a predetermined data format. In particular, transmission processing can be performed even with low-spec network equipment that does not have dedicated hardware or software processing performance for recognizing the data format at high speed. Network transmission / reception system.

  When a terrestrial / BS / CS digital broadcast content is recorded and the DTCP-IP compatible network device on the sending side has a function to transmit the content to an external device, the device itself transmits the recorded data. In addition, the ARIB standard rule that the data size of the PCP packet is divided into a size corresponding to 0.3 to 2 seconds and transmitted, or the DTCP-IP standard that the PCP packet is divided and transmitted every 128 Mbytes. It is necessary to comply with the rules.

In addition, DTCP-IP compatible network devices on the receiving side that have the function of receiving content from the above devices and outputting them to the video output of a television or the like are PCP packets compliant with the above-mentioned ARIB and DTCP-IP standards. It is designed on the assumption that the PCP packet is received, and may not be compatible with PCP packets that do not comply with the standard.
JP 2001-16227 A (FIG. 1)

  In such background technology, conventional DTCP-IP compatible network devices have dedicated hardware or sufficient software processing performance to recognize or edit the content format at high speed. Although it was easy to generate PCP packets that conform to IP standards, PCP that conforms to ARIB standards and DTCP-IP standards for dedicated hardware or low-function network devices that do not have sufficient software processing performance It was difficult to generate a packet.

  Therefore, an object of the present invention is to provide a network device capable of generating a PCP packet even for a network device that does not have dedicated hardware or sufficient software processing performance.

  In order to solve the above-described problems, the present invention provides a network device that receives content data transmitted from a transmitting device that transmits data based on a data format that conforms to the DTCP-IP standard via a network. Recording means for recording the PCP header information added to the content data to be transmitted as it is, and reproducing the PCP packet from the PCP header information of the content recorded in the recording means when the network device operates as the transmitter side And transmitting means for transmitting in the same manner.

  Further, in order to solve the above-mentioned problems, the transmission means generates and transmits one PCP packet from a plurality of PCP data when transmitting received content to another DTCP-IP compatible device. is there.

  A PCP packet can be generated even in a network device that does not have dedicated hardware or sufficient software processing performance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[System configuration when receiving]
FIG. 1 is a system configuration diagram when the network device of this embodiment operates as a receiver side. Reference numeral 0100 denotes a main body of the receiver, and reference numerals 0111 to 0117 denote system configurations in the receiver 0100. Reference numeral 0121 denotes a transmitter compatible with DTCP-IP. Reference numeral 0131 indicates content transmitted from the transmitter 0121 to the receiver 0100. The communication unit 0111 is for transmitting / receiving data to / from an external network device connected to the network. Transmission data transmitted by the transmitter 0121 is input from the communication unit 0111 into the receiver 0100.

  The reception buffer 0112 is a buffer for recording received data. Data received by the communication unit 0111 is sequentially recorded in the reception buffer 0112.

  The decryption processing unit 0113 is a part that performs AES encryption decryption. When the received data recorded in the reception buffer 0112 is a PCP packet, the decryption processing unit communication unit 0113 decrypts the AES cipher applied to the PCP data portion in the PCP packet.

  The decoding buffer 0114 is a buffer for recording the PCP packet decoded by the decoding processing unit 0113. The encryption processing unit 0115 is for performing encryption processing for preventing unauthorized copying of received content. The encryption processing unit 0115 encrypts the PCP data portion in the PCP packet recorded in the decryption buffer 0114. The recording buffer 0116 is a buffer for recording the PCP packet encrypted by the encryption processing unit 0115 in the recording unit 0117.

  The recording unit 0117 is an external storage device having a nonvolatile recording medium such as a hard disk. The recording unit 0117 divides the PCP packet recorded in the recording buffer 0116 into a PCP data part and a PCP header part and records them in a format as shown in FIGS. The processing flow of the recording unit 0117 at this time is shown in FIG.

[System configuration during transmission]
FIG. 2 is a system configuration diagram when the network apparatus according to the present embodiment operates on the transmitter side. Reference numeral 0200 denotes a main body of the transmitter, and reference numerals 0211 to 0217 denote system configurations in the transmitter 0200. Reference numeral 0221 denotes a receiver compatible with DTCP-IP. Reference numeral 0231 denotes content that the transmitter 0200 transmits to the receiver 0221. It is assumed that the content 0231 is recorded in the recording unit 0217 in the format shown in FIGS.

  The recording unit 0217 is an external storage device having a nonvolatile recording medium such as a hard disk. When transmitting the content, the recording unit 0217 reads the PCP data portion and the PCP header portion, generates a PCP packet, and records it in the read buffer 0216. The processing flow of the recording unit 0217 at this time is shown in FIG.

  The read buffer 0216 is a buffer for recording the PCP packet generated by the recording unit 0217.

  The decryption processing unit 0215 is for performing decryption processing of the encryption applied to prevent unauthorized copying of content. The decryption processing unit 0215 decrypts the encryption applied to the PCP data portion of the PCP packet recorded in the read buffer 0216 and records it in the decryption buffer 0214. The decoding buffer 0214 is a buffer for recording the PCP packet decoded by the decoding processing unit 0215.

  The encryption processing unit 0213 is a part that performs AES encryption processing. The PCP data portion of the PCP packet recorded in the decryption buffer 0214 is encrypted with the AES encryption and recorded in the transmission buffer 0212. The transmission buffer 0212 is a buffer for recording the PCP packet encrypted by the encryption processing unit 0213 for transmission.

  The communication unit 0211 is for transmitting / receiving data to / from an external network device connected to the network. The PCP packet for transmission recorded in the transmission buffer 0212 is output from the communication unit 0211 to the network and transmitted to the receiver 0221.

[PCP packet]
FIG. 3 shows a format for one PCP packet. A network device compliant with the DTCP-IP standard transmits and receives content in this PCP packet format. E-EMI0311 indicates copy control information, and indicates restriction information related to content copying such as copy free / copy once / copy prohibited. E-EMI may change during transmission depending on the content.

  The Exchange key label is 0312, a key identification number called a DTCP-IP exchange key. Nc0513 is a value updated at the timing of switching the encryption key. Nc is a value that changes during content transmission, and is updated every 128 MB of content. Content length 0314 indicates the size of the content stored in the PCP data 0321 portion. Content length 0314 is defined as 128 Mbytes in the DTCP-IP standard. However, in the ARIB standard, the PCP data size is limited to a range equivalent to 0.3 to 2 seconds due to the interoperability between devices, so DTCP-IP communication with devices that support the ARIB standard In this case, it is necessary to follow the ARIB rule of 0.3 to 2 seconds. The PCP data size when following the ARIB rule of 0.3 to 2 seconds is as shown in FIG.

  The size 0320 of the PCP data part is always a multiple of 16. For this reason, the size 0320 of the PCP data portion and the content length 0314 may not match. This is a size obtained by adding the size 0300 of one PCP packet, the size 0310 14 bytes of the PCP header portion, and the size 0320 of the PCP data portion.

[PCP data size]
FIG. 4 is a table showing the PCP data size when a PCP packet is divided according to the ARIB standard. For example, when a transmitter conforming to the ARIB standard transmits 16 Mbps content by DTCP-IP communication, the PCP data size needs to be in the range of 0.60 to 4.00 Mbytes.

[received data]
FIG. 5 shows the PCP data size when a PCP packet is divided according to the ARIB standard. For convenience of explanation of the embodiment, the content size is 512 Mbytes, and the bit rate is 16 Mbps (bit / second). In this case, when the transmitter divides the PCP packet with a fixed length of 2 Mbytes, the format is as shown in FIG.

  In the figure, reference numerals 0311 to 0318, 0321 to 0328, 0331 to 0338, and 0341 to 0348 indicate the state of the PCP packet divided into 1 packet and 2 Mbytes. The detailed format for one PCP packet is shown in FIG. Reference numerals 0310, 0320, 0330, and 0340 in the figure indicate PCP packet groups that are divided every 128 Mbytes according to the rules of the DTCP-IP standard.

[PCP data group]
FIG. 6 shows a PCP data group and its format used when the network device of this embodiment operates as the receiver 0100, or when the network device of this embodiment operates as the transmitter 0200. . This PCP data group is recorded in the recording unit 0117/0217. For example, when the receiver 0100 receives the data shown in FIG. 3, the PCP data group shown in FIG. 6 is recorded in the recording unit 0117.

[PCP header information group]
FIG. 7 shows a PCP header information group and its format used when the network device of this embodiment operates as the receiver 0100, or when the network device of this embodiment operates as the transmitter 0200. Yes. This PCP header information group is recorded in the recording unit 0117/0217. For example, when the receiver 0100 receives the data shown in FIG. 3, the PCP header information group shown in FIG.

  It should be noted that the address of the PCP data storage destination corresponding to the PCP header is also shown in the second column of FIG. 7 so that a PCP packet can be generated by combining the PCP data corresponding to the PCP header information at the time of transmission. Record it.

[Transmission data]
FIG. 8 shows an example of transmission data when the network device of this embodiment transmits content. Since the network device of this embodiment regenerates the PCP packet from the PCP header information and PCP data recorded when operating as a receiver, each PCP packet size at the time of transmission is the same as that at the time of reception. Become.

[Flow when receiving]
FIG. 9 shows a processing flow of the recording unit 0117 when the network device of this embodiment operates as the receiver side. By executing the processing steps 0901 to 0905, the received PCP packet is recorded separately into a PCP data portion and a PCP header portion. In process step 0901, the PCP packet is read from the recording buffer. In process step 0902, it is determined whether or not the PCP packet has been read in process step 0901. If the PCP packet cannot be read, the process returns to processing step 0901.

  In process step 0903, the PCP data portion in the PCP packet is recorded in the recording unit 0117. The PCP data recorded here is recorded in a format as shown in FIG. In processing step 0904, the PCP header part in the PCP packet and the address of the PCP data recorded in preprocessing step 0903 are recorded in the recording unit 0117. The PCP header and PCP data addresses recorded here are recorded in a format as shown in FIG. In process step 0905, the process returns to the first process step 0901, and the process is repeated from the beginning.

[Flow when sending]
FIG. 10 shows a processing flow of the recording unit 0217 when the network device of the present embodiment operates on the transmitter side. By executing the processing steps 1001 to 1005, a PCP packet for transmission is regenerated from the separately recorded PCP data portion and PCP header portion. In process step 1001, the PCP header and the address of the PCP data corresponding to the PCP header are read from the recording unit 0217. In processing step 1002, it is determined whether or not the PCP header has been read in processing step 1001. If the PCP header cannot be read, the processing of this processing flow ends. In process step 1003, PCP data is read from the recording unit 0217. The PCP data storage address is the PCP data address read in processing step 1001.

  In process step 1004, the PCP header and PCP data that have been read out are combined to generate a PCP packet. The generated PCP packet is recorded in the read buffer 0216. The PCP packet recorded here is recorded in the read buffer 0216 in the format shown in FIG. In process step 1005, the process returns to the first process step 1001, and the process is repeated from the beginning.

  As described above, the present embodiment has been described. However, in consideration of the interoperability with devices conforming to the ARIB standard and the overhead for cryptographic processing generated when the transmitter generates a PCP packet, the PCP data size Is a size corresponding to 0.3 to 2 seconds and is desirably as large as possible. For example, when transmitting 16 Mbps content, overhead such as encryption processing is reduced by dividing PCP data every 4 Mbytes as shown in FIG. 11 rather than dividing PCP data every 2 Mbytes as shown in FIG. it can. In addition, since the network device of the present embodiment records PCP header information at the time of reception, it is possible to generate one PCP packet from a plurality of PCP data using the PCP header information at the time of transmission.

As described above, the network device of the present embodiment records the PCP header information at the time of content reception without discarding when operating as the receiver side, and records it when operating as the transmission side. Since the PCP packet is generated by using the PCP header information, the content can be transmitted without identifying or editing the content format (MPEG2 TS or the like) at the time of content transmission.

  In addition, since one PCP packet can be generated from multiple PCP data using the recorded PCP header information, overhead such as encryption processing that occurs every time one PCP packet is processed is reduced. Can do.

  Therefore, dedicated hardware or low-spec network devices that do not have sufficient software processing performance to recognize or edit content formats at high speed can interact with network devices that comply with the ARIB and DTCP-IP standards. Connection can be realized.

1 is a system configuration diagram when a network device showing an embodiment of the present invention operates as a receiver side. FIG. It is a system configuration | structure figure at the time of the network device in the embodiment operating as a transmitter side. The format is one PCP packet. It is the figure which showed the PCP data size in the case of dividing | segmenting a PCP packet according to ARIB specification. It is an example of a PCP data size when a PCP packet is divided according to the ARIB standard. The PCP data group used when the network apparatus of this embodiment operate | moves as a transmission or a receiver, and its format diagram. The PCP data group used when the network apparatus of this embodiment operate | moves as a transmission or a receiver, and its format diagram. An example of transmission data when the network device of the present embodiment transmits content. The processing flow of a recording part when the network apparatus of this embodiment operate | moves as a receiver side. The processing flow of a recording part when the network apparatus of this embodiment operate | moves as a transmitter side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 0100 ... Network receiver, 0111 ... Communication part, 0112 ... Reception buffer, 0113 ... Decryption process, 0114 ... Decryption buffer, 0115 ... Encryption process, 0116 ... Recording buffer, 0117 ... Recording part, 0121 ... Transmitter, 0131 ... Content.

Claims (2)

In a network device that receives content data transmitted from a transmitting device that transmits data based on a data format conforming to the DTCP-IP standard via a network,
Recording means for directly recording the PCP header information added to the content data transmitted from the transmitting device;
A network device, comprising: a transmission unit that reproduces and transmits a PCP packet from PCP header information of content recorded in the recording unit when the network device operates as a transmitter. 2. The network apparatus according to claim 1, wherein the transmitting unit generates and transmits one PCP packet from a plurality of PCP data when transmitting the received content to another DTCP-IP compatible device.

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