JP3974443B2 - Recording / reproducing apparatus and recording / reproducing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a recording / reproducing apparatus.And recording / reproducing methodAbout.
[0002]
[Prior art]
FIG. 7 is a block diagram showing a configuration of a conventional recording / reproducing apparatus for recording and reproducing an MPEG (Moving Picture Experts Group) transport stream (hereinafter referred to as MPEG-TS). In the conventional recording / reproducing apparatus shown in FIG. 7, in the recording system 101, MPEG-TS from an external digital device is first supplied to the header detector 112. Then, the header detector 112 detects a periodic byte arranged at the head of the header, and generates a packet synchronization signal indicating the head of the packet. Next, the packet size detector 113 detects the packet size based on the interval between two consecutive headers in the MPEG-TS. The header decoder 114 reads out header information necessary for recording control and reproduction control from the header. After passing through the header detector 112, the packet size detector 113, and the header decoder 114, the MPEG-TS is recorded on the recording medium 115.
[0003]
The packet size and header information are supplied from the packet size detector 113 and the header decoder 114 to the control device 111, and recorded on the recording medium 115 as a parameter file separately from the MPEG-TS data.
[0004]
On the other hand, in the playback system 102, MPEG-TS data is output from the recording medium 115 based on the control of the control device 111, a parameter file is read, and information included in the parameter file is used. MPEG-TS is played back.
[0005]
That is, in the conventional recording / reproducing apparatus, the MPEG-TS is recorded as it is on the recording medium 115 and is reproduced from the recording medium 115 as it is.
[0006]
Such a conventional recording / playback device is realized by connecting peripheral devices and various boards to a personal computer when used in the development of video equipment or in creating a data stream for testing at a broadcasting station. As the recording medium 115, a recording medium 115 that can be used by a personal computer such as a hard disk or a CD (Compact Disc) -R is often used.
[0007]
[Problems to be solved by the invention]
As described above, in the conventional recording / reproducing apparatus, since a recording medium such as a hard disk that is easily removable is used as a recording medium for recording a data stream such as MPEG-TS, a data stream such as MPEG-TS is used. Secondary use of the content becomes easy, and there is a problem that the content in the data stream may be illegally copied to infringe copyright. This problem is particularly noticeable in the broadcasting industry because test data streams are frequently required.
[0008]
Note that there are mainly the following three methods for restricting secondary use of a copyrighted work. However, of the following three methods, the first and second methods are methods used for general consumer products, and the data signal is changed according to the generation of the reproduced data stream. By detecting the change, unauthorized duplication is suppressed.
[0009]
(1) A first method using a limited reception (CAS) function employed in BS digital broadcasting or the like.
[0010]
(2) A second method according to a copy protection standard such as IEEE1394.
[0011]
(3) A third method for encrypting a data stream such as MPEG-TS as it is.
[0012]
However, these three methods have not been adopted for the following reasons in the development of equipment such as video / audio equipment and the conventional recording / playback apparatus for business use in the broadcasting industry.
[0013]
Regarding the first method, since it is necessary to test not only ordinary MPEG-TS but also various data streams such as original data at the time of device development, a CAS function that requires registration with a management company and a communication function is required. Is not suitable for business use.
[0014]
As for the second method, in order to use a standardized copy protection function such as IEEE 1394, it is necessary to incorporate a circuit compliant with the standard, which complicates the apparatus and increases the cost of the apparatus.
[0015]
Regarding the third method, it is difficult to determine what the original data stream is from the encrypted data, and the configuration of the data stream recorded on the recording medium is used for testing. It becomes difficult to edit to create a data stream, and is not suitable for business use that requires a test data stream.
[0016]
  The present invention has been made in view of the above problems, and records a data stream on a recording medium in a state suitable for use in a business application, and illegal duplication of contents in the data stream recorded on the recording medium. Recording / reproducing apparatus capable of suppressingAnd recording / reproducing methodThe purpose is to obtain.
[0017]
[Means for Solving the Problems]
  In order to solve the above-described problem, the recording / reproducing apparatus of the present invention includes a first header / payload separating unit that separates a packet in a data stream into a header and a payload, and a part or all of the packets in the data stream. The first header / payload separating means separates the header and the encryption means for encrypting the payload of the payload, and the header and the payload encrypted by the encrypting means are combined into a first packet Header / payload combining means, first control means for recording packets generated by the first header / payload combining means on a recording medium, and second control means for outputting a data stream recorded on the recording medium The packet in the data stream output from the recording medium, the header and the encrypted payload A second header / payload separating unit that separates the header and a payload separated by the second header / payload separating unit, and a decrypting unit that decrypts the encrypted payload of the encrypted payload; A header and a payload obtained by decoding by the decoding means are combined to form an original packet, and a second header / payload combining means for reproducing the data stream is provided.The data stream is an MPEG transport stream, and the encryption means includes a payload including information on one or more streams included in the data stream among the payloads of a plurality of packets in the MPEG transport stream. Only payloads other than the payload, that is, payloads other than the payload including the program association table are encrypted.
[0018]
Furthermore, the recording / reproducing apparatus of the present invention, in addition to the recording / reproducing apparatus of the present invention,The encryption means encrypts only the payload other than the payload including the program association table or the program map table among the payloads of the plurality of packets in the MPEG transport stream.It is what I did.
[0019]
Furthermore, the recording / reproducing apparatus of the present invention, in addition to the recording / reproducing apparatus of the present invention,The encryption means encrypts only the payload other than the payload including the program association table or the program map table, and the packet ID of each elementary stream in the program map table.It is what I did.
[0020]
The recording / reproducing method of the present invention includes a step of separating a packet in a data stream into a header and a payload, and a step of encrypting the payload in the separated header and payload for some or all of the packets in the data stream. And a step of combining the header and the encrypted payload to form a packet, a step of recording a packet generated from the header and the encrypted payload on a recording medium, and a step of reading the packet recorded on the recording medium. Separating the packet read from the recording medium into a header and an encrypted payload, decrypting the encrypted header of the separated header and the encrypted payload, and decoding the header and And the original packet And a step of reproducing the data stream, wherein the data stream is an MPEG transport stream, and the encrypting step includes a data stream included in a plurality of packet payloads in the MPEG transport stream. Only the payload other than the payload including information on one or more streams to be performed, that is, the payload other than the payload including the program association table is encrypted.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0028]
Embodiment 1 FIG.
The recording / reproducing apparatus according to Embodiment 1 of the present invention includes a recording apparatus 1 (see FIG. 1) that partially encrypts an input data stream and records the partially encrypted data stream on the recording medium 2, and It has a playback device 3 (see FIG. 3) that decrypts the encrypted portion of the data stream recorded on the recording medium 2 and plays back the original data stream. As the recording medium 2, a hard disk device, a writable DVD such as a DVD (Digital Versatile Disc) -R, a writable CD such as a CD-R, or the like is used. In the case of a portable recording medium 2 such as a DVD, a drive device capable of reading and writing data is added to the recording medium 2 to be used. In addition, when editing the data stream recorded on the recording medium 2, among rewritable DVD and CD, rewritable DVD-RW, DVD + RW, DVD-RAM, CD-RW, etc. are recorded. Used as medium 2. Further, for example, a recording medium 2 of another recording / reproducing system such as an MO (Magneto Optic) disk, a semiconductor storage device (flash memory, etc.) may be used.
[0029]
FIG. 1 is a block diagram showing a configuration of a recording apparatus 1 in a recording / reproducing apparatus according to Embodiment 1 of the present invention. In FIG. 1, a control device 11 controls each part based on various signals and information from a header detector 12, a packet size detector 13 and a header decoder 14, and relates to MPEG-TS supplied to this device. This is a circuit for recording information used at the time of editing and reproduction on the recording medium 2 as a parameter file.
[0030]
The control device 11 is a circuit that records a series of packets generated by the header / payload synthesizer 18 on the recording medium 2 as a stream of recording data. The control device 11 is a first control means in the recording / reproducing apparatus according to the first embodiment.
[0031]
The header detector 12 detects a period byte provided in the header of each packet in the data stream, and based on the appearance period of the header byte, the presence / absence of input and whether the supplied data stream is MPEG-TS. It is a circuit that determines whether or not.
[0032]
MPEG-TS is an example of a packetized data stream, and has one or more elementary streams including video and audio data converted by the MPEG system such as MPEG2 and MPEG4 in the payload. MPEG-TS is an ITU-T recommendation H.264 standard. 222.0 and ISO / IEC13818-1. FIG. 2 is a diagram showing the structure of a normal MPEG-TS packet. As shown in FIG. 2, a normal packet of MPEG-TS is composed of 188 bytes, of which a header 51 is composed of 4 bytes, and the rest is a payload 52. In MPEG-TS, a packet may be 204 bytes or 208 bytes. In addition, an adaptation field that is an extension may be added to the header 51. In this case, the payload is shortened by the size of the adaptation field.
[0033]
As shown in FIG. 2, the header 51 is composed of various fields. The cycle byte 61 has a value of “0x47” (“0x” indicates a hexadecimal number) and indicates the head of the packet. The error indicator 62 indicates whether an error that cannot be corrected has occurred in this packet. The start indicator 63 indicates whether or not this packet is the head packet of the elementary stream. The priority 64 has a value of 0 or 1, and indicates the priority of the packet. A packet ID (PID) 65 indicates an attribute of data in the payload 52. The scramble control 66 indicates whether or not to allow scramble. An adaptation field (AF) control 67 indicates whether there is an adaptation field and / or payload after the header 51. The continuity counter 68 is incremented for each packet having the same PID and indicates the continuity of the packet.
[0034]
The packet size detector 13 is a circuit that measures the interval between two consecutive headers and detects the packet size.
[0035]
The header decoder 14 is a circuit that decodes the header of each packet in the data stream and outputs header information. The header information includes the size of the header part. The header part is composed of only a normal header or a header and a header extension part. In the case of MPEG-TS, a normal header is 4 bytes, and when a header extension is present, the header size becomes larger than 4 bytes. Further, the header decoder 14 may generate a separation control signal described later instead of the control device 11 and may be a part of the header information.
[0036]
The header / payload separator 15 is a circuit that separates a packet in the data stream into a header and a payload. The header / payload separator 15 is a first header / payload separator in the recording / reproducing apparatus according to the first embodiment.
[0037]
The encryptor 16 is a circuit that encrypts the payload of the header and payload separated by the header / payload separator 15 for some or all of the packets in the data stream. The encryptor 16 is an encryption unit in the recording / reproducing apparatus according to the first embodiment.
[0038]
The delay unit 17 is a circuit that delays the header separated by the header / payload separator 15 by a time required for encryption of the payload by the encryptor 16 and supplies the delayed header to the header / payload combiner 18.
[0039]
The header / payload synthesizer 18 is a circuit that synthesizes the header and the payload encrypted by the encryptor 16 into a packet. The first header / payload combining means in the recording / reproducing apparatus according to the first embodiment.
[0040]
When the recording device 1 is realized using a computer, a CPU that executes a program describing functions similar to those of the control device 11 is used instead of the control device 11. In this case, the header detector 12, the packet size detector 13, the header decoder 14, the header / payload separator 15, the encryptor 16, the delay 17 and the header / payload synthesizer 18 are connected to a bus inside the computer, for example. An expansion board connected via Alternatively, instead of the header detector 12, the packet size detector 13, the header decoder 14, the header / payload separator 15, the encryptor 16, the delay 17 and the header / payload synthesizer 18, the same functions are described. A CPU for executing the program is used.
[0041]
When various functions are realized by executing the program by the CPU as described above, the CPU executing the program is not limited to the first control means, the first header / payload separation means, the encryption means, 1 header / payload combining means. Some of these means may be realized by a CPU and a program, and the rest may be realized by a dedicated circuit.
[0042]
FIG. 3 is a block diagram showing the configuration of the playback apparatus 3 in the recording / playback apparatus according to Embodiment 1 of the present invention. In FIG. 3, the control device 31 is a circuit that reads a parameter file from the recording medium 2 and controls each unit based on information in the parameter file and header information from the header decoder 32.
[0043]
The control device 31 is a circuit that outputs the data stream recorded on the recording medium 2 from the recording medium 2. The control device 31 is a second control means in the recording / reproducing device according to the first embodiment.
[0044]
The header decoder 32 is configured similarly to the header decoder 14 and is a circuit that decodes the header of each packet in the data stream and outputs header information. The header information includes the header size of each packet.
[0045]
The header / payload separator 33 is a circuit that separates the packet of the data stream output from the recording medium 2 into a header and an encrypted payload. The header / payload separator 33 is a second header / payload separator in the recording / reproducing apparatus according to the first embodiment.
[0046]
The decryptor 34 is a circuit that decrypts the encrypted payload of the header and the encrypted payload separated by the header / payload separator 33. The decoder 34 is a decoding means in the recording / reproducing apparatus according to the first embodiment.
[0047]
The delay unit 35 is a circuit that delays the header separated by the header / payload separator 33 by a time required to decrypt the encrypted payload by the decryptor 34 and supplies the delayed header to the header / payload synthesizer 36. .
[0048]
The header / payload combiner 36 combines the header and the payload decoded by the decoder 16 into an original packet, and reproduces the original data stream (that is, the data stream input to the recording apparatus 1). Circuit. The header / payload combiner 36 is a second header / payload combiner in the recording / reproducing apparatus according to the first embodiment.
[0049]
Note that when the playback device 3 is realized using a computer, a CPU that executes a program describing functions similar to those of the control device 31 is used instead of the control device 31. In this case, the header decoder 32, header / payload separator 33, decoder 34, delay unit 35, and header / payload synthesizer 36 are, for example, expansion boards connected via a bus inside the computer. . Alternatively, instead of the header decoder 32, the header / payload separator 33, the decoder 34, the delay unit 35, and the header / payload synthesizer 36, a CPU that executes a program describing functions similar to those is used.
[0050]
When various functions are realized by executing the program by the CPU as described above, the CPU executing the program has the second control means, the second header / payload separating means, the decoding means, 2 header / payload combining means. Some of these means may be realized by a CPU and a program, and the rest may be realized by a dedicated circuit.
[0051]
The control device 11 of the recording device 1 and the control device 31 of the playback device 3 may be the same control means. In that case, the control means may be realized as a dedicated circuit, or the control means may be realized by executing a program describing the functions of both the control device 11 and the control device 31 by the CPU.
[0052]
Next, the operation of the recording / reproducing apparatus according to the first embodiment will be described.
[0053]
First, the operation of the recording apparatus 1 of the recording / reproducing apparatus will be described. FIG. 4 is a timing chart for explaining the operation of the recording apparatus 1 in the recording / reproducing apparatus according to the first embodiment.
[0054]
In the recording apparatus 1, for example, MPEG-TS as shown in FIG. 4A is supplied to the header detector 12 from the outside. In the MPEG-TS, the header detector 12 detects a periodic byte 61 periodically arranged at the head of each packet header to accurately detect the head portion of each packet, and indicates the head of each packet. A packet synchronization signal is supplied to the control device 11. Based on this packet synchronization signal, the control device 11 recognizes the head of each packet. In FIG. 4A, “H” represents a normal header, “A” represents an extension portion (adaptation field) of the header, and “P” represents a payload.
[0055]
Next, the MPEG-TS is supplied to the packet size detector 13. The packet size detector 13 detects the size of the packet and supplies it to the control device 11.
[0056]
Further, the MPEG-TS is supplied to the header decoder 14. The header decoder 14 extracts header information by decoding the header of each packet and supplies the header information to the control device 11.
[0057]
Based on the header size included in the header information and the packet size from the packet size detector 13, the control device 11 specifies the length of the header and the length of the payload and generates a separation control signal, and MPEG-TS And is supplied to the header / payload separator 15. For example, as shown in FIG. 4B, this separation control signal has a first value (here, “L” in the figure, “L”) in the period corresponding to the header, and other periods (that is, in the payload). In the corresponding period), the second value (here, high level, “H” in the figure) is set.
[0058]
When the separation control signal is generated by the header decoder 14, the separation control signal is sent from the header decoder 14 directly or via the control device 11 in synchronization with the MPEG-TS. It is supplied to the separator 15.
[0059]
When the MPEG-TS and the separation control signal are supplied, the header / payload separator 15 supplies the MPEG-TS data during the period in which the separation control signal is the first value to the delay unit 17 as a header, and performs the separation control. MPEG-TS data in a period in which the signal is the second value is supplied to the encryptor 16 as a payload.
[0060]
Then, for example, as shown in FIG. 4C, the delay unit 17 holds the header for the time Te required for the encryption of the payload by the encryption unit 16 and then supplies it to the header / payload combiner 18.
[0061]
On the other hand, the encryptor 16 encrypts the payload using a predetermined encryption method, and supplies the encrypted payload to the header / payload combiner 18. At this time, for example, as shown in FIG. 4D, the payload is delayed by time Te due to encryption. In FIG. 4D, “P” represents a payload before encryption, and “EP” represents a payload after encryption. If the encrypted payload is shorter than the unencrypted payload, the encryptor 16 adds stuffing data (data not particularly meaningful in the contents) by the difference between the two, Make the size the same.
[0062]
Therefore, immediately after the header of a packet is supplied from the delay unit 17 to the header / payload synthesizer 18, the encrypted payload of the packet is supplied from the encryptor 16 to the header / payload synthesizer 18.
[0063]
For example, as shown in FIG. 4E, the header / payload combiner 18 combines the header from the delay unit 17 and the encrypted payload from the encryptor 16 into a packet.
[0064]
Then, the control device 11 records the packets generated by synthesizing the header and the encrypted payload from the encryptor 16 in order on the recording medium 2 as a stream of recording data. When the writing speed to the recording medium 2 is slower than the MPEG-TS data rate, the header / payload synthesizer 18 is provided with storage means such as a memory, and the recording data is buffered in the storage means. Also good.
[0065]
On the other hand, the control device 11 records the packet size, header information, etc. on the recording medium 2 as a parameter file.
[0066]
Next, the operation of the playback device 3 of the recording / playback device will be described.
[0067]
The recording medium 2 stores a data stream generated by partially encrypting the MPEG-TS as described above by the recording apparatus 1 and a parameter file related to the MPEG-TS.
[0068]
First, the control device 31 reads a parameter file from the recording medium 2 and acquires information such as a packet size. Then, the control device 31 causes the data stream to be output from the recording medium 2. Since the data stream in the recording medium 2 is recorded from the beginning of the packet, a header detector such as the header detector 12 of the recording device 1 is not particularly necessary for the reproducing device 3. Further, since the packet size of the data stream recorded on the recording medium 2 is separately recorded in the parameter file, a packet size detector such as the packet size detector 13 of the recording device 1 is not included in the reproducing device 3. Not particularly necessary.
[0069]
The data stream output from the recording medium 2 is supplied to the header decoder 32. The header decoder 32 extracts the header information by decoding the header of each packet of the data stream, and supplies the header information to the control device 31.
[0070]
Based on the header size included in the header information and the packet size included in the parameter file, the control device 31 specifies the length of the header and the length of the payload, generates a separation control signal, and outputs it from the recording medium 2 The data is supplied to the header / payload separator 33 in synchronization with the data stream. This separation control signal has a first value in the period corresponding to the header and a second value in the other period (period corresponding to the payload).
[0071]
When the separation control signal is generated by the header decoder 32, the separation control signal is sent from the header decoder 32 directly or via the control device 31, and the header / payload is synchronized with the data stream. It is supplied to the separator 33.
[0072]
When the data stream and the separation control signal are supplied, the header / payload separator 33 supplies the data of the data stream in the period in which the separation control signal is the first value to the delay unit 35 as a header, and performs the separation control. Data of the data stream during the period when the signal is the second value is supplied to the decryptor 34 as an encrypted payload.
[0073]
The delay unit 35 holds the header for the time Td required for decryption of the encrypted payload by the decryptor 34 and then supplies the header to the header / payload combiner 36.
[0074]
On the other hand, the decryptor 34 decrypts the payload by a decryption method corresponding to the encryption method used by the encryptor 16, and the original (that is, before encryption) payload is a header / payload synthesizer. 36. At this time, the payload is delayed by time Td due to decoding.
[0075]
Therefore, immediately after the header of a packet is supplied from the delay unit 35 to the header / payload synthesizer 36, the payload of the packet is supplied from the decoder 34 to the header / payload synthesizer 36.
[0076]
The header / payload synthesizer 36 synthesizes the header from the delay unit 35 and the payload from the decoder 34 into an MPEG-TS packet and outputs it in order. As a result, the MPEG-TS is reproduced from the data stream recorded on the recording medium 2.
[0077]
In the first embodiment, the same encryption key is used when encrypting a plurality of packets in the data stream. However, any one of the plurality of encryption keys is used for the payload of each packet. You may make it select and encrypt. For example, the encryption key may be different for each packet ID, and for the payload including the MPEG-TS program specification information, an encryption key different from other payloads may be used.
[0078]
As described above, according to the first embodiment, in the recording apparatus 1, the header / payload separator 15 separates the packet in the data stream into the header and the payload, and the encryptor 16 The header and payload of the payload separated by the header / payload separator 15 are encrypted, and the header / payload synthesizer 18 encrypts the header and the payload encrypted by the encryption means. And the control device 11 records the packet generated by the header / payload combiner 18 on the recording medium 2. In the playback device 3, the control device 31 outputs the data stream recorded on the recording medium 2, and the header / payload separator 33 converts the packet in the data stream output from the recording medium 2 to the header and the encryption. The decryptor 34 decrypts the encrypted payload of the header and the encrypted payload separated by the header / payload separator 33, and the header / payload synthesizer 36. However, the header and the payload obtained by decoding by the decoder 34 are combined into an original packet to reproduce the data stream.
[0079]
As a result, a data stream is recorded on the recording medium 2 in a state suitable for business use without using a copy guard based on other standards, and illegal copying of contents such as video and audio in the data stream is performed. Can be suppressed. That is, even if there is no encryption key necessary for decrypting the payload, the type of data stream before encryption, the boundary between packets, the data rate of the data stream, time information, etc. are identified based on the header. The configuration of the data stream can be edited for business use. On the other hand, since the content in the payload is encrypted by the recording device 1, the content recorded on the recording medium 2 cannot be reproduced even if the recording medium 2 is removed from this device and illegally attached to another device. Have difficulty.
[0080]
Embodiment 2. FIG.
The recording / reproducing apparatus according to Embodiment 2 of the present invention also encrypts and decrypts a payload including information on one or more streams (elementary streams) included in the data stream in addition to the header in the data stream. This is what I did not.
[0081]
In MPEG-TS, program specification information (PSI) is stored in the payloads of a plurality of packets as information about elementary streams included in MPEG-TS. The program specification information includes a program association table (PAT), a program map table (PMT), a network information table (NIT), and a conditional access table (CAT).
[0082]
The PAT holds a correspondence relationship between a program number composed of one or a plurality of elementary streams and a PID value of a packet including the PMT.
[0083]
The PMT holds the types of elementary streams such as video and audio that make up the program, the PID values of the packets that make up each elementary stream, and the like.
[0084]
In MPEG-TS, the PID of a packet including a PAT is defined as “0x0000”. Further, the PID of the packet including the PMT is defined by the PAT. Further, the PID of a packet including NIT is defined by PAT, and the PID of a packet including CAT is defined as “0x0001”.
[0085]
The basic configuration of the recording / reproducing apparatus according to the second embodiment is the same as that of the first embodiment, but the following functions are added to the recording apparatus 1 and the reproducing apparatus 3.
[0086]
Next, the operation of the recording / reproducing apparatus according to the second embodiment will be described.
[0087]
In the recording device 1, the header decoder 14 decodes the header of each packet, detects the PID of each packet, and supplies it to the control device 11 as part of the header information.
[0088]
Further, the header decoder 14 of the recording device 1 detects a packet including a PAT based on the PID of the packet, and when detecting a packet including the PAT, supplies the PAT to the control device 11 together with header information. When supplied with the PAT, the control device 11 analyzes the PAT and determines one or a plurality of PIDs of the packet including the PMT.
[0089]
And the control apparatus 11 specifies the packet containing PAT or PMT based on PID of each packet from the header decoder 14, and controls the encryption device 16 so that the payload of these packets is not encrypted. However, even when the payload is not encrypted in order to synchronize the header and the payload, the encryptor 16 delays the PAT or PMT after delaying by the same time as the delay time Te in the delay device 17. The included payload is supplied to the header / payload synthesizer 18.
[0090]
Thereby, the data stream generated by encrypting only the payload of the packet other than the packet including the PAT or the PMT in the MPEG-TS is recorded on the recording medium 2.
[0091]
On the other hand, in the playback device 3, the header decoder 32 decodes the header of each packet, detects the PID of each packet, and supplies it to the control device 31 as part of the header information.
[0092]
Further, the header decoder 32 of the reproducing device 3 detects a packet including a PAT based on the PID of the packet, and when detecting a packet including the PAT, supplies the PAT to the control device 31 together with header information. When supplied with the PAT, the control device 31 analyzes the PAT and determines one or a plurality of PIDs of the packet including the PMT.
[0093]
And the control apparatus 31 specifies the packet containing PAT or PMT based on PID of each packet from the header decoder 32, Since the payload of these packets is not encrypted, it decodes with respect to those payloads The decoder 34 is controlled not to perform. However, even if the payload is not decoded in order to synchronize the header and the payload, the decoder 34 delays the PAT or PMT after delaying by the same time as the delay time Td in the delay device 35. The included payload is supplied to the header / payload synthesizer 36.
[0094]
Since the other operations of the recording / reproducing apparatus according to the second embodiment are the same as those in the first embodiment, the description thereof is omitted.
[0095]
In the recording / reproducing apparatus according to the second embodiment, among the payloads of packets in MPEG-TS, payloads other than payloads including PAT or PMT are encrypted and decrypted, but PAT, PMT, Only the payload other than the payload including either NIT or CAT may be encrypted and decrypted.
[0096]
In the recording / reproducing apparatus according to the second embodiment, the payload of a packet other than a packet containing PAT or PMT is encrypted and decrypted. In addition, the recording apparatus 1 uses a packet containing PMT. The payload may also be encrypted and decrypted.
[0097]
Further, in the recording / reproducing apparatus according to the second embodiment, when the encryptor 16 does not encrypt the payload including the PAT and the PMT, it is delayed by the time Te required for payload encryption. The header / payload separator 15 supplies the packet including the PAT or PMT to the header / payload synthesizer 18 without separating the packet into the header and payload, and the header / payload synthesizer 18 May be inserted into the stream in order. In that case, in order to maintain the order of the packets, the header / payload separator 15 and the header / payload synthesizer 18 delay the packets by a predetermined time. In this case, a bypass signal path from the header / payload separator 15 to the header / payload synthesizer 18 is provided, and the control device 11 allows the header / payload separator 15 and the header / payload synthesizer 18 as described above. To control.
[0098]
In the second embodiment, since information on the PMT in the PAT is used for encryption and decryption, the data stream is buffered until a packet including the PAT appears. Further, the control device 11 of the recording device 1 includes the PID of the packet including the PMT in the parameter file, and the control device 31 of the reproducing device 3 refers to the parameter file so as to recognize the PID of the packet including the PMT. May be.
[0099]
As described above, according to the second embodiment, in addition to the effects of the first embodiment, the encryptor 16 includes one or more included in the data stream among the payloads of the plurality of packets in the data stream. Only the payload other than the payload including the information on the stream is encrypted.
[0100]
As a result, the data stream recorded on the recording medium 2 can be edited with the content encrypted, with reference to the information about the stream included in the data stream. Note that the editing of the data stream means deletion of a packet including a program specified by a program map table in the data stream.
[0101]
Further, according to the second embodiment, the encryptor 16 encrypts only the payload other than the payload including the program association table or the program map table among the payloads of the packets in the MPEG transport stream.
[0102]
Accordingly, the data stream recorded on the recording medium 2 can be edited with the content encrypted, with reference to the MPEG-TS program specification information. In this case, the configuration of the data stream can be edited in units of elementary streams in MPEG-TS without decoding means.
[0103]
Furthermore, according to the second embodiment, the encryptor 16 encrypts only the payload other than the payload including the program association table among the payloads of the packets in the MPEG transport stream.
[0104]
Accordingly, the data stream recorded on the recording medium 2 can be edited with the content encrypted, with reference to the MPEG-TS program specification information. In this case, the data stream can be edited in units of programs in the MPEG-TS without decoding means.
[0105]
In the second embodiment, the encryptor 16 only receives a payload other than the payload including the program association table or the program map table in the MPEG transport stream, and the packet ID of each elementary stream in the program map table. May be encrypted.
[0106]
Accordingly, the data stream recorded on the recording medium 2 can be edited with the content encrypted, with reference to the MPEG-TS program specification information. Furthermore, since the PID of the elementary stream of each content becomes unknown at the time of editing the data stream by encryption, the safety can be further improved.
[0107]
Embodiment 3 FIG.
The recording / reproducing apparatus according to the third embodiment of the present invention is obtained by adding an editing device 4 to the recording / reproducing apparatus according to the first or second embodiment.
[0108]
FIG. 5 is a block diagram showing the configuration of the editing apparatus 4 in the recording / reproducing apparatus according to Embodiment 3 of the present invention. In FIG. 5, the control device 41 is a circuit that reads a data stream from the recording medium 2, edits the read data stream in accordance with a signal from the input device 42, and records the edited data stream on the recording medium 2. is there.
[0109]
The input device 42 is a device that receives an operation of a user who is an editor and outputs the operation as an electrical signal. As the input device 42, various key switches, a keyboard, a mouse, a jog dial, and the like are used.
[0110]
The display device 43 is a device that displays various supplied information. As the display device 43, a CRT (Cathode Ray Tube), a liquid crystal display, or the like is used.
[0111]
As other components in the recording / reproducing apparatus according to the third embodiment, there are the recording apparatus 1 and the reproducing apparatus 3 according to the second embodiment.
[0112]
The control device 41 may be realized by causing a CPU to execute a program describing similar functions.
[0113]
Furthermore, the control device 11 of the recording device 1, the control device 31 of the playback device 3, and the control device 41 of the editing device 4 may be the same control means. In that case, the control means may be realized as a dedicated circuit, or the control means may be realized by executing a program describing the functions of the control devices 11 and 31 and the control device 41 by the CPU.
[0114]
Next, the operation of the above apparatus will be described.
[0115]
The control device 41 reads the data stream recorded on the recording medium 2 and extracts program specification information such as PAT and PMT in the data stream. At that time, if the payload including the PAT or PMT is not encrypted, the control device 41 extracts the PAT or PMT from the payload. In this case, the encryption key and the decryption process are unnecessary. On the other hand, when the payload including the PMT is encrypted, the control device 41 analyzes the PAT, identifies the PID of the packet including the PMT, and decrypts the payload of the packet having the PID. Further, when the payload including the PAT and the payload including the PMT are encrypted, the control device 41 first extracts the PAT by decrypting the payload of the packet having the PID of “0x0000”, and then extracts the PAT. Is identified, the PID of the packet including the PMT is specified, and the payload of the packet having the PID is decoded.
[0116]
When it is necessary to decrypt a payload including PAT or PMT, an encryption key for the payload including PAT or PMT is prepared in the control device 41. However, even in that case, payloads of packets other than packets including PAT and PMT are not decoded. That is, the control device 41 determines a packet including PAT or PMT based on the PID, for example, decodes only the payload of the packet, and does not decode the payload of other packets. If the payload including PAT or PMT and another payload are encrypted with different encryption keys, only the encryption key obtained by encrypting the payload including PAT or PMT may be prepared in the control device 41. .
[0117]
Then, the control device 41 causes the display device 43 to display the extracted PAT and PMT as a tree or the like.
[0118]
FIG. 6 is a diagram illustrating a display example of a program configuration of a data stream recorded by the recording device 1 according to the third embodiment. As shown in FIG. 6, PAT, PMT defined by PAT, and each elementary stream defined by PMT are displayed as a tree on display device 43. Furthermore, the PIDs of the packets related to them are also displayed. For example, in the example shown in FIG. 6, three PMTs are described in the PAT, and video and audio elementary streams are described in each PMT.
[0119]
Next, a user who is an editor confirms the program configuration displayed on the display device 43 and designates an unnecessary elementary stream or an unnecessary program by an operation on the input device 42.
[0120]
The input device 42 supplies a signal corresponding to the operation to the control device 41. Based on the signal, the control device 41 deletes the elementary stream or program designated by the user.
[0121]
When deleting the elementary stream, the control device 41 deletes all the packets having the PID assigned to the elementary stream, and deletes the description about the elementary stream from the PMT in which the elementary stream is defined. To do.
[0122]
When deleting a program, the control device 41 analyzes the PMT corresponding to the program, deletes all packets having the PID assigned to each elementary stream defined in the PMT, and further deletes the packet. Delete the PMT and delete the PMT description from the PAT.
[0123]
When the user performs a predetermined operation indicating that editing has been completed, the control device 41 re-encrypts the decrypted payload, and then records the edited data stream on the recording medium 2.
[0124]
The processing relating to the recording of the data stream on the recording medium 2 and the reproduction of the data stream from the recording medium 2 is the same as in the case of the second embodiment, and the description thereof is omitted.
[0125]
Since the editing of the data stream configuration by the editing device 4 is offline editing, there is no need to reproduce and edit at the MPEG-TS data rate, and the recording medium 2 can be read and written at a speed limit. It can be carried out.
[0126]
As described above, according to the third embodiment, the editing device 4 reads the data stream from the recording medium 2 and edits the data stream with the payload still encrypted.
[0127]
As a result, it is possible to easily edit the configuration of the data stream while suppressing unauthorized duplication of contents such as video and audio in the data stream.
[0128]
Embodiment 4 FIG.
In the fourth embodiment of the present invention, only the recording apparatus 1 in the recording / reproducing apparatus according to the first or second embodiment is a single apparatus. Note that the configuration and operation of the recording apparatus according to the fourth embodiment are the same as those of the recording apparatus 1 according to the first or second embodiment, and a description thereof will be omitted. Note that the editing device 4 in the third embodiment may be added to this recording device.
[0129]
Embodiment 5 FIG.
In the fifth embodiment of the present invention, only the reproducing device 3 in the recording / reproducing device according to the first or second embodiment is a single device. Note that the configuration and operation of the playback apparatus according to Embodiment 5 are the same as those of playback apparatus 3 in Embodiment 1 or Embodiment 2, and therefore description thereof is omitted. Note that the editing device 4 in the third embodiment may be added to this playback device.
[0130]
Each embodiment described above is a preferred example of the present invention, but the present invention is not limited to these, and various modifications and changes can be made without departing from the scope of the present invention. It is.
[0131]
For example, even if the data stream is other than MPEG-TS, the present invention can be applied as long as it is a data stream packetized by packets including a header and a payload.
[0132]
In each of the above embodiments, when the recording device 1 and / or the playback device 3 is realized using a computer, according to identification information such as a user name and a password used for authentication at the time of login by the operating system, The key used in the encryptor 16 or the decryptor 34 may be determined. That is, keys used for encryption and decryption may be selected in accordance with user identification information input at the time of activation. This makes it difficult for a user to reproduce a data stream recorded on the recording medium 2 using the recording device 1 even if another user uses the reproducing device 3, and there is a possibility of copyright infringement. Can be lower. Similarly, the key used in the editing device 4 may be determined according to the user identification information.
[0133]
Further, in each of the above embodiments, the packet size detector 13 for detecting the size of the packet in the data stream is provided, but when the size of the packet in the data stream is constant, the packet size detector 13 13 may be omitted.
[0134]
Furthermore, in each of the above embodiments, one or a plurality of keys used for encryption or decryption may be input by the user, or may be a fixed one stored in advance in the apparatus. .
[0135]
Further, in each of the above-described embodiments, a known method can be used as the encryption method and the decryption method, and a block encryption method or a stream encryption method may be used. Further, the key method may be either a secret key method or a public key method as long as the delay due to encryption and decryption is not large.
[0136]
【The invention's effect】
According to the present invention, unauthorized duplication of content in a data stream recorded on a recording medium can be suppressed.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a recording apparatus in a recording / reproducing apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a diagram showing the structure of a normal MPEG-TS packet.
FIG. 3 is a block diagram showing a configuration of a playback apparatus in the recording / playback apparatus according to Embodiment 1 of the present invention.
FIG. 4 is a timing chart for explaining the operation of the recording apparatus of the recording / reproducing apparatus according to the first embodiment.
FIG. 5 is a block diagram showing a configuration of an editing apparatus in a recording / reproducing apparatus according to Embodiment 3 of the present invention.
6 is a diagram illustrating a display example of a program configuration of a data stream recorded by a recording apparatus according to Embodiment 3. FIG.
FIG. 7 is a block diagram showing a configuration of a conventional recording / reproducing apparatus.
[Explanation of symbols]
1 Recording device
2 recording media
3 Playback device
4 Editing device
11 Control device (first control means, control means)
15 Header / payload separation (first header / payload separation means, header / payload separation means)
16 Encryptor (encryption means)
18 Header / payload combiner (first header / payload combiner, header / payload combiner)
31 Control device (second control means, control means)
33 Header / payload separator (second header / payload separator, header / payload separator)
34 Decoder (Decoding means)
36 Second header / payload synthesizer (second header / payload synthesizer, header / payload synthesizer)
51 header
52 Payload

Claims (4)

In a recording / reproducing apparatus for recording a packetized data stream on a recording medium and reproducing the data stream recorded on the recording medium,
A first header / payload separating unit that separates a packet in the data stream into a header and a payload, and a part or all of the packets in the data stream are separated by the first header / payload separating unit; An encryption means for encrypting the payload of the header and the payload;
A first header / payload combining unit that combines the header and the payload encrypted by the encryption unit into a packet;
First control means for recording the packet generated by the first header / payload combining means on the recording medium;
Second control means for outputting a data stream recorded on the recording medium;
Second header / payload separation means for separating a packet in the data stream output from the recording medium into a header and an encrypted payload;
Decryption means for decrypting the encrypted payload of the header and encrypted payload separated by the second header / payload separation means;
A second header / payload combining unit that combines the header and the payload obtained by decoding by the decoding unit to form an original packet and reproduces the data stream ;
The data stream is an MPEG transport stream,
The encryption means includes a payload other than a payload including information on one or a plurality of streams included in a data stream among a plurality of packet payloads in an MPEG transport stream, that is, a payload including a program association table. Encrypt only non-payloads,
A recording / reproducing apparatus. 2. The encryption means encrypts only a payload other than a payload including the program association table or program map table among a plurality of packet payloads in an MPEG transport stream. The recording / reproducing apparatus as described. 2. The encryption unit according to claim 1, wherein the encryption unit encrypts only a payload other than the payload including the program association table or the program map table, and a packet ID of each elementary stream in the program map table. Recording / playback device. In a recording / reproducing method for recording a packetized data stream on a recording medium and reproducing the data stream recorded on the recording medium,
Separating packets in the data stream into a header and a payload;
Encrypting the payload of the separated header and payload for some or all of the packets in the data stream;
Combining the header and the encrypted payload into a packet;
Recording the packet generated from the header and the encrypted payload on the recording medium;
Reading a packet recorded on the recording medium;
Separating the packet read from the recording medium into a header and an encrypted payload;
Decrypting an encrypted payload of the separated header and encrypted payload;
Combining the header and the payload obtained by decoding into an original packet, and reproducing the data stream,
The data stream is an MPEG transport stream,
The step of encrypting includes a payload other than a payload including information on one or a plurality of streams included in a data stream among a plurality of packet payloads in an MPEG transport stream, that is, a program association table. Encrypt only non-payload payloads,
A recording / reproducing method characterized by the above.

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