JP3747872B2 - Data stream recording apparatus, data stream recording method and program - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a data stream recording apparatus, a data stream recording method, and a program.
[0002]
[Prior art]
Digital broadcasting that broadcasts content such as images and sounds in the form of a data stream composed of continuous packets including data representing the content is used.
[0003]
Digitally broadcast content can be stored in a storage device as data in digital format, and data deterioration is unlikely to occur during storage.
For this reason, a technique for protecting rights such as copyrights relating to digitally broadcast content is used. Specifically, there is a method of encrypting and storing data representing content.
[0004]
[Problems to be solved by the invention]
However, if the encryption method is not strong enough to attack, the encrypted data can be easily decrypted by a person who does not know the decryption key, and the data cannot be sufficiently protected. .
[0005]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a data stream recording apparatus and a data stream recording method for sufficiently protecting data.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a data stream recording apparatus according to the first aspect of the present invention provides:
A data stream including one or more audio data representing audio is acquired, and among a plurality of packets constituting the acquired data stream, a packet including range identification data indicating a range where the audio data exists is included in the first group. Distribution, thinning means for distributing the remaining packets to the second group;
First storage means having a first storage area that substantially prevents access from other than the thinning means;
Second storage means having a second storage area,
The thinning-out means stores packets belonging to the first group in the first storage area, and stores packets belonging to the second group in a second storage area.
It is characterized by that.
[0007]
Each of the audio data may belong to one PES (Packetized Elementary Stream) packet.
In this case, the range identification data may include a payload unit start indicator indicating a range in which the PES packet exists in the data stream.
[0008]
The thinning-out unit may distribute packets that satisfy a predetermined condition among packets including the range identification data to a first group, and distribute packets that do not satisfy the condition to a second group.
[0009]
The thinning-out means is a packet that further satisfies a predetermined condition common to each section among packets including the range identification data existing in each section obtained by dividing the data stream at predetermined time lengths. The packet may be distributed to one group and packets that do not satisfy the above condition are distributed to the second group.
[0010]
The thinning-out unit may further distribute the packets within the range indicated by the range identification data included in the packet distributed to the first group to the first group.
[0011]
The thinning-out means includes combining means for reading out the packets allocated to the first or second group from the first and second storage areas and restoring the data stream based on the read packets. May be.
[0012]
The thinning-out means generates information indicating the position occupied by the packet allocated to the first or second group in the data stream, and stores the information in the first or second storage area. May be.
[0013]
The thinning-out means converts the acquired data stream into a replaced data stream in which a packet distributed to the first group is replaced with a dummy packet, and stores the converted data stream in the second storage area It may be a thing.
[0014]
The thinning unit may include a processor, and the processor may access the first storage area by executing a predetermined program.
[0015]
The first storage unit and the thinning-out unit may be connected to each other via a bus that enables data transmission when the processor executes a predetermined program.
[0016]
The thinning-out means may encrypt the packet distributed to the first and / or second group and store it in the first and / or second storage area.
[0017]
A data stream recording method according to the second aspect of the present invention provides:
A data stream including one or more audio data representing audio is acquired, and among a plurality of packets constituting the acquired data stream, a packet including range identification data indicating a range where the audio data exists is included in the first group. Sort the remaining packets into the second group,
Storing packets belonging to the first group in a first storage area that substantially prevents access from other than a predetermined access device;
Storing packets belonging to the second group in a second storage area;
It is characterized by that.
[0018]
Each of the audio data may belong to one PES (Packetized Elementary Stream) packet.
In this case, the range identification data may include a payload unit start indicator indicating a range in which the PES packet exists in the data stream.
[0019]
A program according to the third aspect of the present invention is:
Computer
A data stream including one or more audio data representing audio is acquired, and among a plurality of packets constituting the acquired data stream, a packet including range identification data indicating a range where the audio data exists is included in the first group. Distribution, thinning means for distributing the remaining packets to the second group;
First storage means having a first storage area that substantially prevents access from other than the thinning means;
A program for functioning as a second storage means having a second storage area,
The thinning-out means stores packets belonging to the first group in the first storage area, and stores packets belonging to the second group in a second storage area.
It is characterized by that.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a digital broadcast recorder according to an embodiment of the present invention. As shown in the figure, this digital broadcast recorder includes a motherboard 1, a motherboard storage 2, and a receiving unit 3. The motherboard storage 2 is connected to the motherboard 1, and the receiving unit 3 is connected to the motherboard 1 via the connection bus B.
[0021]
The motherboard 1 includes, for example, a processor composed of a CPU (Central Processing Unit), a memory composed of a RAM (Random Access Memory), and a bus controller. The connection bus B is a PCI (Peripheral Component).
Interface) bus.
The memory of the motherboard 1 has a storage area that becomes a work area of the processor of the motherboard 1. The bus controller of the motherboard 1 includes a control circuit for controlling data exchange between the processor of the motherboard 1 and a device external to the motherboard 1 via the connection bus B.
[0022]
The mother board 1 reads out the broadcast recording / reproducing program stored in the motherboard storage 2 and performs the processing described later according to this broadcast recording / reproducing program.
The process controlled by the broadcast recording / reproducing program functionally includes a plurality of processing blocks. Specifically, a demultiplexer 1A, a stream decimation block 1B, a stream synthesis block 1C, a storage recording block 1D, an AAC (Advanced Audio Coding) decoding block 1E, and a storage read block 1F, which will be described later with reference to FIGS. Each processing block is included.
[0023]
The motherboard storage 2 is composed of a hard disk device or the like, and stores the above-described broadcast recording / reproducing program in advance. Then, in accordance with an access from the mother board 1, data supplied by the mother board 1 is stored, or data stored by itself is read out and supplied to the mother board 1.
[0024]
The receiving unit 3 includes a digital broadcast receiving unit 31, a PCI bus bridge 32, a content storage internal memory 33, and an IDE (Intelligent Drive Electronics) bus bridge 34.
[0025]
The digital broadcast receiving unit 31 includes a demodulation circuit and is connected to the PCI bus bridge 32 via an internal bus. The digital broadcast receiving unit 31 restores TS (Transport Stream) packets constituting the data stream by inputting and demodulating a modulated wave representing the data stream digitally broadcast from the outside. Then, the restored TS packet is supplied to the mother board 1 via the PCI bus bridge 32 and the connection bus B.
[0026]
The data stream represented by the modulated wave received by the digital broadcast receiving unit 31 represents content composed of images, sounds, and the like, and is composed of a plurality of continuous TS packets as shown in FIG.
A TS packet is a packet representing an image or sound that forms a content, and has a data structure shown in FIG. That is, the TS packet is composed of a TS packet header and a payload portion (adaptation / payload portion) following the TS packet header.
[0027]
The payload portion is a portion including data representing content. As shown in FIG. 3, each payload portion includes data that constitutes the same frame image (or the same audio, etc.) in the order in which TS packets including these payload portions are arranged. By connecting them together, a PES (Packetized Elementary Stream) packet described later can be formed.
[0028]
As shown in FIG. 2, the TS packet header includes a synchronization byte, TS error data, payload unit start indicator, transport priority data, PID (Program IDentifier), transport scramble control data, and adaptation field control data in order from the top. And continuity indicators.
[0029]
Among these, the payload unit start indicator indicates whether or not the payload portion of the TS packet including the payload unit start indicator itself includes the top data of the PES packet. Specifically, for example, when the value of the payload unit start indicator is “1”, it indicates that the payload portion of the TS packet including the payload unit start indicator itself includes the head data of the PES packet, When it is “0”, it indicates that the payload part does not include the head data of the PES packet.
[0030]
Therefore, one PES packet is, for example, a TS packet including a payload unit start indicator having a value of “1” in the data stream, and immediately before a next TS packet including a payload unit start indicator having a value of “1”. It is generated by concatenating the payload portions of successive TS packets up to TS packets.
[0031]
The PID is data for identifying which content the payload part of the TS packet including the PID itself represents (for example, which audio ES (which will be described later)).
[0032]
As shown in FIG. 3, the PES packet includes a PES header and PES data.
[0033]
Of these, the PES data is composed of data representing images, sounds or other contents. When the PES data represents audio, one piece of PES data is composed of one ADTS (Audio Data Transport Stream), for example, as shown in FIG.
[0034]
The ADTS is composed of AAC format audio data (or audio data having substantially the same data structure as the AAC format audio data) that represents a series of audio. As shown in FIG. 3, ADTSs can be connected to each other to form an audio ES (Elementary Stream), which is a data stream representing content.
[0035]
Returning to the description of the physical configuration, the PCI bus bridge 32 is configured by a bus controller or the like, and is connected to the motherboard 1 via the connection bus B. Also, the IDE bus bridge 34 and the bus bus 32 are connected via the internal bus. The digital broadcast receiver 31 is connected.
[0036]
The PCI bus bridge 32 mediates access to the content storage internal memory 33 which is performed by the mother board 1 according to the control of the broadcast recording / reproducing program. Further, it mediates the supply of data from the digital broadcast receiving unit 31 to the content storage internal memory 33.
[0037]
The content storage internal memory 33 includes a nonvolatile memory such as a compact flash (registered trademark) memory, and an interface circuit for transmitting data via the IDE bus.
[0038]
The IDE bus bridge 34 is composed of a bus controller or the like, and is connected to the PCI bus bridge 32 via an internal bus, while being connected to the content storage internal memory 33 via the IDE bus. The IDE bus bridge 34 mediates access to the content storage internal memory 33 that the motherboard 1 performs according to the control of the broadcast recording / playback program.
[0039]
The PCI bus bridge 32 and the IDE bus bridge 34 substantially prevent this access even if the motherboard 1 accesses the content storage internal memory 33 without following the control of the broadcast recording / reproducing program.
[0040]
(Operation)
Next, the operation of this digital broadcast recorder will be described.
FIG. 4 is a diagram showing a flow of processing for recording content.
FIG. 5 is a flowchart showing processing of the stream thinning block.
FIG. 7 is a diagram showing a flow of processing for reproducing the recorded content.
[0041]
(Recording content)
When a modulated wave representing a data stream is supplied to the digital broadcast receiver 31 of the receiving unit 3, the digital broadcast receiver 31 restores the data stream by demodulating the modulated wave, and the restored data stream Are supplied to the mother board 1 via the PCI bus bridge and the connection bus B.
[0042]
On the other hand, the mother board 1 reads out and executes a broadcast recording / reproducing program from the mother board storage 2 in response to a recording instruction supplied from the outside in accordance with the operation of the operator.
[0043]
When the mother board 1 executing the broadcast recording / reproducing program is supplied with the data stream (that is, when TS packets are sequentially supplied), the TS packet is converted into the TS packet according to the control of the demultiplexer 1A as shown in FIG. The data is delivered to each processing block of the stream synthesis block 1C and the stream decimation block 1B.
[0044]
When the TS packet is delivered from the demultiplexer 1A to the stream synthesizing block 1C (that is, when this digital broadcast recorder receives a digital broadcast), the motherboard 1 specifically processes this TS packet according to the control of the stream synthesizing block 1C. The TS packet is delivered to the AAC decode block 1E without being added.
[0045]
When the TS packet is delivered to the AAC decoding block 1E, the mother board 1 decodes the image and sound represented by the TS packet according to the control of the AAC decoding block 1E, and, for example, as shown in FIG. 4, PCM (Pulse Code Modulation) Output as content data consisting of audio signals such as signals.
[0046]
On the other hand, the mother board 1 performs the processing shown in FIG. 5 according to the control of the stream thinning block 1B.
[0047]
That is, when the TS packet is delivered to the stream decimation block 1B (step S1 in FIG. 5), the mother board 1 determines whether or not the PID included in the TS packet indicates the target audio ES to be accumulated (step S1). S2). If it is determined that the PID does not indicate the target audio ES to be accumulated, the TS packet including this PID is discarded, and the processing of the stream decimation block 1B is returned to step S1 (that is, the next TS packet is returned to the demultiplexer 1A). To the stream thinning block 1B). Note that the target audio ES to be stored may be designated by data supplied from the outside in accordance with the operation of the operator.
[0048]
On the other hand, if it is determined that the voice ES to be accumulated is indicated, the mother board 1 determines whether or not the TS packet including this PID is a thinning target packet (step S3). (In the present specification and drawings, TS packets supplied from the mother board 1 to the receiving unit 3 to be stored in the content storage internal memory 33 are called thinning target packets, and the stream thinning block 1B to the storage recording block 1D. (The TS packet to be delivered is called a non-decimation target packet.)
[0049]
Specifically, in step S3, the mother board 1 sets the value of the payload unit start indicator included in the TS packet including the PID determined to indicate the target audio ES to be accumulated, to the beginning of the PES packet. It is determined whether or not the value indicates inclusion.
[0050]
When it is determined that the TS packet to be determined is a non-decimation target packet (specifically, a value indicating that the beginning of the PES packet is not included), this TS packet (non-decimation target packet) Is transferred to the storage recording block 1D, and the process of the stream thinning block 1B is returned to step S1.
[0051]
On the other hand, if it is determined that the packet is a thinning target packet (specifically, a value indicating that the beginning of the PES packet is included), the motherboard 1 converts the TS packet determined as the thinning target packet into the content of the receiving unit 3. Writing to the internal storage memory 33 (step S4), the process of the stream thinning block 1B is returned to step S1.
[0052]
The motherboard 1 writes the thinning target packet to the content storage internal memory 33 by accessing the content storage internal memory 33 via the PCI bus bridge 32 and the IDE bus bridge 34. That is, when the motherboard 1 accesses the content storage internal memory 33 and the thinning target packet is supplied to the receiving unit 3, the PCI bus bridge 32 of the receiving unit 3 transfers the thinning target packet to the IDE bus bridge 34. The IDE bus bridge 34 accesses the content storage internal memory 33 and stores the thinning-out target packet in the storage area of the content storage internal memory 33.
[0053]
As a result of the processing of the stream thinning block 1B shown in FIG. 5 by the mother board 1, as shown in FIG. 6A, a TS packet including a portion corresponding to the head of the PES packet including ADTS is included in the data stream from the data stream. It is judged. The thinning target packet is stored in the content storage internal memory 33, and the non-thinning target packet is stored in the motherboard storage 2.
[0054]
When the mother board 1 that performs the processing of the stream thinning block 1B delivers the non-thinning target packet to the storage recording block 1D while performing the processing shown in FIG. 5, the thinning target packet of the original data stream received by the receiving unit 3 Is transferred to the storage recording block 1D in the form of a replaced data stream in which the packet is replaced with a dummy packet. The dummy packet may be a packet whose value of a predetermined portion of the TS packet is different from the value of the portion of the TS packet included in the original data stream, for example.
[0055]
Note that the content of the payload portion of the dummy packet is different from the content of the payload portion of the thinning target packet replaced by the dummy packet. It is desirable that there is substantially no correlation between the content of the payload portion of the dummy packet and the content of the payload portion of the thinning target packet at the position of the dummy packet.
[0056]
When the non-decimation target packet is delivered to the storage recording block 1D, the mother board 1 accesses the motherboard storage 2 according to the control of the storage recording block 1D, and as shown in FIG. Store in the storage area of the storage 2.
[0057]
Further, the mother board 1 that performs the processing of the stream thinning block 1B creates a position information table that indicates the position of each thinning target packet in the original data stream, and also passes this position information table to the storage recording block 1D. . The motherboard 1 also stores this position information table in the storage area of the motherboard storage 2 under the control of the storage recording block 1D.
[0058]
Note that in order to identify which content the thinning-out target packet whose position is represented by the position information table represents, the motherboard 1 displays this position information table, for example, by the position information table. What is necessary is just to make it store in association with the non-thinning-out target packet obtained from the data stream common to the thinning-out target packet.
[0059]
(Replay recorded content)
When playing back the recorded content, the motherboard 1 reads out and executes the broadcast recording / playback program from the motherboard storage 2 in response to a content playback instruction supplied from the outside in accordance with the operation of the operator.
[0060]
Then, the mother board 1 accesses the content storage internal memory 33 via the PCI bus bridge 32 and the IDE bus bridge 34 and reads out the thinning target packet. The read-out thinning target packet is supplied to the IDE bus bridge 34. The IDE bus bridge 34 transfers the thinning-out target packet to the PCI bus bridge 32. The PCI bus bridge 32 passes the thinning-out target packet through the connection bus B. To the motherboard 1.
For the thinning-out target packet to be read, for example, the location information table associated with the non-thinning-out target packet representing the content to be reproduced is read from the motherboard storage 2 according to the control of the storage read block 1F. May be specified.
[0061]
As shown in FIG. 7, the mother board 1 delivers the thinning-out target packet read from the receiving unit 3 to the stream synthesis block 1C.
[0062]
On the other hand, when the thinning-out target packet is delivered to the stream synthesis block 1C, the motherboard 1 reads from the motherboard storage 2 a non-thinning-out packet (replaced data stream) whose content is the same as the thinning-out target packet.
[0063]
Specifically, for example, the mother board 1 stores information (for example, a file name and an address of a storage area stored) indicating a non-decimation target packet associated with the previously referred position information table, The data is delivered from the stream synthesis block 1C to the storage read block 1F. Then, the motherboard storage 2 is accessed under the control of the storage read block 1F, the non-decimation target packet indicated by this information is read from the motherboard storage 2, and delivered to the stream synthesis block 1C.
[0064]
The mother board 1 also reads out a table indicating the position of the thinning-out target packet in the original data stream from the mother board storage 2 according to the control of the stream synthesizing block 1C and the storage read block 1F.
[0065]
Next, the mother board 1 sets the arrangement order of the thinning-out target packets and the non-thinning-out target packets delivered to the stream combining block 1C according to the control of the stream combining block 1C before thinning is performed according to the contents of the read position information table. Restore to the state. Specifically, it is assumed that a dummy packet included in the replaced data stream (that is, a set of non-thinning target packets) delivered to the stream synthesis block 1C is at the position of the dummy packet by the read position information table. The original data stream is restored by substituting the specified thinning target packet.
Then, the TS packets whose arrangement order is restored are delivered to the AAC decoding block 1E as shown in FIG.
[0066]
When the TS packet is delivered to the AAC decoding block 1E, the mother board 1 decodes the sound represented by the TS packet according to the control of the AAC decoding block 1E, and outputs it as content data as shown in FIG.
[0067]
The digital broadcast recorder that performs the above-described operation is a content storage internal memory that includes a TS packet including data included in a PES packet including an ADTS in a payload portion and includes the leading portion of the PES packet (a thinning target packet). 33. Then, even if the thinning-out target packet is read out without following the control of the broadcast recording / reproducing program, access is substantially blocked. Therefore, for example, even if the motherboard storage 2 is disconnected and an external computer or the like is used to reproduce audio based on the stored contents of the motherboard storage 2, the range of the PES packet cannot be specified and the audio cannot be reproduced correctly. As a result, content composed of sound can be protected.
[0068]
Further, the thinning-out target packet stored in the content storage internal memory 33 by the digital broadcast recorder is a part of the TS packet including ADTS. Accordingly, the storage capacity of the content storage internal memory 33 may be smaller than the storage capacity required for the configuration in which, for example, all TS packets including ADTS are stored in the content storage internal memory 33.
[0069]
The configuration of this digital broadcast recorder is not limited to the above.
For example, the audio data included in the TS packet (audio data constituting the ADTS) is not necessarily AAC format data, for example, MP3 (MPEG1 audio layer 3) format data or ATRAC (Adaptive TRansform Acoustic Coding) format May be included.
[0070]
The receiving unit 3 may include a plurality of content storage internal memories 33, and the data stream may be distributed into three or more groups.
Further, the non-decimation target packet is not necessarily stored in the motherboard storage 2 in the form of a replaced data stream. That is, the dummy packet is not necessary.
[0071]
Further, it is not always necessary that all TS packets including a portion corresponding to the head of a PES packet including ADTS be a thinning target packet, and a TS packet not including a portion corresponding to the head of a PES packet including ADTS is a thinning target. It may be a packet.
[0072]
Therefore, the mother board 1 may determine the thinning-out target packet based on the reference shown in FIG.
That is, among the TS packets delivered from the demultiplexer 1A to the stream decimation block 1B for T seconds (T is an arbitrary positive number) after the arbitrary TS packet is delivered from the demultiplexer 1A to the stream decimation block 1B. The first TS packet including the portion corresponding to the head of the PES packet including ADTS may be set as a thinning target packet, and the remaining TS packets may be set as non-thinning target packets. (FIG. 6B shows the case where the first TS packet delivered to the stream decimation block 1B during this T second period includes a portion corresponding to the head of the PES packet including ADTS, that is, the first TS (The case where a packet becomes a thinning-out target packet is illustrated.)
[0073]
Further, in step S3, the mother board 1 may determine a thinning target packet based on, for example, a reference illustrated in FIG.
That is, each TS packet delivered from the demultiplexer 1A to the stream decimation block 1B for T seconds after an arbitrary TS packet is delivered from the demultiplexer 1A to the stream decimation block 1B, at the head of the PES packet including ADTS Of the TS packets including the corresponding part, the first N packets (N is an arbitrary positive integer) may be set as the thinning target packets, and the remaining TS packets may be set as the non-thinning target packets. (Note that FIG. 6C shows that the first TS packet delivered to the stream decimation block 1B in the period of T seconds includes a portion corresponding to the head of the PES packet including ADTS, and the value of N is 2. It is an example of a case.)
[0074]
Further, in step S3, the mother board 1 may determine the thinning target packet based on, for example, the reference shown in FIG.
That is, the entire data for one ADTS is transferred from each TS packet delivered from the demultiplexer 1A to the stream decimation block 1B for T seconds after an arbitrary TS packet is delivered from the demultiplexer 1A to the stream decimation block 1B. The first of the set of consecutive TS packets to be included (that is, from the first TS packet including the portion corresponding to the head of the PES packet including ADTS to the next including the portion corresponding to the head of the PES packet including ADTS. TS packets belonging to a set of TS packets up to the TS packet immediately before the TS packet) may be set as thinning target packets, and the remaining TS packets may be set as non-thinning target packets. (Note that FIG. 6D illustrates a case where the first TS packet delivered to the stream thinning block 1B during this T second period includes a portion corresponding to the head of the PES packet including ADTS. .)
[0075]
Further, the mother board 1 may determine the thinning-out target packet in step S3 based on, for example, the reference shown in FIG.
That is, the entire data for one ADTS is transferred from each TS packet delivered from the demultiplexer 1A to the stream decimation block 1B for T seconds after an arbitrary TS packet is delivered from the demultiplexer 1A to the stream decimation block 1B. TS packets belonging to the first M (M is an arbitrary positive integer) set of consecutive TS packet sets may be set as thinning target packets, and the remaining TS packets may be set as non-thinning target packets. (Note that FIG. 6E shows that the first TS packet delivered to the stream decimation block 1B during this T second period includes a portion corresponding to the head of the PES packet including ADTS, and the value of M is 2. It is an example of a case.)
[0076]
Note that when determining the block to be thinned out based on the reference shown in FIGS. 6B to 6E, the mother board 1 determines the start point or the end point of the T-second period described above, for example. Etc., and a timer for supplying information indicating the current time to the processor may be provided. A transmission circuit or the like serving as a clock signal generation source for driving the processor may perform the timer function.
[0077]
In addition, the digital broadcast recorder may include an amplifier circuit, a speaker, and the like for reproducing the sound represented by the content data generated by the motherboard 1. An amplifier circuit, a speaker, and the like may be mounted on the motherboard 1.
[0078]
Further, the mother board 1 stores a position information table indicating the position of the thinning target packet in the content storage internal memory 33 in association with the thinning target packet, and when the recorded content is reproduced, the position information table is stored in the content information table. The data may be read from the storage internal memory 33 and used.
[0079]
Further, the connection bus B is not necessarily limited to the PCI bus, and may be a bus conforming to an arbitrary standard. Therefore, for example, the connection bus B may be composed of a bus conforming to PC Card Standard, may be composed of an ISA (Industry Standard Architecture) bus, or may be composed of a USB (Universal Serial Bus). . However, when the connection bus B is not a PCI bus, the reception unit 3 is provided with a bus controller or the like that mediates data exchange conforming to the standard to which the connection bus B conforms instead of the PCI bus bridge 32.
[0080]
The bus connecting the content storage internal memory 33 and the IDE bus bridge 34 is not necessarily limited to the IDE bus, and may be a bus conforming to an arbitrary standard. Therefore, this bus may comprise a memory dedicated bus, for example. However, when this bus is not an IDE bus, the receiving unit 3 is provided with a bus controller or the like that mediates data exchange conforming to the standard to which this bus conforms instead of the IDE bus bridge 34, and for content storage It is assumed that the interface circuit provided in the internal memory 33 also mediates data exchange conforming to the standard to which this bus complies.
[0081]
Further, the mother board 1 encrypts the non-decimation target packet when recording the content and then stores it in the motherboard storage 2, and reads and decrypts the encrypted non-decimation target packet when reproducing the recorded content. The data stream may be restored after conversion.
Similarly, when content is recorded, the thinning-out target packet is encrypted and then written into the content storage internal memory 33. When the recorded content is reproduced, the encrypted thinning-out target packet is read and decrypted before data is recorded. Stream restoration may be performed.
[0082]
Although the embodiment of the present invention has been described above, the data stream recording apparatus according to the present invention can be realized using a normal computer system, not a dedicated system.
For example, by installing the program from a medium (CD-ROM, MO, FD, etc.) storing a program for causing the personal computer to execute the operations of the mother board 1, the mother board storage 2, and the receiving unit 3 described above, A digital broadcast recorder that executes the above process can be configured.
[0083]
Further, for example, the program may be posted on a bulletin board (BBS) of a communication line and distributed via the communication line. Also, a carrier wave is modulated by a signal representing the program, and the obtained modulated wave is An apparatus that transmits and receives the modulated wave may demodulate the modulated wave to restore the program.
Then, the above-described processing can be executed by starting the program and executing it in the same manner as other application programs under the control of the OS.
[0084]
When the OS shares a part of the processing, or when the OS constitutes a part of one component of the present invention, a program excluding the part is stored in the recording medium. May be. Also in this case, in the present invention, it is assumed that the recording medium stores a program for executing each function or step executed by the computer.
[0085]
【The invention's effect】
As described above, according to the present invention, a data stream recording apparatus and a data stream recording method for sufficiently protecting data are realized.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a digital broadcast recorder according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a data structure of a data stream and a TS packet.
FIG. 3 is a diagram illustrating a data structure of a PES packet and a voice ES.
FIG. 4 is a diagram showing a flow of processing for recording content.
FIG. 5 is a flowchart showing processing of a stream thinning block.
6A to 6E are diagrams schematically illustrating a relationship between a data stream and a thinning target packet.
FIG. 7 is a diagram illustrating a flow of processing for reproducing recorded content.
[Explanation of symbols]
1 Motherboard
2 Motherboard storage
3 receiving unit
31 Digital broadcast receiver
32 PCI bus bridge
33 Internal memory for content storage
34 IDE Bus Bridge
B Connection bus

Claims (14)

A data stream including one or more audio data representing audio is acquired, and among a plurality of packets constituting the acquired data stream, a packet including range identification data indicating a range where the audio data exists is included in the first group. Distribution, thinning means for distributing the remaining packets to the second group;
First storage means having a first storage area that substantially prevents access from other than the thinning means;
Second storage means having a second storage area,
The thinning-out means stores packets belonging to the first group in the first storage area, and stores packets belonging to the second group in a second storage area.
A data stream recording apparatus. Each of the audio data belongs to one PES (Packetized Elementary Stream) packet,
The range identification data is composed of a payload unit start indicator indicating a range in which the PES packet exists in the data stream.
The data stream recording apparatus according to claim 1, wherein: The thinning unit distributes packets that satisfy a predetermined condition among packets including the range identification data to a first group, and distributes packets that do not satisfy the condition to a second group.
The data stream recording apparatus according to claim 1, wherein the data stream recording apparatus is a data stream recording apparatus. The thinning-out means is a packet that further satisfies a predetermined condition common to each section among packets including the range identification data existing in each section obtained by dividing the data stream at predetermined time lengths. Allocating packets to one group and allocating packets that do not satisfy the condition to a second group;
The data stream recording apparatus according to claim 1, wherein the data stream recording apparatus is a data stream recording apparatus. The thinning-out means further distributes the packet within the range indicated by the range identification data included in the packet distributed to the first group to the first group,
5. The data stream recording apparatus according to claim 3, wherein the data stream recording apparatus is a data stream recording apparatus. The thinning unit includes a combining unit that reads packets distributed to the first or second group from the first and second storage areas and restores the data stream based on the read packets.
The data stream recording apparatus according to claim 1, wherein the data stream recording apparatus is a data stream recording apparatus. The thinning unit generates information indicating a position occupied in the data stream by the packet distributed to the first or second group, and stores the information in the first or second storage area.
The data stream recording apparatus according to claim 1, wherein the data stream recording apparatus is a data stream recording apparatus. The thinning-out means converts the acquired data stream into a replaced data stream in which a packet distributed to the first group is replaced with a dummy packet, and stores the converted data stream in the second storage area ,
8. The data stream recording apparatus according to claim 1, wherein the data stream recording apparatus is a data stream recording apparatus. The thinning means includes a processor, and the processor accesses the first storage area by executing a predetermined program.
9. The data stream recording apparatus according to claim 1, wherein the data stream recording apparatus is a data stream recording apparatus. The first storage unit and the thinning unit are connected to each other via a bus that enables data transmission by the processor executing a predetermined program.
The data stream recording apparatus according to claim 9, wherein: The thinning-out means encrypts the packets distributed to the first and / or second groups and stores them in the first and / or second storage areas.
The data stream recording apparatus according to claim 1, wherein the data stream recording apparatus is a data stream recording apparatus. A data stream including one or more audio data representing audio is acquired, and among a plurality of packets constituting the acquired data stream, a packet including range identification data indicating a range where the audio data exists is included in the first group. Sort the remaining packets into the second group,
Storing packets belonging to the first group in a first storage area that substantially prevents access from other than a predetermined access device;
Storing packets belonging to the second group in a second storage area;
A data stream recording method. Each of the audio data belongs to one PES (Packetized Elementary Stream) packet,
The range identification data is composed of a payload unit start indicator indicating a range in which the PES packet exists in the data stream.
The data stream recording method according to claim 12, wherein: Computer
A data stream including one or more audio data representing audio is acquired, and among a plurality of packets constituting the acquired data stream, a packet including range identification data indicating a range where the audio data exists is included in the first group. Distribution, thinning means for distributing the remaining packets to the second group;
First storage means having a first storage area that substantially prevents access from other than the thinning means;
A program for functioning as a second storage means having a second storage area,
The thinning-out means stores packets belonging to the first group in the first storage area, and stores packets belonging to the second group in a second storage area.
A program characterized by that.

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