JP4103693B2 - Information processing apparatus, information processing method, reproduction apparatus, and reproduction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information processing apparatus, an information processing method, a playback apparatus, and a playback method suitable for use in, for example, playback of a DVD (Digital Versatile Disk: hereinafter abbreviated as DVD). Specifically, information processing for a pack of control information in a playback stream can be performed satisfactorily.
Note that the present invention is not limited to the reproduction of a DVD, but in the following description, the reproduction of a DVD that is well known and easy to understand will be described.
[0002]
[Prior art]
Even in conventional DVD playback, information processing is performed by extracting a pack of control information from a playback stream (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
JP-A-10-334589
[0004]
[Problems to be solved by the invention]
FIG. 8 shows the hierarchical structure of the DVD stream. A DVD stream is composed of, for example, a maximum of 99 video object sets (VOBS) per title, and each VOBS is provided with a maximum of 32767 cells (C). Further, each of these cells (C) is composed of a large number of packs (PCK) each having 2048 bytes as a unit.
[0005]
There are four types of packs (PCK): Video Pack, Audio Pack, Sub Picture Pack, and Navigation Pack. Of these, the Video Pack, Audio Pack, and Sub Picture Pack are so-called content information packs composed of data including video and audio information. On the other hand, the Navigation Pack is a pack of control information that has position information related to specific data of a stream and information related to display such as an angle and highlight, and is information necessary for DVD control.
[0006]
Therefore, when playing the above-described DVD stream, the Navigation Pack is earlier than the timing at which other packs such as Video Pack and Audio Pack in the stream start to be actually processed (demultiplexed, decoded, displayed, etc.). Obtained and analyzed. In the lower part of FIG. 8, a specific configuration of the navigation pack is shown.
[0007]
By the way, the detection is performed for obtaining the navigation pack. As a method for the detection, in a conventional apparatus, for example, a method of detecting a stream read from a DVD drive when analyzing by a demultiplexer is used. FIG. 9 shows a system configuration for realizing such a conventional detection method.
[0008]
That is, in FIG. 9, the laser beam from the optical pickup 30 is irradiated onto the disk 31, and a signal obtained by detecting the reflected light is supplied to the processor 32, and the data stream recorded on the disk 31 is read out. The optical pickup 30 to the processor 32 form a DVD drive. The read stream is supplied to the demultiplexer 33, and the demultiplexer 33 detects the navigation pack.
[0009]
In the processing of the stream read from the disk 31, when the stream is directly supplied to the demultiplexer 33 as shown in FIG. 9A, the stream is sent via the data bus 34 as shown in FIG. 9B. In some cases, the data is once buffered in the memory 35 and then supplied to the demultiplexer 33.
[0010]
Further, when the navigation pack is detected by the demultiplexer 33, it is notified to the CPU 36 by interruption or the like, and the CPU 36 receives this and analyzes the navigation pack transferred to the memory 35. Then, processing (demultiplexing, decoding, display, etc.) of Video Pack, Audio Pack, etc. is performed according to the analyzed navigation pack control information.
[0011]
That is, the video and audio streams analyzed and separated by the demultiplexer 33 are sent to the video decoding device 37 and the audio decoding device 38, respectively, and processing such as decoding and display is performed. Further, a memory controller 39 is provided for managing the memory 35, and control of data access to the memory 35 from each block is performed.
[0012]
In this manner, the video signal (Video) and the audio signal (Audio) obtained by analyzing the stream read from the disk 31 are reproduced. The reproduction of the content information is performed according to the navigation pack control information analyzed by the CPU 36 described above.
[0013]
However, in the above-described system, since the input stream is sequentially analyzed while processing other packs, there is a problem that the detection timing of the navigation pack is delayed. In other words, since Navigation Pack analysis is also performed in the order provided in the stream together with Video Pack, Audio Pack, etc., it is difficult to obtain and analyze Navigation Pack earlier than the processing of other packs. .
[0014]
Further, there is no guarantee that the next navigation pack will not be read while analyzing the navigation pack acquired by the CPU. That is, when fast-forwarding playback of a DVD is performed, the next navigation pack may be read during analysis of the previous navigation pack. In this case, in the above-described system, the newly acquired Navigation Pack is ignored, and the control shown there cannot be performed.
[0015]
This application has been made in view of the above points, and the problem to be solved is that in the conventional apparatus, since the detection of the navigation pack is performed by the demultiplexer, the detection timing is delayed. If the next navigation pack is read while analyzing the navigation pack that the CPU was able to acquire, the newly acquired navigation pack is ignored and the control indicated there is executed. It was a problem that could not be done.
[0016]
[Means for Solving the Problems]
For this reason, in the present invention, the pack of control information is determined by a specific pattern in the stream, the stream is stored as it is in the main memory, and the storage position in the main memory when the pack of control information is determined is specified. According to this, the control information pack can be analyzed at an arbitrary timing, and the newly input control information pack information can also be detected. Can be retained and analyzed.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
That is, in the present invention, an information processing apparatus in which a pack of control information is input together with a pack of content information in a single stream, and includes a means for determining a pack of control information according to a specific pattern in the stream, Is stored in the main memory as it is, and means for detecting and holding a value for specifying a storage position in the main memory when the pack of control information is determined is provided.
[0018]
Further, in the present invention, there is provided an information processing method in an information processing apparatus in which a pack of control information is input together with a pack of content information in a single stream, and the pack of control information is determined by a specific pattern in the stream, The stream is stored in the main memory as it is, and a value specifying the storage position in the main memory when the pack of control information is determined is detected and held.
[0019]
The present invention also provides a playback apparatus having playback means for playing back a recording medium in which a pack of control information and a pack of control information are recorded in a single stream together with a pack of content information, and the control information is recorded according to a specific pattern in the stream. A means for discriminating a pack, storing a stream in the main memory as it is, and a means for detecting and holding a value for specifying a storage position in the main memory when the pack of control information is discriminated It is.
[0020]
Furthermore, in the present invention, there is provided a playback method in a playback apparatus for playing back a recording medium in which a pack of control information and a pack of control information are recorded in a single stream, and the pack of control information is recorded according to a specific pattern in the stream. The stream is stored in the main memory as it is, and the value specifying the storage position in the main memory when the pack of control information is determined is detected and held.
[0021]
The present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of a DVD playback apparatus to which an information processing apparatus, an information processing method, a playback apparatus, and a playback method according to the present invention are applied. is there.
[0022]
In FIG. 1, a laser beam from an optical pickup 1 is irradiated onto a disk 2, and a signal obtained by detecting the reflected light is supplied to a processor 3, and a data stream recorded on the disk 2 is read out. A DVD drive is formed by these optical pickups 1 to 3. In the present invention, the read stream is supplied to the demultiplexer 5 through the navigation pack detection mechanism (hereinafter referred to as Navi Pack parser) 4.
[0023]
1 shows a case where the stream is temporarily buffered in the memory 7 via the data bus 6 and then supplied to the demultiplexer 5 as shown in FIG. 9B. The same applies to the case where the signal is directly supplied to the demultiplexer 5 as shown in A of FIG.
[0024]
The Navi Pack parser 4 receives the stream read from the optical pickup 1 (DVD drive) as an input, outputs it as it is to the memory 7, and detects the navigation pack in parallel therewith. As a means, the Navi Pack parser 4 is provided with a configuration as shown in FIG.
[0025]
That is, in FIG. 2, the stream parser 21 for detecting the navigation pack in parallel with the line connecting the input and output, the input pack counter 22 for counting the input stream in units of 2048-byte packs, and the stream parser 21 A counter buffer 23 is provided for holding the counter value of the input pack counter 22 when it is detected.
[0026]
Further, the navigation pack detection performed by the stream parser 21 is performed by matching the header information added to the pack. FIG. 3 shows the location of such information.
[0027]
That is, the navigation pack is provided with a 4-byte Pack Header at the beginning, followed by a 24-byte System Header, and further a 986-byte PCI (Presentation Control Information) and a 1024-byte DSI (Data Search Information). Is provided. In addition, a 6-byte packet header and a 1-byte sub stream id are provided at the top of these PCI and DSI, respectively.
[0028]
In the navigation pack, a code “000001bb [h]” is provided in the system header start code located in the first 4 bytes of the System Header. Also, a code “000001 [h]” is provided in the packet start code prefix located in the first 3 bytes of the first Packet Header of the PCI, and a code “10111111 [b]” is provided in the stream id located in the subsequent 1 byte. . Further, a code “00000000 [b]” is provided in the PCI sub stream id.
[0029]
Therefore, the stream parser 21 determines that it is a navigation pack when these codes all match, and outputs a detection signal. The coincidence can be detected by a hard logic such as a data buffer and a logic gate circuit.
[0030]
That is, the 15th to 18th bytes, the 39th to 42nd bytes, and the 45th byte from the head of the stream are detected, and the match between these values and the above code is determined by the logic gate circuit, thereby detecting the match. Done. Here, the head of the stream can be determined by, for example, a signal separately supplied from the processor 3.
[0031]
When the above Navi Pack parser 4 is used, the address of the memory 7 to which the navigation pack has been transferred is the transfer start address of the memory 7 and the input pack count value obtained from the counter buffer 23 minus 1. It is obtained by adding the value multiplied by 2048.
[0032]
That is, for example, in a DVD playback stream, all packs are composed of 2048 bytes. Therefore, the transfer start address of the memory 7 when transfer is started is set to the input pack count value obtained from the counter buffer 23. By adding the value multiplied by 2048, the address of the memory 7 to which the navigation pack is transferred can be obtained.
[0033]
Such processing can be performed by software in the CPU 8, for example. Furthermore, after calculating the memory address, the CPU 8 can read this memory area and analyze the navigation pack. Then, processing (demultiplexing, decoding, display, etc.) of Video Pack, Audio Pack, etc. is performed according to the analyzed navigation pack control information.
[0034]
That is, the Video and Audio streams analyzed and separated by the demultiplexer 5 are sent to the video decoding device 9 and the audio decoding device 10, respectively, and processing such as decoding and display is performed. Further, a memory controller 11 is provided for managing the memory 7, and control of data access to the memory 7 from each block is performed.
[0035]
In this manner, the video signal (Video) and audio signal (Audio) obtained by analyzing the stream read from the disk 2 are reproduced. The reproduction of the content information is performed according to the navigation pack control information analyzed by the CPU 8 described above.
[0036]
Further, the counter buffer 23 is configured to hold a plurality of counter values, for example, as shown in FIG. The figure is an example when the number of buffers is eight. The number of buffers is determined in consideration of the appearance frequency of the navigation pack in the stream input to the Navi Pack parser.
[0037]
That is, if the number of buffers is insufficient, the CPU 8 receives a navigation pack detection interrupt, and this information is used when the Navi Pack parser 4 detects the next navigation pack before reading the counter buffer 23. A situation that will be missed occurs. Therefore, this situation can be avoided by providing the counter buffer 23 with a plurality of buffers.
[0038]
In the example of FIG. 4, pointer values of 000 to 111 are assigned to the respective buffers, and the value of the input pack counter 22 when the navigation pack is detected is written in the corresponding buffer. In the figure, Pack n indicated by the pointer value 101 represents the oldest input pack count value in time, and the new time input pack count values are held in order of 110, 111,000. The latest input pack count value is Pack n + 7 indicated by 100.
[0039]
The write pointer is a pointer indicating which buffer is written when the next navigation pack is detected, and indicates 101 in the above-described case. Further, the read pointer indicates the position of the buffer to be read next, and indicates 010 in the above case. These write pointers are updated by hardware, and the read pointer is updated by the CPU.
[0040]
In FIG. 4, the input pack count value indicated by the pointer values 101 to 001 indicates that the CPU 8 has already read, and the input pack count value indicated by the pointer values 010 to 100 indicates that it has not been read yet. .
[0041]
Further, FIG. 5 shows a method for updating the write pointer. That is, in FIG. 5, it is determined whether or not a navigation pack is detected in step [1]. If not detected (No), this step [1] is repeated. On the other hand, when a navigation pack is detected in step [1] (Yes), it is determined in step [2] whether a buffer full flag to be described later is set.
[0042]
If the buffer full flag is set in step [2] (Yes), the write pointer WP is kept at the value WP in step [3], and the input pack count value is not written and saved. On the other hand, when the buffer full flag is not raised in step [2] (No), the write pointer WP is updated to the value WP + 1 in step [4].
[0043]
In this way, the value of the write pointer WP is updated. Further, it is determined in step [5] whether or not the write pointer WP is equal to the read pointer RP. If they are equal (Yes), a buffer full flag is set in step [6].
[0044]
As a result, the write pointer WP is updated one by one so that the value of the read pointer RP is not exceeded each time a navigation pack is detected. However, when the buffer is full, the write pointer WP is not updated. This state occurs when the read pointer RP is updated less frequently than the write pointer WP is updated.
[0045]
That is, in the above-described configuration, for example, when the navigation pack is detected in a state where the read pointer RP is 0 and the write pointer WP is 7, the buffer becomes full. At this time, the new count value is not written in the buffer, and the old information is retained. The CPU 8 needs to control the buffer so as not to be in such a state, and it is necessary to select the number of the counter buffers 23 in consideration of the performance of the CPU 8, the appearance frequency of the navigation pack, and the like.
[0046]
Further, FIG. 6 shows a control flow of the counter buffer 23 via the CPU 8 starting from detection of the navigation pack.
[0047]
That is, when the Navi Pack parser 4 detects a navigation pack, a detection interrupt is issued to the CPU 8. In FIG. 6, the CPU 8 determines whether or not there is a navigation pack detection interrupt in step [11]. When there is no detection interrupt (No), step [11] is repeated and when there is a detection interrupt (Yes). Advances to step [12].
[0048]
In step [12], in response to the detection interrupt, the write pointer WP and the read pointer RP of the counter buffer are read. Subsequently, the number N of reference buffers is calculated in steps [13] to [15]. That is, it is determined whether or not “WP-RP> 0” in Step [13]. If “WP-RP> 0” (Yes), “N = WP-RP” is set in Step [14]. If “WP−RP> 0” is not satisfied (No), “N = (WP−RP) +8” is set in step [15].
[0049]
In this way, it is calculated to which buffer the latest information has been written. In step [16], the input pack count values stored in the calculated number N of buffers are read from the buffer indicated by the read pointer RP. Since the information becomes unnecessary after reading, the read pointer RP is updated in step [17]. This updated value is the value of the write pointer WP if the CPU 8 has read all the latest information.
[0050]
In step [18], the address of the navigation pack in the memory 7 is calculated. As described above, this address is calculated by adding the transfer start address of the memory 7 and the value obtained by subtracting 1 from the input pack count value obtained from the counter buffer 23 and 2048.
[0051]
Further, after calculating the memory address, the CPU 8 reads this memory area and analyzes the navigation pack. Then, processing (demultiplexing, decoding, display, etc.) of Video Pack, Audio Pack, etc. is performed according to the analyzed navigation pack control information.
[0052]
Therefore, in this embodiment, the pack of control information is determined by a specific pattern in the stream, the stream is stored in the main memory as it is, and the storage position in the main memory when the pack of control information is determined is specified. By detecting and holding the value, it is possible to analyze the pack of control information at an arbitrary timing and also hold and analyze the information of the pack of newly input control information. .
[0053]
As a result, in the conventional device, since the detection of the navigation pack is performed by the demultiplexer, there is a problem that the detection timing is delayed, and the next navigation pack is read while analyzing the navigation pack acquired by the CPU. If it is issued, the newly acquired Navigation Pack is ignored, causing problems such as being unable to execute the control indicated there, and according to the present invention, these problems are solved. It can be easily solved.
[0054]
Further, FIG. 7 shows another embodiment of the information processing apparatus, information processing method, reproduction apparatus, and reproduction method according to the present invention. That is, in FIG. 7, the optical pickup 1 to the processor 32 have a Navi Pack parser 4 between the DVD drive and the demultiplexer, and further have a dedicated memory 12 provided alongside the Navi Pack parser 4.
[0055]
When the navigation pack is detected, it is stored in the dedicated memory 12 and notified to the CPU 8 by interruption or the like. In response to this interruption, the CPU 8 reads the dedicated memory 12 via the bus 13 to analyze the navigation pack. In this method, the stream is analyzed immediately after being read from the DVD, and the navigation pack is detected. In addition, since the dedicated memory 12 is provided for analysis, the analysis can be performed quickly.
[0056]
However, in this method, considering the case where the next navigation pack is read while analyzing the navigation pack acquired by the CPU 8, it is necessary to have a very large capacity of the dedicated memory 12, and the circuit scale of the local memory Has the problem of increasing the.
[0057]
Further, in the above-described embodiment, the counter buffer 23 holds the counter value obtained by counting the input stream in a pack unit of 2048 bytes. Here, the address of the memory 7 in which the navigation pack is written is stored. You may make it detect and hold | maintain. According to this, although the storage capacity of the counter buffer 23 is slightly increased, it is not necessary to calculate the navigation pack address in step [18] shown in the control flow of FIG.
[0058]
Thus, according to the information processing apparatus described above, the control information pack is provided according to a specific pattern in the stream, and the stream is stored in the main memory as it is, and the main memory when the control information pack is determined. By providing a means for detecting and holding a value for specifying a storage position in the control information pack when the control information pack is input in a single stream together with the content information pack, an arbitrary timing is obtained. Is something that can be done with.
[0059]
In addition, according to the information processing method described above, a pack of control information is determined based on a specific pattern in the stream, and the stream is stored in the main memory as it is, and in the main memory when the pack of control information is determined. By detecting and holding a value specifying the storage position, analysis of the control information pack is performed at an arbitrary timing in the information processing apparatus in which the control information pack is input in a single stream together with the content information pack It is something that can be done.
[0060]
Furthermore, according to the above-described playback device, the control apparatus includes means for discriminating a pack of control information according to a specific pattern in the stream, and stores the stream in the main memory as it is, and in the main memory when the pack of control information is discriminated. By providing a means for detecting and holding a value specifying the storage location of the recording information, it is possible to arbitrarily analyze the control information pack in reproducing a recording medium in which the control information pack is recorded in a single stream together with the content information pack. It can be done at the timing.
[0061]
Further, according to the above-described reproduction method, the pack of control information is determined by a specific pattern in the stream, and the stream is stored in the main memory as it is, and the storage in the main memory when the pack of control information is determined. By detecting and holding a value specifying the position, control information pack analysis can be performed at any timing in a playback apparatus that plays back a recording medium in which the control information pack is recorded in a single stream together with the content information pack. Is something that can be done with.
[0062]
Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
[0063]
【The invention's effect】
Therefore, according to the invention of claim 1, the pack of control information is determined by a specific pattern in the stream, Count the number of packs in the input stream, buffer multiple pack count values, The stream is stored in the main memory as it is, and a value for specifying the storage position in the main memory when the pack of control information is determined. Calculated from the buffered pack count value Thus, the control information pack can be analyzed at an arbitrary timing, and the newly input control information pack information can also be held and analyzed. .
[0068]
Claim 2 According to the present invention, the means for discriminating the pack of control information according to a specific pattern in the stream is a system header start code, a packet start code prefix, a stream id, and a sub stream id provided in the pack of control information in the stream. By including means for detecting all values, it is possible to determine the pack of control information in the stream with a simple configuration.
[0069]
Further claims 3 According to the invention, the pack of control information is determined by a specific pattern in the stream, Count the number of packs in the input stream, buffer multiple pack count values, The stream is stored in the main memory as it is, and a value for specifying the storage position in the main memory when the pack of control information is determined. Calculated from the buffered pack count value Thus, the control information pack can be analyzed at an arbitrary timing, and the newly input control information pack information can also be held and analyzed. .
[0075]
Further claims 4 According to the invention, the pack of control information is determined by a specific pattern in the stream, Count the number of packs in the input stream, buffer multiple pack count values, The stream is stored in the main memory as it is, and a value for specifying the storage position in the main memory when the pack of control information is determined. Calculated from the buffered pack count value Thus, the control information pack can be analyzed at an arbitrary timing, and the newly input control information pack information can also be held and analyzed. .
[0080]
Claim 5 According to the present invention, the means for discriminating the pack of control information according to a specific pattern in the stream is a system header start code, a packet start code prefix, a stream id, and a sub stream id provided in the pack of control information in the stream. By including means for detecting all values, it is possible to determine the pack of control information in the stream with a simple configuration.
[0081]
Further claims 6 According to the invention, the pack of control information is determined by a specific pattern in the stream, Count the number of packs in the input stream, buffer multiple pack count values, The stream is stored in the main memory as it is, and a value for specifying the storage position in the main memory when the pack of control information is determined. Calculated from the buffered pack count value Thus, the control information pack can be analyzed at an arbitrary timing, and the newly input control information pack information can also be held and analyzed. .
[0087]
As a result, in the conventional device, since the detection of the navigation pack is performed by the demultiplexer, there is a problem that the detection timing is delayed, and the next navigation pack is read while analyzing the navigation pack acquired by the CPU. If it is issued, the newly acquired Navigation Pack is ignored, causing problems such as being unable to execute the control indicated there, and according to the present invention, these problems are solved. It can be easily solved.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an embodiment of an information processing apparatus, an information processing method, a playback apparatus, and a DVD playback apparatus to which the playback method according to the present invention is applied.
FIG. 2 is a block diagram of an embodiment showing a configuration of a main part thereof.
FIG. 3 is a diagram for explaining that;
FIG. 4 is a diagram for explaining that;
FIG. 5 is a flowchart for explaining the operation.
FIG. 6 is a flowchart for explaining the operation.
FIG. 7 is a block diagram showing a configuration of another embodiment of an information processing apparatus, an information processing method, a playback apparatus, and a DVD playback apparatus to which the playback method according to the present invention is applied.
FIG. 8 is a diagram showing a hierarchical structure of a DVD stream.
FIG. 9 is a block diagram showing a configuration of a conventional DVD playback apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Optical pick-up, 2 ... Disk, 3 ... Processor, 4 ... Navigation Pack detection mechanism (Navi Pack parser), 5 ... Demultiplexer, 6 ... Data bus, 7 ... Memory, 8 ... CPU, 9 ... Video decoding apparatus, DESCRIPTION OF SYMBOLS 10 ... Speech decoder, 11 ... Memory controller, 21 ... Stream parser, 22 ... Input pack counter, 23 ... Counter buffer

Claims (6)

An information processing apparatus in which a pack of control information is input in a single stream together with a pack of content information,
Means for determining a pack of the control information according to a specific pattern in the stream ;
Means for counting the number of packs of the input stream;
A plurality of buffers for holding the pack count value ,
While storing the stream as it is in the main memory,
Means for calculating and holding a value for specifying a storage position in the main memory when the pack of the control information is determined is calculated from a pack count value held in the buffer; Processing equipment. The information processing apparatus according to claim 1,
The means for discriminating the pack of control information according to a specific pattern in the stream includes all values of system header start code, packet start code prefix, stream id, and sub stream id provided in the pack of control information in the stream. An information processing apparatus comprising: means for detecting An information processing method in an information processing apparatus in which a pack of control information is input in a single stream together with a pack of content information,
Determining the pack of control information according to a specific pattern in the stream;
Count the number of packs of the input stream,
Buffer multiple pack count values ;
While storing the stream as it is in the main memory,
An information processing method, comprising: calculating and holding a value specifying a storage position in the main memory when the pack of the control information is determined by calculation from the buffered pack count value . A playback device having playback means for playing back a recording medium in which a pack of control information and a pack of content information are recorded in a single stream,
Means for determining a pack of the control information according to a specific pattern in the stream ;
Means for counting the number of packs of the input stream;
A plurality of buffers for holding the pack count value ,
While storing the stream as it is in the main memory,
Means for calculating and holding a value for specifying a storage position in the main memory when the pack of the control information is determined is calculated from a pack count value held in the buffer; apparatus. The playback apparatus according to claim 4, wherein
The means for discriminating the pack of control information according to a specific pattern in the stream includes all values of system header start code, packet start code prefix, stream id, and sub stream id provided in the pack of control information in the stream. A playback apparatus comprising: means for detecting A reproduction method in a reproduction apparatus for reproducing a recording medium in which a pack of control information and a pack of content information are recorded in a single stream,
Determining the pack of control information according to a specific pattern in the stream;
Count the number of packs of the input stream,
Buffer multiple pack count values ;
While storing the stream as it is in the main memory,
A reproduction method characterized in that a value for specifying a storage position in the main memory when the pack of control information is determined is calculated and stored by calculation from the buffered pack count value .

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