KR20000040842A - Method for generating and recording time map information of recording digital data stream and method for detecting recording stream - Google Patents

Abstract

PURPOSE: A method for generating and recording the time map information of a recording digital data stream is provided to reduce the amount of operation while detecting a certain recording data stream without increasing the size of the time map information during recording the digital data stream in a recording medium. CONSTITUTION: A received digital data stream is recorded in a recording medium for separating the recorded digital data stream into recording units of identified size. Then, fine detecting information is generated and recorded for each separated recording units. And, detecting information is generated and recorded roughly by a certain time unit. Moreover, to detecting the data stream recorded in the recording medium, the index information of the recording unit in the rough detecting information, which is near the visual information of the recorded data to be detected, is detected. Then, the sum of the recording time sizes in the fine detecting information corresponding to the index information of recording unit is calculated for checking if the sum is larger than the visual information. Therefore, the target sector of detection, which is corresponding to the visual information of the recording data to be detected, is calculated according to the result of check.

Description

Time map information generation and recording method for recording digital data streams

The present invention provides a method of receiving and storing a digital data stream on a recording medium such as a digital video disc, and generating and recording time map information, which is search information for the stored digital data stream, and using the time map information. It is about how to navigate.

In the conventional analog television broadcasting, a video signal to be transmitted is modulated by AM or FM and transmitted through radio waves or cables. Recently, with the development of digital technologies such as digital image compression and digital modulation and demodulation, the standardization of digital television broadcasting is advancing at a rapid pace, and digitalization based on MPEG (Moving Picture Experts Group) is also used in conventional terrestrial, satellite, and cable broadcasting. Doing.

According to the development of digital video / audio compression technology and digital transmission technology, the digital broadcasting can provide higher quality service than analog service, and can transmit a plurality of broadcast programs in the same bandwidth, and use digital communication media and digital storage media. Has the advantage of increasing interoperability.

In such digital broadcasting, a plurality of broadcast programs encoded on the basis of MPEG are multiplexed and transmitted in the form of a transport stream (TS), which is received by a set top box or the like installed on the receiving side. A plurality of broadcast programs included in the transport stream are demultiplexed so that only one desired broadcast program is selected. The selected broadcast program is decoded by a decoder built into the set-top box to decode the original audio and video signal such as a television. It is delivered to A / V output device.

As described above, researches on a system for receiving a digital broadcast signal and outputting it to an A / V output device such as a television, as well as storing, editing, and playing the received broadcast signal in a storage medium, As shown in FIG. 1, a streamer such as a digital video disk (DVD) recording and reproducing apparatus is received through a communication interface 130 or 210 such as an IEEE-1394 serial bus after receiving a digital data stream from the set-top box 100. The digital audio and video can be reproduced through an AV output device such as a television by storing the data in a streamer 200 and editing and reproducing the stored digital stream to the set-top box 100 through the communication interfaces 210 and 130. There is ongoing research into the system.

In such a system, the digital data stream recorded on a recording medium such as a DVD must be generated by recording stream time map information associated with the recording stream for retrieval to use the recorded stream time map information during reproduction. Thus, the desired recorded data stream can be searched and reproduced. Here, the time map information is accumulated time map information generated and recorded corresponding to a predetermined time or a predetermined number of stream recording units for the general search of the stream recording unit, and records generated and recorded corresponding to each stream recording unit for the fine search. It consists of unit time map information.

Therefore, after searching roughly using the time entry information among the time map information recorded in the navigation data area in the search mode, the desired stream recording unit is searched through a fine search using the recording unit entry information, and then the corresponding stream recording unit is recorded. It is possible to wait until the packet arrival time (TS APAT) of the desired transport stream packet is read from the first sector and read from the transport stream packet existing after the time point at which the desired packet arrival time (TS APAT) is read.

As a method of generating the time map information as described above, a recording unit (hereinafter, also referred to as a mapping unit) which is a minimum unit for the recorded data stream for generating time map information is recorded by the data stream. A method of dividing based on the number of sectors and generating visual information corresponding to each mapping unit is being considered. The time information should be expressed as a packet arrival time for each transport stream packet constituting the data stream to the streamer. The packet arrival time is 9 bits represented by 27 MHz and 21 or more represented by 90 KHz. It must be represented by at least 4 bytes including the bits. As such, when the time information generated corresponding to each mapping unit is represented by 4 bytes or more, the data amount of the stream time map information becomes very large.

Accordingly, the time information can be represented with a small amount of data. The time information can be expressed as incremental application packet arrival time (IAPAT) information of a predetermined bit (for example, 12 bits) for a corresponding mapping unit. A method is proposed.

In this method, as shown in FIG. 2, a stream record unit (SOB) recorded on a recording medium is divided into a stream record unit (SOBU) which is a mapping unit having the same size (for example, the same number of sectors). Each of the recording unit time map information (SOBU Time Map) is composed of the packet arrival time increase amount (IAPAT), which is the time size information of the corresponding recording unit (SOBU), each of the accumulated time map information (Accumulated Time Map) It consists of accumulated time size information ACC_TM of M recording units SOBU.

A method of searching for a portion corresponding to a predetermined packet arrival time S_APAT in the recording assembly SOB while the time map information is recorded together with the digital data stream as described above will be described with reference to FIGS. 1 to 3. do.

First, when a search request for a portion corresponding to a predetermined packet arrival time S_APAT is set by the user, the controller 250 of the streamer 200 sets the addition time SUM_TM to 0 in the first internal register (not shown). At the same time, the count value K is set to 1 and stored in the second internal register (step S11).

Thereafter, the controller 250 adds the accumulated time ACC_TM (K) corresponding to the stored count value K to the stored addition time SUM_TM to set a new addition time SUM_TM and sets the new addition time. It is stored in 1 internal register (step S13).

Subsequently, the controller 250 checks whether the stored addition time SUM_TM is greater than the searched packet arrival time S_APAT (step S15), and if it is determined that it is not large, in the second internal register. The stored count value K is increased by one, the newly set count value K is stored in the second internal register (step S17), and the process returns to the above-described step S13 to repeat the same operation as described above.

On the other hand, when it is determined in step S15 that the stored addition time SUM_TM is greater than the searched packet arrival time S_APAT, the control unit 250 determines that the stored addition time SUM_TM is equal to the stored addition time SUM_TM. The accumulated time ACC_TM (K) corresponding to the stored count value is subtracted, set to a new addition time SUM_TM, and stored in the first internal register (step S19).

Thereafter, the controller 250 includes the number of recording units SOBU corresponding to the accumulated time size information ACC_TM of the accumulated time map information in the count value K stored in the second internal register. The value M is multiplied, set to a new count value K, and stored in the second internal register (step S21).

Subsequently, the controller 250 supplies the packet arrival time increase amount [IAPAT (K)] corresponding to the count value K stored in the second internal register at the addition time SUM_TM stored in the first internal register. Addition is made to the new addition time SUM_TM and stored in the first internal register (step S23).

Next, the controller 250 checks whether the stored addition time SUM_TM is greater than the searched predetermined packet arrival time S_APAT (step S25), and if it is determined that the storage time is not large, the second internal register. Increase the count value K stored by 1, store the newly set count value K in the second internal register (step S27), and return to the above-described step S23 to repeat the same operation as described above.

On the other hand, when it is determined in step S25 that the stored addition time SUM_TM is greater than the searched predetermined packet arrival time S_APAT, the control unit 250 stores the count value stored in the second internal register. A value obtained by multiplying (K) by the recording unit size SOBU_SZ is obtained as a target sector Target_Sector corresponding to the searched request packet arrival time S_APAT (step S29). In this case, variables representing time such as addition time (SUM_TM), cumulative time size (ACC_TM), and packet arrival time increase amount (IAPAT) are assumed to use the same time unit, but the time units of the variables are different. In this case, a process of unifying the units is required.

Thereafter, the controller 250 finds a desired recording unit SOBU (SOBU 3M + 2 in FIG. 2) using the target sector Target_Sector obtained above, and searches each transport stream packet from the first sector of the recording unit. A packet arrival time (APAT) is detected, and a target packet arrival time (APAT) corresponding to the searched predetermined packet arrival time (S_APAT) is searched for. Subsequently, the control unit 250 reads the transport stream packet existing after the searched target packet arrival time (APAT) and transmits the read stream processor 240 to the set-top box 100 via the IEEE 1394 interface 210. Will be controlled.

Since the cumulative time size information (ACC_TM1, ACC_TM2, ACC_TM3, ...) of the accumulated time map information (ACC_TM1, ACC_TM2, ACC_TM3, ...) in the time map information made as described above is expressed as the accumulated time size for the M units SOBU. When searching for a part corresponding to the predetermined packet arrival time S_APAT, the cumulative operation of the accumulated time size information [ACC_TM (K)], the subtraction operation of step S19, and the like as in steps S13 to S17 of FIG. Since the multiplication operation of step S21 has to be performed, there is a problem that the amount of calculation of the control unit increases, resulting in a delay of the search time due to such an increase in the amount of calculation.

Accordingly, the present invention has been made in view of the above circumstances, and it is possible to reduce the amount of computation when searching for a predetermined record data stream without increasing the size of the time map information when the digital data stream is recorded on the recording medium. It is an object of the present invention to provide a method for generating and recording time map information of a recordable digital data stream.

Another object of the present invention is to provide a recording digital data stream search method capable of reducing a search time for a digital data stream recorded on a recording medium.

1 schematically shows a system to which a time map information generation recording method of a recording digital data stream and a recording stream searching method are applied;

FIG. 2 is a diagram for explaining the configuration of time map information generated and recorded by the time map information generation and recording method of a conventional recording digital data stream,

FIG. 3 illustrates a conventional flow of searching for a recording data stream using the time map information of FIG. 2,

4 is a diagram for explaining the configuration of time map information generated and recorded by the time map information generation and recording method of the recorded digital data stream according to the present invention;

FIG. 5 illustrates a flow for a method of searching a record data stream using the time map information of FIG. 4.

※ Explanation of code for main part of drawing

100: set-top box 110: station selection processing unit

120: decoder 130210: communication interface

140,250: control unit 150,260: memory

200: streamer 220: storage stream processing unit

230: recording medium (DVD) 240: read stream processing unit

According to the present invention for achieving the above object, a time map information generation recording method of a recording digital data stream includes: a first step of recording a received digital data stream on a recording medium; Dividing the recorded digital data stream into recording units having the same size, and generating and recording fine search information in each partitioned recording unit; And a third step of generating and recording the coarse search information in predetermined time units.

Further, the recording digital data stream search method according to the present invention is a method for searching a data stream recorded on a recording medium, wherein the recording unit index information in the schematic search information is searched in proximity to the time information of the requested recording data. The first step to do; Calculating a cumulative sum of recording time sizes in fine search information corresponding to the searched record unit index information; A third step of checking whether the accumulated sum calculated in the second step is larger than the visual information of the searched record data; And a fourth step of calculating a search target sector corresponding to the time information of the searched requested record data according to the confirmation result.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a method for generating and recording time map information of a recording digital data stream and a searching method for a recording stream according to the present invention will be described in detail with reference to the accompanying drawings.

1 schematically illustrates a system to which a method for generating and recording time map information of a recording digital data stream according to the present invention can be applied. The system includes a set-top box 100, a communication interface (IEEE 1394), and a streamer. And 200).

The set-top box 100 receives a transport stream (TS) multiplexed with a plurality of broadcast programs encoded by a system encoder from a broadcasting station, and demultiplexes the transport stream (TS), which is selected by the controller 140 according to a user's request. The decoder 110 decodes the transport stream for the broadcast program tuned by the system decoder 120 and outputs it through an AV set such as a television, or transmits the broadcast program tuned at the user's request to the IEEE1394 communication interface 130 or 210. The streamer 200 may be transmitted to the streamer 200 so that the streamer 200 records the broadcast program on a recording medium 230 such as a digital video disk (DVD).

In addition, the set-top box 100 receives a broadcast program read from the recording medium 230 by the streamer 200 in response to a user's request via the IEEE1394 communication interface 210 or 130 and decodes it in the decoder 120. The broadcast program can be reproduced by outputting to a television set.

Next, a method of generating and recording time map information of a recording digital data stream according to an embodiment of the present invention will be described with reference to FIGS. 1 and 4.

When recording the digital data stream, the control unit 250 of the streamer 200 controls the storage stream processor 220 to record the input data stream on the recording medium 230. At this time, each transport stream packet of the data stream is recorded sector by sector on the recording medium together with the transport stream packet arrival time (TS APAT).

At this time, the control unit 250 of the streamer 200 is a stream recording unit (Stream OBject Unit) in the same size (for example, N sector) unit of the recorded data stream; SOBU] is divided and recorded, and a packet arrival time increase amount IPAT, which is time size information, is generated for each recording unit as stream recording unit (SOBU) time map information, which is fine search information.

In addition, the control unit 250 is a unit of a predetermined time interval (M sec, where M may be expressed as a time after the decimal point), and the index number of the recording unit SOBU including time data corresponding to every M sec. The recording unit index information (SOBU_N1, SOBU_N2, SOBU_N3, ...) to be expressed is generated as time index map information as schematic search information.

Thereafter, the controller 250 records the generated recording unit time map information and the time index map information in the memory 260 as management information of the corresponding recording aggregate SOB.

1, 4 and 5 for a method of searching for a portion corresponding to a predetermined packet arrival time S_APAT in the recording assembly SOB while the time map information is recorded together with the digital data stream as described above. It demonstrates with reference.

First, when a search request for a part corresponding to a predetermined packet arrival time (S_APAT) is set by a user, the controller 250 of the streamer 200 performs the search request as M sec, which is a partition unit of time index map information. The predetermined packet arrival time S_APAT is divided and the decimal point is discarded from the division result, and only the integer value P is taken (step S31).

Thereafter, the controller 250 sets the recording unit index information (ie, the P-th recording unit index information) of the time index map information corresponding to the integer value P of the division result value to K, and sets the set value K. Is stored in the first internal register (not shown) (step S33), and then the addition time SUM_TM is set to P and stored in the second internal register not shown (step S35).

Subsequently, the controller 250 adds the packet arrival time increase amount IAPAT (K) corresponding to the stored set value K to the stored addition time SUM_TM to set a new addition time SUM_TM. It is stored in a 2nd internal register (step S37).

Next, the control unit 250 checks whether the stored addition time SUM_TM is greater than the searched predetermined packet arrival time S_APAT (step S39), and when it is confirmed that it is not large, the first internal register. The stored set value K is increased by 1 to store the newly set set value K in the first internal register (step S41), and the process returns to the above-described step S37 to repeat the same operation as described above.

On the other hand, when it is determined in step S39 that the stored addition time SUM_TM is greater than the searched packet arrival time S_APAT, the control unit 250 stores the set value stored in the first internal register. The value obtained by multiplying the recording unit size SOBU_SZ by K) is obtained as a target sector Target_Sector corresponding to the searched request packet arrival time S_APAT (step S43). Herein, the variables representing the addition time (SUM_TM), the packet arrival time increase amount (IAPAT), M, and the like are assumed to use the same time unit, but the time units of the variables may be different. In this case, a unit unification process is required.

Thereafter, the controller 250 finds a desired recording unit SOBU (SOBU 3M + 2 in FIG. 4) using the target sector Target_Sector obtained above, and searches each transport stream packet from the first sector of the recording unit. A packet arrival time (APAT) is detected, and a target packet arrival time (APAT) corresponding to the searched predetermined packet arrival time (S_APAT) is searched for. Subsequently, the control unit 250 reads the transport stream packet existing after the searched target packet arrival time (APAT) and transmits the read stream processor 240 to the set-top box 100 via the IEEE 1394 interface 210. Will be controlled.

In the time map information according to the present invention as described above, since the time index map information is expressed by the index number of the recording unit SOBU including corresponding time data in units of predetermined time intervals (M sec), the predetermined packet When searching for a portion corresponding to the arrival time S_APAT, the cumulative operation of the accumulated time size information [ACC_TM (K)], the subtraction operation of step S19, and the like, in the conventional search method as in steps S13 to S17 of FIG. It is not necessary to perform the multiplication operation of step S21.

According to the time map information generation recording method and the recording stream search method of the recorded digital data stream according to the present invention as described above, in the time map information, the time index map information is corresponding to the predetermined time interval (M sec) unit. Since it is expressed by the index number of the recording unit SOBU including data, the computation amount can be significantly reduced when searching for a portion corresponding to a predetermined packet arrival time S_APAT, thereby reducing the searching time compared with the conventional method. It becomes possible.

Claims (8)

A first step of recording the received digital data stream on a recording medium; Dividing the recorded digital data stream into recording units having the same size, and generating and recording fine search information in each partitioned recording unit; And And a third step of generating and recording the coarse search information in predetermined time units. The method of claim 1, And the recording unit is partitioned in units of the same number of sectors. The method of claim 1, And the fine search information is recording time size information for each partitioned recording unit. The method of claim 1, And the coarse search information is represented by an index number of a recording unit including time data corresponding to the predetermined time interval. A method for searching a data stream recorded on a recording medium, A first step of searching for recording unit index information in the coarse search information close to the visual information of the searched requested record data; Calculating a cumulative sum of recording time sizes in fine search information corresponding to the searched record unit index information; A third step of checking whether the accumulated sum calculated in the second step is larger than the visual information of the searched record data; And And a fourth step of calculating a search target sector corresponding to the time information of the searched requested record data according to the verification result. The method of claim 5, The first step, A lower first step of dividing the time information of the searched requested record data by the generation time unit of the schematic search information and taking only an integer part as a division result value; And And searching the recording unit index numbers of the sequence corresponding to the division result value. The method according to claim 5 or 6, And wherein the second step is to add a recording time size corresponding to the searched record unit index number to the division result value. The method of claim 5, In the third step, when it is confirmed that the cumulative sum is not greater than visual information of the searched requested record data, Incrementing the recording unit index number by 1, accumulating a recording time size corresponding to the increased index into the cumulative sum, and checking whether the cumulative result value is larger than the time information of the searched requested record data; And a recording digital data stream searching method.