KR20000055848A - Method for recording search information of digital data stream and searching the recorded data by using the search information - Google Patents

Abstract

PURPOSE: A method for generating and recording searching information of recording digital dat stream, searching method using the method, and recording medium therefor is provided to search a data stream corresponding to requested presentation time information accurately by generating presentation time information, start stream packet receiving time information and time offset information to record information in a recording assembly general information. CONSTITUTION: If a recording start key is inputted by a user(S10), an application packet arrival time(APAT) of a transport packet primarily received(S11). A transmitted data stream is recorded in a recording medium such as a DVD(digital versatile disk) as a unit of a sector(S12). Program clock reference(PCR) information included in adaptation header information of the transport packet is detected(S13). An application packet approval time(APAT) of the transport packet in which primary program clock reference(PCRF) information is detected is detected(S14). If a steam object unit(SOBU) is partitioned(S15), A count value for being counted at a uniform unit time interval while the steam object unit(SOBU) is partitioned is generated as incremental application packet arrival time(IAPAT) information, and generated incremental application packet arrival time(IAPAT) information is recorded in incremental application packet arrival time(IAPAT) information field of a mapping list(MAPL)(S16). If a recording end key is inputted by the user(S17), A data stream partitioned as the stream object unit(SOBU) is partitioned as one recording stream object(SOB)(S18).

Description

Generation for recording search information of digital data stream and searching the recorded data by using the search information

The present invention partitions and records a received digital data stream into a recording assembly and a recording unit on a recording medium such as a digital video disc, and detects navigation information for managing and searching the recorded digital data stream in a data stream within the recording assembly. The present invention relates to a method of generating and recording search information of a recording digital data stream using the same program time reference information, and to use the same in a search operation.

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, Receives a digital data stream from a set-top box and stores it in a streamer, such as a digital video disc (DVD) recorder, via a communication interface such as an IEEE-1394 serial bus, and edits the stored digital stream. And a system capable of reproducing digital audio and video through an AV output device such as a television by reproducing and transmitting the communication interface to a set top box through media.

In such a system, a recording object (Stream OBject (SOB)) which is a recording unit for a digital data stream of a single program and a recording unit (Stream OBject (SOBU)) which constitutes the recording assembly are divided on a recording medium such as a DVD. Research on how to generate and record search information for searching and managing partitioned SOBs and SOBUs, and in particular, request time information selected by a user is particularly desired. There is a demand for a study on how to quickly search the recorded data stream corresponding to the Presentation Time Stamp (PTS) without searching delay and searching error.

Accordingly, the present invention has been made in view of the above circumstances, and records the received digital data stream into recording assemblies and recording units on a recording medium such as a digital video disc, and records the partitioned recording assemblies and recording units. Search and association information for associating the management information for managing with the search request time information selected by the user based on the program time reference information detected in the data stream in the corresponding record set, An object of the present invention is to provide a method of generating and recording a search information of a recorded digital data stream, a search method using the same, and a recording medium according to the same, so that the recorded data stream corresponding to the search request time can be quickly and accurately searched.

FIG. 1 schematically illustrates a search information generation and recording method of a recorded digital data stream and a system to which a search method using the same is applied according to the present invention.

2 shows a configuration of a recording digital data stream according to the present invention,

3 is a diagram illustrating a data stream recording and management information generation and recording process according to the present invention;

4 shows management information of a recording data stream according to the present invention;

FIG. 5 shows some details of management information of a recording data stream according to the present invention; FIG.

6 is a flowchart illustrating an operation of a method of generating and recording search information of a recorded digital data stream according to the present invention;

7 shows an operational flowchart of a method for searching a recorded digital data stream according to the present invention.

※ 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 an aspect of the present invention, there is provided a method of generating and recording search information of a recording digital data stream, the method comprising: partitioning and recording a digital data stream received in units of packets in units of recording aggregates; Generating and recording search time information for searching a packet recorded in the recording aggregate unit based on arrival time information of the packet; and displaying a playback screen display time of the generated and recorded search time information and a search request packet; And generating and recording the linkage information representing the correlation of the corresponding record aggregate.

In addition, the search method of the recording digital data stream according to the present invention, when the packet search corresponding to the search request time from the recording medium in which the digital data stream received in the packet unit is recorded in the recording aggregate unit, the arrival time of the packet A step 1 of reading recorded linking information to show a correlation between recorded search time information generated and recorded based on a playback screen display time of a search request packet: arrival of the search request time and the first packet of the record set Step 2 of calculating relative time length with time: Step 3 of converting the search request time to arrival time information by calculating the read linkage information and the calculated relative time length: and the converted time information and the recording. The time information generated and recorded corresponding to the recording unit constituting the collection is compared to correspond to the search request time. Characterized in that comprises a step 4 for searching the kit.

In addition, the recording medium according to the present invention includes a first area in which digital data streams received in packet units are recorded separately in units of predetermined record aggregates; A second area for recording search time information generated based on a packet arrival time for searching for the received recorded packet; and correlation between the generated recorded search time information and playback screen display time information of the search requested packet; And a third area for recording the linking information indicating the relationship.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, a search method for generating and recording a search information of a recording digital data stream according to the present invention, a search method using the same, and a preferred embodiment of a recording medium according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 schematically illustrates an embodiment of a system to which a method of generating and recording search information of a recording digital data stream according to the present invention is applied, the system comprising a set top box 100, a communication interface (IEEE 1394) and a streamer. The set-top box 100 receives and demultiplexes a transport stream (TS) multiplexed with a plurality of broadcast programs encoded by a system encoder from a broadcasting station. Upon request, the system 140 decodes the transport stream for the broadcast program tuned by the tuner processing unit 110 by the control unit 140 and outputs it through an AV set such as a television, or tuned by a user's request. The broadcast program is transmitted to the streamer 200 through the IEEE1394 communication interface 130 or 210, and the streamer 200 is used to digitally broadcast the broadcast program. It may be recorded in a recording medium 230 such as a video disk (DVD).

In addition, the set-top box 100 receives the broadcast program read from the recording medium 230 by the streamer 200 according to the user's request via the IEEE 1394 communication interface (210, 130) as a decoder 120 The broadcast program can be played by decoding and outputting to a television.

On the other hand, the control unit 250 of the streamer 200, when recording the digital data stream, controls the input stream to be recorded on the recording medium 230 by the storage stream processing unit 220, wherein the data Each transport packet (TSP) of the stream is recorded in sector units on the recording medium together with the application packet arrival time (APAT). In addition, the controller 250 divides and records the recorded data stream into stream record units (SOBU: Stream OBject) units, and maps navigation data for each record unit to search and manage the recorded data streams. Create and record Mapping List (MAPL) information.

The configuration and recording process of the data stream recorded as described above will be described in detail with reference to FIG. 2.

First, FIG. 2 illustrates a configuration of a digital data stream according to the present invention. A transport stream (TS), which is a data stream transmitted from the set-top box 100, is a transport packet (TSP) having a size of 188 bytes. Transport packet (TSP), which includes a 4-byte header field including a packet identifier (PID) and program clock reference (PCR) information. An adaptation header field and a program elementary stream (PES) packet are included. The program elementary stream packet (PES Packet) includes a reproduction output of decoded data. Presentation (Optional PES Header) including the presentation time information (PTS: Presentation Time Stamp, hereinafter 'PTS') field indicating the time The PTS time information included in the optional PES header is used as search time information (ST) that the user selects and designates when searching.

The program time reference (PCR) information recorded in the adaptation header field of the transport packet (TS Packet) configured as described above represents a time reference value for a program of the transport stream. A time obtained from a system encoder (not shown) for encoding a stream is sampled with a system clock of 27 MHz, and the sampling interval uses 0.0037 seconds. Therefore, PCR information represented by 6 bytes (actual 42 bits) can be represented from 0 seconds up to 162890.4 seconds, and is reset to 0 seconds when the maximum is 162890.4 seconds.

On the other hand, the presentation time information (PTS, screen display time information) is a value representing the presentation time of the reproduction output (Presentation) of the decoded data, it is used as the time management information of the data reproduction output, for example, with a precision of 90Khz The length of 33 bits can be used to represent a range of 24 hours. In particular, it is used as search request time information that the user selects and specifies.

Such a relationship between the program time reference (PCR) information and the presentation time information (PTS), in particular, the time relationship within the same transport stream will be described by way of example. First, the transmission speed of the transport stream TS is transmitted. Is 10 Mbps, and the buffering capacity of the decoder for decoding the transport stream (TS) is 10 Mbit, the PTS of the data stream that is varied by buffering and decoding by the PCR time and decoder of the transmitted transport stream. Between times, a time delay (PCR < PTS) from 0 to 1 second is generated.

Therefore, the PCR time corresponding to the PTS _S time, which is the search request time (ST) information selected and specified by the user, that is, the search target PCR _T time is a time difference between the specified PTS time and a maximum of 1 second (PCR _T <= PTS _S). -1 second).

Hereinafter, a method of partitioning and recording the received digital data stream into the SOB and SOBU, and management information therefor, in particular, the PTS _S time, which is the search request time information designated and selected by the user, is recorded. A search information generation and recording method for searching a stream will be described in detail with reference to FIG. 3.

3 illustrates a process of recording and generating management information of a digital data stream according to the present invention. The streamer 200 is a digital data stream received from the set-top box 100, that is, a transport stream TS. Is recorded in a recording unit (SOBU) having a predetermined recording size or a recording size of a predetermined range, and the packet arrival time increase amount (IAPAT), which is the length information of unit time for the partitioned recording unit (IAPAT), hereinafter 'IAPAT Generating and recording information as the time management information of the recording unit, and further partitioning the recorded recording units SOBU into one recording assembly SOB, wherein the recording assembly SOB includes: Continuous recording operation for recording the received data stream on a recording medium such as a DVD, that is, from the time of recording start (Rec Start) to the time of recording stop (Rec Stop) (or recording stop). The recording units partitioned and recorded are divided into one recording assembly SOB, and the controller 250 of the streamer 200 manages the recording assembly SOB and the recording unit SOBU to be partitioned and recorded. The management information for searching is generated and recorded on the recording medium, which will be described in detail with reference to FIGS. 4 and 5.

FIG. 4 illustrates management information of a recording digital data stream, in particular, recording aggregate information (SOBI), according to an embodiment of the present invention. The recording aggregate information (SOBI) is illustrated in FIG. Is composed of general information (SOB_GI: Stream OBject General Information, hereinafter referred to as 'SOB_GI') and a mapping list (MAPL). The mapping list (MAPL) is a unit time of a recording unit (SOBU). Consists of a plurality of Incremental Application Packet Arrival Time (IAPAT) information, which is length information, and the record aggregation general information SOB_GI is a recording unit SOBU as shown in FIG. A recording unit size (MAPU_SZ) field indicating the size of the field; A recording unit unit time shift (MTU_SHFT) field indicating a weight with respect to the unit time of the recording unit; A mapping list entry number (MAPL_ENT_NS) field indicating the number of entries in the mapping list; A start stream packet arrival time (S_S_APAT) field indicating an arrival time of a packet corresponding to the first stream of the recording aggregate SOB; A last stream packet arrival time (S_E_APAT) field indicating an arrival time of a packet corresponding to the last stream of the record aggregation SOB; And a packet of a transmission packet in which the first program time reference (PCR _F ) information representing the first detected program time reference information (PCR) and the first program time reference (PCR _F ) information are detected in the SOB. It consists of a time difference information (T_OFFSET) field between the arrival time (APAT _PCR ), the time difference information (T_OFFSET), the search request time (ST) selected by the user, that is, the PTS _S time to the record set ( It is used as search information for linking the start stream packet arrival time (S_S_APAT) information and the packet arrival time increase amount (IAPAT) information, which is management information for managing the SOB) and the recording unit (SOBU).

On the other hand, the packet arrival time increase amount (IAPAT) information, as shown in Fig. 3, is a unit time that is a count value (number) counted at a predetermined unit time interval (for example, X = 25.1ms) in the recording unit (SOBU) division As the length information, the time difference information T_OFFSET is generated and recorded in the general information SOB_GI, and the packet arrival time increase amount is time management information for each of the recording units SOBU constituting the recording set SOB. (IAPAT) information is recorded in the mapping list MAPL, respectively.

For reference, instead of the time difference T_OFFSET information, a packet arrival time (APAT _PCR ) of a transmission packet (TSP) in which first program time reference (PCR _F ) information and the first program time reference (PCR _F ) information is detected is determined. The data may be recorded in the general information of the aggregate information SOB_GI, and may be read out during the search operation.

Hereinafter, a description will be given in detail of a search method for generating and recording a search information of a recorded digital data stream and a search method using the same according to an embodiment of the present invention with reference to FIGS.

First, FIG. 6 illustrates an operation flowchart of a method for generating and recording search information of a recording digital data stream according to an embodiment of the present invention. First, the recording mode is controlled by the control unit 250 of the streamer 200. ) Is set, when the recording start key (Key) is input by the user (S10), the first time immediately after the recording start key (Key) of the transport stream (TS) transmitted from the set-top box 100 is inputted A packet arrival time (APAT) of the arrived transport packet is detected (S11), and the detected packet arrival time (APAT) is stored in the memory 260 with the start stream packet arrival time (S_S_APAT) information of the recording assembly SOB. The program time to be temporarily stored and recorded in the sector (S12) on the recording medium such as a DVD (Sector) on the recording medium such as DVD, and included in the adaptation header information of the transport packet as described above. Examine the criteria (PCR) information (S13) for, in case the program time reference (PCR) information detected by the first program, the first time reference (PCR _F) information of the recording assembly (SOB) that is temporarily stored in the memory 260.

In addition, the packet arrival time (APAT) of the transmission packet in which the first program time reference (PCR _F ) information is detected (S14), and the packet corresponding to the first program time reference (PCR _F ) information of the recording aggregate. Temporarily stored in the memory 260 as the arrival time (APAT _PCR ) information.

Subsequently, when the recorded unit sectors have a predetermined recording size (for example, 32 sectors) or a recording range (26 sectors to 32 sectors) in a predetermined range, the recorded unit sectors are divided into one recording unit SOBU. When the recording unit SOBU is partitioned in this manner, as shown in FIG. 3, the count value counted at a predetermined unit time interval (for example, X = 25.1 msec) during partitioning of the recording unit SOBU is shown in FIG. 3. The number, e.g., IAPAT = 3) is generated as management information of the recording unit SOBU, that is, packet arrival time increase amount (IAPAT) information, which is unit time length information of the recording unit SOBU. The recording operation of recording (S16) in the IAPAT information field of the MAPL) is repeatedly performed.

Subsequently, when a recording end (or suspend) key is input by the user (S17), the data stream partitioned and recorded into the recording unit SOBU is partitioned into one recording assembly SOB, and The management information described with reference to FIG. 5 is recorded on the general information SOB_GI. In this case, the first program time reference (PCR _F ) information and the first program time reference (temporarily stored in the memory 260) are recorded. PCR _F ) calculates time difference (T_OFFSET = APAT _PCR- PCR _F ) information between the packet arrival time (APAT _PCR ) information of the transmission packet in which the information is detected, and records it on the recording aggregate general information (SOB_GI) (S19); Alternatively, the first program time reference (PCR _F ) information and the packet arrival time (APAT _PCR ) of the corresponding transmission packet (TSP) are recorded on the general information SOB_GI. The time difference T_OFFSET information recorded as described above is search request time ST information that is selected and specified by a user as described above, that is, PTS _S time information and the start stream packet arrival time of the recording assembly SOB ( S_S_APAT information, which is a search information linking the packet arrival time increase amount (IAPAT) information, the start stream packet arrival time (S_S_APAT) information, although the time information on the start stream of the record aggregation (SOB), While the time information is counted by a reference time irrelevant to the PTS time information requested to be searched by a user, the first program time reference (PCR _F ) information has a constant relationship with the PTS _S time information (PTS-1). Time information with seconds &lt; = PCR &lt; PTS).

Accordingly, the time difference T_OFFSET information generated and recorded according to the present invention includes the start stream packet arrival time S_S_APAT and the packet arrival time increase amount IAPAT information of the recording assembly SOB, and the PTS time requested by the user. By making the correlation between the information, the recording position of the recording data stream corresponding to the PTS time information requested by the user is determined by the start stream packet arrival time (S_S_APAT) information, packet arrival time increasing amount (IAPAT) information, and time difference (T_OFFSET). ) Can be searched using information.

On the other hand, the recording medium provided by the recording information generation recording method of the recording digital data stream according to the present invention includes a data area in which the digital data stream is partitioned and recorded in units of recording aggregates, and a search for each of the partitioned recording aggregates. The information is configured to include a management area generated and recorded based on the program time reference (PCR) information.

7 is a flowchart illustrating a method for searching a recorded digital data stream according to the present invention. First, in a state in which a search mode is set by the controller 250 of the streamer 200, When the search request time ST specified by the input is input (S30) to the presentation time information PTS indicating the presentation time of the decoded data, the input search request time ST, in particular, the search request starts. A predetermined time is subtracted from the PTS _S time, which is time, for example, as shown in FIG. 3 to calculate PCR _T time (PCR _T = PTS _S -1 second), which is the search target time (S31). The calculated PCR _T time is necessarily smaller than the PTS _S time for which the search is requested, so that a case in which the data stream to be searched is pasted does not occur. Thereafter, the calculated PCR _T time and the time difference T_OFFSET information generated and recorded in the recording aggregate general information SOB_GI are summed to obtain a target packet arrival time corresponding to the PCR _T time (APAT _T = PCR _T + OFFSET = PCR). _T + APAT _PCR- PCR _F ) information is calculated (S32), and the calculated target packet arrival time (APAT _T ) information is generated and recorded in the recording aggregate general information SOB_GI, and each start stream packet arrival time S_S_APAT is recorded. Compares the information with the information (S33), searches for a record assembly (SOB) having the approximate start stream packet arrival time (S_S_APAT &lt; = APAT _PCR ) information that does not exceed the target packet arrival time (APAT _PCR ) information; When the corresponding record set SOB is searched (S34), the packet arrival time increase amount IPAT recorded in the mapping list MAPL of the searched record set SOB is cumulatively summed (ΣIAPAT). Multiply the unit time interval (e.g. X = 25.1ms) to obtain the SOB The partition position of any recording unit SOBU constituting the unit is searched. That is, a value (ΣIAPAT x 25.1 ms) calculated by multiplying the cumulative sum by a predetermined unit time interval X is subtracted the start stream packet arrival time S_S_APAT from the target packet arrival time APAT _T. Detects the index of the mapping list (MAPL) having a proximity value (ΣIAPAT x 25.1ms &lt; = APAT _T -S_S_APAT = PCR _T + T_OFFET-S_S_APAT) that does not exceed the value (APAT _T -S_S_APAT) and correspondingly The recording unit SOBU is searched and selected (S36).

Thereafter, the PTS information recorded in the data stream of the searched recording unit SOBU, in particular, the packet header area, is detected (S37), and the detected PTS _D information is directly connected to the PTS _S time selected by the user. By comparing (S38) and searching for a matching transmission packet (S39), the position of the data stream corresponding to the PTS _S time, which is the search request time selected by the user, is accurately searched.

Meanwhile, as described above, instead of the time difference information T_OFFSET on the recording aggregate general information SOB_GI, a transmission packet in which first program time reference (PCR _F ) information and the first program time reference (PCR _F ) information are detected. Even if the packet arrival time (APAT _PCR ) information of the TSP is recorded, the target packet arrival time (APAT _T ) information is obtained by using the first program time criterion PCR _F and the packet arrival time APAT _PCR . It can be calculated (APAT _T = PCR _T + APAT _PCR -PCR _F = PCR _T + T_OFFSET). Accordingly, the search operation accurately searches the location of the data stream corresponding to the PTS _S time, which is the search request time selected by the user.

The discovery information generation and recording method of the recorded digital data stream according to the present invention as described above, the search method using the same, and the recording medium according to the present invention, the presentation is the search request time information transmitted from the set-top box 100 by the user's selection designation Time difference (T_OFFSET) information linking time information (PTS), start stream packet arrival time (S_S_APAT) information and packet arrival time increment amount (IAPAT) information for managing the record aggregation SOB and the recording unit SOBU, respectively. Alternatively, the first program time reference (PCR _F ) information and the corresponding packet arrival time (APAT _PCR ) information in the record set SOBU are generated and recorded in the record set general information SOB_GI and used for reading during the search operation. It is a very useful invention that can accurately search the data stream corresponding to the searched presentation time information (PTS).

Claims (10)

Partitioning and recording the digital data stream received in packet units in units of recording aggregates; Generating and recording search time information for searching a packet recorded in the recording aggregate unit based on arrival time information of the packet; and And generating and recording linkage information indicative of a correlation between the generated recorded search time information and the playback screen display time of the search-requested packet in correspondence with the recording aggregate. How to create and record navigation information. The method of claim 1, The linking information comprises: program time reference information initially detected in a data stream in the recording aggregate and arrival time information of a packet from which the program time reference information is detected. Generation recording method. The method of claim 2, The link information is search time information of the recorded digital data stream, wherein the time difference information between the program time reference information first detected in the data stream in the recording aggregate and the arrival time information of the packet from which the program time reference information is detected. Generation recording method. The method of claim 1, And the step (3) records the association information in the general information of the collective information SOB_GI, which is a management information field of the recording aggregate. A method of searching for a packet corresponding to a search request time from a recording medium in which digital data streams received in packet units are classified and recorded in recording aggregate units, the method comprising: A first step of reading the recorded linkage information to indicate a correlation between the search time information generated and recorded based on the arrival time of the packet and the display time of the reproduction screen of the search request packet; Calculating a relative time length between the search request time and the arrival time of the first packet of the record aggregate; Converting the search request time into arrival time information by calculating the read association information and the calculated relative time length: and And comparing the converted time information with the recorded time information corresponding to the recording unit constituting the recording aggregate, and searching for a packet corresponding to the search request time. How to search the stream. The method of claim 5, And said linking information is generated and recorded corresponding to said recording set. The method of claim 5, Time information recorded and generated in correspondence with the recording unit, and packet arrival time increase amount (IAPAT) information for the unit time, which is generated in the recording unit unit. A first area in which digital data streams received in packet units are divided and recorded in predetermined record aggregate units; A second area for recording search time information generated based on a packet arrival time for searching for the received recorded packet; and And a third area for recording linkage information indicating a correlation between the generated recorded search time information and the playback screen display time information of the searched request packet. The method of claim 8, And the linkage information is generated and recorded corresponding to the record collection body. The method of claim 8, And the linking information is relative time information between the program time reference information first detected in the data stream in the recording aggregate and the arrival time information of the packet from which the program time reference information is detected.