KR20000055028A - Method for recording digital data stream and for generating search information thereof - Google Patents

Abstract

PURPOSE: A method for generating and recording the search information of a recording digital data stream is provided to rapidly and exactly search a recording data stream corresponding to a search request time by reading and using search information for a stream object end time. CONSTITUTION: An STMAP_GI(Stream Time Map General Information) is composed of an MAPU_SZ(Minimum Mapping Unit Size) field, an MTU_SHFT(Mapping Time Unit Shift) field, an MAPL_ENT_NS(Number of Mapping List Entries) field, an S_S_APAT(Stream Start APAT) field, an S_E_APAT(Stream End APAT) field, an S_S_PTS(SOB Start PTS) field and an S_E_TIME(SOB End Time). The MAPU_SZ field indicates the size of an SOBU(Stream OBject Unit). The MTU_SHFT field indicates a weight value for the unit time of the SOBU. The MAPL_ENT_NS field indicates the quantity of a mapping list. The S_S_APAT field indicates the arrival time of a packet corresponding to the first stream of the SOB. The S_E_APAT field indicates the arrival time of a packet corresponding to the last stream of the SOB. The S_S_PTS field indicates program clock reference information corresponding to an SOB start stream. The S_E_TIME indicates time information for an SOB end time.

Description

Method for recording digital data stream and for generating search information

The present invention divides 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 generates and records search information on the recorded digital data stream, in particular, the end point of the division of the recording assembly. A search information generation and recording method of a recording digital data stream.

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 how to search for requested data streams, is desired. .

Accordingly, the present invention has been made in view of the above circumstances, and the received digital data stream is divided into recording units and recording units on a recording medium such as a digital video disc, and the recorded digital data stream is managed and Search information to search, in particular, to generate and record search information for the end point of the partition recorded recording aggregate, and to read and use the search information during the search operation, so that the record data stream corresponding to the search request time can be quickly and accurately searched. An object of the present invention is to provide a method of generating and recording search information of a recorded digital data stream.

1 schematically shows a system to which a search information generation and recording method of a record digital data stream according to the present invention is applied,

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

3A and 3B are diagrams illustrating a data stream recording and search information generation 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 the management information of the recording 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 received data stream in units of recording aggregates; And generating and recording search information based on the difference information between the time information detected in the data stream immediately before the partitioning of the partitioned recording assembly and the time information of the head of the next partitioned recording assembly. It features.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of a search information generation recording method of a recording digital data stream 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 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 it to the 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 information.

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

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 having a size of 188 bytes. The transport packet (TSP) may include an adaptation header (PCR) including a header field of 4 bytes including a packet identifier (PID) and program clock reference (PCR) information. An Adaptation Header field and a Program Elementary Stream (PES), wherein the Elementary Stream (PES) comprises: a Packet Start Code Prefix field for providing start information of a PES packet; A stream identification code (Stream_ID) field; A PES Packet Length field for providing data length information of a PES packet; An Optional PES Header field that provides copy related information, such as Copy Protection; And PES Packet Data fields that provide navigation data and the like, wherein the Optional Fields include Presentation Time Stamps (PTS) in which presentation time information is recorded. PTS 'field).

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) encoding a stream is sampled with a system clock of 27 MHz, and the sampling interval uses 0.0037 seconds. Therefore, the PCR information represented by 6 bytes (actual 42 bits) can be displayed from 0 seconds up to 162890.4 seconds. When the maximum 162890.4 seconds is reached, the PCR information is reset to 0 seconds again.

On the other hand, the presentation time information (PTS) recorded in the Optional Fields is a value representing the presentation time of the decoded data and is used as the time management information of the reproduction output. In this case, a range of 24 hours can be expressed using a precision of 90 kHz and a length of 33 bits.

3A and 3B illustrate a process of recording and managing information generation and recording of a digital data stream according to the present invention. The streamer 200 is a digital data stream, that is, a transport stream (TS) received from the set-top box 100. ) Is divided into recording units (SOBUs) 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 divided recording units, IAPAT '.) Information is generated and recorded as time management information of the recording unit, and the partitioned recording units are partitioned into one recording assembly (SOB), wherein the recording assembly (SOB) is received. Continuous recording operation for recording the data stream on a recording medium such as a DVD, i.e., starting from the time of recording start (Rec Start) to the time of recording stop (Rec Stop) (or recording stop). The recording units partitioned by recording are partitioned into one recording assembly (SOB), and the control unit 250 of the streamer 200 generates management information for managing and searching the recording assembly and the recording unit to be partitioned and recorded. Record on the recording medium. Management and search information for the start of the recording aggregate is first recorded in optional fields received in a transport stream, in particular, a program elementary stream (PES), as shown in FIG. 3B. Detects presentation time information (PTS), generates and records the start stream presentation time information (S_S_PTS), which is search information for a start point of the recording set (SOB), and manages and retrieves information about an end point of the recording set. Is a data stream recorded after the last presentation time information (S_E_PTS) and the presentation time information (PTS) detected just before the time point at which the recording aggregate is terminated, until the end of the actual recording aggregation partition (shaded in FIG. 3B). To generate and record the record aggregation section end time information (S_E_TIME), which is the sum of the recording times. Since the time information PTS is intermittently transmitted, the presentation time information PTS corresponding to the point of time when the recording assembly is actually partitioned cannot be detected, and after the presentation time information S_E_PTS is detected. The recording time of the data stream recorded up to the end point of the actual recording aggregate partition is a predetermined time to a count number that counts the number of packets of the data stream recorded after the last presentation time information S_E_PTS, in particular, the program elementary stream PES. A time value obtained by multiplying (for example, 1/30 seconds), that is, a time difference value between the time when the recording assembly is actually partitioned and the time of the last presentation time information S_E_PTS.

On the other hand, management and search information for the end point of the recording aggregate, the difference between the start stream presentation time information (S_S_PTS) and the recording aggregate partition end time information (S_E_TIME), instead of the recording aggregate partition end time information (S_E_TIME). The record aggregation block time information S_D_TIME, which is time information, may be generated and recorded.

Hereinafter, the management information generated and recorded will be described in detail with reference to FIGS. 4 and 5.

FIG. 4 shows recording aggregate information (SOBI: Stream OBject Information or STMAPI: Stream Time Map Information, hereinafter referred to as SOBI), which is management information of a recording digital data stream according to an embodiment of the present invention. The record aggregate information (SOBI) is composed of record aggregate general information (SOB_GI: Stream OBject General Information or STMAP_GI: Stream Time Map General Information, hereinafter referred to as 'SOB_GI') and a mapping list (MAPL). The mapping list MAPL is composed of a plurality of Incremental Application Packet Arrival Time (IAPAT) information, which is unit time length information of a recording unit (SOBU), and the general information of the recording aggregate (SOB_GI) is shown in FIG. 5. A recording unit size (MAPU_SZ) field indicating the size of the recording unit SOBU as shown in (a) of FIG. 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; A start stream presentation time information (S_S_PTS) field indicating program time reference (PCR) information corresponding to the record aggregation start stream; And a record aggregate segment end time information (S_E_TIME) field indicating time information on the end of the record aggregate, while the record aggregate segment end time information (S_E_TIME) field, as described above, starts stream presentation time information (S_S_PTS). ) May be replaced with a record aggregate partition time information S_D_TIME field, which is the difference time information between the record aggregate partition end time information S_E_TIME.

The packet arrival time increase amount (IAPAT) information is composed of packet arrival time increase amount (IAPAT) information, which is unit time length information according to a SOBU partition, as shown in FIG.

As described above, the start stream presentation time information S_S_PTS, which is search information for searching the start stream of the partitioned recording assembly SOB by continuously recording the received data stream as a single program, and the time information for the end point of the recording assembly. The recording aggregate section ending time information (S_E_TIME) or the recording aggregate section time required information (S_D_TIME) indicating are generated and recorded in the general aggregate information SOB_GI, respectively, and the recording unit SOBU constituting the recording aggregate SOB. The packet arrival time increase amount IPAT information, which is time management information for each, is recorded in the mapping list MAPL, respectively.

As described above, the recording set start stream time information S_S_PTS and the record set section end time information S_E_TIME or the record set section required time information S_D_TIME are generated by the search information generation and recording method of the recorded digital data stream according to the present invention. By recording and using the read request during the search request, the search information required for the search operation can be minimized, and the data stream corresponding to the searched presentation time information PTS can be searched more quickly and accurately.

On the other hand, as another embodiment of the search information generation and recording method of the recording digital data stream according to the present invention, the recording using the start stream packet arrival time (S_S_APAT) and the last stream packet arrival time (S_E_APAT) described above. The time information on the start stream of the aggregate and the time information on the end point of the record aggregate may be generated and recorded.

The search information generation and recording method of the recording digital data stream according to the present invention as described above comprises partitioning and recording the received digital data stream into a recording aggregate, and detected in the data stream immediately before the partition of the partitioned recording aggregate (SOB). When the search digital data search request is generated by generating and recording the search information based on the difference information between the time information and the time information on the head of the next partitioned record assembly as the search information for the partition end point of the record assembly SOB. In particular, when a search request is exceeded for one record set, it is a very useful invention to read out the recorded search information and quickly and accurately search for a digital data stream corresponding to the requested search time.

Claims (1)

Partitioning and recording the received data stream in units of recording aggregates; And And generating and recording the search information based on the difference information between the time information detected in the data stream immediately before the partition of the partitioned recording assembly and the time information of the head of the next partitioned recording assembly. A search information generation recording method of a recording digital data stream.