KR20000040346A - Method for recording and detecting recording digital data stream - Google Patents

Abstract

PURPOSE: A method for recording and detecting a recording digital data stream is provided to reduce detecting time while maintaining a time map information into a certain size while recording the digital data stream in a recording medium. CONSTITUTION: A received digital data stream is stored in a recording medium by separating into an SOBU(stream object unit), and the SOBU information is stored in a certain area of the SOBU. To detect the data stream stored in the recording medium, the SOBU including the data stream is detected by using a time map information. Then, an error correcting block including the data stream to be detected is checked by using the SOBU information stored in a certain area of the detected SOBU. And, the data stream to be detected is detected by using the starting point of the checked error correcting block.

Description

Recording and data recording method and searching method

The present invention relates to a method for receiving a digital data stream and storing it in a recording medium such as a digital video disc, recording the recording position information of the stored digital data stream, and searching the recording data using the recorded position information. will be.

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 the set-top box through media.

In such a system, when recording a digital data stream on a recording medium such as a DVD, each transport stream packet is recorded on the recording medium together with a transport stream packet arrival time (TS APAT), and the minimum for the recorded digital data stream is recorded. By recording time map information as navigation data corresponding to a stream recording unit (SOBU) which is a recording unit, it is possible to search for a desired stream recording unit. Here, the time map information includes time entry 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 recording units generated and recorded corresponding to each stream recording unit for fine search. It consists of entry 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.

By the way, for the stream recording unit SOBU, it is possible to consider a method of dividing the data stream to be recorded by a predetermined time unit, but this method has the following problems. That is, for example, when a digital data stream input at a bit rate of 10 Mbps is divided into stream recording units (SOBUs) of 1 sec and recorded, the size of the recording units (SOBUs) becomes 10 Mbits, The maximum seek time in the stream record unit (SOBU) (the time to wait until the desired packet arrival time is read from the first sector of the desired stream record unit) is (10 Mbits / 10.08 Mbps) = about 992 ms (where The decoding of the stream takes a very long time (assuming 10.08 Mbps).

On the other hand, when the partition unit time for the recording unit of the input data stream is set to a small value, for example, 0.1 sec, in order to reduce the search time, the digital data stream inputted at a bit rate of 1 Mbps is 4.7. When recording on a G Byte recording medium, the size of the recording unit (SOBU) becomes 0.1 Mbits, and the maximum seek time in one stream recording unit (SOBU) is very short (0.1 Mbits / 10.08Mbps) = 10 ms. Takes However, assuming that the recording unit entry information is 2 bytes, the recording unit entry information interval is 0.1sec, the time entry information is 4 bytes, and the time entry information interval is 10sec, the number of time entry information is (4.7G Byte) / (input bit transfer rate x time). Entry interval) = (4.7 × 1024 × 8) / (1 × 10) = 3850 pieces, and the number of recording unit entry information is (4.7 G Byte) / (input bit rate x time entry interval) = (4.7 × 1024) X 8) / (1 x 0.1) = 385024 pieces, and the size of the navigation data for the time map information becomes (3850 x 4) + (385024 x 2) = 767 KByte. This is not applicable to a 4.7-Gbyte real-time rewritable digital video disc (DVD-RTRW) which is configured to allocate the entire navigation data amount to 512 Kbytes and to allocate approximately 212 Kbytes to the time map information.

Therefore, research on a method of reducing search time while maintaining time map information at a constant size is desired.

Accordingly, the present invention was created in view of the above circumstances, and when recording a digital data stream on a recording medium, the recording digital data stream recording method can reduce the search time while maintaining the time map information at a constant size. And a search method.

1 schematically shows a system to which a recording digital data stream recording method and a searching method according to the present invention are applied,

FIG. 2 is a diagram schematically illustrating an embodiment of recording position information of a recording stream recorded by the recording digital data stream recording method according to the present invention;

FIG. 3 is a diagram for explaining the configuration of recording position information of the recording data stream shown in FIG.

4 is a diagram schematically illustrating a position search method using recording position information of a recording 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 recording digital data stream recording method comprising: a first step of dividing a received digital data stream into units of stream recording units and recording them on a recording medium; And a second step of inserting and recording recording unit information in a predetermined area of the stream recording unit.

The method of searching for a recorded digital data stream according to the present invention is a method of searching for a data stream recorded on a recording medium, the method comprising: searching for a stream recording unit including a searched data stream using time map information; step; A second step of identifying an error correction block including a searched data stream using recording unit information recorded in a predetermined area of the found stream recording unit; And a third step of searching for the searched requested data stream using the start position of the identified error correction block.

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

1 schematically illustrates an example of a system to which a recording method and a searching method 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 recording position information recording method and a data searching method of a recording digital data stream according to an embodiment of the present invention will be described with reference to FIGS.

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 (TS Pkt 1 to TS Pkt k) of the data stream is recorded in sectors (Sector 1 to Sector n) on the recording medium together with the transport stream packet arrival time (TS APAT). .

In this case, when the control unit 250 stores the recorded data stream in a track buffer (not shown) of the storage stream processing unit 220, for example, a packet arrival time of 6 bytes for each transport stream packet of the data stream (TS APAT). ) Is inserted in front of the corresponding transport stream packet (TS Pkt) and stored. Then, each stored packet arrival time (TS APAT) and transport stream packet (TS Pkt) are error-corrected and divided into unit of error correction block (ECC block). The divided error correction block is converted into a stream recording unit corresponding to time map information (SOBU MAP) for searching [SOBU; SOBU 1 to SOBU q]. Thereafter, the control unit 250 inserts recording unit information SOBU Inf. Into the head region (first sector) of each stream recording unit. The recording unit information includes the corresponding stream recording unit as shown in FIG. 3. The location information of the first transport stream of each error correction block belonging to is recorded. In this case, the head region is composed of one sector, and the position information is a start time of an error correction block, and is an arrival time (TS APAT) of a first transport stream packet.

Subsequently, the controller 250 records a data stream in which recording unit information stored in a track buffer (not shown) of the storage stream processor 220 is inserted on a recording medium. In this case, the controller 250 generates stream recording unit entry information (SOBU Entry) for each recorded stream recording unit and records the same in the navigation data area of the memory 260 and corresponds to a predetermined time or a predetermined number of stream recording units. Time entry information is generated and recorded in the navigation data area of the memory 260. Here, the embodiment of FIG. 2 is for an embodiment in which the time map information SOBU MAP is configured by dividing the stream recording unit SOBU at a predetermined time interval, and the stream recording unit entry information SOBU Entry is a corresponding stream recording unit. And a time entry is the size (number of sectors) of the preceding stream recording unit in the corresponding stream record object (SOB). A cumulative size (ACC_SZ), which is a cumulative value, and an index number (SOBU_N) of the corresponding stream recording unit.

On the other hand, the present invention can also be applied to an embodiment in which the time map information SOBU MAP is configured by dividing the stream recording unit SOBU in another manner.

Thereafter, the control unit 250 generates the reproduction order information Cell 2 with respect to the data stream recording assembly SOB2 recorded as described above, and records it as the reproduction order information corresponding to the record RCD2 which is a recording unit once. do.

When the user inputs and sets the time (HH: MM: SS: FF) to search for the recording position in the state where the digital data stream is recorded on the recording medium by the above recording operation, the control unit of the streamer 200 ( 250) searches for the record [RCD] corresponding to the set time (HH: MM: SS: FF) using the creation time (PG1_Create_TM, PG2_Create_TM, PG3_Create_TM) of the records [RCD1 to RCD3], and the searched record [RCD]. ; In FIG. 2, the above setting is made using the playback start time (C1_S_TM, C2_S_TM, ..., Cn_S_TM) and the playback end time (C1_E_TM, C2_E_TM, ..., Cn_E_TM) of the playback order information (Cell 1 to Cell n) included in REC2. The playback order information (Cell (Cell 2 in FIG. 2)) corresponding to the time (HH: MM: SS: FF) is searched for.

Thereafter, the control unit 250 controls the set time (HH: MM: SS: FF) in the time map information SOBU MAP for the stream recording assembly SOB 2 corresponding to the found reproduction order information Cell 2. Searches for a time entry close to the time minus the start time (SOB_S_TM) of the aggregate. That is, for example, the operation result value of [stream record unit index number (SOBU_N) x stream record unit partition unit time (constant time) + record aggregation start time (SOB_S_TM)]] is the set time (HH: MM: SS: FF). ), The stream recording unit index number SOBU_N closest to the set time (HH: MM: SS: FF) is calculated. The time entry having the closest stream record unit index number is searched without exceeding the stream record unit index number SOBU_N calculated as described above, and the accumulated size (ACC_SZ) included in the searched time entry is searched. The recording unit size SOBU_SZ from the SOBU entry referred to by the searched time entry to the SOBU entry corresponding to the calculated stream recording unit index number SOBU_N is added and the desired value (number of sectors) is used. The recording unit SOBU (SOBUg in FIG. 2) is found.

Subsequently, the controller 250 stores each error correction block recorded in the recording unit information SOBU Inf. Recorded in the first sector of the searched recording unit SOBU (SOBUg in FIG. 2), and the start time ST1 to the first sector. STn; see FIG. 3), and the error correction block (Block) closest to the set time (HH: MM: SS: FF) without exceeding the set time (HH: MM: SS: FF) is shown. Block4). In this case, when the error correction block to be searched is more than a predetermined block, the controller 250 controls the optical pickup servo not shown to search for the target error correction block by track jump. That is, as shown in FIG. 4, the target position is not waited from the head position (point A) of the searched unit SOBU (SOBUg in FIG. 2) to the target error correction block position (point B), but by track jump. Get there quickly.

Thereafter, the controller 250 detects the packet arrival time TS APAT of each transport stream packet from the first sector Sector1 in which the target error correction block (block4 in FIG. 2) found as described above is recorded, and the setting is performed. The target packet arrival time TS APAT corresponding to the time HH: MM: SS: FF is searched. Subsequently, the controller 250 reads out a transport stream packet (TS Pkt 2; see FIG. 2) that exists after the searched target packet arrival time TS APAT and sets the box 100 through the IEEE1394 interface 210. The read stream processor 240 is controlled to transmit to the.

As described above, according to the present invention, it is possible to search by track jump to the target error correction block by using the position information recorded at a predetermined position of the stream recording unit, thereby reducing the search time of the recording data.

According to the recording method and search method for recording digital data streams according to the present invention as described above, when a digital data stream is received and stored in a recording medium such as a digital video disc, the recording unit is configured at a predetermined recording position of the stream recording unit. By recording the recording position information for the error correction block to be recorded, it is possible to search by the track jump to the target error correction block by using the recording position information recorded at a predetermined position of the stream recording unit when the recording data stream is searched. While the map information can be maintained at a constant size, the search time of the recorded data can be reduced.

Claims (8)

A first step of dividing the received digital data stream into units of stream recording units and recording them on a recording medium; And And a second step of inserting and recording recording unit information in a predetermined area of the stream recording unit. The method of claim 1, The first step is A lower step of dividing the received digital data stream into units of error correction blocks; And dividing the partitioned error correction block into units of a stream recording unit and recording the partitioned error correction block. The method of claim 1, And wherein the second step records position information of the first data stream packet of each error correction block belonging to the corresponding stream recording unit as recording unit information. The method of claim 3, And the position information is the arrival time of the first data stream packet. The method of claim 1, And the predetermined area is the head of the stream recording unit. The method according to claim 1 or 5, And said predetermined area is composed of one sector. A method for searching a data stream recorded on a recording medium, Searching for a stream recording unit including a searched data stream using time map information; A second step of identifying an error correction block including a searched data stream using recording unit information recorded in a predetermined area of the found stream recording unit; And And searching for the searched data stream using the identified start position of the error correction block. The method of claim 7, wherein And wherein the third step includes searching for the identified error correction block by track jump when the checked error correction block is equal to or larger than a predetermined block.