METHOD FOR PROVIDING PROGRAM SPECIFIC INFORMATION RECORDED ON HIGH DENSITY DISC MEDIUM

Abstract: The present invention relates to method and apparatus of providing data stream together with program specific information (PSI) requisite for data stream selecting, separating, and decoding of a digital TV set. The present invention, when transmitting PSI to a digital TV set, measures time length of the PSI, creates time information preceding a transport time of the first TP belonging to data stream by the measured time length, converts PSI to at least one TP the created time information is added to, and transmits the converted PSI TPs before data stream TPs. Owing to the PSI provided along with a digital data stream, the digital data stream from a recording medium can be selected, separated, and decoded at a digital TV set without data loss. Furthermore, even though PSI is additionally provided, continuity among time information written succesive TPs of PSI and data stream is always ensured.

Description: D E S C R I P T I O N METHOD FOR PROVIDING PROGRAM SPECIFIC INFORMATION RECORDED ON HIGH DENSITY DISC MEDIUM 1 . Technical Field The present invention relates to method and apparatus of providing data stream read from an information recording medium such as a high-density digital versatile disc (HDVD) for a digital television set together with program specific information (PSI) which is requisite for digital data stream selecting, separating, and decoding of the digital television set. 2. Background Art In these days, a digital television (TV) set developed for presenting high-quality pictures carried by a digital TV broadcast signal is gradually spread. The digital TV broadcast signal to be received by the digital TV set includes not only digital video and audio data but also intermittently inserted PSI to provide a variety of information about broadcast programs. The PSI is sometimes differently called PSIP (Program System Information Protocol) . The digital TV set selects a channel, separates and decodes digital stream of the chosen channel to pictures and sound with reference to the PSI received intermittently. In the meantime, a high-density disk device, which is being developed to reproduce a HDVD whose recording standard is under discussion, is expected to be connected to a digital TV set through IEEE 1394 standard as shown Fig. 1. However, when receiving and presenting the data stream from the disk device 100, the digital TV set 200 still requires PSI to select the data stream and to control presentation of the selected data stream. Therefore, when the disk device 100 reproduces MPEG-formatted data stream recorded on a HDVD and sends to the digital TV set 200 connected through a digital interface such as IEEE 1394 standard, it must provide PSI, which may consist of a program association table (PAT) , a program map table (PMT) , a conditional access table (CAT) and so forth, as shown in Fig.2, for the digital TV set 200 in the format of transport stream (TS) consisting of 188-byte-long transport packets (TPs) . To provide the digital TV set with PSI for recorded data stream intermittently or periodically as for a digital TV broadcast signal, it may be considered that PSI is recorded dispersedly and repeatedly in a data recording area Λ AREA 1' of a HDVD as shown in Fig. 3 and the repeatedly written PSI is retrieved and transmitted sequentially along with data stream. However, if PSI is recorded dispersedly and repeatedly on a data recording area of a disk, the recording area for real data, namely, video and/or audio data is greatly reduced, which causes to decrease recording efficiency of a disk. In addition, the digital TV set can not present received data stream until it receives PSI retrieved in regular sequence from the PSI recorded dispersedly on the data recording area even though data receiving is resumed after a reproduction point is moved according to a key command of a user or a digital interface such as IEEE 1394 standard is reset. Because the digital TV set can not select data stream to decode to real pictures and/or sound until the PSI prepared for the data stream is received, there is inevitably discontinuity in video and/or audio or blank screen for a while. In the meantime, the digital TV set determines when to decode and present received TPs based on PCRs (Program Clock References) included intermittently in the TPs . Thus, if PCRs are not continuous, there may occur errors in decoding and presenting received TPs. Accordingly, For preventing such possible malfunction, time information of PSI must be in continuity with PCRs included in consecutive TPs containing real data when PSI is converted to TPs and inserted into TS of real data. 3. Disclosure of Invention It is an object of the present invention to provide a PSI providing method enabling a connected digital TV set to present video pictures and/or sound stably. It is another object of the present invention to provide a PSI recording method and a recording medium making it possible for a digital TV set to present video pictures and/or sound stably. It is another object of the present invention to provide an information recording/reproducing apparatus enabling a connected digital TV set to present video pictures and/or sound stably. A PSI providing method and an apparatus conducting said method in accordance with the present invention are characterized in that they transmit TPs made of PSI prior to data stream transmission whenever data stream starts to be transmitted. A PSI providing method and an apparatus conducting said method in accordance with the present invention are characterized in that they, when transmitting PSI, measure time length of the PSI to be transmitted, create time information preceding a transport time of the first TP among data stream by the measured time length, convert PSI to at least one TP the created time information is written in, and transmit the converted PSI TPs before data stream TPs. Owing to the PSI providing method and apparatus in accordance with the present invention, a digital TV set can synchronize its local clock with time information written in received PSI TP or TPs and then decode and interpret PSI TPs after synchronization. Afterwards, it can separate and decode data stream TPs successively without missing any TP. Therefore, even though PSI is additionally provided for a digital TV set, time information written in successive TPs of PSI and data stream ensures continuity in time so that possible data loss which might be caused from time discontinuity is prevented radically. 4. Brief Description of Drawings The accompanying drawings, which are included to provide a further understanding of the invention, illustrate the preferred embodiments of the invention, and together with the description, serve to explain the principles of the present invention. In the drawings : Fig. 1 shows a disk reproducing device and a digital TV set connected each other; Fig. 2 shows several information elements constituting program specific information (PSI) ; Fig. 3 shows partitioned recording areas of a disk recording medium and contents to be recorded thereon; Fig. 4 shows partitioned recording areas of a disk recording medium and contents to be recorded thereon according to the present invention; Fig. 5 shows PSI general information for managing generally all PSI concentrated on an area of a recording medium; Fig. 6 is a block diagram of a disk device to conduct a method of providing data stream together with PSI in accordance with the present invention; and Fig. 7 is an illustrative format of stream transmitted to a connected digital TV set. 5. Modes for Carrying out the Invention In order that the invention may be fully understood, preferred embodiments thereof will now be described with reference to the accompanying drawings. Fig. 4 is an area partitioned HDVD capable of supporting a PSI transmitting method in accordance with the present invention. The HDVD of Fig. 4 has two recording areas AREA 1 ' and Λ AREA 2 ' , the one AREA 1' being for real data such as video and/or audio data which is unitized by stream object unit (SOBU) , the other Λ REA 2' being for management information such as navigation data which is used for controlling reproduction and presentation of recorded SOBUs constituting a stream object (SOB) which is usually corresponding to a single program or digital stream section recorded continuously from recording start to stop. As shown in Fig. 4, all of PSI, which will be provided for a digital TV set connected through a digital interface such as IEEE 1394 to select a data stream from a disk player and to decode the selected stream, is concentratedly written in the management information recording area AREA 2 ' without repetition, so that the storage capacity of the data recording area Λ AREA 1' prepared for video and/or audio data is not decreased. For recording all of PSI concentratedly, the following procedures are conducted sequentially. First, PSI, which consists of PAT, PMT, CAT, and so on mentioned above referring to Fig. 2, inserted intermittently in a digital TV broadcast signal is detected and separated from the received digital TV broadcast signal. Each separated PSI is processed into a digital stream adequate to recording format of a writable HDVD and, at the same time, each separated PSI is compared with previously detected PSI to know whether the separated PSI is new, namely, the separated PSI contains data which is different from that of the previous PSI. If the separated PSI is new, it is sequentially written on the management information area λ AREA 2 ' of the writable HDVD. When each PSI is written, each linking information between the written PSI and a SOB is created and appended to each written PSI. The linking information consists of start and end time of a corresponding SOB. When each PSI is processed, control information for various presentation appropriate to a data stream provided from a recording medium may be added to PSI besides information of PAT, PMT, and CAT and some fields of PSI may be replaced for better presentation of recorded data stream other than broadcast data stream. Fig. 5 shows PSI general information for managing generally all PSI written ' concentratedly on the area Λ AREA 2 ' of a HDVD. As shown in Fig. 5, a PCR offset field marked x PCR__offset' is added to the PSI general information. The PCR offset field shall be filled with time length of TPs each payload of which contains PSI, thus, the first TP belonging to PSI TPs has time information preceding a transport time (or PCR) of the first TP among data stream TPs, which will be transmitted after PSI TPs, by the time length written in the field Λ PCR__offset' . For example, if it is assumed that 500 is written in the PCR offset field, the first TP including partial PSI which will be followed by TPs of data stream has time information of a transport time TT1' (or PCR) of the first TP of data stream subtracted by 500, namely, λ TTl-500' . If PSI is to be transmitted twice prior to data stream transmission, the first TP of PSI transmitted first has time information of λ TTl-500x2' and the first TP of PSI transmitted second has λ TTl-500xl' . Generally speaking, if PSI is to be provided N times, then the first TP of PSI transmitted at M-th has time information of TTl-500 (N-M+l) ' Accordingly, the time information included in PSI TP or TPs is always in continuity in time with data stream TPs following the PSI TPs, so that a digital TV set can synchronize its local clock with time information written in a TP or some TPs of PSI received before data stream TPs, and then decode and interpret PSI TPs received after synchronization. Afterwards, it can separate and decode data stream TPs successively without missing any TP. Fig. 6 is a block diagram of a disk device such as a HDVD player to conduct a method of providing data stream together with PSI in accordance with the present invention. The disk device 300 shown in Fig. 6 comprises an optical pickup 32 detecting recorded signals of a HDVD 31 having PSI written in the area AREA 2 ' concentratedly; an analog signal processor 33 processing the electrical signal from the pickup 32 to convert it to a binary signal; a digital signal processor 34 processing the binary signal to obtain real data and PSI; a TS multiplexer 35 multiplexing the real data and PSI and converting the multiplexed data to TS; an interfacing unit 36 transmitting the TS to a digital television 200 connected through IEEE 1394 standard; a microcomputer 37 supervising the overall reproduction operation; and a memory 38 for storing temporary data produced during disk reproduction . In the disk device 300 configured as Fig. 6, the microcomputer 37 conducts an operation to provide PSI, which is associated with the present data stream being reproduced, for the digital TV set 200. To do so, it reads the PSI first from the management information recording area AREA 2 ' when a key command is entered directly from a user, a packet command is received from the digital TV set 200 connected through IEEE 1394 standard, or there occurs a bus reset on the IEEE 1394. Then, the digital TV set 200 interprets the PSI received before data stream through the IEEE 1394 bus, and selects and decodes data stream based on the interpretation of the PSI. This briefly mentioned operation is explained below in detail Fig. 7 is an illustrative format of stream transmitted to a connected digital TV set. To transmit PSI and data stream like as shown Fig. 7, the microcomputer 37 checks whether reproduced data is changed to next SOB during reproduction of the HDVD 31. If changed from the N-th SOB to the (N+l)-th, the microcomputer 37 reads out PSI associated with the (N+l)-th SOB from the area AREA 2 ' and applies the read PSI to the TS multiplexer 35 which converts the inputted PSI to a TP or several TPs (called ' • TP Group') if needed. The TS multiplexer 35 will transmit the converted TP or TP Group before the first TP belonging to the (N-f-l)-th SOB under control of the microcomputer 37. It is preferable to provide the PSI TP or TP Group repeatedly more than once to prevent possible errors in transmitting and/or receiving. The example of Fig. 7 is drawn for the case that PSI transmission before data stream is conducted five times and PSI is carried by a plurality of TPs, namely, a TP Group. To transmit PSI five times, the microcomputer 37 reads the PCR offset field of the PSI general information and transport time information or PCR written in the first TP of the SOB # (N+l) , then, it calculates each time information for the first TP of each PSI TP Group using the read offset value and transport time (or PCR) . The five time information ' PCR1- (PCR_offset x 5)', • PCR1- (PCR_offset x 4)', ' PCR1- (PCR_offset x 3)', 'PCR1- (PCR__offset x 2) ', and * PCRl- (PCR_offset x 1) * are obtained from the calculation of the microcomputer 37 if the transport time information or PCR written in the first TP of the SOB #(N+1) is PCR1' . The obtained five time information are written in the first TP of each PSI sequentially from the time 'PCRl- (PCR_offset x 5) ' . Because the same PSI is provided several times, even if the first and the second PSI are totally missed and an internal clock of the digital TV set is synchronized with the time information of the first TP of the third PSI, information about data stream can be obtained from interpretation of the successfully received TPs of the fourth and the fifth PSI. Therefore, the digital TV set can select data stream following the PSI TPs and separate and decode the selected data stream based on the interpretation of PSI. Besides at the time when a reproduced program is changed, namely, next SOB starts to be reproduced, the PSI is also provided for the digital TV set before data stream in the following various cases where: a) data stream is transmitted for the first time; b) a long track jump in which reproduction position on a recording medium is largely changed is conducted at a request from user' s key input; c) a command is received by the microprocessor 37 of the disk device 300 through the digital interface when the digital TV set 200 connected with the disk device 300 through the IEEE 1394 standard is turned on or its channel is changed; and d) the connecting interface between the disk device 300 and the digital TV set 200 is reset. In the above embodiment of the present invention, a HDVD is used as a recording medium. However, the present invention is also applicable, without any modification and variation, to a video recording/reproducing apparatus of a magnetic recording medium on which video contents are recorded in digital data stream. If a recording medium has not PSI unlike the 5 aforementioned HDVD containing PSI, a reproducing apparatus may create PSI itself and transmit it to a digital TV set before reproduced data stream as explained above. For example, if a disk inserted in the disk device of Fig. 6 is a conventional DVD having no PSI, the microcomputer 10 37 creates a TP or TPs of PSI, which may be referred for parsing digital data stream into video and audio stream, using basic PSI-related information pre-stored in the memory 38 and inserts time information, which is obtained from the above-explained time calculation method, in the PSI TP or TPs . 15 The created PSI TPs including time information are provided for a connected digital TV set before reproduced data stream when data stream is transmitted for the first time or when a command related with an event that the connected digital TV set is turned on or its channel is changed is received.

Claims: 1. A method of providing program specific information (PSI) for a connected device when transmitting data to the connected device in transport stream (TS) format, comprising the steps of: (a) reading data from a recording medium; and (b) transmitting at least one transport packet (TP) of PSI before transmitting the read data whenever initial data transmission is to be conducted. 2. The method of claim 1, wherein said step (b) comprises the steps of: (bl) measuring time length of the PSI; (b2) creating time information preceding a transport time of a first data TP by the measured time length; (b3) adding the created time information to a TP converted from the PSI; and (b4) transmitting the PSI TP including time information to the connected device before data TPs. 3. The method of claim 2, wherein the time length has been written in a management information area allocated for managing the PSI. 4. The method of claim 1, wherein said step (b) creates at least two TPs containing the PSI and transmits all created PSI TPs before the first TP containing data. 5. The method of claim 1, wherein the initial data transmission means a first transmission after data reproducing position on the recording medium is changed. 6. The method of claim 1, wherein the initial data transmission means a first transmission after the connected device is turned on. 7. The method of claim 1, wherein the initial data transmission means a first transmission of a new stream object after a stream object being reproduced is changed. 8. The method of claim 1, wherein the initial data transmission means a first transmission after a data bus carrying the PSI TPs and data TPs to the connected device is reset. 9. The method of claim 1, wherein the initial data transmission means a first transmission after a receiving channel of the connected device is changed. 10. An apparatus of providing program specific information (PSI) for a connected device when reproducing data written on a recording medium, comprising: a reading unit reading data recorded on the recording medium; and a controlling unit creating and transmitting at least one transport packet (TP) of PSI before transmitting the data read by said reading unit whenever initial data transmission is to be conducted. 11. The apparatus of claim 10, wherein said controlling unit writes time information preceding a transport time of a first TP belonging to the read data in the created PSI TP before transmitting the PSI TP to the connected device. 12. The apparatus of claim 10, wherein said controlling unit creates and transmits at least two TPs containing the PSI. 13. The apparatus of claim 10, wherein said controlling unit creates the PSI TP based on information pre-recorded on the recording medium. 14. The apparatus of claim 10, wherein said controlling unit creates the PSI TP based on information pre-written on an information storage medium other than the recording medium. 15. A method of recording program specific information (PSI) along with data stream on a recording medium, comprising the steps of: (a) receiving a digital stream; (b) extracting PSI from the received digital stream and recording the digital stream from which the PSI is extracted on a data recording area of the recording medium; and (c) writing the separated PSI on another recording area separated from the data recording area. 16. A recording medium, comprising: a first area for recording digital data stream of video and/or audio content; and a second area, separated from the first area, for recording management information used for controlling the reproduction and/or presentation of the data stream written on the first area, wherein program specific information associated with the digital data stream written on the first area has been written on the second area.

Inventors: KIM BYUNG JIN, SEO KANG SOO, UM SOUNG HYUN, YOO JEA YONG, KIM, BYUNG, JIN, SEO, KANG, SOO, UM, SOUNG, HYUN, YOO, JEA, YONG
Applicants: KIM BYUNG JIN, LG ELECTRONICS INC, SEO KANG SOO, UM SOUNG HYUN, YOO JEA YONG, KIM, BYUNG, JIN, LG ELECTRONICS INC., SEO, KANG, SOO, UM, SOUNG, HYUN, YOO, JEA, YONG
Application year: 2000
Main classification: G11B20
IPC codes: G11B20, G11B27, H04N5, H04N7, H04N9