FR3009917A1 - APPARATUS AND METHOD FOR PROVIDING DIGITAL MULTIMEDIA BROADCAST VIDEO SERVICE - Google Patents

Abstract

An apparatus for providing a digital terrestrial multimedia broadcast video service (400) stores transport stream packets of a sub-channel of a video service for transmission via a communication network in association with a broadcast network (500) in a stream database (450), and when a request for a video stream at a bookmarked position is received from a user via the communication network, the apparatus searches the stream database (450) for a transport stream packet at the bookmarked position, and transmits it as an IP stream broadcast over the communication network.

Description

Field of the Invention The present invention relates to an apparatus and a method for providing a digital terrestrial multimedia broadcast video service, and more particularly to an apparatus and method for providing a service. terrestrial digital multimedia broadcast video at a bookmarked position by a receiving terminal in a hybrid network as an association of a broadcast network and a communication network, via a communication network . TECHNOLOGICAL BACKGROUND Terrestrial Digital Multimedia Broadcasting (T15 DMB), whose purpose is to provide a multimedia service including video, audio, and data services in a mobile environment, has been developed on the basis of the Eureka-147 system, which is a European digital sound broadcasting (DAB) system. In order to configure a variety of services provided by service providers in a set and transmit it through a single terrestrial DMB channel, a terrestrial DMB transmission device uses an ensemble multiplexer. The ensemble multiplexer is the heart of the terrestrial DMB transmission device, and an Ensemble Transport Interface (ETI), which is an output from the terrestrial DMB transmission device, is used. as a basic interface in a terrestrial DMB transmission network. That is, the ensemble multiplexer multiplexes data of a variety of services into a group of a set and converts the multiplexed set into an ETI interface. An Encoded Orthogonal Frequency Division Multiplexing (COFDM) encoder encodes the ETI interface and transmits the encoded ETI interface as a DMB signal. Also, in addition to being used in the case where the ensemble multiplexer transmits the multiplexed set of a plurality of services to the COFDM encoder of a transmitter, the ETI interface can also be used to transmit a single service or plurality of services to the ensemble multiplexer unidirectionally. The ensemble multiplexer may also retrieve a subchannel stream from a designated service in the ETI interface received from each service encoder, configure a main stream data sub-channel ("Main Stream Data") or MST), generate a Fast Information Channel (FIC), and deliver the generated FIC channel to the COFDM encoder.

A terrestrial DMB video service uses MPEG-4 Advanced Video Coding (AVC) and MPEG-4 bit-rate arithmetic coding (BSAC) as source coding standards, and uses an MPEG-2 system and an MPEG-4 system for the purpose of synchronization and multiplexing. Similarly, in order to improve Bit Error Rate (BER) performance required for a CODFM transmission technique and multimedia transmission, a convolutional interleaver and a Reed-Solomon (RS) encoder, as external encoders, are applied. In order for a terrestrial DMB receiving terminal to provide a terrestrial DMB video service, the terrestrial DMB receiving terminal extracts a selected video service subchannel stream from a received DMB signal, extracts a transport stream ("Transport Stream "or TS) MPEG-2 via a convolutional deinterleaver and an RS decoder of an external decoder, and decodes a video service. In accordance with the activation of terrestrial DMB services, devices comprising a wired / wireless communication function and a DMB reception function, such as laptops, tablets, and the like, as well as mobile communication terminals, such as smart phones or cell phones, have been developed. As the use of terrestrial DMB terminals and receivers having a DMB reception function develops, new convergence services combining broadcast and communication in a mobile environment can be provided. In general, a broadcast service via a broadcast network and a data service via a communication network have been provided independently, but because of the diversity of a reception environment , the need to configure a system in which a broadcast network and a communication network are associated to provide a unified service, when a mobile device enters a shadow zone, has appeared. A network in which a broadcast network and a communication network are combined is called a hybrid mobile network, and services provided via the hybrid mobile network are referred to as broadcast and communication convergence services. In order to configure such a hybrid mobile network, functions such as DMB reception of a terminal, bidirectional communication services, flow synchronization and associated services between heterogeneous networks, and the like, are required. As for a DMB broadcast provided in a DMB network, a DMB broadcast for providing bidirectional services by convergence between a broadcast network and a communication network and various types of additional services, an additional module for the wireless communication association, and methods controlling these have been sought. A broadcasting device, such as a DMB receiving terminal, is a mobile receiving device.

Here, when a reception environment is rapidly aggravated when a user enters a broadcast reception or broadcast broadcast unavailability zone during a move, a phenomenon in which a broadcast reception rate is considerably Reduced can occur frequently, and in this situation, it is difficult to normally reproduce a DMB content. Thus, the development of a technique for providing a video-related service is also required to unified a DMB service using a hybrid mobile network. The service associated with the video is based on the assumption of receiving video streams via a communication network. However, in a mobile environment, the two reception environments of a broadcast network and a communication network may deteriorate, therefore, in preparation for this, a method for continuously providing a DMB service when the use of a communication network is available thereafter is also required. DISCLOSURE OF THE INVENTION The present invention has been made in an effort to provide an apparatus and method for providing a terrestrial digital multimedia broadcasting (DMB) broadcast video service having unified delivery benefits of a DMB video service, and having advantages of continuously providing a DMB video service stream at a bookmarked position according to a reception state of a communication network. An illustrative embodiment of the present invention provides a method for providing a terrestrial digital multimedia (DMB) broadcast video service by a terrestrial DMB video service providing apparatus. The method for providing a terrestrial DMB video service includes: storing Transport Stream (TS) packets of a subchannel of a video service to be transmitted via a communication network in association with a broadcast network in a database (or DB for "DataBase") stream; transmitting the TS packets as an IP stream broadcast to a DMB receiving apparatus; receiving a request from a video service at a bookmarked position from the DMB receiving apparatus via the communication network; searching the video stream in a stream DB at the bookmarked position; and transmitting the video stream, at the bookmarked position, to the DMB receiving apparatus via the communication network. The reception may include receiving terminal bookmark search information generated by the DMB receiving apparatus, and the terminal bookmark search information may include the bookmarked position and a read time of a TS packet. corresponding to the bookmarked position. The bookmarked position may include a program clock reference value (or PCR for Program Clock Reference). The search may include determining a search range of the video stream based on a playback time of the video stream, and searching the video stream at the bookmarked position within the search range of the video stream. .

The search may include generating server bookmark search information, and the server bookmark search information may include the bookmarked position and a storage time of a TS packet corresponding to the bookmarked position. The storage time of the TS packet may comprise a Coordinated Universal Time (UTS) value as an index of the TS packet corresponding to the bookmarked position. The storage may include: detecting a TS packet including a PCR value from the TS packets; calculating a UTC value as a function of a system time of the terrestrial DMB video service providing apparatus; and adding the UTC value as an index to the TS packet including a PCR value among the TS packets, and subsequently storing it in the stream DB. The calculation may include correcting the UTC value by using a correction value of a time difference between a read time of the TS packet and a storage time of the TS packet. The method may further include transmitting the video service subchannel to the DMB receiving apparatus via the broadcast network. Another embodiment of the present invention provides an apparatus for providing a terrestrial digital multimedia (DMB) broadcast video service. The terrestrial DMB video service providing apparatus may include a stream processor, a search output processor, and a streaming server. The stream processor can store Transport Stream (TS) packets of a sub-channel of a video service to be transmitted over a communication network in association with a network. broadcasting, in a database ("DataBase" or DB) of flow. The search output processor may receive a request for a video stream at a bookmarked position from a user via the communication network, and search a TS packet at the bookmarked position from the DB stream database. The streaming server can transmit the desired TS packet as an IP stream broadcast over the communication network. The request for a video stream may include terminal bookmark search information including the bookmarked position and a read time of the TS packet corresponding to the bookmarked position, and the search output processor may search for a packet TS having a PCR value identical to a PCR value indicating the bookmarked position. The search output processor may determine a search range in the stream DB based on the read time, and search for a TS packet having a PCR value identical to the PCR value indicating the bookmarked position in the range. of research. The search output processor may generate server bookmark search information including a storage time of the searched TS packet and the PCR value indicating the bookmarked position, and transmit the server bookmark search information generated by via the communication network. The flow processor may include: a time stamp detector configured to detect a TS packet including a time stamp value among the TS packets; a Coordinated Universal Time Coordinated (UTC) generator configured to calculate a time information value as a function of a system time of the terrestrial DMB video service delivery apparatus; and an index adder configured to add the indexed time information value to the TS packet including the time stamp value and store it in the stream DB. The storage time may include a time information value of the searched TS packet. The timestamp value may include a Program Clock Reference (PCR) value. The apparatus may further comprise: an Ensemble Transport Interface (ETI) processor configured to receive TS packets including at least one video stream from a video encoder via an ETI interface frame; and an ETI interface output processor configured to convert the ETI interface frame to an ETI interface signal, and transmit the converted ETI interface signal via a DMB transmission apparatus of a broadcast network. LIST OF FIGURES FIG. 1 is a view schematically illustrating a terrestrial Digital Multimedia Broadcasting (DMB) transmission apparatus. Fig. 2 is a view schematically illustrating a hierarchical structure of an Ensemble Transport Interface (ETI). Figure 3 is a view illustrating a structure of a frame LI ("Logical Interface" or logical interface) ETI. Figure 4 is a conceptual view illustrating a terrestrial DMB service in a hybrid mobile network according to an illustrative embodiment of the present invention. Fig. 5 is a view illustrating a terrestrial DMB video service apparatus of Fig. 4. Fig. 6 is a view schematically illustrating a bookkeeping service providing method according to an illustrative embodiment of the present invention. Fig. 7 is a view illustrating a method for searching a video stream, by a search output processor, of the terrestrial DMB video service providing apparatus according to an illustrative embodiment of the present invention.

Fig. 8 is a view illustrating a flow processor of Fig. 6. Fig. 9 is a view illustrating an example of a video stream stored in a flow database ("DataBase" or DB) according to an embodiment illustrative of the present invention. DETAILED DESCRIPTION In the following detailed description, only certain illustrative embodiments of the present invention have been shown and described, merely by way of illustration. It will be understood by those skilled in the art that the described embodiments may be modified in a variety of different ways, all without departing from the spirit or scope of the present invention. Therefore, the drawings and description should be considered illustrative and should not be considered restrictive. Similar reference numerals refer to similar elements throughout this patent. In the entirety of the patent and claims, unless expressly stated otherwise, the word "understand" and variations such as "include" or "comprising" will be understood to mean the inclusion of specified elements, but not the exclusion of any other elements. Hereinafter, an apparatus and method for providing a terrestrial Digital Multimedia Broadcasting (DMB) video broadcast service 30 according to an illustrative embodiment of the present invention will be described in detail.

Figure 1 is a view schematically illustrating a terrestrial digital media broadcasting (DMB) transmission apparatus. With reference to FIG. 1, a terrestrial DMB transmission apparatus 100 includes an ensemble multiplexer 110 and a signal transmitter 120. The ensemble multiplexer 110 multiplexes a plurality of service streams provided from a plurality of One group of service providers, called together, for transmitting the service streams through a signal transmission frequency corresponding to a terrestrial DMB channel, converts the multiplexed set into a transport interface frame. The ETI for the "Ensemble Transport Interface", and delivers the converted ETI interface frame to the signal transmitter 120. Here, the assembly refers to the largest unit of a service group. transmitted in a single frequency band. A plurality of service streams may comprise at least one of audio, video, and data streams corresponding to a basic DMB service. Also, the plurality of service streams can be converted to an ETI interface frame by each service encoder and enter the set multiplexer 110. In this case, the set multiplexer 110 can extract a stream of designated service from the input ETI frame, reconfiguring the extracted service stream as an ETI interface frame, and delivering the reconfigured ETI interface frame to the signal transmitter 120.

The signal transmitter 120 receives the ETI interface frame from the ensemble multiplexer 110, configures the ETI interface frame in a transmission frame, modulates the transmission frame configured into a DMB signal, and transmits the DMB to a terrestrial DMB receiving apparatus 200. The DMB receiving apparatus 200 receives the DMB signal to reproduce (or read) a DMB service. Fig. 2 is a view schematically illustrating a hierarchical structure of an Ensemble Transport Interface (or ETI). Referring to FIG. 2, the ETI interface is defined by a logical interface layer (or LI layer for "Logical Interface"), a network independent layer (or NI layer for "Network Independent"), and a network adaptation layer (or NA layer for "Network Adaptation"). The LI layer, a basic logical structure, defines basic information for generating a set. The NI layer, which is a physical interface layer mapping the LI layer, is used as the base interface with respect to related equipment at the ETI interface. The NA layer, which is a physical interface layer mapping the LI layer like the NI layer, performs forward error correction on data to protect the data for use in a network environment in which an error can easily occur, compared to the NI layer. Fig. 3 is a view illustrating a structure of an ETI logic interface frame according to an illustrative embodiment of the present invention. Referring to Fig. 3, the logical interface frame ETI comprises a status field (STATus, denoted STAT) and a logical interface data field (or LIDATA field for "Logical Interface 10 DATA"). The STAT field comprises an error status field (Error, denoted ERR), and the ERR field delivers information concerning an error state of the ETI interface LI frame. The LIDATA field comprises a header and a payload. The header includes a Frame Characterization (FC) field, a STream Characterization (STC) field, and an end-of-header field ("End Character"). Of Header "or EOH). The payload includes a main stream data field ("Main STream data" or MST), an end of frame ("EOF"), and a timestamp field ("TIme STamp"). or TIST). The FC field comprises a Frame Counter (FCT) field, a Fast Information Channel Flag (FICF) field, a number of stream number field ("Number of STreams "or NST), a frame phase field (FP), a mode identity field (" IDentity Mode "or MID), and a frame length field (" Frame Length " or FL). The STC field includes a plurality of sub-stream characterization fields ("SubSTream Characterization" or SSTC1-SSTCNST) representing a characterization of a plurality of data streams, respectively. The EOH field includes a multiplex network signaling channel (MNSC) field and a header cyclic redundancy check (CRCh) field. The FC field includes general data characteristics applied to a frame corresponding to the entire LI layer. In the FC field, the FCT field indicates counter values with common interleave frames (CIFs), and has values ranging from 0 to 249 corresponding to the number of CIF frames. Here, one or more CIF frames are included in a main service channel of a transmission frame, and correspond to at least one MST field. The FICF field indicates whether FIC data exists in the MST field. The NST field 25 provides information regarding the number of data streams that can be transmitted by the STC field and the MST field. The FP field informs a transmitter of a time at which transmitter identification information is to be inserted. The MID field includes information about a mode identification required for COFDM modification ("Coded Orthogonal Frequency Division Multiplexing" or Orthogonal Frequency Division Multiplexing with Coding). The FL field includes information indicating the sum of lengths of an STC field, an EOF field, and an MST field. In the header field, the STC field includes information about the service flow characteristics of each subchannel corresponding to the MST field. That is, the STC field includes SSTC fields, and SSTC1 to SSTCNST fields corresponding to subchannels of a plurality of service streams of the MST field, respectively. Fields SSTC1 to SSTCNST each include a Sub-Channel Identification (SCID) field, a Start Address (SAD) field, a protection level field ( "Protection Level" or TPL), and a stream length field ("STream Length" or STL). In the SSTC1 to SSTCNST fields, each SCID field includes information indicating sub-channels of a service flow. The SAD field includes a start address of a subchannel of a service flow. The TPL field includes information about a protection level and a type of a stream subchannel.

The STL field includes information indicating a length of a stream subchannel. In the EOH field of the header, the MNSC field indicates a signaling channel between the ensemble multiplexer 110 and the signal transmitter 120. The CRCh field indicates information required to perform a cyclic redundancy check ("Cyclic Redundant Check "or CRC) on the FC field, the STC field, and a multi-channel signaling channel. The payload MST field comprises FIC data and a plurality of service streams (service streaml to service stream-NST) - The EOF field includes a CRC field and a reserved field ("Reserved field" or Rfu). In the MST field, the presence of FIC data can be known from the FICF field, and the FIC data is uncoded data. The plurality of service stream streams (service stream stream-NST) each comprise stream data, and the service stream stream data (service streaml to service streamNsT) is transmitted dividedly into a plurality of sub-streams. canals. The MST field FIC data and service stream flow data (service streaml to service streamNsT) are generated as transmission frames by the signal transmitter as such 120 and transmitted as a broadcast signal. . In the EOF field, the CRC field includes information required to perform the CRC check on the MST field, and the Rfu field is an additional resource that is prepared in advance. The TIST field comprises information required to transmit a transmission frame corresponding to an ETI interface frame. The ETI logic interface frame as described above is delivered to the signal transmitter 120, and the signal transmitter 120 generates a transmission frame from the logical interface frame ETI, modulates the frame according to a COFDM system, and transmits a broadcast signal to the DMB receiving apparatus 200. The DMB receiving apparatus 200 may comprise devices comprising a wired / wireless communication function and a DMB reception function, such as laptops, tablets, and the like, as well as mobile communication terminals, such as smart phones and cell phones. Due to the increase in the number of devices comprising the wired / wireless communication function and the DMB reception function, the terrestrial DMB transmission apparatus 100 must be able to provide a terrestrial DMB service in a hybrid mobile network combining broadcast and a communication network. Hereinafter, an apparatus and method for providing a terrestrial DMB video service in a hybrid mobile network will be described in detail with reference to Figs. 4-9. Fig. 4 is a conceptual view illustrating a terrestrial DMB service in a hybrid mobile network according to an illustrative embodiment of the present invention. Referring to Fig. 4, a video encoder 300 converts a supplied video service stream from a service provider into an ETI interface frame and delivers the converted ETI interface frame to a service provider apparatus. video service 30 terrestrial DMB 400.

The terrestrial DMB video service providing apparatus 400 processes the ETI interface frame and transmits an ETI interface signal for video service stream transmission to the terrestrial DMB transmission apparatus 100. The Terrestrial DMB transmission 100 processes the ETI interface signal and transmits a DMB broadcast signal through a broadcast network 500.

Similarly, a terrestrial DMB video service provider 400 processes the ETI interface frame and transmits an IP stream broadcast MPEG-2 transport stream through a communication network 600.

The reception apparatus DMB 200 receives a video service via the broadcast network 500 or the communication network 600, and reproduces (or reads) it. When the DMB video service is reproduced, it may be impossible to receive a DMB video service according to a user's intent or in a reception state of the communication network 600. In case it is difficult for the DMB video service to be normally reproduced, the reception apparatus DMB 200 inserts a bookmark into a final reproduction position. When the bookmark is selected by a user, the DMB receiving apparatus 200 may request a video stream at a bookmarked position from the terrestrial DMB video service provider 400 via the communication network. 500, receive a MPEG-2 TS packet ("Transport Stream" or Transport Stream) at the bookmarked position from the terrestrial DMB video service delivery apparatus via the communication network 600, and reproduce a video service, starting from the final playback position. Fig. 5 is a view illustrating a terrestrial DMB video service apparatus of Fig. 4.

Referring to FIG. 5, the terrestrial DMB video service provider 400 comprises an ETI interface input processor 410, an ETI interface output processor 420, an ETI 430 interface decoder, a stream processor 440, a stream data base DB 450, a stream timing controller 460, a search output processor 470, and a stream streaming server 480. ETI interface input 410 receives an ETI signal and extracts an ETI interface frame. The input processor of ETI 410 delivers the extracted ETI interface frame to the ETI interface output processor 420 and the ETI decoder 430. The video encoder converts a video service stream provided from a service provider into an ETI interface frame, and sends the converted ETI interface frame to the ETI interface input processor 410. The ETI interface output processor 420 stores the delivered ETI frame frame from the ETI interface input processor 410, delays the corresponding ETI interface frame to a preset output delay value, and thereafter sends an ETI interface signal for transmission of a service flow video to the terrestrial DMB transmission apparatus 100 via the broadcast network 500. Namely, the ETI interface output processor converts the ETI interface frame into an ETI signal, and transmits the signal ETI interface to the broadcast network 600 via of the terrestrial DMB transmission apparatus 100. The ETI interface input processor 410 may receive an ETI interface signal sent from the set multiplexer (110 in FIG. 1) instead of the video encoder. and, in this case, the ETI interface output processor 420 transmits the ETI interface signal to the signal transmitter 120 of Fig. 1. Namely, the terrestrial DMB video service delivery apparatus 400 provided in a illustrative embodiment of the present invention may be used between the ensemble multiplexer (110 in Fig. 1) and the signal transmitter (120 in Fig. 1) as well as between the video encoder and the ensemble multiplexer (110 in Figure 1). The ETI interface decoder 430 decodes the ETI interface frame delivered from the ETI interface input processor 410 and selects a subchannel of a video service to be transmitted via the communication network. 600 in association with the broadcast network 500, among subchannels of a plurality of video services. An MPEG-2 transport stream is transmitted via a sub-channel of the MPEG-2 transport stream, and here the MPEG-2 transport stream is externally encoded via RS coding. (Reed-Solomon) and convolutional interleaving in order to be transmitted. An MPEG-2 TS packet that has not been externally encoded has a length of 188 bytes, and an externally encoded TS MPEG-2 packet has a length of 205 bytes. The last 16 bytes of the TS MPEG-2 packet correspond to parity data generated by RS coding for error correction. The stream processor 440 processes the non-externally encoded TS MPEG-2 packet of the selected video service's subchannel and stores the processed MPEG-2 TS packet in the stream 450 DB. TS MPEG-2 packet may include a time value field, a Program Clock Reference (PCR) control field, and a PCR value field. The time value field indicates a time at which the corresponding MPEG-2 TS packet is to be sent through the broadcast network 500, and may arrive at a msec unit. The PCR control field is set to 1 in case a PCR value is included in the corresponding MPEG-2 TS packet, and a PCR value of the corresponding MPEG-2 TS packet is set in the PCR value field. In the meantime, if a PCR value is not included in the corresponding MPEG-2 TS packet, the PCR control field is set to 0, and in this case, each bit of the PCR control field can be set to 0 or 1. The stream processor 440 adds time information to the MPEG-2 TS packet including a PCR value as an index, and stores it in the stream DB 450. The stream DB 450 has the TS MPEG-2 packet stored in it.

The stream synchronization controller 460 controls an output time of a stream transmitted via the broadcast network 500 and an output time of a stream transmitted through the communication network 600. The synchronization controller flow controller 460 sets an output delay value to adjust an output delay time of the broadcast network 500 and an output delay time of the communication network 600 in the ETI interface output processor 420 and the broadcast server in stream 480, before the streaming server 480 starts a stream output operation. The search output processor 470 processes a stream request from a user who has accessed through the communication network 600. The stream request may include a request for a video stream at a set position. bookmarked, and may include a PCR value indicating a start position of the requested time or flow information.

The search output processor 470 searches for an MPEG-2 TS packet, in the stream DB database 450, of a video stream corresponding to the PCR value included in the user's stream request, and delivers the TS MPEG packet. -2 searched at streaming server 480.

The streaming server 480 delays the MPEG-2 TS packet of the video stream delivered from the search output processor 470 according to an output delay value, and transmits it as a determined type of IP stream transmission. to the DMB reception apparatus 200 via the communication network 600. The reception apparatus DMB 200 receives the video service via the broadcast network 500 or the communication network 600, and reads the video service. this. When the DMB video service is reproduced, it may not be possible to receive the DMB video service according to user intent or because of a reception state of the communication network 600. In case the DMB video service can not Normally reproduced, the receiving apparatus DMB 200 inserts a bookmark into a final reproduction position. When the bookmark is selected by the user, the DMB receiving apparatus 200 may request a video stream at the bookmarked position from the terrestrial DMB video service delivery apparatus 400 through the home network. communication 600, receiving a TS MPEG-2 packet at the bookmarked position from the terrestrial DMB video service providing apparatus via the communication network 600, and reproducing the video service, starting from the final breeding position. Fig. 6 is a view schematically illustrating a bookkeeping service providing method according to an illustrative embodiment of the present invention.

Referring to FIG. 6, the reception apparatus DMB 200 receives a video service via the broadcast network 500 or the communication network 600 and reproduces it. In this case, when it is difficult to reproduce the DMB video service according to the intention of a user or because of a reception state of the communication network 600, the reception apparatus DMB 200 inserts a bookmark into a final breeding position (S610).

The DMB receiving apparatus 200 generates bookmark search information according to the final playback position (S620), and adds the bookmark search information to a bookmark list (S630). The bookmark search information generated by the DMB receiving apparatus 200 will be referred to as the terminal bookmark search information. The DMB receiving apparatus 200 transmits a bookmark service request including terminal bookmark search information to the terrestrial DMB video service delivery apparatus 400 (S640). The search output processor 470 of the terrestrial DMB video service provider 400 searches for a requested video stream per bookmark service in the stream DB 410, using the terminal bookmark search information included in the bookmark service request (S650).

When the packet MPEG-2 TS of the requested video stream by bookmark service is searched in the stream DB database 412, the search output processor 470 generates bookmark search information (S660). The bookmark search information generated by the terrestrial DMB video service provider 400 will be referred to as the server bookmark search information. The streaming server 480 of the terrestrial DMB video service provider 400 transmits a bookmark service response including the server bookmark search information to the DMB receiving apparatus 200. Also, the server Streaming method 480 transmits the MPEG-2 TS packet of the desired video stream as a determined type of IP stream broadcast to the DMB receiving apparatus 200 via the communication network 600 (S670). The receiving apparatus DMB 200 updates terminal bookmark search information stored in a list of bookmarks with the server bookmark search information received from the terrestrial DMB video service delivery apparatus 400 (S680). , and processes the MPEG-2 TS packet of the received video stream as streaming to reproduce a DMB video service (S690). After this, the DMB receiving apparatus 200 may use the updated server bookmark search information in case of a bookmark service request at a bookmark position, and the terrestrial DMB video service delivery apparatus 400 may send a stream to a position designated by the server bookmark search information, without any additional search method, to provide a bookmark service. The bookmark search information may include a bookmark information identifying field, a timestamp field, and a time information field. The bookmark search information identifier field includes a bookmark search information identifier. The bookmark search information identifier serves to identify terminal bookmark search information and server bookmark search information. Namely, terminal bookmark search information and server bookmark search information may be identified by the bookmark search information identifier. The timestamp field is defined in a video stream standard such as a program clock reference ("Program Clock Reference" or PCR), a Composition Time Stamp (CTS), and the like, of a video stream. In an illustrative embodiment of the present invention, the time stamp field comprises the PCR reference. Such a timestamp field value may indicate a bookmark start of service position. The temporal information field includes time information. In the case of the DMB reception apparatus 200, time information is defined as a system time of the reception apparatus DMB 200 during which a video stream corresponding to a time stamp position is reproduced, and in the In the case of the terrestrial DMB video service provider 400, time information is defined as a system time of the terrestrial DMB video service provider 400 during which an MPEG-2 TS packet is stored. The timestamp value is a counter value that has a period. Thus, in the event that the DMB receiving apparatus 200 adds a bookmark and requests a bookmark service after the passage of a certain amount of time, rather than immediately accessing the terrestrial DMB video service delivery apparatus 400, streams with the same PCR value can be generated, or a time sequence can not be discriminated due to a change in the counter value of the time stamp. For this purpose, a TS MPEG-2 packet read time of the DMB reception apparatus 200 and a MPEG-2 TS packet storage time of the stream processor 440 of the terrestrial DMB video service delivery apparatus 400 are defined as time information, and are used to limit a range to search a video stream for a time information value. In this case, it is assumed that a system time of the receiving apparatus DMB 200 and that of the terrestrial DMB video service providing apparatus 400 are within a generally accepted error range as being the same time interval, but not exactly the same, and it is also assumed that the system time of an exemplary embodiment of the present invention, a search range may be set to a value smaller than the counter period of the present invention. time stamp, rather than being designated by output information provides an identical to a specific value. The search processor 470 generates only server bookmark search and bookmark service when a value (X-PCR) value of the time stamp of the terminal bookmark search information is found within the search range. , and, if a stream having the same timestamp value is not found within the search range, the search output processor 470 recognizes this as erroneous bookmark search information and transmits a message. error at DMB receiving apparatus 200. Fig. 8 is a view illustrating a flow processor of Fig. 6.

Referring to Figure 8, the stream processor 440 includes a time stamp detector 442, a Universal Time Coordinated (UTC) generator 444, and an index adder 446.

The time stamp detector 442 detects a time stamp, i.e. a packet including a PCR reference. The time stamp detector 442 detects a packet of MPEG-2 TS including a PCR reference, out of non-externally encoded TS PMEG-2 packets, of a subchannel of a video service. selected by the ETI interface decoder 430. The UTC generator 444 calculates a UTC value based on a system time of the terrestrial DMB video service provider 400. The system time of Terrestrial DMB video service provider 400 may be synchronized with a Network Time Protocol (NPT) server. There may be a difference between a stream storage time of the terrestrial DMB video service delivery apparatus 400 and a stream reception time of the DMB reception apparatus 200 due to a delay time in transmission to the DMB receiving apparatus 200 via the signal transmitter 120. Here, the UTC generator 444 corrects a UTC value using a correction value which can correct the time difference, thereby minimizing the time difference when the same stream is reproduced by the receiving apparatus DMB 200 and stored in the terrestrial DMB video service apparatus 400. The index adder 446 adds the UTC value calculated by the UTC generator 444 to the MPEG TS packet. -2 detected by PCR, as an index, and stores it in the flow DB database 450. Here, when the terrestrial DMB video service provider 400 and the DMB reception apparatus 200 use the same time calculation method, a time representation other than the UTC time can be used. The UTC value is inserted into a server bookmark lookup information time information field when server bookmark search information is generated. Fig. 9 is a view illustrating an example of a video stream stored in a flow database ("DataBase" or DB) according to an illustrative embodiment of the present invention. Referring to FIG. 9, the video stream stored in the stream DB 450 may comprise an MPEG-2 TS packet including a PCR reference having a UTC value in index form and a general MPEG-2 TS packet. including no PCR reference. The terrestrial DMB video service provider 400 searches the stream DB database 450 for a TS MPEG-2 packet having a value which is identical to a value of a time stamp of terminal bookmark search information. , uses a UTC value as an index of the desired MPEG-2 TS packet as temporal information, and adds the UTC value to a time information field to generate server bookmark search information. In this case, the value of the time stamp is identical to a value of a time stamp of terminal bookmark search information, and a bookmark search information identifier is set to a value corresponding to the information of the time stamp. search for server bookmark. In this manner, the terrestrial DMB video service providing apparatus 400 can provide the bookmarked video service to the DMB receiving apparatus 200 via the communication network 600, and the DMB receiving apparatus 200. can continue viewing the video service whose visualization has been stopped temporarily.

According to illustrative embodiments of the present invention, a video service identical to a DMB broadcast may be provided via a communication network. Thus, a DMB broadcast reception area can expand, and a DMB video service can be unified. Similarly, when a position of a video service, when a user watches the video service, is bookmarked by a user voluntarily if necessary or when receiving environments of a broadcast network as well as a network of communication deteriorates and thus it is difficult to continuously provide the video service, the user can bookmark a position viewed last, and after that, he may request a streaming video service at the set position. in corresponding bookmark, whereby the user can watch continuously the video service whose viewing has been stopped. Via a service, the accessibility of DMB content can be improved. The illustrative embodiments of the present invention are not necessarily implemented only through the preceding devices / apparatus and / or methods but may also be implemented through a program to perform functions. corresponding to the embodiments of the embodiments of the present invention, a recording medium comprising the program, or the like, and such an implementation may be readily accomplished by one skilled in the art to which the present invention relates from of the foregoing description of the embodiments. Although the present invention has been described in association with what is currently considered to be practical illustrative embodiments, it should be understood that the invention is not limited to the embodiments described, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims (17)

REVENDICATIONS1. A method for providing a digital terrestrial multimedia broadcast video service by a terrestrial digital multimedia broadcast video service delivery apparatus (400), the method comprising: storing transport stream packets of a sub-channel of a video service intended to be transmitted via a communication network in association with a broadcast network (500) in a stream database (450); transmitting the transport stream packets as an IP stream broadcast to a digital media delivery receiving apparatus (200); receiving a request for a video service at a bookmarked position from the digital media broadcast receiving apparatus (200) via the communication network; searching the video stream in a stream database (450) at the bookmarked position; and transmitting the video stream at the bookmarked position to the digital media broadcasting receiving apparatus (200) via the communication network. The method of claim 1, wherein the receiving comprises receiving terminal bookmark search information generated by the digital media broadcast receiving apparatus (200), and the terminal bookmark search information includes bookmarked position and a read time of a transport stream packet corresponding to the bookmarked position. The method of claim 2, wherein the bookmarked position comprises a program clock reference value. The method of claim 2, wherein the searching includes: determining a search range of the video stream based on a video stream playback time; and searching the video stream at the bookmarked position within the search range of the video stream. The method of claim 2, wherein the search includes generating server bookmark search information, and the server bookmark search information includes the bookmarked position and a packet storage time. transport stream corresponding to the bookmarked position. The method of claim 5, wherein the storage time of the transport stream packet comprises a coordinated universal time value as an index of the transport stream packet corresponding to the bookmarked position. The method of claim 5, wherein the storing comprises: detecting a transport stream packet comprising a program clock reference value from the transport stream packets; calculating a value universal time coordinated according to a system time of the terrestrial digital multimedia broadcast video service delivery apparatus; and adding the coordinated universal time value as an index to the transport stream packet comprising a program clock reference value among the transport stream packets, and subsequently storing it in the flow database (450). The method of claim 7, wherein the calculating comprises correcting the UTC value by using a correction value of a time difference between a read time of the transport stream packet and a storage time of the transport stream packet. The method of claim 1, further comprising transmitting the video service subchannel to the digital media broadcasting receiving apparatus (200) via the broadcast network (500). Apparatus for providing a terrestrial digital multimedia broadcast video service (400), the apparatus comprising: a stream processor (440) configured to store transport stream packets of a video service subchannel intended to be transmitted over a communication network in association with a broadcast network (500), in a stream database (450), a search output processor (470) configured to receive an requesting a video stream at a bookmarked position from a user via the communication network, and searching for a transport stream packet at the bookmarked position from the stream database (450); and a streaming server (480) configured to transmit the desired transport stream packet as an IP stream broadcast over the communication network. Apparatus (400) according to claim 10, wherein the request for a video stream comprises terminal bookmark search information including the bookmarked position and a read time of the transport stream packet corresponding to the bookmarked position, and the search output processor (470) searches for a transport stream packet having a program clock reference value identical to a program clock reference value indicating the bookmarked position . Apparatus (400) according to claim 11, wherein the search output processor (470) determines a search range in the stream database (450) as a function of read time, and searches for a packet of transport stream having a program clock reference value identical to the program clock reference value indicating the bookmarked position in the search range. The apparatus (400) of claim 11, wherein the search output processor (470) generates server bookmark search information including a storage time of the searched transport stream packet and the reference value of program clock indicating the bookmarked position, and transmits the server bookmark search information generated via the communication network. The apparatus (400) of claim 13, wherein the stream processor (440) comprises: a time stamp detector (442) configured to detect a transport stream packet including a time stamp value among the packets transport flow; a coordinated universal time generator (444) configured to calculate a time information value as a function of a system time of the terrestrial digital multimedia broadcast video service delivery apparatus; and a subscript subscriber (446) configured to add the time information value as an index to the transport stream packet including the time stamp value and store it in the stream database (450). ). The apparatus (400) of claim 14, wherein said storage time comprises a time information value of the searched transport stream packet. Apparatus (400) according to claim 14, wherein the time stamp value comprises a program clock reference value. The apparatus (400) of claim 10, further comprising: an ensemble transport interface input processor (410) configured to receive transport stream packets including at least one video stream from a video encoder (300) via an assembly transport interface frame; and an ensemble transport interface output processor (420) configured to convert the overall transport interface frame to an ensemble transport interface signal, and transmit the interface signal of overall transmission converted through a digital media broadcasting transmission apparatus (100) of a broadcast network (500).