KR0182463B1 - Image searching method in an interactive image service system - Google Patents

Abstract

The present invention provides an interactive video service system that enables service transmission from an image packet part corresponding to an extracted marker by searching for and marking an image part of an image program provided from a server system. Provides a video search method.

Accordingly, the present invention provides an interactive service system having a set-top unit 6 as a subscriber terminal for receiving TS packet stream data of a video service program provided from a server system 2 and playing the video through a video playback device 8. In; A first step of generating PTM (Program Time Marker) information for a predetermined TS packet section among TS packets according to the video service program supplied from the set-top unit 6, and transmitting the same to the server system 2; In the second step, the system 2 searches for TS packets of the video service program corresponding to the PTM information supplied from the set-top unit 6 and transmits the TS packets corresponding to the PTM information to the set-top unit 6 side. Characterized in that made.

Description

Image Searching Method in Interactive Video Service System

1 is a block diagram of an interactive video service system implementing the video search method of the present invention.

2 is a block diagram showing the configuration of the set-top unit shown in FIG.

3 is a diagram illustrating a data structure of a TS packet according to an MPEG bitstream.

4 is a flowchart illustrating the method of the present invention.

* Explanation of symbols for main parts of the drawings

2: Server System 4: Network Interface Unit (NIU)

6: set-top unit (STU) 8: video player

10: NIU interface 12: Descrambler

14: MPEG2-TS Demultiplexer 16: MPEG2 Video Decoder

16A: MPEG memory 18: Graphic overlay controller

18A: Graphic Memory 20: RGB Encoder

22: MPEG audio decoder 24: RF modulator

26: function setting unit 28: key input unit

30: memory 32: timer

34: main processor

The present invention relates to a video scanning method in an interactive video service system, and more particularly, to search for and re-view / re-record a predetermined part of a video program serviced by an interactive network communication between a server system and a set-top unit. The present invention relates to a video search method in an interactive video service system.

At present, an interactive video service system for transmitting a service 2 to a video program or other video / audio added program through interactive two-way network communication has been developed and commercialized. VOD (Video On Demand) service that allows you to apply for and play video programs such as movies through the network, game services that allow you to apply for and enjoy games you want through the network, and receive news programs you want. Various interactive program services such as NOD (News On Demand) service and distance learning service that can execute educational function by forming virtual classrooms are possible.

Such an interactive video service system includes a service supply system as a provider for a transmission program, that is, a server system, a delivery system that enables two-way network communication between a service provider and a subscriber, and a subscriber terminal. It consists of a set top unit.

According to the service supply system, for example, a broadcasting station, an intermediate company, or a private transmission station is used to process desired information by receiving addressed information contents from a subscriber, and to transmit the desired information to a corresponding subscriber. Main control means for the control of the recognition and control of the corresponding information and the conversion of the video data of the program to be provided, and the accounting calculation means for applying the billing for the subscribers who are subscribed by the scramble function. An information source for providing a plurality of target video programs, and video data of the video program extracted from the information source is encoded by a video compression method using, for example, the MPEG2 algorithm, for example, in an appropriate information packet unit such as MPEG2-TS. Multiplex and split into stream data Data conversion means for transmitting and receiving, and interface means for performing an interface function for information with a network.

In addition, the transmission system transmits the information of the subscribers from the set-top unit or the like to the server system without error and transmits the service program performed from the server system through the formation of the network. It is possible to transmit the video data in the form of a packet mainly in the form of an ATM packet by the ATM (Asynchronous Transfer Mode) method. In addition, the set-top unit receives specific information from the server system through the transmission system, converts it into a non-network information characteristic, and transmits information on service requests without difficulty. And a scrambled service program in the form of a packet, which is multiplexed by MPEG2 algorithm, for example, by the selection of the service menu used as a request for service delivery, as a condition of limited subscription. By demultiplexing and decoding, the information can be output to an information reproducing apparatus such as a television or a video tape recorder.

However, at the present time, by selecting and designating a predetermined video program provided from the server system, the playback start function (Plyback) can not only be sequentially received and played back according to the contents order of the program, but also the played program. Since only the Stop / Pause function is provided, the function is difficult to realize when there is a request for re-viewing or recording a predetermined portion of the program content being watched. If the user wants to re-view the contents, the service must be requested for the program as a whole, resulting in inefficient system operation.

As a result, it is not only necessary to easily designate a desired part of a desired program for re-watching or recording the corresponding program, but also a new method for extracting and transmitting the exact required part by searching for the designated program content. Is required.

Accordingly, the present invention has been made in view of the above circumstances, and the image packet portion corresponding to the extracted marker is searched for by marking and marking any image portion of the image program provided from the service system. An object of the present invention is to provide a video search method in an interactive video service system that enables service transmission.

According to the video search method in the interactive video service system according to the present invention to achieve the above object, the subscriber to the TS packet stream data of the video service program provided from the server system to be reproduced through the video playback video device An interactive service system having a set top unit as a terminal; A first step of generating PTM information for a predetermined TS packet section among TS packets according to an image service program supplied from the set-top unit, and transmitting the PTM information to the server system; The present invention provides a video searching method in an interactive video service system comprising a second step of searching for a TS packet of a corresponding video service program and transmitting the TS packet corresponding to the PTM information to the set-top unit.

Preferably, according to the present invention, the PTM information generated in the first step includes PATH information for checking the supplied video service program, PID information included in the TS packet, and PCR included in the AF field of the TS packet. Consists of information.

More preferably, according to the present invention, if the TS packet having the PID information and the PCR information corresponding to the PID information and the PCR information of the PTM information is found in the second step, the PCR is larger than the PCR information according to the PTM information The information is started from the TS packet having the information. If the TS packet having the PID information corresponding to the PID information of the PTM information does not include an AF field, the PTM information of the next TS packet of the TS packet is searched. Is done.

In addition, in the first step, a plurality of PTM information may be designated for the service program of the TS packet so that the start section and the end section for the re-viewing and re-recording of the TS packet may be set.

In addition, it is characterized in that the step-fast forward / reverse root is executed by adding or subtracting the step size value calculated in units of n minutes in the first step to the value of the PCR information.

According to the present invention configured as described above, the PTM information for the predetermined TS packet of the video service program supplied, that is, the PATH, while the video service program provided from the server system is supplied from the set-top unit in the interactive service system. Information, PID information, and PCR information are generated and transmitted to the server system, the server system searches for the TS packet of the video service program corresponding to the PTM information, and sends it to the video service program according to the PATH information of the PTM information. According to the TS packet, the TS packet having the PID information and the PCR information corresponding to the PID information and the PCR information of the PTM information can be extracted and transmitted to the set-top unit from the TS packet. Re-viewing or re-recording can be performed.

Hereinafter, the present invention configured as described above will be described in detail with reference to the accompanying drawings.

That is, FIG. 1 is a block diagram of an interactive video service system implementing the video search method according to the present invention. In FIG. 2, reference numeral 2 is provided to provide a video service to a subscriber who is limitedly subscribed to by a scramble function. Server system.

The server system (2) receives the service request information requested from the subscriber and has a variable length packet form as an elementary stream of video data encoded by the video compression method of the MPEG2 algorithm for the requested video program included in the video source. Multiplexed into a plurality of TS (Transport Stream) packets having a fixed length in a packetized elementary stream (PES) packet having a fixed length, and can be transmitted as a downstream stream, through network communication from the set-top unit 6 described later. The video portion can be extracted and retransmitted through re-viewing / recording request information, that is, program time marker (PTM) information, for a predetermined portion of the transmitted video program.

In this case, the transport stream (TS) is divided into a plurality of TS packets having 188 bytes and transmitted as shown in FIG. 3, and the 4-bit TS header serving as a header for each packet and the MPEG2 algorithm are used. Comprising payload data having encoded video / audio data, the TS header includes 13-bit PID (Program IDentification) information for program recognition and a system clock of the set-top unit 6 described later. In order to force adjustment, each TS packet is equipped with AF (Adaptation Field) information including 42-bit PCR (Program Clock Reference) information having a reference time of 100 ms or less.

The TS packet type video / audio data stream information may be converted into an ATM cell on a network and transmitted.

Further, the server system 2 transmits the PATH information for the video program selected and designated by the set-top unit 6 to be described later, so that the video program can be identified through the PATH information. A PSI (Program Specific Information) table can be transmitted through a TS packet. The PSI table information includes information necessary for decoding TS stream data.

Further, reference numeral 4 receives the video / audio data stream information, which is transmitted downstream from the server system 2 in the form of an ATM cell, and program information having a menu for service request, and converts it into a non-network TS packet form. In addition, a network interface unit for transmitting service request information from the set-top unit 6 described later to the server system 2 as an upstream through the network is shown.

Further, reference numeral 6 decodes the video / audio data stream information having the MPEG2 algorithm through the network interface unit 4 so that it can be reproduced as an RF signal and selects a video program to be reproduced through the program information. Indicates a set-top unit having a selection function for a predetermined portion of a video program to be re-watched / recorded, and 8 denotes a composite signal from the set-top unit 6 for receiving a composite image from the screen and speakers. A video reproducing apparatus made up of a television, a video tape recorder, and the like for reproducing or recording audio.

Here, the set-top unit 6 includes the NIU interface 10, the descrambler 12, the MPEG2-TS demultiplexer 14, the MPEG2 video decoder 16, and the graphic overlay controller as shown in FIG. 18, RGB encoder 20, MPEG audio encoder 22, RF-modulator 24, function setting unit 26, key input unit 28, memory 30, timer 32, and main processor It consists of 34.

In the set-top unit 6 as shown in FIG. 3, the NIU interface 10 performs an interface operation with the network interface unit 4, and the descrambler 12 in order to satisfy a limited subscriber reception condition. When descrambling using the stream-based or block-based technique through the initialization value and data of the TS packet stream, the MPEG2-TS demultiplexer 14 extracts the initialization value and data from the TS packet stream and descrambles the descrambler ( 12), the scrambled packet is read as descrambled data and demultiplexed.

In addition, the MPEG2 video coder 16 has an MPEG memory 16A having a storage capacity of at least 2M bytes as a data work area, and decodes and decompresses the demultiplexed video data stream based on the MPEG2 algorithm.

In addition, the graphic overlay control unit 18 has a graphic memory 18A made up of at least 1.5 Mbytes of DRAM as a data work area, which is addressed by the main processor 34 and by the MPEG2 video decoder 16. Graphic Overlay Data having a menu screen for decoded service request is signal-processed to be displayed on screen, and the RGB encoder 20 encodes the decoded image data into, for example, an NTSC signal.

The MPEG audio decoder 22 decodes the MPEG sound data demultiplexed by the MPEG2-TS demultiplexer 14 by an MPEG algorithm, and the RF modulator 24 encodes the encoded RGB signal and MPEG decoding. The modulated voice signal is RF-modulated to be output in the form of a composite signal.

In addition, the function setting unit 26 is made of a remote control for remote control to select the service menu and set the key for re-viewing / recording the predetermined portion of the video program to be reproduced, the key input unit 28 Receives a key setting signal in the form of a remote signal from the function setting unit 26 and decodes it recognizably.

Here, the function setting unit 26 performs key setting for generating PTM information at the reproduction time of the portion to be re-watched / recorded on the reproduction screen of the video program currently being reproduced.

In addition, the memory 30 is, for example, EEPROM (Electrically) for storing the PATH information, the PID information, and the PCR information of the TS packet corresponding to the key setting time for generating the PTM information by the function setting unit 26. Eraserable Programmable ROM (Flash Memory) type, and the timer 32 indicates that the internal clock is matched by reference click data having a resolution of 27 MHz of PCR information transmitted in the TS packet data. It will work.

Then, the main processor 34 is provided to the function setting unit 26 through the key input unit 28 in the state that the service program from the server system 2 is provided and the video / audio MPEG stream data is supplied. PID included in the TS packet corresponding to the key setting period by the function setting unit 26 among the TS packets demultiplexed by the MPEG2-TS demultiplexer 14 by receiving the key setting signal for generating PTM information from In addition to extracting the information and PCR information in the memory 30, along with the PATH information for identifying the service program, and controlled to be transmitted to the server system (2) via the network interface unit (10).

In the server system 2, if the PTM information (IPATH (Input PATH) information, IPID (Input PID) information, and IPCR (Input PCR) information) from the set-top unit 96 are received through the network, IPATH If the searched and extracted packet is a PSI table (i.e., a table with information necessary for TS decoding) by searching for a service program corresponding to the information and searching for a packet having the same PID information as the IPID information in the searched service program, If the AF field exists in the TS packet in which the same PID information exists, it is transmitted from the TS packet having the PCR information larger than the IPCR information in the PCR information included in the AF field. If the field does not exist, it proceeds to the next TS packet and recognizes the presence of PCR information larger than the IPCR information and transmits it from the corresponding TS packet.

Next, the operation of the present invention made as described above will be described in detail with reference to the flowchart of FIG.

First, when a service request for a predetermined video service program is generated from the set-top unit 6 in step 40 and the service request information is transmitted by the network interface unit 4 and obtained through a network, the server system 2 side The service-required program is compressed by video compression technique using MPEG2 algorithm to demultiplex and transmit TS packet in the form of TS packet. On the network, the video data converted from TS packet to ATM cell is transmitted through network interface unit (4). The data is converted into non-network data and input through the NIU interface 10 of the set-top unit 6.

At this time, the MPEG2-TS demultiplexer 14 performs the demultiplexing operation through the initialization value and the data of the TS packet stream in the set-top unit 6, and the descrambler 12 descrambles the TS packet type image data. While the image data is read in a blank state, the MPEG-2 video decoder 16 is restored by the MPEG2 algorithm for the image data, and is encoded by the RGB encoder 20 as an RGB signal, for example, an NTSC system, and the MPEG audio decoder for the audio data. As a result of decoding by (22), the video service is performed by being modulated into an RF signal by the RF modulator 24 and transmitted to the video reproducing apparatus 8 as a composite signal.

In that state, the process proceeds to step 41 where the main processor 34 of the set-top unit 6 performs a key operation for generating PTM information from the function setting unit 26 through the key input unit 28. Judge.

As a result of the determination in step 41, if it is determined that the function setting unit 26 is performing a key operation for generating the PTM information, the control proceeds to step 42 where the 13-byte PTM information used for confirmation of the corresponding service program is obtained. 3 bit PID information included in the TS packet from the MPEG2-TS demultiplexer 14 supplied at the time when the function setting unit 26 is operated, and in the AF field. In addition to extracting the 42-bit PCR information contained in the memory 30, the extracted PTM information, PATH information, PID information, and PCR information through the network interface unit (4) server system (2) Will be sent to

On the other hand, in step 43, the server system 2 receives PTM information (i.e., IPATH information, IPID information, and IPCR information) transmitted through the network, and proceeds to step 44 where IPATH among a plurality of service program sources. The service program corresponding to the information is retrieved.

Then, the process proceeds to step 45 to search for the packet having the PID information corresponding to the IPID information in the service program searched by the IPATH information, so that if the packet according to the search result corresponds to the PSI table, the set top unit 6 If a packet having the same PID information as the IPID information is extracted, the process proceeds to step 46 to determine whether an AF field exists in the TS packet from which the same PID information is extracted.

If it is determined in step 46 that the AF field does not exist in the corresponding TS packet, control proceeds to step 47 and the control proceeds to the next TS packet, and the operations of steps 44 to 46 are performed again.

However, if it is determined in step 46 that the AF packet is included in the TS packet, then the control proceeds to step 48, whereby PCR information in the AF field is compared with IPCR information according to the PTM information, and then the IP packet information is determined. The transmission starts from the larger TS packet.

Accordingly, in step 49, the set-top unit 6 receives the TS packet stream data designated by the PTM information transmitted through the network, and undergoes the demultiplexing operation, the MPEG2 decoding, and the RGB encoding operation, thereby performing the video playback device 8 ) Can be played back or recorded.

On the other hand, the present invention described above is not limited to the above embodiment and can be modified and implemented in various ways without departing from the yoke, the embodiment according to the present invention by specifying the PTM information once Although the video service program can be viewed or re-recorded, for example, TS packet data, which is limited from an arbitrary start section to an end section of the video service program being viewed, can be selectively re-supplied to be played back or re-recorded. It is possible.

In addition, in the embodiment according to the present invention, it is possible to implement the step-rewinding / fast-forwarding function by modifying the function of finding the starting point of the TS packet by using the PCR information, so that the PCR information has a resolution of 27 MHz. The step size value is calculated as 27M × n × 60 when the rewinding or fast-forward movement interval is set to n minutes. If the step-fast forwarding function is added, the step size value is added to the current PCR information. For step-rewinding, subtract the step size from the current PCR information.

According to the present invention as described above, the TS packet of the program is executed and supplied in the interactive service system employing the set-top unit as a subscriber station receiving the service program from the server system, the re-viewing or re-recording By designating and transmitting PTM information about a desired TS packet, it can be transmitted from the TS packet designated by the corresponding PTM information, so that the user can easily specify and re-view or re-record the broadcasting section of a desired program. It has the advantage that it is.

Claims (6)

An interactive service system having a set-top unit (6) as a subscriber terminal for receiving TS packet stream data of a video service program provided from a server system (2) to be reproduced through a video playback device (8), wherein the set-top unit A first step of generating PTM (Program Time Marker) information for a predetermined TS packet section among TS packets according to the video service program supplied from (6), and transmitting the same to the server system 2; A second step of searching for TS packets of the video service program corresponding to the PTM information supplied from the set-top unit 6 and transmitting the TS packets corresponding to the PTM information to the set-top unit 6 side. A video search method in an interactive video service system. The PTM information of claim 1, wherein the PTM information generated in the first step comprises PATH information for checking a supplied video service program, PID information included in a TS packet, and PCR information included in an AF field of a TS packet. Image search method in an interactive video service system, characterized in that. The method of claim 1 or 2, wherein in the second step, if a TS packet having PID information and PCR information corresponding to the PID information and the PCR information of the PTM information is found, the PCR becomes larger than the PCR information according to the PTM information. A video searching method in an interactive video service system, characterized by starting transmission from a TS packet having information. The method according to claim 1 or 2, wherein if the TS packet having the PID information corresponding to the PID information of the PTM information does not include an AF field in the second step, the PTM information is searched for the next TS packet of the TS packet. And a video searching method in an interactive video service system, characterized in that it is done. The method of claim 1, wherein, in the first step, a plurality of PTM information is designated for the service program of the TS packet so that the start section and the end section for re-viewing and re-recording the TS packet can be set. Image Searching Method in Interactive Video Service System. The method of claim 1 or 2, wherein the step size value calculated in units of n minutes in the first step is added to or subtracted from the PCR information to execute the step-fast forward / rewind function. Image Searching Method in Interactive Video Service System.