KR20020015232A - Apparatus for Storing Transport Stream and Broadcast Signal Receiver Employing the Same - Google Patents

Abstract

PURPOSE: A transport stream storing device and a broadcasting signal receiver employing the transport stream storing device are provided to easily play back the stored broadcasting signals at a random location by collectively storing a transmission packet stream about a digital TV with the receiving times of packets. CONSTITUTION: A broadcasting signal receiver comprises a channel unit, a multiplexer, a transport stream decoder, a video decoder/graphic processor, and an audio decoder. The broadcasting signal receiver receives digital broadcasting signals, decodes the broadcasting signals, and outputs video signals and audio signals. A transport stream storing unit(108) adopted to the broadcasting signal receiver comprises a storing unit(200) generating a storage packet of a TS(Transport Stream) packet of a channel to be stored and storing the storage packet in a storing medium(107), a reading unit(220) reading the packet stored in the storing medium, feeding back the TS packet, and outputting the packet, and a storing medium interface(240) connecting the storing unit and reading unit with the storing medium. The transport stream storing unit has plural motion modes including a normal mode and a trick mode. In the trick mode, specific numbers of transport packets continuing from the random-accessible transport packets are output. Therefore, the broadcasting data at a desired time point are easily played back.

Description

Apparatus for Storing Transport Stream and Broadcast Signal Receiver Employing the Same}

The present invention relates to a digital broadcast receiver, and more particularly, to a device for storing a received broadcast signal and a digital television broadcast receiver employing the same.

In general, in a TV broadcast, a signal transmitted from a broadcasting station is transmitted to a receiver of a viewer in real time. Therefore, a TV viewer can watch a desired program only at a fixed time. If the TV cannot be watched at a fixed time due to an unavoidable reason, a scheduled recording must be made by using a VCR. However, in order to record VCR reservations, it is inconvenient to read the manual of owning VCR and perform complicated operation process. Accordingly, general viewers do not attempt reservation recording at all or give up in the middle of attempting it. to be.

On the other hand, in recording the received broadcast signal, the above-described VCR is commonly used. By the way, since the VCR sequentially stores signals on a tape wound on a reel inside the cassette, it is impossible to randomly access them in reproducing the stored signals. In order to partially solve this problem, the conventional VCR makes it possible to scan the contents of a stored signal by utilizing a 'fast forward (REW)' or 'fast forward (FF)' function. However, since digital VCRs (DVCRs) corresponding to digital TVs, which are to be spread in earnest, store signals in the form of MPEG transport streams, it is difficult to implement REW or FF functions.

In this regard, a personalized video recorder (PVR) proposed in the United States has attempted to store broadcast signals on a hard disk. The PVR is based on analog TV broadcasting, and a receiving apparatus includes an MPEG encoder to encode a received broadcast signal in MPEG format and store the result in an MPEG program stream. However, there have been no proposals for providing FF or REW functions in relation to PVR. As described above, none of the conventional video recording apparatuses is able to partially access random access and provide the FF and REW functions.

On the other hand, as broadcasting channels are diversified and broadcast contents are specialized, broadcasting viewing authority is gradually being paid. In response to this trend, future video recording apparatuses are strongly required to prevent a third party from arbitrarily transferring and reproducing the recorded video in order to consider and respect copyright of the broadcast.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems and to meet market demands, and enables a user to store and reproduce digital broadcast signals transmitted from broadcasting stations, and in particular, to enable random access in reproducing stored signals. It is a technical problem to provide a transport stream storage device. In particular, the present invention is to provide a transport stream storage device that enables the scanning of stored broadcast signals by implementing the 'fast forward' and 'fast forward' functions.

In addition, another object of the present invention is to provide a broadcast signal receiving apparatus employing such a broadcast signal storage device.

1 is a block diagram of an embodiment of a digital broadcast receiving apparatus according to the present invention;

2 is a detailed block diagram of the transport stream storage unit shown in FIG.

3 is a view for explaining a process of storing a broadcast signal received in the transport stream storage unit of FIG.

4 shows the format of a storage packet generated by the packager shown in FIGS. 2 and 3;

5 is a structural diagram of a random access table generated to implement a trick mode.

FIG. 6 is a diagram for describing a process of reading a signal to reproduce a broadcast signal stored in the transport stream storage unit of FIG. 2; FIG.

7 is a block diagram of another embodiment of a digital broadcast receiving apparatus according to the present invention;

8 shows the data format of a typical transport packet stream.

<Description of the symbols for the main parts of the drawings>

101: channel section 102: multiplexer

103, 303: transport stream decoder 104: video decoder / graphics processor

105: audio decoder 106.306: CPU

107: storage medium 108: transport stream storage unit

109, 309: Smart card 110: Modem

111: descrambler 200: storage unit

202: PID filter 204: First reference counter

206: time attachment 208: TS packet counter

210: random access detection unit 212: scrambler

214: Packager 216: first memory

220: reader 222: depacketizer

224: second memory 226: descrambler

228: time comparison sending unit 230: second reference counter

240: storage medium interface

Summary of the Invention

The transport stream storage device of the present invention for achieving the above technical problem accepts a transport packet stream for the digital television signal and stores at least some of the transport packets included in the transport packet stream in a storage medium. The storage unit adds arrival time information to each of the transmission packets to be stored, generates a storage packet, stores the storage packet in the storage medium, and determines whether random access to each of the transmission packets to be stored is possible. The reading unit reads the storage packets stored in the storage medium, restores the packets, and outputs the packets. The storage medium interface unit connects the storage unit and the reading unit to the storage medium.

The transport stream storage device has a plurality of modes of operation, including normal mode and trick mode. The reading unit outputs each of the recovered transport packets while maintaining the arrival time interval in the normal mode, and outputs only a predetermined number of transport packets consecutively started from each of the randomly accessible transport packets in the trick mode. In trick mode, the number of transport packets output starting from each of the randomly accessible transport packets is preferably determined so that one intra frame can fit sufficiently, the specific value of which correlates with the video transmission rate.

On the other hand, the broadcast signal receiving apparatus for achieving the another technical problem includes a channel unit, a transport stream decoder, a video decoder and an audio decoder, and a control means for controlling the overall operation of the apparatus. The channel unit receives the digital television broadcast signal and demodulates it to output a transport packet stream including a plurality of transport packets. The transport stream decoder extracts only transport packets for a predetermined channel to be tuned by the user from the transport packet stream and restores the video stream and the audio stream. The video decoder accepts and decodes the video stream to produce an analog video signal, and the audio decoder receives and decodes the audio stream to produce an analog audio signal. The apparatus for receiving broadcast signals further includes a storage medium and a transport stream storage unit for receiving the transport packet stream and storing at least some of the transport packets included in the transport packet stream in the storage medium. The transport stream storage unit has a configuration corresponding to the transport stream storage device mentioned above.

In a preferred embodiment, the control means generates a random access table for storing the detection time for each of the transport packets determined to be randomly accessible by the storage and the storage location on the storage medium. The control means controls the reader to output only a predetermined number of transmission packets starting from each of the randomly accessible transport packets in the trick mode with reference to the random access table. The storage unit may further include a packet counter that counts the number of video transport packets among transport packets to be stored. In this case, the control means calculates the transport packet rate based on the counted number of packets, and determines the number of transport packets output starting from each of the randomly accessible transport packets in the trick mode based on the rate.

In addition, the apparatus for receiving broadcast signals may further include a modem for internet access and may be implemented to enable internet access. When the internet connection is made via the modem, the control means may automatically control the transport stream storage unit to start the transport packet storage operation.

On the other hand, such a broadcast signal receiving apparatus may be a television receiver having a display and a speaker for outputting a video signal and an audio signal, respectively, and may be a set-top box for supplying the video signal and the audio signal to an external television receiver. It may be.

Most stations do not transmit broadcast signals during the late night hours, when there are few viewers and the economic burden to provide a quality broadcast program is high. As such, if an operator such as a private institute can transmit educational broadcasts through a late-night broadcast channel in which the broadcast signal is interrupted, it may be a good opportunity not only for the renter but also for the broadcaster or the general viewer. will be. The transport stream storage device proposed by the present invention may be used to store such a late night broadcast. In this case, the renter of the channel can reduce the cost of the broadcast and the viewer can watch the stored program at a convenient time. It becomes possible.

In particular, in the case of providing such a late-night broadcast for a fee, the viewing authority may be granted only to a person who has a licensed smart card or a broadcast signal receiving device equipped with the same. You can double your protection. In addition, when the transport stream storage device according to the present invention is applied to a broadcast receiving device equipped with an internet connection modem or the like, in addition to a simple internet access function, the content of a website related to a program currently being broadcast may be browsed. Therefore, there is an advantage in that the reserved recording function can be easily given to the transport stream storage device.

Description of the Preferred Embodiments

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same or corresponding parts.

1 shows an embodiment of a digital broadcast receiving apparatus according to the present invention. The illustrated broadcast receiving apparatus includes a channel section 101, a multiplexer 102, a transport stream decoder 103, a video decoder / graphics processor 104, and an audio decoder 105, and receives a digital broadcast signal. This is decoded to output a video signal and an audio signal. Such a broadcast receiving apparatus may be a television receiver having a display and a speaker for outputting video and audio signals, respectively, or may be a set top box for supplying the video and audio signals to an external television receiver. In the following description, a description will be given mainly on the case where the receiver of Fig. 1 is a television receiver.

Meanwhile, the broadcast receiving device of FIG. 1 includes a storage medium 107 and a transport stream storage unit 108, and has a function of storing a broadcast stream. On the other hand, the broadcast receiving device is preferably equipped with a smart card 109 that allows only qualified persons to operate it, and has a modem 110 for internet access.

The channel unit 101 receives a digital television broadcast signal through a satellite, terrestrial wave, cable, and the like, demodulates it, and outputs it in the form of a transport stream (TS). The channel unit 101 may select any one of several types of network interface modules (NIMs) such as a satellite channel unit, a terrestrial channel unit, and a cable TV channel unit according to a transmission method adopted by a broadcaster or a receiver type selected by a viewer. May contain. Of course, there are several NIMs to receive signals of various transmission methods. Although not shown, each NIM includes a tuner, a demodulator, and an error correction decoder. In particular, the demodulator may be a VSB demodulator, a QAM demodulator, or a QPSK demodulator, depending on the transmission scheme.

The transport stream decoder 103 extracts only the TS packets related to the channel selected by the viewer from the demodulated TS packets and restores the video stream and the audio stream in the form of a packetized elementary stream (PES), and the video stream is sent to the video decoder 104. And the audio stream to the audio decoder 105. The video decoder / graphics processor 104 decodes the video stream from the transport stream decoder 103 to generate video pixel data, and generates a graphic screen to overlay on the display. The audio decoder 105 decodes the audio stream from the transport stream decoder 103 to generate an analog audio signal.

The transport stream storage unit 108 receives a TS packet from the channel unit 101, extracts a packet to be stored therein, and stores the packet to be stored in the storage medium 107 in the form of a new storage packet. When the viewer wants to watch the stored broadcast, the transport stream storage unit 108 reads the storage packet from the storage medium 107 to restore the TS packet, and provides it to the transport stream decoder 103. The multiplexer 102 is used to select either a TS read from the storage medium 107 and a TS directly input from the channel unit 101. Here, for example, a hard disk, a recordable CD (CD-RW), or the like may be used as the storage medium 107.

FIG. 2 shows the transport stream storage unit 108 shown in FIG. 1 in more detail.

The transport stream storage unit 108 generates a storage packet for a TS packet of a channel to be stored and stores the storage packet 200 in the storage medium 107 and a broadcast stored in the storage medium 107. The readout 220 for reading out the storage packet stored in the storage medium 107 to restore and output the TS packet, and connecting the storage 200 and the readout 220 to the storage medium 107. It has a storage medium interface 240 for.

In a preferred embodiment, the storage unit 200 is a packet identifier (hereinafter referred to as a 'PID') filter 202, a first reference counter 204, a time attachment unit 206, TS packet counter ( 208, a random access detection unit 210, a scrambler 212, a packager 214, and a first memory 216. In addition, the reader 200 includes a depacketizer 222, a second memory 224, a descrambler 226, a time comparison transmitter 228, and a second reference counter 230. Here, the first memory 216 and the second memory 224 may use the same physical memory medium. In another embodiment of the present invention, the scrambler 212 and the descrambler 226 may be omitted.

3 and 4, the operation of the transport stream storage unit 108 of FIG. 2 will be described. FIG. 3 is a diagram illustrating a process of storing a broadcast signal received by the transport stream storage unit of FIG. 2, and FIG. 4 is a diagram illustrating a format of a storage packet generated by the packager illustrated in FIGS. 2 and 3. Drawing.

First, a broadcast signal storing process will be described with reference to FIG. 3. The PID filter 202 extracts only TS packets corresponding to a broadcast channel to be stored among the TS packets input from the channel unit 101, and TS packets of the broadcast channel which are not viewed are blocked by passing them to the rear end and are destroyed. The PID extraction process is enabled by the CPU 106 setting PIDs for each of video, audio, and Entitlement Control Massage (ECM) in the PID filter 202.

For reference, the format of the MPEG transport packet stream input from the channel section is shown in FIG. As shown in Fig. 8A, the TS packet is composed of a header of 4 bytes and a payload of 184 bytes and has a total length of 188 bytes. The specific format of the header is shown in Figure 8 (b). The Adaptation_field_control value in the header indicates the presence or absence of the Adaptation field. If the Adaptation_field_control value is '10' or '11', it means that the Adaptation field exists. If the adaptation field is present, its structure follows the format of FIG. 8 (c). Meanwhile, the PID value included in the header includes information about the channel and information for distinguishing whether the payload included in the packet is a video signal or an audio signal.

Accordingly, the PID filter 202 may select packets of a specific channel based on the PID. The time attaching unit 206 receives the TS packet selected by the PID filter 202, extracts the count value of the first reference counter 204 at this moment, and attaches the count value to the front of the TS packet as the arrival time information. The first reference counter 202 is a counter that counts up using a 27 MHz clock.

The TS packet counter 208 counts the number of packets (video TS packets / sec) transmitted in one second for the video TS packets among the TS packets output from the PID filter 202 and transmits them to the CPU 106. do. Based on this count value, the CPU 106 can estimate the transmission rate of the video stream as shown in the following equation.

Rate (bit / sec) = 188 (byte) × 8 (bit / byte) × TS (1 / sec)

The random access detector 210 detects whether the random access is possible by checking the header of the video TS packet output from the PID filter 202 and informs the CPU 106 of the detection result of whether the random access is possible. The detection signal is a function of indicating whether a screen about a current TS packet or a next TS packet having the same PID is a position where random access is possible. Payload_unit_start_indicator is set to '1' in the header of the video TS packet shown in FIG. 8 (b), Adaptation_field_control is set to '10' or '11', and Random_access_indicator of the Adaptation field shown in FIG. Is set to '1', the TS packet is determined to be in a random access state.

The scrambler 212 scrambles a TS packet to be copyright-protected among TS packets to be stored in the storage medium 107 using a scramble key unique to the receiving device. To this end, the CPU 106 provides the scrambler 212 with a scrambled key uniquely set for the receiving device. The scrambler 206 may be omitted in the transport stream storage device for general broadcast storage. However, as will be described later, when the transport stream storage unit 108 of the present invention is applied to a limited reception system, the scrambler 212 and the descrambler 226 may be transferred or copied to another system. By preventing the reproduction, excellent copyright protection effect can be expected.

The packager 214 sequentially stores the packets of the [arrival time + TS packets] structure generated by the time attachment unit 206 and scrambled by the scrambler 212 in the first memory 216. Create a new storage packet of the form shown in Figure 4. The header of the packet generated by the packager 217 includes information regarding the position of a randomly accessible TS packet. Meanwhile, as described above, the storage packet may be generated based on unscrambled data. The operating state of the packager is constantly reported to the CPU 106.

The storage medium interface 240 accepts the storage packets from the packager 214 and causes the storage packets to be stored in a storage location designated by the CPU 106 on the storage medium 107.

On the other hand, when the CPU 106 is informed from the random access detection unit 205 that the TS packet is in a randomly accessible state, the CPU 106 receives the detection time of the TS packet from the first reference counter 204 and stores the TS packet. The random access table is generated by referring to the storage location of the packet. As shown in Fig. 5, the random access table has a field structure of [detection time, storage location]. This random access table may be used to implement a trick mode such as 'fast forward' or 'fast forward' when watching a later stored broadcast. The random access table may be stored in the storage medium 107 or the first or second memories 216 and 224.

Next, a process of reading a signal to reproduce the digital broadcast signal stored in the transport stream storage unit 108 of FIG. 2 will be described. Referring to FIG. 6, the depacketizer 222 reads a storage packet stored in the storage medium 107 through the storage medium interface 240 and temporarily stores it in the second memory 224. At this time, the position of the storage packet to be read from the storage medium 107 is designated by the CPU 106. The depacketizer 222 checks the states of the descrambler 226 and the time comparison transmitter 228 so that the depacketizer 222 and the descrambler 226 are ready to receive data. The storage packets temporarily stored in the memory 224 are sequentially output to the descrambler 226. The descrambler 226 descrambles the scrambled portion of the storage packet and then outputs the descrambled packet data to the time comparison transmitter 228. In the modified embodiment in which the scrambler 212 and the descrambler 226 are omitted, the depacketizer 222 outputs the storage packet directly to the time comparison transmitter 228.

The time comparison transmitter 228 extracts the arrival time 1 from the first arrival packet [arrival time 1 + TS packet 1], and initializes the second reference counter 230 to the arrival time 1 using the TS. Output packet 1. Here, the second reference counter 230 is an up counter operating by the same clock as the first reference counter 204. The time comparison transmitter 228 compares the arrival time i with the increment value of the second reference counter 230 with respect to the [arrival time i + TS packet i] inputted after the second time, and thus the value of the second reference counter 230. When this arrival time i becomes equal, TS packet i is outputted. Accordingly, the transport stream storage unit 108 can output each TS packet at the same time interval as the time interval at which each TS packet is input and stored. Each TS packet (TS packets 1 to TS packet n) output from the time comparison transmitter 228 may be input to the transport stream decoder 103 through the multiplexer 102 and decoded.

Trick mode implementation

In general, when playing and watching a broadcast stored by an analog VCR, a 'fast forward' or 'fast forward' function is often used. However, in the case of a digital signal formatted as an MPEG stream, since the signal format is complicated, the decoding process is complicated, and it takes a lot of time to prepare for reproduction, and it is difficult to reproduce from any point of time. However, in the broadcast receiving apparatus of the present invention, since the random access table can be generated and used during reproduction, the broadcast reception device can easily reproduce the broadcast at a desired time point and shorten the decoding preparation time.

In the present invention, the trick mode implementation extracts the position of I-picture data including a complete frame video signal from the I-picture, B-picture, and P-picture data constituting the digital video signal, and arranges them in a table form. It uses the principle of referencing this during playback. In addition, in order to predict the number of TS packets to be skipped in the trick mode, the transmission rate of the video stream is measured using the number of video TS packets per second counted by the TS packet counter.

First, in the case of 'fast forward', a predetermined amount of data is read from a storage location related to a random access detection time of a TS packet at a later time based on the random access detection time of a current TS packet. 200), if the 'fast forward' command is continuously input, it continuously transmits a certain amount from the connected storage location in order of detection time. For example, assuming that the current time is (detection time 2) and the 'fast forward' command is input, the packet separation and output unit reads a certain amount from (storage location 3) connected to (detection time 3). Transfer to 20. In this case, if the searched position is not the desired position, the fast forward command is input again. The transport stream storage unit then reads a predetermined amount of the storage packet from (storage position 4) and transmits it. This operation is repeatedly performed. Here, a certain amount means a sufficient amount of TS packets that can accommodate one intra frame, and has a correlation with the video data rate. This is expressed as the following equation.

Amount = A × Video Data Rate

Here, the specific value of the scaling factor A can be obtained empirically through experiments.

In the case of 'fast forward', on the other hand, a predetermined amount of data is read from a storage location related to the random access detection time of the TS packet at a previous time based on the random access detection time of the current TS packet, 200), and if the 'fast forward' command is continuously input, the detection time is searched in reverse order to repeatedly transmit a predetermined amount of data from the connected storage location to the packet separation and output unit 20. .

Copyright protection considerations

7 is another embodiment of a digital broadcast receiving apparatus according to the present invention, and the illustrated apparatus is suitable for a limited reception system.

The broadcasting station can scramble and transmit the TS packet so that only a part of subscribers who have the authority to view the program can watch the program, and the receiving device can descramble the scrambled signal using the decryption key to watch the broadcast. It is called a limited reception system.

In a broadcast receiving apparatus suitable for a general limited reception system, the channel unit 101 demodulates a received signal and outputs a scrambled TS packet to the transport stream decoder 303. The transport stream decoder 303 extracts an ECM message and provides it to the CPU 306, where ECM means a message that encrypts a key used when scrambled a TS packet. The CPU 306 sends the ECM message to the smart card 309 and then receives a decryption key that decrypts the ECM message from the smart card 309. The CPU 306 sends this decryption key to the descrambler 311 to descramble the scrambled TS packet. In general, the descrambler 311 is embedded in the transport stream decoder 303.

However, in such a limited reception system, if a transmitted broadcast program is stored in a storage medium and transferred or copied and transferred to a receiving device of another person, the intended purpose of the limited reception system may be lost, and problems of copyright protection may occur. . Therefore, when storing broadcasts in a medium according to the present invention under the limited reception system, it is preferable to scramble and store broadcast data as well as to store related ECM messages. To this end, the stream storage unit 308 of FIG. 7 inserts and stores an ECM packet in the storage packet header shown in FIG. 4 when generating the storage packet.

A broadcast signal storing and reproducing operation of the broadcast receiving device of FIG. 7 will be described below. First, with respect to the primary scrambled TS packet output by the channel section 101, the scrambler 212 of the stream storage unit 107 uses a receiver-specific scramble key for a payload of 184 bytes except for 4 bytes of the header. The second scramble is stored in the storage medium 107. When reading the storage packet, the descrambler 226 of the stream storage unit 108 secondary descrambles the scrambled 184 bytes of payload. The descrambled TS packet is input to the transport stream decoder 303, and the CPU 306 reads ECM information in the header of the storage packet and transmits it to the smart card 309. Thereafter, the CPU 306 reads the decryption key from the smart card 309 and transmits the decryption key to the descrambler 311 to descramble the scrambled TS packet. The TS packet thus decrypted is processed by the transport stream decoder 303 and then output as analog video and audio signals through the video decoder / graphics processor 104 and the audio decoder 105.

In the apparatus of FIG. 7, the secondary scramble key and secondary decryption key used by the stream storage unit 108 are each different from the primary scramble key used by the broadcast station and the primary decryption key provided by the smart card 309, respectively. It may be the same but different is preferred. In this case, the secondary scramble key and the secondary decryption key may be generated and used by the CPU 306 based on the receiving device serial number, or may be provided by the smart card 309 as described with reference to FIGS. 3 and 6.

Interworking with the Internet

The broadcast receiving device according to the present invention is preferably implemented in the form of an Internet TV that can obtain information by accessing the Internet. In general, a broadcasting station produces and operates a website that is related to a program that is being broadcast or scheduled to be broadcast in the future. If the URL of the corresponding page of the web site is transmitted together with the digital broadcast signal in order to make the web site accessible through the Internet TV, the user of the broadcast reception device according to the present invention can easily perform program reservation recording. As one of methods for transmitting a URL, program guide data may be used. For example, in the European DVB standard, guide information about each program is transmitted through data called an event information table (EIT). There are several descriptors. You can add the URL descriptor here to send the URL for the program.

When providing information about each program through the Internet as described above, the broadcaster may cause the program information to be downloaded to the user terminal, as well as the description of each program as well as the start time and the end time. The broadcast reception device may receive the data through the Internet and store the data in a memory, and the CPU may automatically store the broadcast signal based on the data stored in the memory. Such a function may be implemented by a simple program. Since a specific implementation method may vary according to a data format provided by a broadcasting station and can be easily implemented by those skilled in the software industry, a detailed description thereof will be omitted. Meanwhile, the Internet TV embodying the present invention may allow a broadcast screen and internet information to be simultaneously displayed through a double window or PIP while the viewer is connected to the Internet. In addition, only the Internet screen is shown, and during this time, broadcast contents may be automatically stored, which will be described.

Viewers can watch the program and press the Internet access button on the remote control if they want more information about the program configuration plan. When the digital broadcasting receiver recognizes the Internet access button, the digital broadcasting receiver attempts to access the Internet by searching for the URL of the broadcasting station that transmits the current program. In this way, broadcasts received in real time while connected to the Internet are continuously stored by the transport stream storage unit according to the present invention according to the above-described method together with the time of the attempt to connect to the Internet. In this case, the screen may display only Internet information. If you want to watch the program you have been watching again after performing the interactive service function by connecting to the Internet, you can play in the trick mode and start playing from the moment you try to connect to the Internet, or jump to the content that is currently being broadcast. .

Modified Embodiment

The above description illustrates a preferred embodiment of the present invention, and the present invention is not limited thereto and may be variously modified. For example, in the description of the preferred embodiment, the transport stream is stored only for one channel that the user tunes in or is watching immediately before the Internet connection. In another embodiment of the present invention, the transport stream is stored for a plurality of broadcast channels. This may be done. In addition, although the CPU of the broadcast receiving apparatus generates and stores the random access table, in the modified embodiment, the random access detection unit 210 of the transport stream storage unit 108 performs random access by itself. You can also create a table. On the other hand, of course, a separate microcontroller or microprocessor may be provided in the transport stream storage unit 108.

As such, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not as restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

As described above, when the received MPEG transport stream is stored, the present invention stores information on a time when the transport stream arrives and randomly accessible state information, thereby enabling the stored broadcast to be reproduced at an arbitrary position. At this time, since a hard disk or a CD-RW can be used as the storage medium, it is possible to easily store and access a large amount of data. In addition, since the storage unit itself has a built-in scrambler and a descrambler, when applied to a limited reception system, double encryption can be performed to enhance the copyright protection function. In addition, when applied to a broadcast receiving device having an internet access function, a program can be easily reserved and stored, and operation in a trick mode can be easily performed, thereby facilitating interworking between internet access and broadcasting viewing.

Claims (19)

A transport stream storage device for receiving a transport packet stream relating to a digital television signal and for storing at least some of the transport packets included in the transport packet stream in a storage medium. A storage unit for generating a storage packet by adding arrival time information to each of the transport packets to be stored, and storing the storage packet in the storage medium, and determining whether random access is possible to each of the transport packets to be stored; A reading unit configured to read the storage packets stored in the storage medium and to restore and output the packets; And A storage medium interface for connecting the storage unit and the reading unit to the storage medium; And a plurality of operation modes including a normal mode and a trick mode, wherein the reader outputs each of the restored transport packets while maintaining the arrival time interval in a normal mode, and randomly accessible transport packets in a trick mode. A transport stream storage device for outputting only a predetermined number of transport packets starting from each of them. The method of claim 1, wherein the storage unit And filtering means for extracting only transport packets for a predetermined broadcast channel from the transport packet stream as the transport packets to be stored, based on a packet identifier included in each of the transport packets. The method of claim 1, wherein the storage unit A time attachment unit attaching arrival time information to each of the transport packets to be stored; A random access detector to determine whether random access is possible for each of the transport packets to be stored; And A storage packet generation unit generating the storage packet by adding a predetermined header to the plurality of transport packets to which the arrival time information is attached; Transport stream storage device further comprising. The method of claim 3, wherein the storage unit Table generating means for generating a random access table for storing a detection time for each of the transport packets determined to be randomly accessible by the random access detection unit and a storage location on the storage medium; Further provided, And the reading unit outputs only a predetermined number of transmission packets starting from each of the randomly accessible transport packets in the trick mode with reference to the random access table. The method of claim 4, wherein the storage unit And a packet counter for counting the number of video transport packets among the transport packets to be stored. And the reading unit determines the number of transport packets output starting from each of randomly accessible transport packets in the trick mode by a bit rate determined based on the counted number of packets. The transport stream storage device of claim 3, wherein the storage packet header includes ECM and randomly accessible transport packet information. The method of claim 3, wherein the reading unit A storage packet releasing unit configured to read the storage packet from the storage medium through the storage medium interface, and to disassemble the read storage packet and restore the transport packets to which the arrival time information is attached; And Separating the arrival time information from the transmission packets to which the arrival time information is attached, outputting each of the restored transmission packets while maintaining the arrival time interval in the normal mode, and transmitting the randomly accessible transmission in the trick mode. An output unit for outputting only packets; Transport stream storage device comprising a. The method of claim 7, wherein the storage unit And encryption means for encrypting at least a portion of each of the transport packets to which the arrival time information is attached, such that the storage packet generator generates the storage packet based on the encrypted data, And the reading unit further includes decrypting means for decrypting an encrypted portion of an encrypted storage packet and providing decrypted data to the output unit. The method of claim 7, wherein the storage unit A first reference counter which counts up by a clock having a predetermined frequency and supplies a first count value to the time attaching part, wherein the time attaching part uses the count value as the arrival time information, The reading part And a second reference counter which counts up by the clock and supplies a second count value to the output unit, wherein the output unit extracts the arrival time attached to the first transmission packet to be reproduced and the second reference counter. Initializing a counter and outputting the first transmission packet, and outputs when the second count value is equal to the arrival time attached to the transmission packet for the subsequent reproduced transmission packet. A channel unit which receives a digital television broadcast signal and demodulates it and outputs a transport packet stream including a plurality of transport packets; A transport stream decoder for extracting only transport packets for a predetermined channel selected by a user from the transport packet streams and restoring a video stream and an audio stream; A video decoder that accepts and decodes the video stream to produce an analog video signal; An audio decoder that accepts and decodes the audio stream to produce an analog audio signal; And A control unit for controlling the operation of the channel unit, the transport stream decoder, the video decoder and the audio decoder; Storage media; And A transport stream storage unit for receiving the transport packet stream and storing at least some of the transport packets included in the transport packet stream in the storage medium; Further provided, The transport stream storage unit A storage unit to generate a storage packet by adding arrival time information to each of the transport packets to be stored, to store in the storage medium, and to determine whether random access is possible to each of the transport packets to be stored; A reading unit configured to read the storage packets stored in the storage medium and to restore and output the packets; And a plurality of operation modes including a normal mode and a trick mode, and in the normal mode, the reader outputs each of the recovered transport packets to the transport stream decoder while maintaining the arrival time interval, and the trick mode Wherein the reader outputs only a predetermined number of transmission packets starting from each of randomly accessible transport packets to the transport stream decoder. The method of claim 10, wherein the control means Generating a random access table storing a detection time for each of the transport packets determined to be randomly accessible by the storage unit and a storage location on the storage medium, And the read unit controls to output only a predetermined number of transmission packets starting from each of the randomly accessible transport packets in the trick mode with reference to the random access table. The method of claim 11, wherein the storage unit And a packet counter for counting the number of video transport packets among the transport packets to be stored. The control unit calculates a transmission rate of the transport packet based on the counted number of packets, and determines a number of transport packets output from each of the transport packets randomly accessible in the trick mode based on the transmission rate. . The method of claim 10, wherein the storage unit And filtering means for extracting only transport packets for a predetermined broadcast channel from among the transport packet streams as the transport packets to be stored, based on a packet identifier included in each of the transport packets. The method of claim 10 or 13, wherein the storage unit A time attachment unit attaching arrival time information to each of the transport packets to be stored; A random access detector to determine whether random access is possible for each of the transport packets to be stored; And A storage packet generation unit generating the storage packet by adding a predetermined header to the plurality of transport packets to which the arrival time information is attached; Broadcast signal receiving apparatus further comprising. 15. The apparatus of claim 14, wherein the storage packet header includes ECM and randomly accessible transport packet information. The method of claim 14, wherein the reading unit A storage packet releasing unit configured to read the storage packet from the storage medium through the storage medium interface, and to disassemble the read storage packet and restore the transport packets to which the arrival time information is attached; And Separating the arrival time information from the transmission packets to which the arrival time information is attached, outputting each of the restored transmission packets while maintaining the arrival time interval in the normal mode, and transmitting the randomly accessible transmission in the trick mode. An output unit for outputting only packets; Broadcast signal receiving apparatus having a. The method of claim 16, wherein the storage unit And encryption means for encrypting at least a portion of each of the transport packets to which the arrival time information is attached, such that the storage packet generator generates the storage packet based on the encrypted data, And the reading unit further includes decrypting means for decrypting an encrypted portion of an encrypted storage packet and providing decrypted data to the output unit. The method of claim 16, wherein the storage unit A first reference counter which counts up by a clock having a predetermined frequency and supplies a first count value to the time attaching part, wherein the time attaching part uses the count value as the arrival time information, The reading part And a second reference counter which counts up by the clock and supplies a second count value to the output unit, wherein the output unit extracts the arrival time attached to the first transmission packet to be reproduced and the second reference counter. And a counter for initializing the counter and outputting the first transmission packet, and outputting the reproduced transmission packet when the second count value is equal to the arrival time attached to the transmission packet. The method of claim 10, A modem for internet access; And the control means automatically controls the transport stream storage unit to start a transport packet storage operation when an internet connection is made through the modem.