KR100640346B1 - Digital stream controller and a broadcast receiving system having the same - Google Patents

Abstract

The present invention relates to a broadcast signal receiving system capable of simultaneously supporting time delay viewing and recording and playback of a broadcast signal. The present invention relates to storing a digital stream input in real time on a recording medium of a random access storage device and efficiently reproducing it. Of course, the present invention relates to a controller for controlling input and output of a digital stream so as to support trick play, and a broadcast receiving system including the same. To this end, in the embodiment of the present invention, only the transport packet of the channel to be recorded is extracted from the received broadcast signal, and a time stamp indicating the arrival time of the extracted transport packet is inserted into the transport packet. In this way, a header is inserted into a group of transport packets, which are time stamped, to create a disk packet and record the disk packet. During playback, the transport packet is extracted from the reproduced disk packets, and then the transport packet is output to the data decoding unit at the time indicated by the time stamp.

Time stamps, disk packets, digital transport streams

Description

Digital stream controller and broadcast receiving system including the same {DIGITAL STREAM CONTROLLER AND A BROADCAST RECEIVING SYSTEM HAVING THE SAME}             

1 is a block diagram of a broadcast receiving system having a digital stream controller according to an embodiment of the present invention.

2 is a block diagram of a digital stream controller 20 according to an embodiment of the present invention.

3 is a disk packet structure diagram according to an embodiment of the present invention.

4 is an exemplary disk packet size in accordance with an embodiment of the present invention.

5 is a diagram illustrating a picture storage location table for trick mode support according to an embodiment of the present invention.

6 is a view for explaining a process up to recording a transport stream (TS) on a hard disk drive (HDD) in accordance with an embodiment of the present invention.

7 is a view for explaining a process of transmitting a video stream reproduced from a hard disk drive (HDD) according to an embodiment of the present invention.

The present invention relates to a broadcast receiving system capable of simultaneously supporting time delay viewing and recording and playback of a broadcast signal, and in particular, a digital stream controller for storing a digital stream on a hard disk and supporting a trick mode, and a broadcast including the same. A receiving system and a method for recording / reproducing a video stream.

The hard disk drive, which is a secondary memory device of a computer system, can be randomly accessed, and the data transmission speed is high, and it can be cheaper and larger in capacity than other auxiliary memory devices. It is used as an access storage device.

A broadcast receiving system having a random access storage device is a system capable of simultaneously recording and playing back digital transport streams and viewing time delays. Simultaneous recording and reproducing of the time-delayed viewing and transport stream of the broadcast signal can be implemented by buffering the digital stream input / output to the hard disk drive.

A general broadcast reception system capable of supporting time delay viewing and recording and playback of a broadcast signal simultaneously performs A / D conversion of the received analog broadcast signal to store a digital transport stream on a hard disk, and then converts it into MPEG. The encoder converts the digital video stream and stores it on the hard disk. Therefore, a general broadcast reception system requires an additional hardware configuration such as an A / D converter and an MPEG encoder in order to store a digital stream on the hard disk surface, so that the broadcast reception system is enlarged.

In addition, considering multimedia products such as multimedia PC, video on demand (VOD), high definition TV, digital broadcasting, digital communication, etc., the real-time transmission of digital streams is stored on the hard disk, and it supports time delay watching and trick play. To do this, a controller for effectively controlling the input and output of the digital stream is required.

Accordingly, an object of the present invention is to store a digital stream input in real time on a recording medium of a random access storage device and to efficiently reproduce it, as well as to analyze the digital stream so as to support trick play and extract necessary information and use the controller. And a broadcast receiving system including the same.

It is still another object of the present invention to provide a recording and reproducing method of recording a digital stream or playing back a recorded stream in a random access storage device in a broadcast receiving system capable of simultaneously supporting time delay viewing and recording and playback of a broadcast signal. Is in.

The present invention for achieving the above object is a broadcast receiving system having a hard disk drive for supporting time delay viewing and recording and playback at the same time,

A channel circuit for inputting a broadcast signal into which an error correction code is inserted, digitally modulated and transmitted, and converting it into a digital transport stream;

Inserts new PAT information and time stamp into the selected transport packet in the transport stream input from the channel circuit or a single video stream input from an external network, and transmits the new PAT information and time stamp to the hard disk drive, and the time stamp reproduced from the hard disk drive. A digital stream controller for accessing the inserted transport packet and outputting only the transport packet to the video decoder;

A memory for storing a time stamped transport packet transmitted from the digital stream controller;

When recording, a header is added to a group of time-stamped transport packets stored in the memory to create a disk packet and control the recording to be recorded on the hard disk drive, and the desired disk packet is controlled by controlling the hard disk drive when playing recording information. Characterized in that the system control unit for storing in the memory,

The digital stream controller may include a filter for selectively outputting only PIDs of transport packets of only a recording channel selected from an input digital transport stream;

PAT inserting unit for generating a new PAT packet having only the information on the currently selected channel at the time when the PAT having the information on the multiple channels arrives, replacing the PAT packet with a PAT having multiple channel information,

A time stamp inserter for capturing and inserting an internal clock counting value that is increased in a predetermined cycle period when the transport packet is input from the PAT inserter, and inserting it into the transport packet;

A picture which extracts a video packet from the time stamped transport packet according to the set video PID value, finds a picture header from the extracted video packet, sets a picture header detection bit, and sets picture type information of the current picture. A header detector,

A controller for controlling transmission of the time stamped transport packet to the random access storage device, and accessing and outputting the time stamped transport packet reproduced in the random access storage device;

A memory for temporarily storing a time stamped transport packet output from the controller;

And a timing controller for outputting only the transport packet to the decoding unit from the time stamp-inserted transport packet output from the memory.

Hereinafter, the configuration and operation of a digital stream controller and a broadcast receiving system including the same will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a broadcast receiving system having a digital stream controller according to an embodiment of the present invention, and FIG. 2 is a detailed block diagram of a digital stream controller 20 according to an embodiment of the present invention. It is shown.

Referring to FIG. 1, a digital stream controller 20 according to an exemplary embodiment of the present invention is connected to a channel circuit 10 and an IEEE 1394 40 to receive an MPEG transport stream. The channel circuit 10 is a functional block that must be provided according to a channel type such as terrestrial wave, satellite, cable, etc., and includes a demodulator for demodulating a modulated signal and an error correction unit for correcting an error accompanying transmission. It includes. That is, the channel circuit 10 inputs a broadcast signal transmitted through a unique channel, converts it into an MPEG transport stream (hereinafter referred to as a TS stream), and outputs it.

The IEEE 1394 40 transmits a single bit stream transmitted from the 1394 network 30 to the digital stream controller 20.

The digital stream controller 20 inserts new PAT information and time stamps into the TS stream input from the 1394 network or the channel circuit 10 and transmits the new PAT information and time stamps to the memory 1 90 through the PCI bus 50 and the HDD 70. Transmits the TS stream reproduced from the A / V decoder according to the value of the time stamp inserted in the storage.

The HDD interface 60 interfaces TS streams transmitted and received between the hard disk drive (HDD) 70 and the memory 1 90.

The HDD 70 includes a plurality of disks for recording and storing TS streams transmitted through the HDD interface 60, and heads for recording TS packets or reading recorded TS packets on the disk surface.

The bridge circuit 80 converts signals between the intrinsic bus of the system controller 100 and the PCI bus 50 to enable transmission and reception of signals. That is, when the system controller 100 wants to write data to a function block existing on the PCI bus, the system controller 100 converts the intrinsic bus signal into a PCI bus signal to exist on the PCI bus 50. Allows to write to the block.

The memory 1 90 stores a 192-byte TS packet containing a time stamp (4 bytes) transmitted from the digital stream controller 20 and controlled by the system control unit 100, or a disk packet reproduced from the HDD 70. Temporarily save.

The system controller 100 includes a memory configured to include a RAM for temporarily storing data generated during a system control operation and a ROM in which system control program data is stored. The system controller 100 is connected to a user interface unit (such as a remote control unit or an operation panel unit) 110 to perform a series of control operations for simultaneously supporting time delay viewing and recording and playback according to a user's operation command. For example, the system controller 100 controls a disk packetized TS packet stored in the memory 1 90 to be transmitted to the HDD 70, and controls the disk packet reproduced from the HDD 70 to be stored in the memory 1 ( 90) to be stored. In addition, the system controller 100 creates a picture type table for trick mode support during TS stream recording and stores the picture type table in the internal memory.

Referring to FIG. 2, which shows a detailed configuration of the digital stream controller 20 described above, the digital stream controller 20 includes a transport stream (TS) demux (DEMUX) 21 and a PAT insertion unit 22. And a time stamp inserter & PH (picture header) detector 23, a DMA controller 24, a FIFO memory 25, and a timing controller 26.

The TS DEMUX 21 is composed of a PID filter 21a and a scrambler 21b. The PID filter 21a selects and outputs only PIDs necessary for recording only a single channel to be recorded on the HDD. If the channel is changed by the user's selection, the PID value of the changed channel is newly set by the control of the system controller 100. The PID to be selected includes a program association table (PAT), a program map table (PMT), a video PID, an audio PID, a data PID, and an ECM PID.

The scrambler 21b scrambles and outputs the AV stream transmitted from the IEEE 1394 network. That is, the scrambler 21b exists to scramble the unscrambled AV stream. If the input channel is scrambled, the scrambler 21b bypasses the scrambler 21 without having to scramble it again. Such control is performed by the control of the system control unit 100.

The PAT inserting unit 22 generates a new PAT packet having only information on the currently selected channel at the time when the PAT having information on several channels on the air arrives and replaces it with a PAT having information on several channels to transmit the TS stream. Insert in

In the time stamp inserter & PH detector 23, the time stamp inserter captures and inserts an internal counter value incremented by 27 MHz clock into the input TS packet upon arrival of the TS packet. By inserting the time stamp into the TS packet as described above, the HDD 70 is initialized with the time stamp inserted into the first TS packet during playback, and then the time stamp value inserted into the next TS packet is compared with the internal counter value which is continuously increasing. If the same, the TS packet can be transmitted. The time stamp is assumed to have a size of 4 bytes in the following description.

The picture header (PH) detector in the time stamp inserter & PH detector 23 sets the video PID value of the internal register under the control of the system controller 100. The PH detection unit finds a picture header in a video TS packet, sets a picture header detection bit, and simultaneously sets picture type information of a current picture. The picture header detection bit set as described above is used when configuring the header information for recording the disk packet on the HDD 70.

On the other hand, when storing the transport stream on the hard disk, the DMA controller 24 transmits the TS packet input from the time stamp inserting unit & PH detecting unit 23 to the memory 1 90, and reads the TS stream from the hard disk. Under the control of the system control unit 100, only valid data (TS packets inserted with a time stamp except for a header) is read from the disk packet stored in the memory 1 90 and transmitted to the target memory 25. The DMA controller 24 has a plurality of registers therein. For example, the DMA controller 24 has two registers for DMA transfer of an input TS packet. That is, DMA operation is performed by using a pair of registers, and after the interrupt is generated, TS packets are continuously transmitted using the remaining pair of registers automatically. In order to perform this process smoothly, not only the register set related to the DMA has two pairs, but the register for reporting the result of processing by the PH detection unit also has two pairs and is used in connection with the aforementioned DMA register.

The PoBee memory 25 temporarily stores the TS-packet inserted into the TS packet input through the DMA controller 24 and outputs the first-in first-out method.

The timing controller 26 reads out the TS packet having the time stamp inserted from the packet memory 25 and outputs 188 bytes of TS packet excluding the time stamp to the A / V decoder when the time written in the time stamp is reached. .

Hereinafter, a process of disc packetizing and recording a TS stream input from a channel to the HDD 70 will be described in detail with reference to FIGS. 3 to 6.

First, FIG. 3 illustrates a structure of a disk packet according to an embodiment of the present invention, and FIG. 4 illustrates an exemplary diagram of a disk packet size according to an embodiment of the present invention. 5 illustrates an example of a picture type table for trick mode support according to an embodiment of the present invention.

A disk packet according to an embodiment of the present invention refers to a TS packet recorded on a disk surface, and is divided into a header part and data. The data consists of a TS packet and a time Tn at which each TS packet arrives. The arrival time of the TS packet refers to the value of the inserted time stamp. The reason for constructing the disk packet as described above is to improve the speed during data access by writing successive TS packets to successive sectors on the disk surface. The registers in the DMA controller 24 for storing the data in the memory 1 90 and disk packetizing are as shown in Table 1 below.

            Register name                   Explanation      Disk packet start address Start address when saving TS packet to memory 1             TS packet size MPEG: 192             TS Packet Count Number of TS packets that need to be sent to construct disk packets             Control / command

That is, 192 bytes of TS packets including the time stamps from the DMA controller 24 can be collected in the memory 1 90 to generate one disk packet. In this case, the size of the disk packet can be varied as shown in FIG. Can be. The larger the size of the disk packet, the more space for storing the TS packet is required in the memory 1 90. Since several pictures may exist in one disk packet, it is desirable to determine the size of the disk packet in consideration of this point. .

Meanwhile, the header, which is an element of the disk packet, may have items as shown in Table 2 below.

Header Information Number of bytes Explanation Header 2 Disk packet header Validity of header information One Data validity flag PMT PID   2 each (optional)   PSI Information for Single Program Video PID Audio PID ECM PID Data PID Random access indicator  One Whether to include picture header and whether to include I picture  TS Pointer Indicates which TS packet among n TS packets has a picture header. Picture header type One Time Key size One The size of the encrypted key Encrypted Key One Key to unlock if TS is scrambled

In Table 2, information such as a random access indicator, a TS pointer, and a picture header type is set using information transmitted from the PH detector.

Meanwhile, a picture type table is created to support disk packet packetization and trick forward (fast forward, rewind) operation. Such a picture type table is illustrated in FIG. 5 and stored and used in an internal memory. In FIG. 5, C, H, and S indicate a position value of a disk surface on which a picture header is stored, and represent cylinder, head, and sector numbers, respectively. For example, in the case of high-speed search, after searching the picture type table and reading the C, H, and S values for the I picture or the IP picture and transmitting them to the HDD interface 60, only the required picture data can be read from the disk surface. have.

Hereinafter, a process of packetizing a 192-byte TS packet including a time stamp into a 2K-byte disk packet and recording and storing it in the HDD 70 will be described with reference to FIG. 6.

First, when a command for recording a digital broadcast signal to the HDD 70 is input through the user interface 110, the system controller 100 needs to record only a selected (or changed) broadcast channel (eg, a PID value). Set them). After the channel selection or change process, the TS stream output from the PID filter 21a is output through the scrambler 21b, and a new PAT packet having only information on the channel selected by the PAT inserter 22 is inserted. A time stamp inserting time stamp indicating the TS packet arrival time is inserted by the time stamp inserting unit & PH detecting unit 23 and sequentially transferred to the memory 1 90 through the DMA controller 24. During the DMA transfer, the DMA controller 100 designates the TS packet storage location (address) of the memory 1 90 in step 210, and then proceeds to step 220 and transmits the input TS packet to the memory 1 90. As a result, a group of TS packets are sequentially transmitted to the memory 1 (90). If it is determined in step 230 that the TS packet transmission of the first group is completed, the DMA controller 24 proceeds to step 240 to generate an interrupt to the system controller 100. The group of TS packets may be defined as ten TS packets constituting a disk packet in the following description.

On the other hand, when an interrupt occurs, the system control unit 100 inserts a picture header (detected by the PH detection unit) into a group of TS packets in step 300 to make one complete disk packet, and then proceeds to step 310 and stores the disk storage positions (C, H, S or Logic Block Address). When the storage location of the disk packet is specified as described above, the system controller 100 transmits the disk packet to the HDD 70 to record and store the picture and updates the picture type table in step 320. Since TS packets are DMA-transmitted continuously during the transmission of such disk packets, two pairs of registers related to the DMA transfer are performed to perform one pair of DMA transfers, and after the interrupt is generated, the remaining one pair of registers is automatically used. Allow TS packets to be sent.

Therefore, a group of TS packets transmitted from the DMA controller 24 is disk packetized under the control of the system control unit 100 and recorded and stored in a predetermined position of the HDD 70, and the storage position of each picture type is stored in the picture type table. By being updated, the system control unit 100 can then support the trick mode.

Hereinafter, a process of transmitting a video stream reproduced from the hard disk drive 70 will be described with reference to FIG. 7.

FIG. 7 is a diagram illustrating a process of transmitting a video stream reproduced from a hard disk drive (HDD) according to an embodiment of the present invention. Referring to FIG. 7, if there is a playback command through the user interface 110, the system controller 100 searches for a start address of a video stream to be played in step 420. That is, a step of searching where the video stream to be played is located on the disk surface can be obtained by searching a file system. Therefore, when the search for the start address of the video stream to be played is completed, the system controller 100 proceeds to step 430 to control the HDD 70 to play the desired video stream. As described above, the video stream of a predetermined size (assuming disk unit in the embodiment of the present invention) reproduced from the HDD 70 is stored in the memory 1 90 through the HDD interface 60 in step 440. Although not shown in the figure, the storage location of the disk packet is designated by the system controller 100 prior to storing the disk packet reproduced in the HDD 70 in the memory 1 90.

On the other hand, the DMA controller 24 reads only valid data (data excluding the header from the disk packet) from the disk packet stored in the memory 1 90 and transfers the control to the target memory 25 as many times as set. With the same registers.

           Register name                   Explanation    Disk packet start address  Start address of disk packet in memory    Disk Packet Valid Data Offset  The offset where the valid data is placed in the disk packet          TS packet size      Length of TS + Time Stamp (MPEG: 192B)       Disk packet size              Disk packet size        Disk Packet Count         The number of disk packets to send        Control / status register

That is, the DMA controller 24 first reads only valid data of a disk packet and transmits the read data to the target memory 25 by referring to the register value set by the control of the system controller 100 in step 510. In operation 520, the number of times of valid data transmitted to the pipo memory 25 is counted. In operation 530, it is determined whether the number of valid data transfers is performed as many times as the set number of times. The reason for determining whether the effective data has been transmitted by the set number of times is that the playback speed of the video stream of the HDD 70, the data storage capacity of the memory 1 90, and the TS packets stored in the Popo memory 25 are determined by the timing controller ( This is because the time required for output to the A / V decoder is considered. Therefore, if data is transmitted as many times as set in step 530, the DMA controller 24 generates an interrupt to the system control unit 100 in step 540, and in response, the system control unit 100 controls the HDD 70 again to control the video. Play the stream continuously.

As described above, referring to the path through which the video stream is transmitted during playback, the video stream played back from the HDD 70 is stored in the memory 1 90 under the control of the system controller 100, and the valid data of the stored disk packet is The DMA controller 24 transmits the data to the timing controller 26 through the target memory 25. Then, the timing controller 26 holds the TS packet until the time stamped time reaches the valid data, and then outputs the 188-byte TS packet to the A / V decoder when the time stamp value reaches the time stamp value.

As described above, the present invention can record a signal received through a transmission channel on a hard disk without any additional hardware such as an A / D converter and an MPEG encoder. In comparison, there is an advantage that the circuit configuration of the broadcast reception system can be simplified and downsized. In addition, there is an advantage that can easily support trick play by inserting new PAT information and time stamp into the signal transmitted in digital form.

Claims (10)

A digital stream controller in a broadcast receiving system having random access storage for simultaneously supporting time delay viewing and recording and playback, A filter for selectively outputting only the PID (Packet ID) of the transport packet of only the selected recording channel among the inputted digital transport streams; A PAT inserting unit for generating a new PAT packet having only information on a channel currently selected at the time when a PAT (Program Association Table) having information on various channels arrives, and inserting it into the transport packet; A time stamp inserter for capturing and inserting an internal clock counting value that is increased in a predetermined cycle period when the transport packet is input from the PAT inserter, and inserting it into the transport packet; Extracting a video packet from the transport packet having the time stamp inserted according to the set video PID value, finding a picture header from the extracted video packet, setting a picture header detection bit, and setting picture type information of the current picture; A picture header detector, A controller for controlling transmission of the time stamped transport packet to the random access storage device, and accessing and outputting the time stamped transport packet reproduced in the random access storage device; A memory for temporarily storing a time stamped transport packet output from the controller; And a timing controller for outputting only the transport packet to the decoding unit from the transport packet into which the time stamp output from the memory is inserted. The digital stream controller of claim 1, further comprising a scrambler for selectively scrambled the transport packet between the filter and the PAT inserter. The digital stream controller of claim 1, wherein the timing controller delays a corresponding transport packet for a time indicated by an input time stamp. In the broadcast receiving system having a hard disk drive for simultaneously supporting time delay viewing and recording and playback, A channel circuit for inputting a broadcast signal transmitted through a unique channel and converting the same into a digital transport stream; A new PAT (Program Association Table) information and a time stamp are inserted into a transport packet selected from a transport stream input from the channel circuit or a single video stream input from an external network, and transmitted to the outside, and reproduced from the hard disk drive. A digital stream controller for accessing a transport packet with a time stamp and outputting only the transport packet to a video decoder; A memory for storing a transport packet including a time stamp transmitted from the digital stream controller; When recording, a header is added to a transport packet inserted with a group of time stamps stored in the memory to create a disk packet, and it is controlled to be recorded on the hard disk drive. And a system controller for storing a packet in the memory. The digital stream controller of claim 4, further comprising: a digital stream controller; A filter for selectively outputting only PIDs of transport packets of only a recording channel selected from a digital transport stream input from the channel circuit; A PAT inserting unit for generating a new PAT packet having only information on a currently selected channel and inserting it into the transport packet when a PAT having information on several channels arrives; A time stamp inserter for capturing and inserting an internal clock counting value that is increased in a predetermined cycle period when the transport packet is input from the PAT inserter, and inserting it into the transport packet; Extracting a video transport packet from the time-stamped transport packet according to the set video PID value, finding a picture header from the extracted video transport packet, setting a picture header detection bit, and picture type information of the current picture A picture header detection unit for setting A controller for controlling transmission of the time stamped transport packet to the random access storage device and accessing and outputting the time stamped transport packet reproduced in the random access storage device; A memory for temporarily storing a time stamped transport packet output from the controller; And a timing controller for outputting only the transport packet to the decoding unit from the transport packet with the time stamp inserted from the memory. 6. The broadcast receiving system according to claim 5, wherein the digital stream controller further comprises a scrambler for scrambling a single video stream input from the external network. In the transport stream recording method in a broadcast receiving system having a hard disk drive for simultaneously supporting time delay viewing and recording and playback, Extracting only a transport packet of a channel to be recorded from among the received broadcast signals; Inserting a time stamp indicating the arrival time of the extracted transport packet into the transport packet; Detecting a picture header from the transport packet; A fourth process of storing the transport packet having the time stamp inserted in the memory; A fifth process of disc packetizing the transport packet by adding the detected header information to a transport packet having a time stamp inserted in the memory; And a sixth step of recording and storing the disk packets on the hard disk surface. A method of reproducing a video stream in a broadcast receiving system in which time-inserted transport packets are disk-packed and recorded on a hard disk surface. A first step of searching for a start address of a video stream to be played and playing the video stream on the hard disk; A second process of storing the disk packets of the played video stream in a memory; And reading only valid data from the disk packets stored in the memory and outputting only the transport packet to a data decoding unit after a predetermined time delay. 10. The method of claim 8, wherein the valid data includes time stamps and transport packets except for header information in each disk packet. 9. The method of claim 8, wherein each of the transport packets is delayed by a time indicated by a time stamp that is one component of the valid data.

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