KR100455946B1 - Broadcasting signal receiver having a descrambler - Google Patents

Abstract

The present invention relates to a method for storing and reproducing a paid broadcast stream in a broadcast signal receiver having a single descrambler. The receiver according to the present invention provides a demultiplexer for viewing to demultiplex a transport stream or a playback stream of an inputted viewing channel. Wow; A recording demultiplexer for demultiplexing the transport stream of the recording channel; A descrambler for descrambling the demultiplexed stream into a codeword received; When one or more paid broadcast transport streams are received through a viewing and recording channel, a part of RSMS information is obtained from one demultiplexed stream and transmitted to the CAS interface unit, and the codeword received in response thereto is transmitted to the descrambler. A control unit; A memory for temporarily storing stream information output from the recording demultiplexer and reproduction stream information read from the magnetic recording medium; And a memory controller for controlling access of the memory together with the magnetic recording medium.

Description

A paid broadcast stream storage and playback method in a broadcast signal receiver having a single descrambler {BROADCASTING SIGNAL RECEIVER HAVING A DESCRAMBLER}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a system for receiving broadcast signals embedded in a magnetic recording medium, and more particularly, to a method for storing and playing pay broadcast streams in a broadcast signal receiver having a single descrambler.

The hard disk drive, which is an auxiliary memory device of a computer system, can be accessed randomly, and the data transmission speed is high, and it can be cheaper and larger than other auxiliary memory devices. It is widely used as a random access storage device. A broadcast signal receiving system having a random access storage device is a system capable of recording, reproducing, and viewing time delay of a transport stream TS, which is a broadcast signal.

Such broadcast signal receiving systems include satellite TV signal set-top boxes and PVRs (Personal Video Recorders). For example, typical broadcast signal receiving systems are provided with two descramblers to record another paying broadcast while watching one pay broadcasting channel.

That is, in a general broadcast signal receiving system, a broadcast stream received through a viewing channel is descrambled using a single descrambler and then output as A / V (Audio / Video) data through an MPEG decoder, and a recording channel is used. A method of descrambling a received broadcast stream using another descrambler and then storing the received broadcast stream in a storage device (HDD) is adopted.

Therefore, if one descrambler is used to watch paying broadcasts and record other paying broadcasts at the same time, the system configuration can be simplified and the system cost can be lowered.

In a general broadcast signal receiving system, when a broadcast stream of a recording channel is stored in a storage device, unnecessary data, for example, data such as PMM (Program Management Message) information among SI (Service Information) information is stored together, thereby reducing the recording capacity. There is a problem that causes waste.

Accordingly, an object of the present invention is to provide a method for storing and reproducing a paid broadcast stream in a broadcast signal receiver capable of simultaneously viewing and simultaneously recording a paid broadcast stream of a separate channel with a single descrambler.

It is still another object of the present invention to provide a method for storing and reproducing a paid broadcast stream in a broadcast signal receiver capable of maximizing the recording capacity utilization of the storage device by extracting and storing only necessary information required for reproducing at the time of storing the received broadcast stream. In providing.

1 is a block diagram of a broadcast signal receiver according to an embodiment of the present invention.

2 is a view for explaining the operation of the broadcast signal receiver according to an embodiment of the present invention.

Broadcast signal receiver according to an embodiment of the present invention for achieving the above object,

A plurality of tuners for tuning one channel broadcast signal out of the received broadcast signal, link units for demodulating and error-correcting the broadcast signal tuned in each tuner, and outputting a transport stream, a magnetic recording medium and an MPEG decoder In addition to the broadcast signal post-processing unit comprising:

A viewing demultiplexer for demultiplexing transport stream or reproduction stream information of an input viewing channel;

A recording demultiplexer for demultiplexing the transport stream of the recording channel;

A descrambler for descrambling the demultiplexed stream into a codeword received;

Control unit for acquiring RSMS information from one demultiplexed stream and transmitting it to the CAS interface unit when receiving one or more paid broadcast transport streams through a viewing and recording channel, and transmitting the received codeword to the descrambler in response thereto. Wow;

A memory for temporarily storing stream information output from the recording demultiplexer and reproduction stream information read from the magnetic recording medium;

And a memory controller for controlling access of the memory.

That is, in the broadcast signal receiver according to an embodiment of the present invention, when a pay broadcast transport stream is received through a viewing channel and a recording channel, the broadcast signal receiver performs descrambling only on the stream received through the viewing channel, and the stream received through the recording channel is simply Only demultiplexing is performed to store in the storage device, and then descrambling is performed during playback.

In addition, the broadcast signal receiver according to an embodiment of the present invention, if a pay broadcast transport stream is received as a recording channel, descrambles and stores the data in a storage device, and during playback, the descrambled stream is simply passed through a demultiplexer for viewing. Characterized in that the transmission to the MPEG decoder.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

1 is a block diagram of a broadcast signal receiver according to an embodiment of the present invention.

Referring to FIG. 1, first, tuners 1, 2, and 10 tune a satellite antenna signal under the control of the controller 85, and the quadrature phase signal I and the quadrature phase signal of the quadrature phase shift keying (QPSK) signal. Outputs (Q).

The A / D converters 15 and 55 and the links 1 and 2 (20 and 60) demodulate the QPSK signals output from the respective tuners 10 and 50, correct the error, and output the transport stream. This transport stream is input to each demultiplexer 25, 65. In the exemplary embodiment of the present invention, the demultiplexer 1 25 is defined as a demultiplexer for viewing, and the demultiplexer 2 65 is defined as a demultiplexer for recording.

The viewing demultiplexer 1 25 demultiplexes the transport stream of the viewing channel output from the link 1 20 or the reproduction stream information output from the memory 70 into a video signal sequence audio signal sequence and an additional information signal sequence. For reference, the "playback stream" refers to a stream received through a recording channel and stored in a storage device HDD and then played back according to a recording playback command.

Meanwhile, the descrambler 30 descrambles the demultiplexed stream into a codeword CW transmitted by the control of the controller 85 and outputs the descrambled stream. This descrambler 30 is used to descramble the demultiplexed streams in one demultiplexer 25,65.

The demultiplexer 65 for recording demultiplexes the transport stream of the recording channel and outputs it. The demultiplexer 65 for recording extracts only part of a Resource and Subscriber Management System (RSMS) message (ECM / EMM), CAT (Coditional Access Table) and Program Map Table (PMT) from the demultiplexed stream. And the memory 70 is output to the memory 70 at the later stage. The reason for extracting only part of the RSMS information and storing it in the storage device (HDD) is to increase the space utilization of the recording medium.

The controller 85 controls the overall operation of the broadcast signal receiver according to the embodiment of the present invention. To this end, the control unit 85 includes a memory in which control program data is stored. Data generated during the system control operation is also stored in the internal memory. As a representative example of the system control operation of the control unit 85, the control unit 85 acquires an RSMS message from one demultiplexed stream when one or more pay-transport transport streams are received through a viewing and recording channel. The decoded A / V stream is normally descrambled by transmitting the codeword CW to the descrambler 30.

The remote control receiver 90 receives the wireless remote control signal transmitted from the remote controller and interfaces with the control unit 85. The CAS interface unit 95 controls the control unit 85 and the CAS system (smart card or cas dedicated chip). Interface the signal transmitted between).

When the MPEG decoder 35 at the rear end of the viewing demultiplexer 25 decodes the compressed A / V stream and restores the original signal to the NTSC encoder 40 and the audio D / A converter 45, respectively. The NTSC encoder 40 encodes the video signal decoded by the MPEG algorithm into a video signal that conforms to the NTSC method, and outputs the audio signal. Send it out.

On the other hand, the memory 70 behind the recording demultiplexer 65 is accessed and controlled by the memory controller 80 as a DRAM, which is demultiplexed by the recording demultiplexer 65 at the time of recording. When the stream is stored and the playback of the recorded broadcast is performed, the recording element stream (also referred to as a recorded broadcast program) read from the storage device HDD is stored. The memory controller 80 controls the memory 70 through one of a first in, first out, or DMA method. For reference, an interface unit 75 for data interface is located between the storage device HDD and the memory 70.

Hereinafter, an operation of the broadcast signal receiver having the above-described configuration will be described with reference to FIG. 2.

The operation of the broadcast signal receiver according to an embodiment of the present invention is largely performed when the viewing of the free broadcasting channel and the recording of the pay broadcasting channel are simultaneously performed, and the viewing of the first pay broadcasting channel and the recording of the second pay broadcasting channel are simultaneously performed. It can be divided into cases.

FIG. 2 is a diagram illustrating an operation of a broadcast signal receiver according to an exemplary embodiment of the present invention. More specifically, an operation in the case where viewing of a free broadcasting channel and recording of a pay broadcasting channel are simultaneously performed will be described. It is for.

Referring to FIG. 2, first, if a user selects and watches a free broadcast, the transport stream of the viewing channel tuned through the tuner 1 (10) is demultiplexed in the viewing demultiplexer 1 (25) and then the MPEG decoder ( Decoded by the MPEG algorithm at 35), and then displayed and output as a video signal and an audio signal through the NTSC encoder 40 and the audio D / A converter 45 (step 100). In this case, if a user issues channel information and a recording command to record a program received from a pay broadcasting channel (step 110), the control unit 85 controls the tuner 2 50 in response to the transport stream of the recording channel. Input to the demultiplexer 2 (65) for recording through the link unit 2 (60). In this case, the demultiplexer 2 65 for recording demultiplexes the transport stream of the recording channel (step 120). When the control unit 85 acquires an RSMS message from the stream of the demultiplexed recording channel (step 130) and transmits the RSMS message to the CAS interface unit 95, the control unit 85 receives a codeword (CW) from the CAS system (step 140). do. When the codeword CW transmitted as described above is transmitted to the descrambler 30, the descrambler 30 descrambles the stream of the demultiplexed recording channel using the received codeword CW in step 150. Output to the memory 70. Then, the memory controller 80 transmits the stream stored in the memory 70 to the storage device through the interface unit 75 by either a first-in, first-out method or a DMA method. The broadcast program is to be stored (step 160). At this time, in order to maximize the recording capacity, the demultiplexer 2 65 for recording may filter only the RSMS message and the CAT and PMT and output the same together with the A / V stream.

As described above, when the stop command is input by the user while storing the paying broadcast program (step 170), the controller 85 switches to the standby mode (step 180) in response thereto. It may be assumed that the video signal and the audio signal for the viewing channel are continuously displayed even in the standby mode.

If the user issues a program selection and playback command to select and play the recorded pay broadcasting program (step 190), the control unit 85 issues a play command (Control Signal: CS) of the selected pay broadcasting program in response thereto. Then, the selected pay broadcast program is read from the storage device and written to the memory 70, and after the broadcast signal including the MPEG decoder 35 through the demultiplexer 1 25 for viewing again under the control of the memory controller 80. Through the processing units 40 and 45, the video signal and the audio signal are normally output.

Therefore, only a single descrambler 30 may be used to simultaneously watch a free broadcast channel and perform recording of a paid broadcast channel, as well as to play and view the recorded pay broadcast program normally.

If it is assumed that the viewing of the first paying channel and the recording of the second paying channel are simultaneously performed,

First, the pay broadcast transport stream of the viewing channel tuned through the tuner 1 (10) is demultiplexed in the demultiplexer 1 (25) for viewing. When the control unit 85 acquires an RSMS message from the stream of the demultiplexed viewing channel and transmits the RSMS message to the CAS interface unit 95, the control unit 85 receives the codeword CW from the CAS system. When the codeword CW received as described above is transmitted to the descrambler 30, the descrambler 30 descrambles the stream of the demultiplexed viewing channel using the received codeword CW to decode the MPEG decoder 35. ) Then, the MPEG decoder 35 outputs the decoded digital video and audio signals, and these signals are displayed and output as video and audio signals through the NTSC encoder 40 and the audio D / A converter 45, respectively. By doing so, the user can watch the paid broadcast for the viewing channel.

Meanwhile, the transport stream received through the recording channel is input to the recording demultiplexer 2 65 and demultiplexed. As described above, the stream information of the demultiplexed recording channel is transferred to the storage device HDD through the memory 70 under the control of the memory controller 80. At this time, the stored stream information is maintained in a scrambled state.

Thereafter, when a user selects a play instruction of a pay broadcasting program stored in the HDD, stream information of the selected pay broadcasting program is read and transmitted to the viewing demultiplexer 1 25 through the memory 70. Then, the demultiplexer 1 (25) demultiplexes the transmission stream information transmitted, and the control unit 85 obtains an RSMS message from the demultiplexed stream information and transmits the RSMS message to the CAS interface unit 95. ) Will be sent. When the codeword CW received as described above is transmitted to the descrambler 30, the descrambler 30 descrambles the demultiplexed playback stream information using the received codeword CW to decode the MPEG decoder 35. Will output Then, the MPEG decoder 35 outputs the decoded digital video and audio signals, and these signals are displayed and output as video and audio signals through the NTSC encoder 40 and the audio D / A converter 45, respectively. By doing so, the user can normally watch the playback stream.

Therefore, the single descrambler 30 may be provided at the same time as the viewing of the paying broadcasting channel and the recording of the paying broadcasting channel, and of course, the recorded paying broadcasting program can be played back normally.

As described above, the present invention can simultaneously record a broadcast signal of another pay broadcast channel while watching one pay broadcast channel even with a single descrambler, thereby simplifying the configuration of a broadcast signal receiver capable of time delay viewing. As well as being able to produce a product, there is an advantage that can lower the manufacturing cost of the product.

In addition, the present invention has the advantage of maximizing the capacity recorded in the storage device by extracting and storing only the necessary information required for reproduction when storing the broadcast stream.

On the other hand, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined only by the appended claims.

Claims (6)

delete delete delete delete delete In the method of storing and playing pay-TV streams of a broadcast signal receiver having a built-in magnetic recording medium capable of descrambling separate transport streams received through a plurality of channels using a single descrambler, When viewing of the first paying channel and recording of the second paying channel are performed at the same time, the broadcast stream of the viewing channel is obtained using a codeword obtained by demultiplexing a transport stream received through the viewing channel and transmitting RSMS information. Descrambling and decoding and outputting the A / V signal; Demultiplex the transport stream received over the recording channel, and in that demultiplexed stream only part of the Resource and Subscriber Management System (RSMS) message (ECM / EMM), CAT (Coditional Access Table) and Program Map Table (PMT) Extracting and storing the payload program along with an A / V stream in the magnetic recording medium; Accessing the pay broadcast program from the magnetic recording medium; And descrambling and decoding the pay broadcast program with a codeword obtained by transmitting RSMS information acquired from an accessed pay broadcast program, and outputting the pay broadcast stream as an A / V signal. Way.