CN201298872Y - Multi-display digital TV set-top box - Google Patents
Multi-display digital TV set-top box Download PDFInfo
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- CN201298872Y CN201298872Y CNU2008201045635U CN200820104563U CN201298872Y CN 201298872 Y CN201298872 Y CN 201298872Y CN U2008201045635 U CNU2008201045635 U CN U2008201045635U CN 200820104563 U CN200820104563 U CN 200820104563U CN 201298872 Y CN201298872 Y CN 201298872Y
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Abstract
The utility model discloses a multi-display digital TV set-top box, which comprises a high-frequency head, at least two tuning modules, a quadrature amplitude demodulation module, a de-multiplexing module, a decoding module and a conditional access module. The tuning modules, the quadrature amplitude demodulation module, the de-multiplexing module and the decoding module are all made by simply adding one or a plurality of simplex modules onto one simplex module, thereby realizing the multiplexing different signal channel selection input, the modulation of digital signals from analog signals and the de-multiplexing of the program stream. However, the decryption and descrambling module is not the simple combination of two simplexes. Because the intelligent card can only input and output simplex signals, the multi-display digital TV set-top box adopts the time-division multiplexing principle to decrypt and descramble the multiplexing program signals, thereby realizing the display of the identical or different multiplexing program signals on different display screens.
Description
(1) technical field:
The utility model belongs to Digital Television and receives field, particularly a kind of multi-display digital television set-top box.
(2) background technology:
Along with the all-round popularization of Digital Television, popularizing of Digital Television will be following radio and television industry development.Because conversion from the simulated television to the Digital Television needs long transition period, can receiving digital television signal in order to make existing simulated television, need a kind of conversion equipment, digital TV set-top box is arisen at the historic moment.Digital TV set-top box be a kind of can receiving digital television signal, finish the audio-video signal of respective handling and output simulation, by the domestic electronic appliances of simulated television broadcast items.The major function of digital TV set-top box is the reception of finishing digital television signal, specifically be exactly the high-frequency signal of tuner reception from wired network, finish channel-decoding by the quadrature amplitude demodulation device, from carrier wave, isolate and comprise sound, the program stream and the information flow of video and other data message, then distinguish different programs by demultiplexing module then, extract corresponding program stream and information flow, send into decoder and the corresponding software of resolving, finish the reduction of digital information, decoder is finished the decompression of audio-video signal, intend conversion through Video Decoder and audio frequency D/A digital-to-analogue, restore the analog audio-video signal, on the conventional simulation television set, show high quality graphic, and the multichannel sterego program is provided.
For pay TV, need the adding Conditional Access Module that program stream and information flow are implemented descrambling, and adopt the smart card that contains the identification user and carry out accounting feature to be decrypted, the assurance validated user is normally watched.The main purpose of Conditional Access Module is to control the user to the visit of pay TV and assurance operator's income, has only the user who has an agreement with network operater just can obtain special service.In the realization of whole Conditional Access Module, Entitlement Control Message (ECM) and Entitlement Management Message (EMM) safety of transmission are most important.The process of Conditional Access Module deciphering and descrambling the program stream of the scrambling of demultiplexing module output, is that Entitlement Control Message and Entitlement Management Message carry out corresponding processing procedure with information flow mainly.Entitlement Management Message is obtained the authorization by smart card, and then Entitlement Control Message is decrypted, the control word (CW) of deciphering output, and the program stream by control word and scrambling carries out descrambling again, the audio/video flow of the program stream of output reduction at last.Because each condition receives provider's use and respectively identifies oneself safe algorithm, therefore fail safe that these algorithm guaranteed conditions receive and profit purpose have domestic digital TV set-top box now and can only connect a television set.For one family, everyone hobby may be all different, if having only a television set to watch, the spectators of different hobbies require to watch that simultaneously different TV programme just can not realize.If increase the platform number of television set, must increase digital TV set-top box, must increase service charge accordingly.The digitized popularization of current domestic television runs into very big difficulty, and wherein very big reason is exactly that a digital TV set-top box can not connect multiple TV set, puts to no little inconvenience to the user, and the user has increased expense but reduced service.Therefore in order to solve the problem of many shared digital TV set-top box of TV, we propose new digital TV set-top box design, this new digital TV set-top box can make many TVs receive different TV programme mutually independently, give user's better service, thereby television digitization is more successfully promoted.
Watch simultaneously for realizing the multi-path digital TV programme, there is different separately execution modes, as Chinese invention patent CN200710118007.3 application disclosed " one drag two digital TV set-top box ", its digital TV set-top box adopts principal and subordinate's form, wherein master terminal comprises that a plurality of descrambler, a plurality of decoder carry out program descrambling function, do not need information flow stream is carried out descrambling from terminal.What the communication of principal and subordinate's terminal room transmitted is audio/video flow and control word information.Yet the digital TV set-top box of this structure is owing to the handled information of principal and subordinate's terminal is asymmetric, this just needs to improve speed and the capacity of master terminal chip CPU, thereby not only make the type selecting of master terminal and difficulty increasing, the production cost of design increase, in case and master terminal breaks down, and will influence the operation of whole system; Secondly, the process of information flow descrambling is all carried out in same master terminal, and the phenomenon of phase mutual interference just may appear in the audio/video flow of descrambling deutomerite, influences the decoding effect of digital TV set-top box, finally makes the degradation of digital television signal.
(3) utility model content:
Technical problem to be solved in the utility model provides a kind of information processing symmetry, simplicity of design and lower-cost multi-display digital television set-top box.
For addressing the above problem, the multi-display digital television set-top box of the utility model design includes:
A tuner is used to receive high-frequency TV signal, and high-frequency TV signal is carried out down-conversion, exports two-way medium-frequency TV signal at least;
At least the two-way tuner module carries out filtering and frequency-selecting to the intermediate-freuqncy signal of tuner input;
At least two-way quadrature amplitude demodulation module, every road quadrature amplitude demodulation module links to each other with one road tuner module, is responsible for the TV signal after filtering and the frequency-selecting is carried out demodulation, decoding;
At least the two-way demultiplexing module is elected program streams different on the same channel and information flow respectively, and according to spectators' selected channel respective program is spread and to deliver to corresponding decoder module, and the information flow with selected channel is sent to Conditional Access Module simultaneously;
A Conditional Access Module, reception is from the information flow of above-mentioned each road demultiplexing module, be Entitlement Management Message and Entitlement Control Message, and Entitlement Management Message that time-division processing is not gone the same way in the cycle period of a control word and Entitlement Control Message, the control word information that last timesharing output is not gone the same way is sent deciphering stream is carried out descrambling;
At least the two-way decoder module carries out audio/video decoding with the TV programme that the Conditional Access Module descrambling comes out, and restores the identical or different audio/video flow of two-way at least simultaneously.
The described described Conditional Access Module of such scheme comprises smart card, controller, authorization message selector, control word selector and authorization message buffer, descrambler and the program stream buffer of two-way Entitlement Control Message and Entitlement Management Message at least; Each road authorization message buffer links to each other with the demultiplexing module of not going the same way respectively; Controller links to each other with the control end of authorization message selector with the control word selector respectively, be used for selecting the wherein input of one road Entitlement Control Message and Entitlement Management Message input smart card, and wherein one group of control word that control control word selector selects the output smart card to decrypt exports corresponding descrambler at control word cycle period inner control authorization message selector; Descrambler is connected with the program stream buffer, and the audio/video flow that each control word cycle period descrambling is come out carries out buffer memory, and the audio/video flow of the program stream that comes out until next control word cycle period descrambling is sent into.
Way N according to the digital television program of required demonstration, select tuner module, quadrature amplitude demodulation module, demultiplexing module, audio/video decoding module, authorization message buffer, descrambler and the code stream buffer of corresponding number, the way that is above-mentioned each device is identical with the way N of the digital television program of required demonstration, and its value is between 1～3 the tunnel.
In the such scheme, described authorization message selector is that 2N selects 2 data selectors, and the input of this authorization message selector links to each other with each road authorization message buffer by bus, and output links to each other with smart card by lead.Described control word selector is that N selects 1 data selector, and the input of this control word selector links to each other with smart card by lead, and output links to each other with each road descrambler by bus.
Watch when realizing two-way or the above TV programme of two-way, adopted time division multiplexing principle to handle multi-channel TV signals, can realize that in order to prove the two-way program watches simultaneously, just must the proof smart card can be in a control word cycle period can timesharing deciphering two-way or different Entitlement Control Message and Entitlement Management Message more than the two-way, promptly be that smart card must decrypt other one tunnel control word before one tunnel new Entitlement Control Message and Entitlement Management Message are sent into smart card.Therefore smart card of the present invention preferably carries out five equilibrium with a control word cycle period by the way N of the digital television program of required demonstration, and branches such as each 1/N are handled one road Entitlement Control Message and Entitlement Management Message.
The Entitlement Control Message and the Entitlement Management Message of not going the same way for time-division processing, the time of each road Entitlement Control Message of the processing of described smart card and Entitlement Management Message should guarantee between 0.5～1.5 second, guaranteeing before the Entitlement Control Message of next cycle or Entitlement Management Message arrive, it can decrypt the Entitlement Control Message on each road in this cycle and Entitlement Management Message the control word on each road all.
According to the demultiplexing module design principle of single channel, can be simply or the demultiplexing module stack of single channel more than the two-way together.Each is the single channel demultiplexing module independently, and they are formed by identical programming, and finishes the demultiplexing of one road signal mutually independently independently.Because above used the designing program of demultiplexing of two-way or two-way is the same, thus preferably the program compilation of two-way or the single channel more than the two-way in same chip, be integrated into an independently module, just our needed two-way demultiplexing module.
The multi-display digital television set-top box that the utility model is designed, its tuner module, quadrature amplitude demodulation module and demultiplexing module all are to increase single channel module more than a tunnel on the single channel module more simply, thereby realize the demultiplexing that the different signal channel selection input of multichannel, analog signal demodulate digital signal and MPEG-2 program stream.The deciphering and descrambling module then is not the merging of simple two single channel, because the input and output of smart card can only be one road signals, so the present invention uses time-multiplexed principle to handle the deciphering and descrambling of multi-channel program signal by the hardware and software that improves Conditional Access Module, realizes showing simultaneously identical or different multi-channel program signal with this on different displays.
The utility model compared with prior art, a kind of design of multi-display digital television set-top box is proposed, can connect two above simulated televisions simultaneously, and on two above television sets, watch different TV programme simultaneously, and be provided with Conditional Access Module innovatively, input and expense with the minimizing user are purpose, make two television sets enjoy business such as video request program, interactive game, surfing on the net, online upgrading simultaneously.
(4) description of drawings:
Fig. 1 is the theory diagram of a kind of preferred embodiment of the utility model multi-display digital television set-top box.
Fig. 2 selects flow chart for the utility model program.
Fig. 3 is single channel quadrature amplitude demodulation module principle figure.
Fig. 4 is the software flow of this enforcement demultiplexing module.
Fig. 5 is the timing diagram of present embodiment smart card input Entitlement Control Message, Entitlement Management Message and output control word.
Fig. 6 is the workflow diagram of two-way Conditional Access Module.
Fig. 7 is the theory of constitution figure that the utility model a kind of three tunnel shows top box of digital machine.
Fig. 8 is the theory of constitution figure that the two-way of a kind of two remote controllers control of the utility model shows top box of digital machine.
Fig. 9 is that the two-way of a kind of single remote controller control of the utility model shows top box of digital machine theory of constitution figure.
(5) embodiment:
Fig. 1 is the theory diagram of a kind of preferred embodiment of the utility model multi-display digital television set-top box, includes a tuner, the tuning mould of two-way, quadrature amplitude demodulation module, demultiplexing module, audio/video decoding module and a condition receiving system module and constitutes.Below above-mentioned each module is described in detail:
1, tuner and and tuner
The digital TV set-top box input is that one road cable inserts, and the high-frequency TV programme signal of 45MHz～860MHz is transmitted above the cable of road at this.The analog channel of one road 8MHZ can transmit the TV programme of 6～8 cover single-definitions in the digital television signal transmission course, and different TV programme signal can pass at same analog channel, also can pass at different analog channels.The effect of tuner or high-frequency amplifier be to the high-frequency signal that transmits 45MHz～860MHz on the cable network receive, amplification and frequency conversion, a tuner just can receive all analog channels, therefore only needs a tuner.The digital TV set-top box input has only a coaxial cable to insert, and high-frequency TV signal enters tuner and amplifies back branch two-way low-converter or frequency mixer or tuner, output two-way intermediate-freuqncy signal.The effect of tuner is equivalent to filter, is used to select to watch the channel at program place.When two TV programme will watching are in same analog channel, then need two identical local oscillation signals of frequency to be added to and produce two intermediate-freuqncy signals that frequency is identical on the tuner; When two TV programme will watching during not at same analog channel, then need two different local oscillation signals of frequency to be added to and produce two intermediate-freuqncy signals that frequency is identical on the tuner, could guarantee the different TV programme signal of output two-way like this.
Select flow chart as Fig. 2 for program, carry out remote control two television sets, so digital TV set-top box needs two remote controller inputs, television set of a remote controller control.Remote controller is selected TV programme by digital TV set box software operating system electronic program guide (EPG).The pairing list of television programmes of program guide is stored in the same internal memory, when control is selected in two remote controller inputs, their control information is read the program control information in the mode of First come first served, Program Association Table PAT from internal memory reads the program identifier PMT_PID of the Program Map Table bag of the program of seeing respectively, is respectively PMT1_PID and PMT2_PID.Because the TV programme of selecting is different, the program identifier PMT_PID value of the Program Map Table bag of each TV programme correspondence also is different, so first value with them deposits in respectively in two different internal memories.Demultiplexing module reads the value of PMT1_PID and PMT2_PID again, leaches different two-way Program Map Table PMT information by the different program identifier value PID of two-way, is respectively PMT1 and PMT2.Finding out the pairing network associate table of program NIT information from Program Map Table, is respectively NIT1 and NIT2.At last the network associate table NIT information of two programs is sent to corresponding tuner control end respectively, and then controls the tuner frequency-selecting, select the Frequency point at the program place of seeing.
2, quadrature amplitude demodulation module
As Fig. 3 is single channel quadrature amplitude demodulation module principle figure, the quadrature amplitude demodulation module is in the later half end of digital TV set-top box, be responsible for the digital TV tuner of front end is down-converted to intermediate frequency, processing by the demodulate reception special chip obtains the MPEG-2 output signal, and the code stream of exporting after the demodulation is the standard that meets DVB-C/ITU J83-A and ITU J83-C.Quadrature amplitude modulation is a kind of associating amplitude, phase modulation method, and its amplitude and phase place can both be carried information thereby be had very high band efficiency.Because amplitude, the phase place of modulated signal all have different values, so the planform of its planisphere can have many kinds, as circle, triangle, rectangle, hexagon etc.For the quadrature amplitude modulation signal with identical M system, because the planisphere difference, minimum range is also different between the each point, thereby corresponding modulation system has different error performances.Because channel distortions and noise can cause higher bit error rate, must before to signal decision, carry out the recovery of wave distortion to I, Q two-way baseband signal with matched filter and equilibrium.Through equalizer to the equilibrium of impairment signal, then through decision device L → 2 after (L=4,16 quadrature amplitudes) level conversion, at last by the parallel/serial initial data that is converted to.After demodulation is finished, also to carry out differential decoding, symbol to mapping, the deconvolution of byte interweave, RS decodes, synchronous first byte is inverted again, descrambling, could obtain data and clock from the base band physical interface.
Two quadrature amplitude demodulation modules of present embodiment independently module of respectively doing for oneself does not have control end, has only input and output side.Quadrature amplitude demodulation module can only a Frequency point of demodulation TV signal, and present embodiment requires different two-way TV signal, therefore will solve two paths of signals separates timing, then needs two independently quadrature amplitude demodulation modules.The output of the input termination tuner of quadrature amplitude demodulation module promptly is the modulated digital program stream signal that chooses by remote controller, through being output as the digital signal mpeg 2 transport stream after the quadrature amplitude demodulation.
3, demultiplexing module
The effect of demultiplexing module is that program streams different on the same channel and information flow are elected respectively, and according to the selected program of spectators audio frequency and video is sent to descrambler, also Program Specific Information (PSI) information is sent to memory simultaneously.Demultiplexing module can be simply the stack of the demultiplexing module of two single channel together according to the demultiplexing module design principle of single channel.Two single channel demultiplexing module independently, they are formed by identical programming, and finish the demultiplexing of one road signal mutually independently independently.Because designing program that two-way is used is the same, thus the demultiplexing module of present embodiment the program compilation of two single channel in same chip, be integrated into an independently module, just our needed two-way demultiplexing module.The input of demultiplexing module is the mpeg 2 transport stream signal of quadrature amplitude demodulation, and output is the audio-video signal and the program data information of program.
The software flow of present embodiment demultiplexing module as shown in Figure 4, two-way program stream TS1 that the demodulation of quadrature amplitude demodulation module is come out and TS2 enter demultiplexing module separately respectively, at first pass through synchronous detecting, find out the frame head (0x47) of each frame, and every frame of finding out deposits in the FIFO buffer memory, if in the transport stream buffer memory of FIFO untreated bag is arranged, from FIFO transport stream buffering area, take out this bag, value according to program identifier PID, if PID=0, represent that current bag is Program Association Table PAT, so just this bag is resolved, according to selected program number, definite program identifier PID that needs the Program Map Table PMT bag of decoding, upgrade the program identifier PID of Program Map Table in the program identifier pid information table, the mode bit of Program Map Table PMT is set at needs decoding.
According to the mode bit of Program Map Table PMT,, just abandon this bag if do not need decoding.If the mode bit of Program Map Table PMT needs decoding, enter Program Map Table PMT bag and resolve subprogram, extract this decoding corresponding audio, the program identifier PID of video transmission stream bag, with the audio frequency that extracts, the program identifier pid value of video transmission stream bag upgrades program identifier pid information table.
If program identifier PID equals audio frequency, video program identifiers pid value in the program identifier pid information table, so just enter into the audio frequency and video handling procedure, the transport stream packets of audio frequency and video is unpacked configuration on-chip DMA direct memory access controller.By the content of direct memory access controller with the Packet Elementary Stream PES of correspondence bag, just the code stream of Shi Ji audio/video flow sends in the audio frequency, screen buffer of chip external memory SDRAM, and audio frequency, the Video Decoder of confession next stage are finished decoding function.Finally finish the decode procedure of MPEG2 code stream.Because the working procedure of two-way demultiplexing module all is the same, so in the demultiplexing process, only need the memory capacity that increase internal memory more, and the program identifier pid information table of the program identifier PMT_PID of the program identifier PAT_PID of their Program Association Table bag, Program Map Table bag and program stream existed respectively in the different buffer memorys, so that read and upgrade.
4, Conditional Access Module
Key of the present utility model is to decrypt the different control word of two-way, and different control words is then again by different Entitlement Control Messages and Entitlement Management Message deciphering.
Generally, in the Entitlement Control Message packet, can transmit two encrypted control word: the scrambling control word of current time and the scrambling control word of following one-period.General 2～the 10s of control word changes once, so the Entitlement Control Message packet must distribute in this period for several times, receives new Entitlement Control Message packet to guarantee the user before the control word replacing.The Entitlement Control Message packet is only relevant with the product number in this transport stream, and irrelevant with number of users, all users use identical Entitlement Control Message packet.The number TV set-top box receives that can send user smart card to behind the Entitlement Control Message packet is used for decryption control words.
Transmit the product key of encryption or the group key of encryption in the Entitlement Management Message packet, the information of Entitlement Management Message packet is for each user's difference.Each receiver user at first filters out one's own Entitlement Management Message packet according to oneself user number User-ID or group number Group-ID, send packet to user smart card then, user smart card decrypts group key, decrypt product key by group key again, decrypt control word and send outside the smart card and to give the digital TV set-top box descrambling in smartcard internal according to Entitlement Control Message.Common product cipher key number hour is changed once, the Entitlement Management Message packet that contains the product key enciphered message somewhat in distribution once; Group key a couple of days is changed once, and the Entitlement Management Message number-of-packet hour distribution that contains the group key enciphered message once.
Because Entitlement Control Message and Entitlement Management Message packet all are just to change once several seconds, control word is to change along with the variation of Entitlement Control Message and Entitlement Management Message, generally also be that 2～10s just changes once, that is to say that the control word of 2～10s program map stream descrambling all is same control word.Therefore suppose that the smart card input has two-way (different) Entitlement Control Message and Entitlement Management Message, be respectively ECM1 and EMM1, ECM2 and EMM2, enter smart card in the different moment, smart card is handled different Entitlement Control Messages and Entitlement Management Message respectively in the different moment then, exports different control word information at last and carries out descrambling.Present embodiment as a cycle period, is handled the decrypting process of different two-way with 1s every 0.5s.0.5s is decrypted Entitlement Control Message ECM1 and Entitlement Management Message EMM1 taking-up input smart card from internal memory before in the one-period, output control word CW1, and, deposit in the memory with stylish Entitlement Control Message ECM2 and Entitlement Management Message EMM2 depositing in the memory.Back 0.5s is decrypted Entitlement Control Message ECM2 and Entitlement Management Message EMM2 input smart card from internal memory, output control word CW2, and depositing in the memory, deposit in the memory with stylish Entitlement Control Message ECM1 and Entitlement Management Message EMM1.The next cycle repeats above process, finally can export two different control words in the 1s clock.
Because control word just can change more than 2s, so when descrambling, the control word of taking out from memory in the time at 2s can not change.Simultaneously, guaranteed that Entitlement Control Message and Entitlement Management Message constantly upgrade, can guarantee that also control word constantly upgrades in 2s one road Entitlement Control Message and Entitlement Management Message deciphering 2 times in the time.Through circular treatment Entitlement Control Message and Entitlement Management Message, control word is upgraded incessantly, and then the transport stream that has guaranteed descrambling not descrambling incessantly.Only guaranteed two-way transport stream is descrambling constantly, could guarantee that TV programme plays incessantly, finally reach the desired digital TV set-top box design of this paper: a digital TV set-top box connects two television sets, and can watch different TV programme simultaneously.Be illustrated in figure 5 as the timing diagram of present embodiment smart card input Entitlement Control Message, Entitlement Management Message and output control word.
Entitlement Control Message ECM1 that two-way is different and Entitlement Management Message EMM1, Entitlement Control Message ECM2 and Entitlement Management Message EMM2 are from the demodulation multiplexer output, the effect of Entitlement Control Message and Entitlement Management Message buffer memory is exactly to store Entitlement Control Message and Entitlement Management Message, usually constitute with the FIFO memory, typical Entitlement Control Message data packet length 188 bytes, and the Entitlement Management Message data packet length that contains the product key enciphered message is 37 bytes, and the Entitlement Management Message data packet length that contains the group key enciphered message is 38 bytes.Usually Entitlement Control Message packet information 2s clock upgrades once, by finding the CA_descriptor in Program Map Table again, and finding out the program identifier (PID) of corresponding Entitlement Control Message code stream, the program identifier PID by Entitlement Control Message leaches Entitlement Control Message at last.In order to guarantee that Entitlement Control Message do not lose, should adopt memory very slow because its upgrades, so as long as the internal memory that 256 bytes are arranged as store information.Same Entitlement Management Message packet information 10s is above to be upgraded once, it is CA_system_ID and other smart card information that will therefrom read smart card IC by decoder, in program stream, find and filter out CAT Conditional Access Table (CAT) (PID=0x0001), by the CA_descriptor in the CAT Conditional Access Table, find out CA_PID that should CA_system_ID, this CA_PID is the program identifier to Entitlement Management Message that should condition, and the program identifier by Entitlement Management Message leaches Entitlement Management Message at last.In order to preserve Entitlement Management Message, make it not lose, then need the internal memory of 150 bytes.When guaranteeing intelligent card in processing one road Entitlement Control Message ECM1 and Entitlement Management Message EMM1 like this, the preservation that another road Entitlement Control Message ECM2 and Entitlement Management Message EMM2 can be intact, and when its is handled by the time and do not have an obliterated data.
The processing speed of smart card was discussed the most afterwards, and for the Entitlement Control Message and the Entitlement Management Message of the different two-way of time-division processing, the speed of smart card must be considered.Because smart card will guarantee that it can be good the different Entitlement Control Message of two-way and Entitlement Management Message information processing before the next one new Entitlement Control Message or Entitlement Management Message arrival.The output information control word 2s of smart card changes once, the length of control word is 64bit, and the baud rate of the transfer of data of smart card is 9600bps, and just smart card can be handled the data of output 9600bit in one second, is far longer than the speed of two-way control word information output.Again according to hardware FPGA emulation to decipherment algorithm in the smart card, in processing clock is that control word of deciphering needs about 0.3s among the FPGA of 5MHZ, therefore change multipotency in control word in the time at 1s and handle 3 times, also do not lose in the time of guaranteeing decryption control words and upgrade.Therefore propose smart card among the present invention and in 0.5s, decipher one road Entitlement Control Message and Entitlement Management Message, in another 0.5s, decipher another road Entitlement Control Message and Entitlement Management Message again, drawing the different control word information of two-way at last, also is can guarantee that control word is not lost can upgrade on request simultaneously.
The effect of controller is that control input end Entitlement Control Message ECM1, Entitlement Management Message EMM1 or Entitlement Control Message ECM2, Entitlement Management Message EMM2 select input, and output then is that control word CW1 or control word CW2 select output.TS1 ' and TS2 ' are the MPEG-2 video and the audio code stream of not descrambling, TS1 and TS2 are video and the voice data after the descrambling, their stream rate is between 3mb/s～38.5mb/s, so the buffer memory that also needs at least one second, needs the internal memory of 38.5mb size.The buffer memory of control word is also very important, and control word may several seconds just changes once, guarantee that control word in seconds do not lose, and it needs the internal memory of 128bit as memory.
As Fig. 6 is the workflow diagram of two-way Conditional Access Module, and input is imported not the program stream TS1 ' and the TS2 ' code stream of descrambling, passes through the FIFO caching process respectively, and program identifier PID detects and differentiates the packet what type is program stream pack belong to then.When testing result is the packet of CAT Conditional Access Table CAT, whether be Entitlement Management Message or Entitlement Control Message, leach Entitlement Management Message EMM1 and Entitlement Control Message ECM1, Entitlement Management Message EMM2 and Entitlement Control Message ECM2 data message at last if detecting again.The S square-wave generator is to be the square-wave generator of 1s in the cycle, when S is ' 1 ', judge that Entitlement Management Message EMM1 and Entitlement Control Message ECM1 pass through, Entitlement Management Message EMM1 and PDK authorize deciphering, decrypted result is carrying out the deciphering second time with business cipher key SK, decipher controlled word CW1 through the DES Cipher algorithm again, control word CW1 carries out descrambling with the program stream TS1 ' stream of descrambling not, obtains audio frequency and video TS1 code stream at last.In like manner, when S is ' 0 ', judge that EMM2 and ECM2 pass through, EMM2 and private data PDK authorize deciphering, decrypted result is carrying out the deciphering second time with SK, deciphering obtains CW2 through the DES algorithm again, and control word CW2 carries out descrambling with the program stream TS2 ' stream of descrambling not, obtains audio/video flow at last.
By above each Module Design, tuner module, quadrature amplitude demodulation module and demultiplexing module all are to increase at least one road single channel module on the single channel module more simply, thereby realize that two-way or the above different signal channel of two-way are selected to import, analog signal demodulates digital signal and MPEG-2 program TS stream demultiplexing.The way of tuner module, quadrature amplitude demodulation module, demultiplexing module is identical with the way N of the digital television program of required demonstration, and its value is between 1～3 the tunnel.The deciphering and descrambling module then is not the merging of simple two or more single channel, because the input and output of smart card can only be one road signals, so can not while deciphering and descrambling two-way programme signal.In order to realize two-way programme signal deciphering and descrambling, present embodiment uses time-multiplexed principle to handle the deciphering and descrambling of two-way programme signal.
The 4-1 control module is handled
Smart card will be deciphered two-way Entitlement Control Message and Entitlement Management Message, just necessary timesharing circular treatment, because smart card output control word 2s at least just changes once, so the 2s quadrisection, 0.5s deciphering first via signal, next 0.5s deciphers the second road signal again, and another 0.5s gets back to deciphering first via signal again, and last 0.5s deciphers the second road signal again.So circulation deciphering Entitlement Control Message ECM and Entitlement Management Message EMM information will not lost, and can not in time not decipher when new Entitlement Control Message ECM and Entitlement Management Message EMM arrival yet.
The control program step of control module is: the control module output is 1 o'clock, 4 to select 2 data selector inputs be Entitlement Control Message ECM1 and Entitlement Management Message EMM1, output is Entitlement Control Message ECM1 and Entitlement Management Message EMM1, smart card output output control word CW1; The control module output is 0 o'clock, and 4 to select 2 data selector inputs be Entitlement Control Message ECM2 and Entitlement Management Message EMM2, and output is Entitlement Control Message ECM2 and Entitlement Management Message EMM2, and the smart card output is control word CW2.
The processing of 4-2 smartcard certificate
Before module realizes, filter out Entitlement Management Message EMM, the two-way Entitlement Control Message ECM of two-way earlier by digital TV set-top box, and it is kept in the internal memory, be transferred to smart card by controller control and with it, smart card deciphering related data and passback.The purpose of preserving Entitlement Management Message EMM and Entitlement Control Message ECM is in order to guarantee to decipher one road Entitlement Management Message EMM and Entitlement Control Message ECM information, another road Entitlement Management Message EMM and Entitlement Control Message ECM information are preserved or are upgraded, and make it not lose.
Each road Entitlement Control Message ECM and Entitlement Management Message EMM will be through the processes of smart card deciphering related data and passback.When smart card inserts digital TV set-top box, decoder will therefrom read CA_system_ID and other smart card information of smart card, in TS stream, find and filter CAT (PID=0x0001), by the CA_descriptor among the CAT, find out CA_PID that should CA_system_ID, this CA_PID is the program identifier to Entitlement Management Message EMM that should CA.After obtaining Entitlement Management Message EMM code stream, decrypt SK with the PDK that solidifies in the smart card.After finishing above step, decoder finds the CA_descriptor in Program Map Table again, and find out the PID of corresponding Entitlement Control Message ECM code stream, deciphering just can obtain CW to Entitlement Control Message ECM with the SK that obtains, descrambler with CW as the input Control Parameter, just can carry out descrambling, recover primary signal bit stream data.Its concrete steps are:
A. the processing of Entitlement Management Message EMM message
Entitlement Management Message EMM message mainly provides the mandate and the management information of watching pay TV to the user.
The first step: digital TV set-top box obtains CA_system_ID from the 0xEF00 of smart card;
Second step: find the CA_PID corresponding among the CA_descriptor of digital TV set-top box from the CAT table, be the Entitlement Management Message EMM_PID of this program of control descrambling with this CA_system_ID;
The 3rd step: proprietary screening parameter and instruction are provided with Entitlement Management Message EMM message filtering device to Conditional Access Module according to Conditional Access Module, Entitlement Management Message EMM message is taken out give smart card;
The 4th step: smart card will be with being stored in PDK among the 0x0002 to Entitlement Management Message EMM decrypt messages, authorized and management information;
The 5th step: repeat " the 3rd step ", wait for new Entitlement Management Message EMM message.
B. the processing of Entitlement Control Message ECM message
Entitlement Control Message ECM message provides the information such as criterion and descrambling parameter of watching of watching scrambled program.
The first step: the user seeks the program that will watch by electronic program guide (EPG);
Second step: the sponsored program that user's selection will be watched, digital TV set-top box finds the CA_PID corresponding with this CA_System_ID from the CA_descriptor of this joint joint order mapping table table, be the Entitlement Control Message ECM_PID of this program descrambling of control, set up the descrambling parameter list;
The 3rd step: Conditional Access Module is provided with Entitlement Control Message ECM table section screening washer according to its proprietary screening parameter and instruction, Entitlement Control Message ECM message is taken out give smart card;
The 4th step: smart card obtains receiving criterion from Entitlement Control Message ECM message, and the rating power of preserving with smart card compares.Not in the rating scope of authority, then tell the user to have no right to watch this program if watch criterion by response message;
The 5th step: drop in the rating power if watch criterion, with the deciphering of the descrambling parameter in the Entitlement Control Message ECM message, controlled word CW gives digital TV set-top box by response message and uses smart card with the SK that decrypts;
The 6th step: digital TV set-top box is kept at control word CW in the descrambling parameter list;
The 7th step: digital TV set-top box is received transmission package, if the scrambling control bit in packet header is that " 10 " or " 11 " (annotate: in DVB, " 00 " expression transport layer is not by scrambling; " 01 " is expressed as from now on, and DVB reserves; Even key is adopted in the scrambling of " 10 " expression transport layer; Strange key is adopted in the scrambling of " 11 " expression transport layer), then the PID according to transmission package searches the descrambling parameter list, if the parity of scrambling control bit is identical with current control word parity, then uses current control word descrambling; If the parity difference is then upgraded current control word, next control word is set at current control word, and is used for descrambling;
The 8th step: digital TV set-top box is passed to smart card with new Entitlement Control Message ECM bag, for fear of repeat to transmit Entitlement Control Message ECM message to smart card, digital TV set-top box only just transmits new Entitlement Control Message ECM message to smart card when upgrading current control word.
The processing of 4-3 descrambler module
Descrambler has very important effect in Conditional Access Module.The program stream of scrambling, when flowing through descrambler, must carry out scramble process after, could be correctly decoded by sound, Video Decoder.At condition receiving system, the DVB normal structure proposes a kind of general Descrambling Algorithms (Common ScrambleAlgorithm) that adds, the front end scrambling part that this unified various different conditions of algorithm specificationization receive, make with close mode is handy and (be meant that with close mode front end uses identical control word, but use different encrypted circuits and information sender.The design of decoding chip on descrambling circuit that also standardize simultaneously can be applicable in the different condition receiving systems decoding chip.Though be the common scrambling algorithm, its ins and outs are covert, a sealed contract just can obtain after the confidentiality agreement of DVB organizational member.
Program stream is carried out descrambling,, the structure and the initial condition of pseudo-random sequence generator are weaved into one group of data, be called control word, the control word input descrambler that at first the smart card deciphering is obtained for guaranteeing the synchronous of transmitting-receiving two-end sequence; Moreover use control word to produce pseudo-random binary sequence, just as the stream of the TS in the DVB transmission system diffusion descrambling that carry out (making a start), back (receiving end) before the sign indicating number coding outside, transmitting-receiving two-end uses identical pseudo random sequence; Call Descrambling Algorithms at last, use pseudo random sequence being recovered by the data flow of scrambling.
Present embodiment is not limited only to the foregoing description, can also for
Three tunnel demonstration top box of digital machines as shown in Figure 7, comprise that a set-top box has four inputs and three outputs, one of them input is for inserting wire cable, other three inputs corresponding respectively three remote controllers, three outputs connect different television sets respectively.Remote controller 1 control television set 1, remote controller 2 control television sets 2, remote controller 3 control television sets 3.When supposing that remote controller 1 uses separately, smart card is only deciphered a circuit-switched data, therefore has only television set 1 that program output is arranged, and television set 2 and 3 does not have program output.When having only three remote controls to use simultaneously, three circuit-switched data are deciphered in the smart card timesharing, and therefore three television sets have program output.
Or be the two-way demonstration top box of digital machine of remote controller control as shown in Figure 8, comprise that a set-top box has three inputs and two outputs, one of them input is for inserting wire cable, two other input corresponding respectively two remote controllers, two outputs connect different television sets respectively.Remote controller 1 control television set 1, remote controller 2 control television sets 2.When supposing that remote controller 1 uses separately, smart card is only deciphered a circuit-switched data, therefore has only television set 1 that program output is arranged, and television set 2 does not have program output.When having only two remote controls to use simultaneously, smart card timesharing deciphering two paths of data, therefore two television sets have program output.
Again or be that the two-way of single remote controller control as shown in Figure 9 shows top box of digital machine, comprise that a set-top box has two inputs and two outputs, one of them input is for inserting wire cable, and another one input correspondence a remote controller, and two outputs connect different television sets respectively.Remote controller can be controlled television set 1 and television set 2 respectively, this moment, remote controller needed a control button, was control television set 1 when this button is pressed, and was control television set 2 when pressing again, not only again by once but also return control television set 1, so loop control television set 1 and 2.
Claims (5)
1, multi-display digital television set-top box is characterized in that: include
A tuner is used to receive high-frequency TV signal, and high-frequency TV signal is carried out down-conversion, exports two-way medium-frequency TV signal at least;
At least the two-way tuner module carries out filtering and frequency-selecting to the intermediate-freuqncy signal of tuner input;
At least two-way quadrature amplitude demodulation module, every road quadrature amplitude demodulation module links to each other with one road tuner module, is responsible for the TV signal after filtering and the frequency-selecting is carried out demodulation, decoding;
At least the two-way demultiplexing module is elected program streams different on the same channel and information flow respectively, and according to spectators' selected channel respective program is spread and to deliver to corresponding decoder module, and the information flow with selected channel is sent to Conditional Access Module simultaneously;
A Conditional Access Module, reception is from the information flow of above-mentioned each road demultiplexing module, be Entitlement Management Message and Entitlement Control Message, and Entitlement Management Message that time-division processing is not gone the same way in the cycle period of a control word and Entitlement Control Message, the control word information that last timesharing output is not gone the same way is sent deciphering stream is carried out descrambling;
At least the two-way decoder module carries out audio/video decoding with the TV programme that the Conditional Access Module descrambling comes out, and restores the identical or different audio/video flow of two-way at least simultaneously.
2, multi-display digital television set-top box according to claim 1 is characterized in that: described Conditional Access Module comprises smart card, controller, authorization message selector, control word selector and authorization message buffer, descrambler and the program stream buffer of two-way Entitlement Control Message and Entitlement Management Message at least; Each road authorization message buffer links to each other with the demultiplexing module of not going the same way respectively; Controller links to each other with the control end of authorization message selector with the control word selector respectively, be used for selecting the wherein input of one road Entitlement Control Message and Entitlement Management Message input smart card, and wherein one group of control word that control control word selector selects the output smart card to decrypt exports corresponding descrambler at control word cycle period inner control authorization message selector; Descrambler is connected with the program stream buffer, and the audio/video flow that each control word cycle period descrambling is come out carries out buffer memory, the sending into of program stream that comes out until next control word cycle period descrambling and information flow.
3, multi-display digital television set-top box according to claim 2, it is characterized in that: the way of described tuner module, quadrature amplitude demodulation module, demultiplexing module, audio/video decoding module, authorization message buffer, descrambler and program stream buffer is identical with the way N of the digital television program of required demonstration, and its value is between 1～3 the tunnel.
4, multi-display digital television set-top box according to claim 3, it is characterized in that: described authorization message selector is that 2N selects 2 data selectors, the input of this authorization message selector links to each other with each road authorization message buffer by bus, and output links to each other with smart card by lead.
5, according to claim 3 or 4 described multi-display digital television set-top boxes, it is characterized in that: described control word selector is that N selects 1 data selector, the input of this control word selector links to each other with smart card by lead, and output links to each other with each road descrambler by bus.
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| CNU2008201045635U CN201298872Y (en) | 2008-09-11 | 2008-09-11 | Multi-display digital TV set-top box |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102088632A (en) * | 2010-12-09 | 2011-06-08 | 深圳国微技术有限公司 | Condition receiving apparatus capable of supporting two program sources and implementation method thereof |
| CN102186030A (en) * | 2011-05-10 | 2011-09-14 | 天津三星电子有限公司 | Multi-user television |
| CN102340696A (en) * | 2011-06-24 | 2012-02-01 | 太仓南极风能源设备有限公司 | Household trunking set top box |
| EP2571262A1 (en) * | 2010-11-02 | 2013-03-20 | Huawei Device Co., Ltd. | Method and device for processing image display |
| CN108377388A (en) * | 2018-03-29 | 2018-08-07 | 珠海迈科智能科技股份有限公司 | A kind of double Tuner modules TV signal measuring instruments and method |
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2008
- 2008-09-11 CN CNU2008201045635U patent/CN201298872Y/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2571262A1 (en) * | 2010-11-02 | 2013-03-20 | Huawei Device Co., Ltd. | Method and device for processing image display |
| EP2571262A4 (en) * | 2010-11-02 | 2014-01-15 | Huawei Device Co Ltd | Method and device for processing image display |
| CN102088632A (en) * | 2010-12-09 | 2011-06-08 | 深圳国微技术有限公司 | Condition receiving apparatus capable of supporting two program sources and implementation method thereof |
| CN102186030A (en) * | 2011-05-10 | 2011-09-14 | 天津三星电子有限公司 | Multi-user television |
| CN102340696A (en) * | 2011-06-24 | 2012-02-01 | 太仓南极风能源设备有限公司 | Household trunking set top box |
| CN108377388A (en) * | 2018-03-29 | 2018-08-07 | 珠海迈科智能科技股份有限公司 | A kind of double Tuner modules TV signal measuring instruments and method |
| CN108377388B (en) * | 2018-03-29 | 2023-09-08 | 珠海迈科智能科技股份有限公司 | Dual Tuner module television signal measuring instrument and method |
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