Method of encoding and decoding television signals and system for encoding a television signal

 

(57) Abstract:

Method for encoding and decoding information signals, usually organized as a sequence of lines of active information, and each row has a beginning reference line clocking, such as color video signals. Active videocast shift in time relative to the part of the horizontal synchronization of the corresponding row, using a predefined, slowly changing function of a temporary edviga. Information time offset is passed to the side of the decoding, encoding the instantaneous value of the signal time offset for the beginning of each field in the part of the blanking retrace field sweep this field. To ensure a reasonable range of time offset part of the slice of the active video in the previous line and part of the front of the active video signal on the current line drop. During decryption drop the initial signal line clocking and color burst and generate new signals, which are time-shifted from the active video portion to an initial value defined before encryption. 2 S. and 3 C.p. f-crystals, 13 ill.

The invention relates is sitsa to method for encoding and decoding of such signals, to prevent unauthorized use.

It was invented many methods for encoding and decoding information signals time domain. The goal of these methods is always the same, namely: to prevent unauthorized use of signals. In the case of information signals of the type of video the unauthorized use of which is necessary to prevent, is usually a visual reproduction of information signals for entertainment or learning. Such signals may be illegal to use a number of ways. For example, if the transmit signals via satellite or microwave links, illegal users are trying to intercept the signals and play them without paying for a subscription service. To counter such unauthorized use of broadcast video information has been used successfully a number of specific methods of signal scrambling.

Other means of transmission of video information from one place to another is a video tape. For example, film studios is common distribution of the original tapes of movies around the world. If videotapes stolen or "lost" in transit, there will be the possibility of a violation of copyright the tape was to be used by the client, with descramblers and corresponding codes. Such a system of scrambling should have two important features: it must be very reliable and compatible with electronics recording/playback preferably all professional and consumer video devices.

There are many known ways of scrambling video signals. Two simple methods are synchromedia and sinhronizovani, each of which, however, can easily be upset by using simple methods of processing video signals, and in any case cannot be written. Another method is called the pseudo inverse of videorola, which are relatively difficult to upset, but which suffers from a lack of a strong loss of image quality due to the nonlinearity in the process of recording/playback. Another method is to rearrange the order of the rows, also known as "shuffling rows where rearrange the order of the rows in a raster scan image. For example, instead of the serial transmission lines: line number 1 line number 2 line number 3 and so on, information can be passed as the line number 182, line number 99, line number 4 and so on, Such a system can be very reliable (is tzvetnosti, which is built on the adjacency of lines to get a correct state color during playback.

Another method is a pseudo-random rotation lines, where some randomly selected row of the image are passed to the inverse temporal order (i.e. from right to left), while the remaining lines transmit normally (i.e. from left to right). Another method is called segmentation lines with random selected points split, where each row is divided into two randomly selected segment and transmit the first right and then left segments. Both of these methods of scrambling video signals lead to strong distortion of color between the left and right sides of the image when used on any format that applies podtsvetkoy record.

In addition to the above-mentioned disadvantages of the three last mentioned method suffer from another disadvantage, namely the fact that the treatment is incompatible with the processing of compensation for loss of signal, used in most video recording devices. While in principle these three methods you can use to format processing of video signals, which are not used podtsvetkoy account, such as odnogolosy formats type B and type C, this is possible controls system diskriminirovaniya. This will require special modification of the playback equipment, which will increase to an undesirable value the cost and complexity of encryption/decryption.

None of the above methods videocamsliveweb not fully meet the required system videocamsliveweb, according to which: a scrambled video image is to be recorded and subsequently reproduced in any format film professional or household - and descrambling when playing with minimal loss of image quality; a method of scrambling is virtually impossible to upset any illegal user; scrambled video should not be affected by passage through different types of processing equipment used in the television equipment, satellite communication and cable networks.

In the application of the U.S. N 203.676 disclosed a method and apparatus that provide a very reliable method of encoding and decoding the information signal of videotape, compatible with all formats of tapes and transmission systems and is free from deterioration of the image caused by the interaction of scrambling algorithm and color of th is m in the application method is encrypting information signals of videotape using individual time offset of the active video portion of at least some lines of the video signal relative to the beginning of the reference line clocking (horizontal synchronization coding system NTSC) with indication of completed time offset for later decryption. For a color video information signal time shift is prohibited on the part of the line synchronization signal and of the color reference signal. This way is not a temporary shift of inactive videocosta field or frame information (i.e., vertical quenching parts). Decoding of encrypted signals is performed by use of the process, the reverse process of encryption. For best results and compatibility between the method of encryption and other conventional methods of signal processing (in particular, in the color heterodyne system video tape recorders) the value of the time offset limit N cycles of the color subcarrier (in the preferred embodiment), where N is an integer, preferably 0 or 1). In addition, the maximum aggregate time shift of the active video portion limit so that the active videocast does not cover any part of the color burst, or a portion of the horizontal reference synchronization separate lines.

Although the above method of ciphering/deciphering high-performance, optimal implementation requires the use of digital videoshome to descramble side (i.e., television monitoriranje includes a method and apparatus for providing a very reliable method of encoding and decoding information such as video, which is compatible with all formats of tapes and transmission systems, is free from distortion caused by the interaction of scrambling algorithm and systems of linear averaging color consistency in color heterodyne recording, and can be implemented much cheaper than the system described above.

From the point of view of method, the invention includes encrypted information signals, usually organized as a sequence of lines of active information, and each row has a beginning reference line clocking; how are the basic steps individual time offset of the active information of at least some of the rows of signals in relation to part of the starting line clocking, and it provides an indication of the time difference made in step a time offset in order to make subsequent decoding. For information signals are video signals containing signal part of the horizontal synchronization signal and of the color synchronization, the time shift is performed on the active video portion with respect to these two parts separate lines. The inactive part of the field frame for can include any of a variety of slowly varying functions, such as the signal is sinusoidal or linear sawtooth signal. The intensity of the signal changes should be relatively slow in comparison with the lower frequency to be processed input signals. For signals of videotape ideal sine wave form having a frequency of not more than 20 Hz, while for the ramp of the sawtooth signal is appropriate slew rate comparable magnitude. The absolute number of completed temporary shift in the preferred embodiment is limited to a maximum value, which in the case of NTSC video signals, do not exceed a total of 4 µs (2 μs in each direction).

The instantaneous value of the function waveform time offset at the beginning of each field is passed along with the information field is usually during the period of vertical blanking. For example, relative to the sinusoidal function of time shift of the initial amplitude of the waveform within the specified field transmit during the interval of the vertical blanking as one byte of information, which, when combined with the separately-provided key permissions allows the scheme descrambler to synthesize the function waveform scrambling. The Dechy is depending between the horizontal synchronizing and color sync) and active videocast the corresponding row. Do this by using the new generation lowercase temporal reference signals (horizontal sync and color burst), which have the same time dependence to the active video portion that initial lowercase temporary reference signal before encryption. The resulting diskriminirovaniya signals still contain errors base time, but these errors are detectable and correctable following television monitor/receiver.

The invention can be implemented by using most conventional analog circuitry for the device of descrambler that makes the device diskriminirovaniya economical to manufacture and easy to repair.

In Fig. 1 shows a diagram illustrating a single line of information videotype to which the invention is applicable; Fig. 2 is a diagram illustrating the visual effect of sinusoidal temporal shift on three consecutive fields of information; Fig. 3-4 diagram illustrating the signal scrambling and diskriminirovaniya; Fig. 5-6 is a block diagram of a scrambling device, and Fig. 7 is a more detailed block diagram illustrating portions of the input device, output device and the generator synchronizaton of the flowchart of Fig. 5-6; Fig. 9 is a block diagram of the controller 34 that is used to generate a waveform of a temporary shift; Fig. 10 is a block diagram illustrating a device descrambler; Fig. 11-12 is a series of diagrams illustrating the selected waveforms from the flowchart of Fig. 8; Fig. 13 is a block diagram illustrating the synth waveform of descrambler.

The basic principle of the invention can best be understood in the examples of Fig. 1-4. Fig. 1 illustrates one line of the NTSC video with active videocast line, compressed along the horizontal scale. As can be seen from Fig. 1, one line of the active video portion that lies between the front line signals of neighboring rows, includes part of the reference color burst signal, followed by active videocast. Front line sync pulse identifies the beginning of the line and serves as the origin of the clocking of the line. In accordance with the invention, the active videocast line shift in time relative to the active video portion of other lines in a predetermined way. For example, in Fig. 1 shows the normal position of the active video portion. While encryption is a position shift in time or forward (i.e. closer to the end of the horizontal synchronization Yes the line). To save the most active video portion in each row, the relative and total time offset impose maximum limits. In a preferred version of the video for this value is 2 µs (generally 4 ISS).

The execution path of a time offset is determined in advance, it must be relatively slow in relation to the lower frequency information signals to ensure correct processing of the signals after diskriminirovaniya, as will be described in more detail below. To control the magnitude and direction of the time shift you can use many different types of functions waveforms. Examples of such forms are sine, square, sawtooth waveforms and low-frequency random or pseudo-random noise signals. Other relevant functions of the time difference known to the specialists in this field of technology. It was empirically determined that, in practice, the maximum frequency on the time-varying form of the signal used to control the time-shift is about 20 Hz for modern equipped with television monitors and receivers are equipped to handle NTSC signals.

Fig. 2 in which the relatively slowly varying sinusoidal temporal shift on the active videocast video information signals. Here the rectangular outline illustrates the entire image (including the invisible side of each row), and the vertical dotted lines represent the normal position of the beginning of the visible part of each line. The solid curved lines illustrate the distortion of the image when the three consecutive fields use a slowly varying sinusoidal signal time offset. This level of distortion is enough to make a high-quality image. It should be understood that the size of the temporary shift, illustrated in Fig. 2, is exaggerated for clarity.

Fig. 3-4 show how the decoding or diskriminirovaniya encrypted or scrambled signals at the receiving side. In Fig. 3 shows three successive lines of video NTSC, which were sequentially shifted in time increasing quantities. As in the case of the circuit of Fig. 1, the active video portion of the lines in Fig. 3-4 is shown only partially. The top row represents the row that does not have a time offset between the active videocast, and the time between the beginning of the horizontal sync and active videocast denoted as t1. The next line N+I endured is the active video portion is t2that is greater than t1. Line N+2 has undergone an even greater shift towards delay value, denoted as t3that is greater than t2. These three consecutive rows can represent strings from the top of the raster, schematically depicted in Fig. 2A. It is important to note that some temporary string clocking each of the rows N, N+1, N+2 temporarily aligned: the front part of the horizontal synchronization each line exactly aligned with the front of the horizontal sync portion of the other strings. The same is true for the location of parts of the color synchronization. The active video portion, however, deliberately incorrectly expressed in rows N+1 and N+2 relative to the row n

Fig. 4 illustrates the signals for the same three lines after diskriminirovaniya or decoding. Here, the front portions of the horizontal synchronization three lines anymore not exactly aligned, and are fairly consistently, however, the distance between the front horizontal synchronizing part and the beginning of the active video portion is the same for all three rows, namely t1. Similarly, no longer are temporarily aligned with the color burst signals of three lines, they placed the second video portion of the three rows is the same.

Although diskriminirovaniya signals still aligned correctly, the exact time dependence of t1between the front horizontal sync and the start of active video portion ensures proper playback of each line of information when processing subsequent television receiver or monitor, provided that a temporary error in this line is not beyond the range of the capture of sinhaseni television receiver or monitor. It was empirically determined that you can guarantee the synchronization of each line of the video portion, provided that the function of the time offset used for the initial encryption of the signals does not vary with frequency exceeding a value of about 20 Hz for encoded NTSC video. Although other maximum frequency limits can be applied to other coding systems television information signals (as, for example, PAL or SECAM), the General rule is that the time shift applied to the original signals during encryption, should be relatively slowly varying in comparison with the lower frequency. In other words, a temporary error introduced into the signal in the process scramble the existing television receiver or monitor.

Fig. 5-6 are block diagram of the scrambling system, capable of providing the above-mentioned encryption. As can be seen from Fig. 5-6, subject to encoding the input video signal related to the input terminal 11 of the input device 12. The CPU 12 operates to normalize the incoming signal relative to the gain, offset and DC bandwidth and is stable buffer with low resistance for a video signal present on output terminal 13. In addition, the coming of the vertical and horizontal sync is separated from the input video signal processor unit 12 and serves as an input signal to the generator synchronization/clocking and system phase automatic frequency 15, as is more fully illustrated in Fig. 7.

The signals coming from the processor device 12, which are present on output terminal 13 connected with a conventional NTSC decoder and device protection filter-aliasing 16, where the separation of the component Y and the I and q chrominance components I, Q for parallel processing in a digital representation. The output Y of the device 16 is connected with the analog-to-digital conversion 18, cotogno gate clock signal, supplied through the input clock line 19. The output of the Converter device 18 is connected with the input part of the storage device brightness 20 with double entrance. The storage device 20 has a memory configuration in which the word is recorded from the analog-to-digital Converter 18 during each cycle of operation of the memory, and for each cycle of operation of the memory will read the word to the digital-to-analog Converter 22. The storage capacity of the luminance memory 20 must be at least equal to the number of multi-bit characters (bytes) required to store one full-line information of brightness at the selected clock frequency. The signals for controlling the recording/reading and a multi-bit address signals served in the storage device brightness 20 from the device control memory 24. The output of the storage device brightness 20 is connected to the input of digital-to-analog Converter 22, in which the multi-bit digital words issued from the storage device 20, is converted into analog samples with a clock frequency by the clock signals from the device 15 on the input clock line 23. The output of the Converter device 22 is connected to the input of the encoder and the device of the lowpass filter 25, where the signal is constant current. Quadrature components of color are treated essentially the same way as the component Y, as already described above, in the devices 18', 20', 22' that work the same way as the devices 18, 20, 22.

The device clock synchronization 15 is used to generate the input clock signal used to clock Gating analog-to-digital Converter devices 18, the supply of the clock signal writing and reading from the storage device 20 and a clock Gating digital-to-analog Converter device 22. In a preferred embodiment, the device 15 consists of pasticcino detector, the number of sampling frames of samples of the error amplifier and the crystal oscillator.

The above described device associated with the interface device 32, such as a keyboard terminal, via the controller device 34 and the set of control registers 36. The controller 34 includes a circuit shown in Fig. 9, for generating a waveform for a time offset that is used to time shift of the signals undergoing the encryption. The controller 34 also generates the encrypted bytes of data containing the data required by descrambler DL the ode encryption, and the result is inserted into one of the unused rows interval blanking retrace vertical scan.

Fig. 7 illustrates the key parts of the input video processor 12, the output of the video processor 26 and generator synchronization/clocking 15, which is shown in Fig. 5-6. As can be seen from this drawing, the video signal present on input terminal 11, is connected to the sync separator 31, which is the detection of parts of line and field synchronization. The pulse synchronization fields issued from the sync separator 31, excite the pulse generator field 32, which is connected with a reset signal to its original state with the input of the counter 33 dividing by 525, working as a row count. The pulses of the horizontal synchronization provided by sync separator 31 is used for the excitation system of the horizontal phase of the automatic frequency control 35, which generates the first output line 36 of the clock signal to the counter 33, having a frequency which is twice the line frequency (31.5 kHz). System horizontal phase lock frequency 35 also generates on the lower frequency pulse, which is 2 mm wider than the usual quenching impulse lines (Fig. 8, 40 generates a pulse with a width of 2.0 µs (signal 8 (D), run along the front of the input signal. Multivibrator circuit 41 generates a pulse width of 2.0 µs (signal 8 (E) that run on this slice of the input signal. Output signals from multivibrator devices 40, 41 are passed through the scheme, OR 45, the output of which (signal 8 (F) is connected as one input to the circuit And 47. Another input circuit And 47 is the output of the detection logic state (preferably programmable permanent memory, EPROM) 50, which supplies the gate signal field synchronization. The gate signal field synchronization received from the device 50 is a locking signal for the circuit And 47, it has a duration of nine horizontal rows and works in such a way as to block the output of the circuit And 47 for the period interval field synchronization.

The output of the circuit 47 is connected with the switch blanking 52 and serves to increase the blanking interval to 2 microseconds on each side of the normal time damping. Although this leads to some loss of active video on the cut of the previous line and the front of the active video signal on the current line, this loss is small. The output of switch blanking 52 (signal 8H) is connected to the input decoder. The scheme of the color burst Gating 55 affects the control signal issued from the device in standby multivibrator 57 (signal 81), which is the pulse duration of 3.5 μs, starting on the shear horizontal synchronization and is used to gate the part of the color burst of the input video signal on the schema parametric subcarrier generator 59. Circuit 59 generates a color subcarrier signal with a frequency of eight times the nominal subcarrier frequency, and the output signal generating circuit 59 is used as the clock signal for the analog-to-digital devices 18, 18' digital-to-analog Converter devices 22, 22', device, memory controller 24, the count of rows 30 and any other schemes that require synchronization clocking. The output of the generator circuit 59 is also connected to the input circuit 61 that is configured to divide by eight, the output of which provides subcarriers with frequency to 3.58 MHz, automatically adjust the phase for incoming color synchronization. This subcarriers (signal 8 (J) is connected to the circuits to decode and encode NTSC 16,25.

Output multivibrator circuit 57 is also connected with the scheme of fixing the rear quenching vibratory circuit 40 is connected as the excitatory input to the circuit standby multivibrator 65, started by slice of the input signal, which generates a pulse blanking lines of normal duration (11 MS; signal 8G). Output multivibrator circuit 65 is connected via a scheme OR 66 with the control input videoerectile circuit 68. Another input supplied to the switching circuit 68 via a scheme OR 66, a signal Gating blanking retrace field sweep generated by the device detection logic state 50. Signal Gating blanking retrace field sweep is permissive signal having a duration of 21 line and appearing during the interval blanking retrace field scan of each field.

The purpose videoerectile circuit 68 is an alternation of two shifted versions time-signals: those that pass through videointercom circuit 70, and those that bypass videointercom circuit 70. The video signal from the encoder NTSC 25 (Fig. 5-6) is connected to the input circuit of the fixing rear quenching pulse 72, which also controls the output multivibrator circuit 57. The output of the circuit fixing rear quenching pulse 72 is connected to two input terminals of the switch 68: the signal of the light level).

The output of switch 68 (signal 8LN) is connected through amplifier 78, he serves as the output La later use (usually either for broadcast or for recording on the tape).

As noted above, the time shift is performed in the digital representation of the quadrature components of luminance and chrominance synchronous way. After making a temporary shift transform digital signals into analog representation and recombine in the scheme of the encoder 25. Then shifted in time video invert during active videocosta through inverter circuits 70 and switch 68 to generate shifted in time, inverted, scrambled video signals, shown as L and N in Fig. 8. In particular, waveform 64 illustrates the result of a temporary shift of the active line of the video signal in the direction of advance. Form 8L shows the result of passing this out in time of the signal through videointercom circuit 70 in the time of the active video portion. Similarly, the form 8M illustrates the result of a temporary shift of the active line of the video signal in the direction of delays, while form 8 N shows the result of passing this sdven the As can be seen in Fig. 9, the portion of the controller 34 that is used to generate a waveform of a temporary shift, includes a generator of low-frequency noise signal 101 that is able to generate any appropriate waveform with a relatively low frequency for use in the function definition time offset. As noted above, the signal may be sinusoidal, sawtooth shape, the shape of a rectangular pulse or a form of random noise. Such devices are well known in the art and will not be further described. The signal generated by the generator of low-frequency noise signals 101, connected to the analog-to-digital Converter 103, which converts the digital amplitude output signal generator 101 with a frequency of one sample on the information field. Sampling controlled by the signal present on input terminal 104 of the controller. This control signal is obtained from the detection device logical status 50 (Fig. 7), and in a preferred embodiment, it represents the momentum generated during the appearance of one of the rows, as, for example, line 21, in the interval blanking retrace field sweep. The discretized output analoge Converter 106. Analog-to-digital Converter 106 takeroot clock pulses generated with the frequency of the horizontal synchronization (signal B in Fig. 8, for example). The output of the analog-to-digital Converter 106 is connected with the memory controller 24 via control registers 36, it is used to control the actual value of the time shift is performed on the active video portion of each line.

The output of the analog-to-digital Converter 103 is also connected through a Gating circuit 108, that unlocks during line 21, the encoder 110, which provides the above-mentioned encryption for byte signal time offset. The output signal of the encoder 110 is added to the signal through amplifier 78 (Fig. 7). Thus transmit the encrypted bytes of the amplitude information signal time offset at the beginning of each field on each descramblers device together with the scrambled video signals and other transient signals.

Fig. 10 illustrates descramblers device used to decode signals received after encryption using the process described above. Descrambler uses many of the same devices as the scrambler shown in Fig. 7, and such device shall Olenye initial temporal interdependencies between the horizontal sync and color burst each line of a video signal and an active videocast this line. Below will be described the operation involving circuits of the signal shown in Fig. 11-12.

The signal received at the input terminal 11, is connected to the input of the sync separator 31 and to the input circuit of the fixing rear quenching pulse 63. The output of sync separator 31 is connected to the input of the pulse generator field 32, the input of the system phase of the automatic frequency control lines 35, entrance 3,5-ISS sleep multivibrator 57 used for excitation scheme of fixing the rear platform of the quenching pulse 63, and the input descramblers synthesizing circuit waveform 80. To the second input of synthesizing circuit 80 serves signal enabling key generated by the user (i.e. the subscriber), which is used to decode the incoming data byte a time offset of the signal encrypted by the controller 34. This key separately inform the subscriber of any safe path, i.e., through electronic devices, by mail, by phone, etc., the Other input to the synthesizer 80 is input 11, which contain information on the instantaneous values of the signal time offset at the beginning of the field information. As will be described in more detail below with reference to Fig. 13, synthesizing scheme is 82; the voltage change during the presence of the field in accordance with the nature of the signal time offset. For example, if during the encryption applied time shift signal of sinusoidal form, the decryption requires the same sinusoidal waveform for generating the varying reference voltage for each row of the field. At the beginning of the next field during blanking retrace field scan in the received video signal to provide a new byte of information time offset of the waveform, and this information serves on synthesizing circuit 80.

The system phase of the automatic frequency control lines 35 generates a first output pulse (signal 11H), with duration equal to 6.0 ISS, but advanced in phase relative to the horizontal sync to a predetermined value (1.5 km ISS in the preferred embodiment). This signal is fed through the output conductor 37 to the input of 1.5-ISS sleep multivibrator 83 and also to the input of the oscillator circuit saws 85. The schema generator saws 85 generates a sawtooth voltage (signal 11I) with linear frequency, and this sawtooth voltage is connected to another input of the voltage comparator 82. When the level of the sawtooth her scheme 80, the voltage comparator 82 generates an output signal which is used to initialize the 9-ISS scheme standby multivibrator 87 and 4.7-μs scheme standby multivibrator 88. Multivibrator circuit 88 generates a new prestavlenny pulse horizontal sync to be added to the video signal 12L), this clock pulse is connected to one input of the generator horizontal and color burst 89. Output multivibrator circuit 88 is also connected to the input of 0.9-ISS scheme standby multivibrator 90, and the output of the circuit 90 (signal 12M) connected to the input circuit standby multivibrator 92. The output of the circuit 92 (signal 12N) is connected to the input circuit of the color burst generator 94, which gates the color burst signal at the color subcarrier frequency of the generator circuit 59 to the other input of the mixing circuit horizontal and color burst 89. The output of the mixing circuit 89, which includes properly paratactically in relation to active information part of the given string lowercase and color burst, is connected to the input terminal 74 videoerectile circuit 68".

Output multivibrator scheme 83 (signal 11J) is connected to the input circuit standby multivibrator 65 which generates the second scan. This signal is passed through a scheme OR 66 together with the output signal multivibrator circuit 87 and serves at the first input circuit And 95. The other input signal for the circuit And 95 is the gate signal of the field synchronization generated by the detector logic state 50, which serves to prevent flow through the circuit And 95 extremely 68" control signal during the first 9 rows of vertical synchronization inside each field. Thus, the extremely 68" can be switched from the normally closed terminal 75 to terminal 74 is, when the output pulse signals from multivibrator scheme 65 or 87, active (signals 11K, 12R). When the switch 68 is connected to terminal 74, the output of the mixing circuit horizontal and color burst 89 is connected with the output of amplifier 78. Otherwise, the output of amplifier 78 is connected to the active video output from videoerectile 68'.

On the extremely 68' serves two input video signal is a direct signal that has passed through the clamper rear quenching pulse signal 12P), or its inverted version (signal 12Q), provided by the inverter 70. The state of the switch 68' control Gating signal aboutparliament 68' is connected to terminal 74, and goes straight to the video. All other times the output of the switch 68' via terminal 75 connected to the inverted version coming from the inverter circuit 70.

The scheme descrambler shown in Fig. 10, discards incoming lowercase and color synchronization; generates a new line and color burst at the proper time dependence with respect to the active video portion of the incoming row. New synchronization lines and color, provide a mixing circuit 89, connected via terminal 74 and the switch 68" as a new part of the horizontal and color burst recreated invert the signal through inverter 70 and is connected to the output amplifier 78 to recreate the entire row. During the last 12 lines part of the blanking retrace vertical scan field active videodrome pass directly through the first and second videoprilozhenie circuit 68', 68". During the gate part of the framing of the specified field scheme And 95 are locked to prevent adding to the incoming video signal synthesized lowercase and color sync.

Fig. 13 illustrates subdevice, the composition is of Italia data 112, which detects information in line 21 of field, which characterizes the amplitude of the signal time offset at the beginning of this field. Because these data are encrypted form, connect them to the input of the decoder 114 together with the key resolution submitted by the subscriber/user by any suitable means, for example, through the keyboard. The decoded digital value of the amplitude is served from decoder 114 to the input 20 Hz lowpass filter that replicates or recovers slowly changing the shape of the signal time offset. Output 20 Hz low pass filter 116 is connected with the voltage comparator 82 for providing the reference voltage signal.

As is now clear, the invention provides a completely reliable method for encoding and decoding signals of videotape, compatible with all formats of tapes and transmission systems and providing adequate concealment image, removing the meaning from the program. In addition, as almost all circuit elements and sub-nodes in descrambler are the usual issues of industry schemes and components, scramblers the device is relatively inexpensive to manufacture and repair.

While the mean is m in this field of technology can meet various modifications, alternative constructions and equivalents. For example, despite the fact that it was stated a limit of 2 μs at the maximum time advance and delay of the shift, you can select other values. In General, the higher the total maximum time advance and delay, the greater the loss of active rear part of the previous line and the front of the line, undergoes a temporal offset. Therefore, the above description and illustrations should not be considered limiting the scope of protection of the invention defined by the attached claims.

1. Method of encoding and decoding television signals, which move in time some leaf of the video signal in accordance with a specified algorithm, and the value of the time shift of each line may differ significantly from the time shift of the previous row, characterized in that provide signal indications of a shift in time, carried out on a specific line, by introducing a new bit of information about the shift in time and add it to the original signal, restores the original temporary value for each row between the time indications of the synchronizing pulse of this string and the information is billaut signal testimony to the information line.

2. The method according to p. 1, characterized in that when the recovery of encrypted information in one part of the synchronization line replace the newly generated clock pulses.

3. The method according to p. 1, characterized in that the active part of the line shift relative to the active portion of the video signal of the other line by a predetermined algorithm, and the maximum shift value active part of the line is subject to specific limitations.

4. The method according to p. 1, characterized in that when the recovery of encrypted information portion of the color reference signal is replaced with a new part of the reference signal with the subsequent addition of this signal with the information part of the video.

5. System for encoding a television signal containing video processor, configured to generate a sync signal and video signal, the input of which is the input video signal, and the output connected to the input of the filter unit separating luminance and chrominance output signals Y and Q which are connected respectively to the inputs of the first and second analog-to-digital Converter, the output of which is connected to the inputs of the synchronization of the second and third analog-to-digital is dynany respectively to the inputs of the first, the second and third memory blocks whose outputs are connected to inputs of first, second and third digital-to-analog converters connected to the first, second and third inputs of the encoder synchronization input connected to the output of the clock synchronization unit of clock synchronization, characterized in that the control unit memory, the first and the second input of which is connected to the output of the clock synchronization with the output of the second analog-to-digital Converter, the first and second outputs of a memory management unit connected to the input of the third memory block, and the third and fourth terminals are connected to the first input of the block of control registers, the output of which is connected to the input of the third digital-to-analog Converter, the pulse generator field, the output of which is connected to the input of the controller, the output of which is connected to the input of the block of control registers, and the outputs are the outputs of the block encryption.

 

Same patents:

The invention relates to the field of radio and can be used in the cable television system (CATV) to ensure protection from unauthorized access (unauthorized access) subscriber special (paid) TV channels

The invention relates to the field of radio and, in particular, to devices for signal encoding in pay-TV systems, using both cable networks and broadcasting through radio channels

The invention relates to television technician

The invention relates to a television technique can be used in cable systems television commercial

The invention relates to a television technique and can be used to prevent unauthorized access to transmitted masking information

FIELD: access control systems.

SUBSTANCE: proposed signal processing method involves reception of digital input signal incorporating first component of scrambled signal and second component of scrambled signal; binding of input signal with detachable intelligent card unit for processing first scrambled signal component and generation of first descrambled signal which is internal with respect to intelligent card unit and for processing second scrambled signal component in case of response to first descrambled signal to generate second descrambled signal and to integrate first scrambled signal component of input signal and second descrambled signal so as to produce output signal; reception of output signal from intelligent card unit and processing of second descrambled signal to shape signal adapted for display.

EFFECT: improved control of access.

1 cl, 9 dwg

FIELD: television.

SUBSTANCE: device converts signals to digital video information. Compression device is made in such a way, that it receives digital video data, coming from source data generator, and compresses digital images. Encoding device receives compressed digital video data coming from compression device and encodes compressed digital video data. Recording device stores encoded compressed digital audio data at data carrier.

EFFECT: higher data transfer speed.

3 cl, 17 dwg

FIELD: broadcasting systems.

SUBSTANCE: method includes broadcasting of message, including text portion intended to reach user, while said message is transferred in form of conditional access message.

EFFECT: broader functional capabilities.

5 cl, 7 dwg

FIELD: digital audio and video technologies.

SUBSTANCE: device for storing information is made with possible receipt of data carrier, decoder is made with possible receipt of compressed encoded signals from data carrier and transmitting signals to decrypter. Decrypter is made with possible decryption of compressed encoded data encrypted data and transmitting these to decompressor. Decompressor is made with possible receipt of compressed encoded signals from decrypter and decompression of compressed encoded signals to reproduce the image.

EFFECT: higher precision, higher efficiency.

3 cl, 17 dwg

FIELD: engineering of systems for loading and reproducing protective unit of content.

SUBSTANCE: in accordance to invention, in receiving device 110 for protected preservation of unit 102 of content on carrier 111 of information unit 102 of content is stored in protected format and has associated license file, file 141 of license being encrypted with usage of open key, associated with a group of reproduction devices 120,121, and, thus, each reproduction device 121 in group can decrypt file 141 of license and reproduce unit 102 of content, and devices not belonging to group can not do that, while device 121 for reproduction may provide the open key, specific for given device, to system for controlling content distribution, and then system for controlling content distribution returns secret key for group, encrypted with open key of device 121 for reproduction, after that device 121 of reproduction by protected method receives secret key of group and may decrypt file 141 of license.

EFFECT: creation of system for loading and reproducing protected unit of content, making it possible to constantly control usage of unit of content.

3 cl, 4 dwg

FIELD: copy/access protection.

SUBSTANCE: audio/video stream processing system includes module for inputting audio/video stream, which receives audio/video stream, containing field of information about audio/video content, including first copy control information, and audio/video content field, including second copy control information; reading module which extracts first and second copy control information from received audio/video stream and determines whether first copy control information is modified; and module for decoding audio/video stream, which processes received audio/video stream in accordance to predetermined criteria, if first copy control information is modified.

EFFECT: protection of content, prevented unsanctioned processing of content.

15 cl, 8 dwg

FIELD: cryptographic protocols, in particular, efficient encoding at content level.

SUBSTANCE: method is provided for generation of digital data with cryptographic protection, encoding content and composed into messages. Encoding of at least a part of the message is performed and encoded messages are provided in form of output signal in format, allowing the interface of server service to compose a message in form of at least one packet, including at least one header and useful load, where at least one header includes information, which allows the service interface in the client to assemble each message for decoding application using useful load of packets. Each message is divided onto the first and at least one additional section of the message. At least one of the message sections is encoded in such a way that it may be decoded independently from other message sections. Assembly of encrypted message is performed by addition of resynchronization marker, separating the message section from adjacent message section and including precise information about synchronization, at least for additional sections of the message.

EFFECT: synchronized decoding process in case of data loss.

14 cl, 8 dwg

FIELD: receivers/decoders of services, provided in conditional access mode, in particular, receivers having storage block (memorization device), such as a hard drive.

SUBSTANCE: method is claimed for storing an event, encrypted with usage of at least one control word (CW) in receiver/decoder (STB), connected to safety block (SC), where at least one control word and access privileges for aforementioned event are contained in access control messages (ECM-messages), method includes following operations: recording of encrypted event, and also of at least one ECM-message in storage block; transmission of at least one ECM-message into safety block (SC), verification of the fact that safety block (SC) contains access privileges for aforementioned event, generation of receipt (Q), which contains data related to management of event in reproduction mode, where receipt (Q) contains signature (SGN), generated on basis of the whole ECM-message or its part with usage of secret key (K) contained in safety block (SC) and specific for every safety block, where during later consumption of event the authenticity of the receipt (Q) is verified in prioritized manner compared to conventional access privileges, stored in safety block (SC), storage of aforementioned receipt (Q) in storage block.

EFFECT: provision of method for storing an event.

6 cl, 3 dwg

FIELD: receivers/decoders of services, provided with certain conditions, in particular in a system for accessing an encrypted data stream, priced per time unit.

SUBSTANCE: system contains control center (2), which transmits a data stream through a broadcasting channel, encrypted by means of control words, which are included in composition of access control messages, and meant for receipt by at least one user device (1), connected to safety block (3), having unique address and containing credit, which is reduced with purchase of products or consumption of data stream, where safety block (3) is provided with means for reducing credit for value, dependent on product, or for value, dependent on duration of access to data stream, where aforementioned values and/or duration are determined in access control messages or in conditional access messages, and system contains means, made independent from user device (1), for transmitting identifier, representing a unique number, and price code which indicates size of credit subject to load, in control center (2), and control center (2) additionally contains devices for receipt and verification of price code and for transmission of an encrypted message through broadcasting channel, having a unique address, corresponding to identifier, and giving a command to the safety block (3) to load the credit in defined amount.

EFFECT: development of a new approach to provision of access to paid television for broad clientele, substantially reduced subscriber management related costs.

5 cl, 1 dwg

FIELD: information encryption.

SUBSTANCE: system contains an encrypted data broadcasting centre, at least one control centre, a terminal device, a decoder located between the encrypted data broadcasting centre and the terminal device, the decoder includes an encrypted data reception and decryption module and a data access authority control module; the data access authority control module contains a protection module.

EFFECT: provision of system allowing to simplify access authority control at broadcasting centre level and ensuring optimal data security.

12 cl, 2 dwg

Up!