JP2913825B2 - Paid subtitle broadcast transmitter / receiver - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pay subtitle broadcast transmitting / receiving apparatus for pay television broadcasting.

2. Description of the Related Art In recent years, satellite broadcasting has been in full swing, and commercialization of pay broadcasting using satellite is imminent.

Hereinafter, an example of the conventional paid subtitle broadcast transmitting / receiving apparatus described above will be described with reference to the drawings.

FIG. 2 is a block diagram showing a configuration of a conventional paid subtitle broadcast transmitting / receiving apparatus. In FIG. 2, reference numeral 1 denotes a television signal transmitting device. 2 is a video signal. Reference numeral 3 denotes a video scrambler for scrambling the video signal 2. 4
Is an audio signal. Reference numeral 5 denotes an audio signal scrambler for scrambling the audio signal 4. Reference numeral 6 denotes a pseudo-random number generator. Reference numeral 7 denotes an audio pseudo-random number sequence for scrambling the audio signal 4 among the pseudo-random number sequences generated by the pseudo-random number generation unit 6. Reference numeral 8 denotes a video pseudo-random number sequence for scrambling the video signal 2 out of the pseudo-random number sequence generated by the pseudo-random number generation unit 6. Reference numeral 9 denotes related information for obtaining the original video signal and the original audio signal on the receiving side. 10 is related information 9
Is an encrypting unit for encrypting. 11 is encrypted related information. Reference numeral 12 denotes key information for encrypting the related information 9.
Reference numeral 13 denotes an audio signal scrambled by the audio scrambler 5. Reference numeral 14 denotes a video signal scrambled by the video scrambler 3. Reference numeral 15 denotes a multiplexing unit that multiplexes the scrambled audio signal 13 and the encrypted related information 11 on a transmission line. 16 is a multiplexed audio signal and related information. 17 is a transmission path. 35 is caption information. Reference numeral 36 denotes a character multiplex signal encoding unit that encodes the subtitle information 35 into a character multiplex signal format. 37 is a program number control for setting and controlling the program number in the character multiplexing of the subtitle information 35. 38 is a character multiplex signal. Reference numeral 39 denotes a superimposer for superimposing a character multiplexed signal 38 on the scrambled video signal 14.

Reference numeral 18 denotes a television signal receiving device. Reference numeral 40 denotes a signal separation unit that separates a video signal and a character multiplex signal. 41 is
These are scrambled video signals separated by the signal separation unit 40. Reference numeral 42 denotes a character multiplexed signal separated by the signal separating unit 40. Reference numeral 19 denotes a separation unit that separates the multiplexed audio signal and related information. 20 is a separated audio signal. Reference numeral 21 denotes separated related information. Reference numeral 22 denotes a decryption unit that decrypts the encryption of the separated related information 21. 23 is key information for decryption by the decryption unit 22. Numeral 24 is information corresponding to the contract condition in the decrypted related information. Numeral 25 is initial value information of the pseudo-random number generator among the decoded related information. Reference numeral 26 denotes a contract condition comparison unit that compares whether the contract conditions of the receiving device 18 match the received contract conditions.
Reference numeral 27 denotes a pseudo random number generator control signal for controlling the pseudo random number generator as a result of the comparison of the contract conditions. 28 is a pseudo random number generator. Numeral 29 denotes a pseudo-random number sequence for audio among the pseudo-random number sequence generated by the pseudo-random number generator 28. 30 is a pseudo-random number generator 28
Is a pseudo-random number sequence for video among the pseudo-random number sequences generated in. An audio descrambler 31 descrambles the received audio signal. Reference numeral 32 denotes a video descrambler that descrambles the received video signal. Reference numeral 33 denotes a descrambled video signal, which is equal to the original video signal 2. Reference numeral 34 denotes a descrambled audio signal, which is equal to the original audio signal 4. Reference numeral 43 denotes a character multiplexed signal decoding unit. Reference numeral 44 denotes a program selection unit for selecting a character multiplex program. 45 is
This is a program selection signal. 47 is a signal indicating the program attribute of the selected text multiplex program. Reference numeral 46 denotes a screen control unit for switching the screen and superimposing or controlling the character information in accordance with the program attribute signal 47. 48 is a screen control signal.
49 is character information. Reference numeral 50 denotes a switching unit that controls switching between the descrambled video signal 33 and the subtitle information 49 by the screen control signal 48. Reference numeral 51 denotes a video signal in which caption information is superimposed on a screen.

The operation of the pay caption broadcast transmitting / receiving apparatus configured as described above will be described below.

In pay broadcasting, only those who have subscribed properly can receive programs correctly, and non-subscribers cannot receive programs correctly. In order to realize this, it is necessary to scramble the video signal 2 and the audio signal 4 in the transmitting device 1 and descramble them in the receiving device 18. In order to descramble, information for the descrambling is required, and the information is related information 9. The related information 9 includes an initial value of the pseudorandom number generator 6 and contract conditions. The initial value is set in the pseudo-random number generator 6, and as a result, a pseudo-random number sequence is generated. The generated pseudo-random number sequence is divided into audio 7 and video 6. In the audio scrambler 5, for example, a scramble method of converting the audio signal 4 into PCM data and then adding the audio pseudo-random number sequence 7 to the PCM data is used. For the video, the video scrambler 3 converts the original video signal 2 into digital data and then uses the video pseudo-random number sequence 8 to perform, for example, a signal switching method within a scanning line or a scanning line transition order designating method for changing the order of scanning lines. By scrambling. The related information 9 is transmitted to the receiving side so that the scrambled video signal 14 and the scrambled audio signal 13 can be descrambled in the receiving side device 18. The data is encrypted in the encryption unit 10 of the transmitting device 1. For this encryption, key information 12 is used as a key. The encrypted related information 9 is multiplexed with the scrambled audio signal 13 and sent to the transmission path 17 as a multiplexed signal 16.

On the receiving side 18, the separating section 19 separates the scrambled audio signal 20 and the encrypted related information 21 from the multiplexed signal 16. The separated related information 21 is decrypted by the decryption unit 22 using the same key information 23 as the key information 12 of the transmission side device 1. The initial value 25 for the pseudo-random number generator 28 in the decoded related information is set in the pseudo-random number generator 28. Further, the contract condition of the decrypted related information is sent to the contract condition comparing unit 26, where the agreement with the contract condition of the receiving device 18 is compared. The pseudo-random number generator control signal 27 controls the pseudo-random number generator 28 to operate normally when it is determined that the subscriber is a contractor based on the result of the comparison. The random number generator 28 is controlled not to operate normally. In the case of the contractor, the pseudo-random number generator 28 generates a correct pseudo-random number sequence, which is composed of an audio pseudo-random number sequence 29 and a video pseudo-random number sequence.
Divided into 30. In the audio descrambler 31, the original PCM audio data is obtained by adding the audio pseudo-random number sequence 29 to the scrambled audio signal 20, and as a result of converting it into an analog signal, the same audio signal as the original audio signal 2 is obtained. A signal 34 is obtained. The video descrambler 32 performs a descrambling process using the video pseudo-random number sequence 30, and obtains the same video signal 33 as the original video signal 2.

Also, in pay broadcasting, as in the case of conventional broadcasting, a subtitle broadcasting service for the hearing impaired can be considered. In that case, in the transmitting side device 1, after the subtitle information 35 is encoded as a character multiplexed program in the character multiplexed signal encoding unit 36 and an appropriate program number is assigned in the program number control unit 37,
As in the current teletext broadcasting, there is a method in which the superimposing unit 39 superimposes the video signal on the vertical blanking period. In the receiving side device 18, the program selecting unit 44 is converted from the character multiplexed signal 42 separated by the separating unit 40.
The character multiplexed signal decoding unit 42 decodes the program selected in step 2 to obtain caption information 49. If the selected text information program is subtitle information, the screen control unit 46 superimposes the subtitle information on the original screen by a signal 47 indicating the attribute,
A screen control signal 48 is generated, and subtitle information 49 is superimposed on the video signal 33 descrambled by the switch 50.

However, in the above configuration, since the scrambled video and audio signals and the subtitle information program are completely unrelated, even non-subscribers can view only the subtitle information program. Have a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a pay subtitle broadcast transmission / reception device that allows only a pay broadcast subscriber to obtain subtitle information of the contract program.

Means for Solving the Problems To solve the above problems, a pay subtitle broadcast transmitting / receiving apparatus of the present invention comprises a scramble unit for scrambling a video signal on a television video signal transmitting side, and encoding subtitle information into a character multiplex signal. Character multiplexing signal encoding means, a character multiplexing signal obtained by the character multiplexing signal encoding means, which is superimposed on the video signal scrambled by the scrambling means, and which is sent to a first transmission path; Related information encrypting means for encrypting related information including a program number and a contract condition, multiplexing means for multiplexing the encrypted related information with another signal, and sending the multiplexed related information to a second transmission path; Program number control means for determining a program number of caption information in the character multiplexing signal encoding means according to the content of First separating means for separating the scrambled video signal and the character multiplexed coded subtitle information from the transmission line of the above, and descrambling means for the scrambled video signal separated by the first separating means Second separating means for separating the encrypted related information from the second transmission path, and related information decoding for decoding the encrypted related information separated by the second separating means. Means, a contract condition comparing means for comparing the content of the decrypted related information with a contract condition, and the decryption when the content of the decrypted related information matches the contract condition in the contract condition comparing means. A program selection unit for selecting a program of the subtitle information obtained from the first separation unit based on a program number of the subtitle information obtained from the obtained related information; Decoding means for decoding the subtitle information subjected to character multiplexing, screen control means for controlling a screen according to the contents of the character multiplexed program, and signal switching means for switching between the descrambled video signal and the character multiplexed screen. It is provided.

Operation According to the present invention, with the above-described configuration, the subtitle information is included in the related information, and only the subscriber can obtain the subtitle information on the receiving side.

Embodiment A pay subtitle broadcast transmitting / receiving apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a pay subtitle broadcast transmitting / receiving apparatus according to an embodiment of the present invention. In the figure, the transmission side apparatus 1 includes the program number of the subtitle information 35 in the related information 9. In the receiving device 18, 52 is a contract condition comparing unit 26.
This is a program number signal indicating the program number of the subtitle information 35 extracted from the program.

The operation of the pay caption broadcast transmitting / receiving apparatus configured as described above will be described below with reference to FIG.

First, in the transmitting device 1, the related information 9 is the subtitle information.
Includes 35 program numbers. Normally, the related information is updated about every one second to change the state of scrambling and to increase confidentiality. At that time, the program number of the subtitle information 35 is also changed each time. Then, the subtitle information is encoded into a character multiplexed signal format in the character multiplexed signal encoding unit 36. The character multiplexed signal 38 is superimposed by the superimposing device 39 on the vertical retrace period of the scrambled video signal. By doing so, the non-subscriber cannot correctly select the subtitle information.

On the receiving side, the demultiplexer 40 separates the character multiplexed signal. Further, after the related information 21 separated by the separation unit 19 is decoded by the decoding unit 22, if the contract conditions are matched by the contract condition comparison unit 26, the program number of the subtitle information 35 Is obtained from the related information, and the program number signal 52 controls the program selection unit 44, so that the subtitle information is decoded in the character multiplexed signal decoding 43, and the subtitle information signal 49 is obtained. The screen control unit 46 generates a screen control signal 48 for superimposing the subtitle information 49 on the descrambled video signal 33 on the screen, and controls the switch 50.

On the television video signal transmitting side, a scrambling means for scrambling the video signal, a character multiplexing signal coding means for coding caption information into a character multiplexing signal, and the character multiplexing signal coding on the video signal scrambled by the scrambling means. Superimposing means for superimposing the character multiplexed signal obtained by the encrypting means and sending the superimposed signal to the first transmission line; related information encrypting means for encrypting related information including the program number of the subtitle information and contract conditions; Multiplexing means for multiplexing the obtained related information with another signal and sending the multiplexed information to a second transmission path, and program number control for determining a program number of caption information in the character multiplexing signal coding means according to the content of the related information Means for separating the scrambled video signal and the character multiplexed encoded subtitle information from the first transmission path on the receiving side A first separating unit, a descrambling unit for the scrambled video signal separated by the first separating unit, and a second separating unit for separating the encrypted related information from the second transmission path. Separating means, related information decoding means for decoding the encrypted related information separated by the second separating means, and contract condition comparing means for comparing the contents of the decrypted related information with contract conditions And a program number of subtitle information obtained from the decrypted related information when the content of the decrypted related information matches the contract condition in the contract condition comparing means. A program selecting unit for selecting a program of the subtitle information, a decoding unit of the subtitle information multiplex-encoded by the first separating unit, and a screen according to the contents of the multiplexed program. Gosuru by providing a signal switching means for switching between the screen control unit the descrambled video signal and teletext screen, only subscribers can view the subtitle information of the contracted program.

As described above, according to the present invention, the program number is changed according to the related information including the contract conditions, and the related information is encrypted and transmitted. On the receiving side, after decrypting the encrypted related information, the program number can be obtained only when the contract conditions are met, and the subtitle information can be obtained from the text multiplex signal using the program number. Only the user can see the subtitle information of the subscribed program.

[Brief description of the drawings]

FIG. 1 is a block diagram of a pay subtitle broadcast transmitting / receiving apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional pay subtitle broadcast transmitting / receiving apparatus. 3 ... video scrambler, 9 ... related information, 10 ... encryption unit, 15 ... multiplexing unit, 19 ... separation unit, 22 ... decryption unit,
26 …… Contract condition comparison part, 32 …… Video descramble part,
36: character multiplex signal encoding unit, 37: program number control unit,
39 superimposing section, 40 separating section, 43 character multiplex signal decoding section, 44 program number selecting section, 46 screen controlling section, 50
Switcher.

Claims (1)

(57) [Claims] 1. A television video signal transmitting side, comprising: a scramble unit for scrambling a video signal; a character multiplex signal encoding unit for encoding subtitle information into a character multiplex signal; and a video signal scrambled by the scramble unit. Superimposing means for superimposing the character multiplexed signal obtained by the character multiplexed signal encoding means and sending the multiplexed signal to a first transmission line; and related information encryption means for encrypting related information including the program number of the subtitle information and contract conditions. Multiplexing means for multiplexing the encrypted related information with another signal and sending the multiplexed related information to a second transmission path; and arranging the program number of the subtitle information in the character multiplexed signal coding means according to the content of the related information. And a program number control means for determining, on the receiving side, the scrambled video signal from the first transmission path and the character multiplexed code. First separating means for separating the closed caption information, descrambling means for the scrambled video signal separated by the first separating means, and transmitting the encrypted related information from the second transmission path. Second separating means for separating; related information decrypting means for decrypting the encrypted related information separated by the second separating means; comparing the content of the decrypted related information with a contract condition. The contract condition comparing means, and the program number of subtitle information obtained from the decrypted related information when the content of the decrypted related information matches the contract condition in the contract condition comparing means. A program selecting unit for selecting a program of the subtitle information obtained from the separating unit; a decoding unit of the subtitle information multiplexed by character multiplexing separated by the first separating unit; Screen control means for controlling a screen in accordance with the contents of the set; and signal switching means for switching between the descrambled video signal and the character multiplexed screen. Are matched, the changed program number can be acquired, and the subtitle information can be continuously viewed.