RU2666521C2 - Multiple television programs images simultaneous displaying method - Google Patents

Abstract

FIELD: image processing means.SUBSTANCE: invention relates to the images transmission field for the multiple images simultaneous displaying on the television receiver screen. Technical result is achieved due to the fact, that, in contrast to the known satellite and cable digital television signals reception method, including the signals from the cable television network in the frequency range from 50 to 850 MHz supply and processing, as well as signals from the satellite communication channel receiving device in the frequency range of 1–2 GHz, signals for the given frequency band conversion to the intermediate frequency of 27/36 MHz, analog-to-digital conversion of signals, performing signals processing operations, reverse to the digital television system transmission part, including the signals demodulation, errors correction, descrambling of signals, the transport stream demultiplexing with the main TV program selection for its viewing, program stream demultiplexing by means of the elementary streams formation and the signals in MPEG-4 standard decoding for video and audio, video and audio signals digital-to-analog conversion, selected TV program images signals displaying on the TV receiver screen, in which, during the transport stream demultiplexing, further selecting the other TV programs image and sound signals from this packet program group, forming their elementary streams and performing further processing, signals in the MPEG-4 standard decoding for video and audio, video and audio signals digital-to-analog conversion, after which performing the several broadcast programs image signals displaying on the TV receiver screen in the “several pictures in picture” mode.EFFECT: technical result consists in providing the possibility to display the image signals of several TV programs from the group of programs of this package for their simultaneous viewing on the TV receiver screen in the “several pictures in picture” mode using one high-frequency signals converter (tuner).5 cl, 3 dwg

Description

The present invention relates to the field of image transmission and may find application in broadcast and applied television for the simultaneous display of several images on the screen of a television receiver for watching broadcast television programs or video surveillance and monitoring of objects using specialized television systems.

The introduction of methods and means of digital image signal processing in broadcast television makes it possible to widely use various algorithms and software, which ultimately allows you to expand the services provided by broadcasters of television (TV) programs. So, for example, the technology "picture in picture" ("picture in picture") provides for the display on the screen of the reproducing device of the image signals, usually two TV channels at the same time, with one of the programs displayed in full size, the second, smaller - displayed in one of the corners of the TV receiver screen.

TV receivers having a “picture in picture”, “picture out of picture” mode and so on are quite well known. For example, TV receivers having such features are described in US patents [1, 2]. Also known is a color TV receiver with a picture-in-picture mode [3], in which the rise in the frequency response of the video signal in the high frequency region for various types of input video signals is changed.

A TV receiver with a picture-in-picture mode is also known, characterized in that a non-linear signal processing processor for the luminance signal is introduced into it, which functions to stretch the signal in the black region to improve the distinguishability in low-brightness areas of the main image by applying high gain to low-signal signals level than to high-level signals, and connection means connected to a non-linear processing processor to prohibit non-linear processing during the time interval during which the second output is not The switch is connected to the picture-in-picture processor [4]. The TV receiver according to the invention comprises a signal source for generating the first and second video signals to be displayed on the receiver screen.

In recent years, there has been a tendency to record one TV program while watching another, or to record TV programs of your choice automatically in a predetermined scenario. The TV receiver is configured to receive signals representing TV programs and schedule data of television programs, and has a recording device containing a “hard disk” for recording received TV programs. The hard disk also allows you to record simultaneously two different TV programs received on different channels. For this, two tuners are used in the TV receiver [5].

The closest in the set of operations and technical features is a method and apparatus for receiving signals of satellite and cable digital television [6]. Digital TV programs can be received either by an integrated decoder or by a set-top box to a television. Regardless of whether the digital TV signal comes from the terrestrial radio-television transmitter, from satellite or cable, most of the functions of the receiving device remain the same in all cases.

Consider the principle of operation and technology for receiving digital TV programs. Common for receiving installations of satellite television in the range of 11 ... 12 GHz is a circuit with double frequency conversion. An individual microwave receiver of a digital satellite system contains a parabolic antenna with a diameter of 0.6-1.2 m behind the reflector of which an outdoor unit (converter) is located. The converter first converts the frequency of the signal received by the antenna in the frequency band 10.95-11.7 GHz or 11.7-12.5 GHz into a signal of the first intermediate frequency 0.95-1.75 GHz or 0.95-2 , 21 GHz [6]. After the first conversion, the received signal is amplified and transmitted through a coaxial cable to the input of the indoor unit - the receiver, which has a second frequency converter and an amplifier of the second intermediate frequency with a bandwidth of 27/36 MHz. The heterodyne of the second converter is tunable, with a step of 10 kHz. To do this, the digital receiver has a frequency synthesizer with a control unit.

In a digital decoder (TV set-top box), the reverse operations of the transmitting part of the digital television system are performed on the signal, namely:

- demodulation of quadrature phase shift keying and channel decoding;

- implementation of error correction and received data (Reed-Solomon code decoder);

- descrambling signals in accordance with the terms of access to TV programs;

- demultiplexing the transport data stream and the formation of elementary streams of video, sound and data;

- decoding signals according to the MPEG-2/4 standard, the formation of digital brightness signals, two color-difference signals, audio signals and signals of the teletext type;

- receiving analog video and sound signals.

Consider as an example the general structural diagram of a TV set-top box (Fig. 1). Such a device receives digital television signals over a cable line from a satellite dish and receiver. It carries out analog-to-digital and digital-to-analog signal processing and converts them into analog TV signals for supply to a conventional television receiver [6].

The TV set-top box has a high-frequency tuner, which has two inputs. A cable TV network line is connected to one of them (KTV). The frequency range of the signal at this input is from 50 to 850 MHz. The second input of the tuner (STV) receives a signal from the receiver of the satellite communication channel. This signal is transmitted at a carrier frequency in the range of 1-2 GHz, which is transferred to the converter located directly at the receiving antenna. When working with any of these inputs, the tuner allows you to select the desired television channel and transfers the signal from the carrier frequency of the selected channel to the intermediate frequency.

In the case of receiving cable television, the intermediate frequency (IF) signal from the tuner output is fed to the ADC. Further signal processing is performed digitally. In the next block, the quadrature amplitude manipulation (with 4, 16, 32, 64, or 256 possible states) is demodulated.

In the case of receiving satellite television, the signal from the tuner output is sent to a unit in which demodulation of quadrature phase shift keying (having 4, 16, 32, 64 or 256 possible states) and channel decoding are performed.

In both reception modes, the signals after demodulation and channel decoding are fed to the error corrector (Reed-Solomon decoder), in which error correction in the received data is performed. At the output of this block, an MPEG-4 transport stream is formed. Then, in the next block (Fig. 1), the operation of descrambling the signal is performed, that is, in accordance with the conditions of access to a specific TV program, data is decrypted. Next, demultiplexing the transport data stream. At the end of this process, a transport stream is formed that contains 188-byte multiplexed packets related to four or five different TV programs. Before image restoration, packets related to the selected program must be identified and placed in the necessary order, which characterizes the process of demultiplexing the transport stream and this happens in the transport demultiplexer. The transport demultiplexer receives an 8-bit transport stream at its input, containing video, audio or service information related to four or five different TV programs, presented in the form of 188-byte packets. Each packet contains a synchronization word for synchronization, a packet identifier, a program synchronization reference signal, and bits of video, audio, and service data.

Further, the use of the operation of demultiplexing the program stream allows you to get elementary streams of video data and sound in accordance with the standard data compression. The received elementary streams, after data multiplexing, are sent to the corresponding MPEG-4 decoders. In these blocks, synchronization is carried out according to the received time stamps of the built-in 27 MHz clock generator. Here, the complete decoding of image data, sound, additional text and graphic information in accordance with the main level of the MPEG-2/4 profile and the formation of digital output image signals (ICRC Recommendation 601) and sound accompaniment are carried out. Image data is output as digital luminance signals Y, color difference signals R-Y and B-Y in a 4: 2: 2 format of 8 bits per pixel. Next, digital signals are fed to the corresponding DACs.

After digital-to-analog signal conversion, it is planned to generate signals of various types - full signals of PAL or SECAM systems, as well as an S-video standard signal, when a luminance signal and a color signal are generated on the subcarrier. There is also a mode for outputting the luminance signal Y and the color difference signals R-Y (U) and B-Y (V) or signals of primary primary colors RGB. The choice of this or that type of signals is due to the presence of the corresponding inputs of the used TV receiver. The disadvantage of this method is the inability to provide the viewer with a picture-in-picture service or a few picture-in-picture service. The latter service provides for displaying on the TV receiver screen in large format (size) the images of the main TV program and in small format (size) of several images of other TV programs.

The presence of such a service allows you to watch TV programs of one channel and monitor the content of TV programs of other channels and, if necessary, use them for viewing as the main TV program, by replacing the display locations of TV programs of certain broadcast channels.

EFFECT: provision of the ability to display image signals of several TV programs from a group of programs of a given package for simultaneous viewing on a TV receiver screen in the "several picture-in-picture" mode.

The technical result is achieved in that, in contrast to the known method of receiving satellite and cable digital television signals, including the supply and processing of signals from a cable television network in the frequency range often from 50 to 850 MHz, as well as signals from the receiver of a satellite communication channel in the frequency range 1 -2 GHz, converting signals for a given frequency band to an intermediate frequency of 27/36 MHz, analog-to-digital signal conversion, performing signal processing operations that are inverse to the transmitting part of the digital system television, including signal demodulation, error correction, signal descrambling, transport demultiplexing with the choice of a TV program for viewing, demultiplexing a program stream by forming elementary streams and decoding them in MPEG-4 standard for video and sound, digital-to-analog signal conversion video and sound, displaying the video signals of the selected TV program on the screen of the TV receiver, in which, when the transport stream is demultiplexed, an additional signal The channels of images and sound of other TV programs from the program group of this package form their elementary streams and carry out further processing, decode the signals in the MPEG-4 standard for video and sound, digital-to-analog conversion of video and sound signals, and then display the video signals of several TVs programs on the screen of the TV receiver in the "multiple picture-in-picture" mode.

To achieve this goal, a method is proposed for simultaneously displaying images of several TV programs, including receiving signals from satellite and cable digital television, processing signals from a cable television network in the frequency range often from 50 to 850 MHz, as well as signals from a receiver of a satellite communication channel in the frequency range 1 -2 GHz, signal conversion for a given frequency band to an intermediate frequency of 27/36 MHz, analog-to-digital signal conversion, signal processing operations, reverse the transmitting part of a digital television system, including signal demodulation, error correction, signal descrambling, transport demultiplexing with the choice of a TV program for viewing, demultiplexing a program stream by forming elementary streams and decoding their signals in MPEG-4 standard for video and sound, digital analog conversion of video and sound signals, display of video signals of the selected TV program on the screen of the TV receiver, characterized in that when demultiplexing trans The mercury stream additionally extracts the image and sound signals of other TV programs from the program group of this package, forms their elementary streams and performs further processing, decoding the signals in the MPEG-4 standard for video and sound, digital-to-analog conversion of video and sound signals, and then carry out displaying image signals of several broadcast programs on the screen of the TV receiver in the "multiple picture-in-picture" mode.

In FIG. 2 presents a structural diagram of a TV set-top box that implements the proposed method. It includes: antenna 1, tuner 2, demodulator 3, signal descrambler 4, transport stream demultiplexer 5, program stream demultiplexer 6, switchboard distributor of program stream 7, program control block 8, block of video and sound decoders 9, image and sound generation block in the "multiple picture-in-picture" mode 10, the tuner control unit 11, the frame memory unit 12, the video and sound DAC unit 13, the TV receiver 14, the random access memory 15 (RAM), the read-only memory 16 (ROM), the user interface one 7, a remote control 18, a synchronization unit 19. The decoder unit 9 contains m-separate decoders for decoding MPEG-4 signals for video and sound.

The principle of operation of a TV set-top box is as follows. The radio frequency signal containing the TV program is fed to the antenna 1, the signal from which goes to tuner 2, where the carrier frequency is extracted from the entire spectrum of the signal and the operation is performed to lower the signal frequency to an intermediate frequency. The intermediate frequency signal is fed to the input of demodulator 3, where the signals are demodulated and converted into a serial digital stream of binary symbols, which is a transport stream (TP). If the TP has cryptographic protection, it is sent to the descrambler of signals 4. The descrambler performs decryptography, and if it is absent, leaves the TP unchanged. Next, the TP is fed to the demultiplexer of the transport stream 5, where the necessary information is selected, which contains the bit rate, number of channels, their location, etc. In the demultiplexer of program stream 6, video, sound, and service information, if present, are extracted directly in the selected programs. Since in TP all multimedia information, including video and sound, is transmitted in a sequential code, it is easily shared not only within the same program, but also between different programs. The control unit of the decoders 8 distributes the digital stream, presented in sequential form between different decoders, discretizing it at different time intervals. When the user selects only one TV program, using the remote control 18, through the user interface 17, only one decoder (for example, decoder 9 ₁ ) will be activated and the system will operate in normal mode, the signal from the output of the demultiplexer of program stream 6 is received through the switch- a distributor 7 at the input of the first decoder. In this case, the imaging unit 10 does not perform any operations. Block frame memory 12 contains all the information about the bit field of the image, which should be displayed on the screen. The DAC unit 13 converts the digital signal into an analog image signal for display on the TV receiver 14. When selecting several TV programs, the switch-distributor 7 distributes the program streams to separate decoders 9 ₁ , 9 ₂ , ...., 9 _m . For each decoder, separate memory areas are allocated in RAM 15. The TV image generation unit in the “multiple picture-in-picture” mode 10 generates a common TV image signal based on image signals received from individual decoders, the number of which can be equal to m, where 2 ≤m≤W. In the same block, the location and size of the windows for displaying additional other TV programs is determined, which is done by scaling and moving around the raster of the TV screen. The newly formed image is stored in the memory block 12 as a bit field, and then the image signals are read and fed to the input of the TV receiver 14 through the DAC unit 13. Rules and conditions for selection, scenarios for the exchange of data flows between the blocks, as well as their sequence and priority are contained in the control unit 8. Also, the control unit 8 interacts with all the hardware-software units of the set-top box. The synchronization and joint work of the milestones of the blocks and units of the set-top box is carried out using clock and synchronizing pulses generated at the output of the side 19.

Initially, it is envisaged that sound is provided for the main selected TV program. If necessary, sound accompaniment can be selected for any other displayed TV program. To do this, a control signal is supplied to the corresponding decoder 9 _i , where the sound signal is decoded and its supply is provided through block 10 to the input of the DAC 13, and then to the input of the TV receiver 14.

In FIG. 3 shows a TV picture in the "multiple picture-in-picture" mode. Here, the initially selected TV program is displayed in large format, and the other three TV programs in small format, the location of which, for example, is selected on the right side of the TV frame field. The number, size and location of additional small-format programs on the TV receiver screen can be fixed or variable. Their adjustment is carried out using the remote control 18, through the program control unit 8.

Information sources

1. US patent No. 4890162. Published December 26, 1989

2. US Patent No. 4768083. Published August 30, 1988

3. RF patent №2107405. Color television receiver. Published March 20, 1998

4. RF patent No. 2129757. TV receiver. Published 04/27/1999

5. RF patent No. 2390965. The receiver of television signals. Published April 27, 2005

6. Zubarev Yu.B., Sagdullaev Yu.S., Sagdullaev T.Yu. Video information technology communication systems. M .: Publishing house "Sputnik +", 2011 - 296 p.

Claims (5)

1. A method for simultaneously displaying images of several television programs, including receiving signals from satellite and cable digital television, processing signals from a cable television network in the frequency range from 50 to 850 MHz, as well as signals from a receiver of a satellite communication channel in the frequency range of 1-2 GHz , converting signals for a given frequency band to an intermediate frequency of 27/36 MHz, analog-to-digital signal conversion, performing signal processing operations that are inverse to the transmitting part of the digital system television, including signal demodulation, error correction, signal descrambling, transport stream demultiplexing with a choice of television programs for viewing it, program stream demultiplexing by forming elementary streams and their decoding of signals in MPEG-4 standard for video and sound, digital-to-analog signal conversion video and sound, the display of image signals of the selected TV program on the screen of the TV receiver, characterized in that when transport demultiplexing additionally extract the image and sound signals of other TV programs from the program group of the given transport stream, form their elementary streams and carry out further processing, decode the signals in the MPEG-4 standard for video and sound, digital-to-analog conversion of video and sound signals, and then carry out displaying image signals of several broadcast programs on the screen of the TV receiver in the "multiple picture-in-picture" mode. 2. The method according to claim 1, characterized in that the number of displayed broadcast programs on the screen of the TV receiver in the "multiple picture-in-picture" mode can be m≥2. 3. The method according to claim 1, characterized in that the location and size of the images of additional TV programs on the screen of the TV receiver have a fixed value on the frame field of the entire TV image. 4. The method according to claim 3, characterized in that the location and image size of additional TV programs on the screen of the TV receiver can vary across the frame field of the entire TV image. 5. The method according to claim 3, characterized in that sound can be provided for any of the displayed TV programs on the screen of the TV receiver in the "multiple picture-in-picture" mode.

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