KR20070002722A - Apparatus and method for reducing zapping time in digital broadcasting with mosaic epg system - Google Patents

Abstract

An apparatus and a method for reducing channel changing time of a digital broadcasting in a mosaic EPG(Electronic Program Guide) system are provided to display a mosaic EPG image with low resolution during the channel change processing time. When a conversion event to a mosaic EPG mode is generated in order to search a channel(S410), a digital broadcasting receiving system provides a mosaic image on a TV screen. When a user moves a cursor to one of plural sub pictures(S420), the video/audio signals are outputted from the channel corresponding to the sub picture(S430). When a desired channel is discovered, the corresponding channel is selected(S440). Whenever the channel is changed by the cursor, the video/audio signals are outputted.

Description

Apparatus and Method for Reducing Zapping Time in Digital Broadcasting With Mosaic EPG System}

1 is a block diagram of a digital broadcasting system to which a mosaic EPG is applied.

2 is a block diagram of a digital broadcast receiving system according to the present invention;

3 shows a TV screen change when channel switching is selected according to the present invention.

4 is a flowchart illustrating an operation flow in a digital broadcast reception system during channel switching according to the present invention.

* Description of the symbols for the main parts of the drawings *

111: Mosaic Screen Generator 112: Mosaic Information Generator

200: digital broadcast receiving system

210: tuner 220: demodulator

230: demultiplexer 240: MPEG decoder

250: graphics module 260: reception limit processing unit

270 control unit

The present invention relates to channel switching in digital broadcasting, and more particularly, to an apparatus and method for reducing digital broadcasting channel switching time in a mosaic EPG system for displaying a selected low quality image in a mosaic EPG screen during a channel switching time. It is about.

Digital broadcasting compresses program data for each channel with high efficiency based on the MPEG encoding standard, and multiplexes and transmits programs corresponding to a plurality of channels based on a digital modulation method for each transmission medium. Due to this characteristic, digital broadcasting can broadcast dozens or hundreds of channels without using a large amount of repeaters as in analog broadcasting. In other words, digital broadcasting has the advantage of eliminating the shortage of broadcasting channels by significantly improving the efficiency of frequency use compared to analog broadcasting.

In addition, the plural use of professional pay broadcasting and interactive service broadcasting software is enabled, which has the advantage of securing the opportunity for the broadcasting industry to develop into the composite media industry.

For these reasons, digital broadcasting is being expanded to cable and terrestrial broadcasting, including satellite broadcasting, and is emerging as a next generation broadcasting technology.

Despite the many advantages of digital broadcasting, it has to be acknowledged that there are some disadvantages compared to analog broadcasting, one of which is channel switching (or zapping) time.

Channel switching time refers to the time taken from the time of zapping to the complete zapping. In analog broadcasting, there is little channel switching time, whereas in digital broadcasting, a channel switching time of 1 to 2 seconds occurs. It's about a second or two, but it can be a big complaint for viewers familiar with analog broadcasts.

Channel switching time occurs regardless of digital cable, terrestrial or satellite broadcasting. Especially, digital cable broadcasting is known to have a weaker channel switching time than other broadcasting media.

The main causes of current channel switching time include command processing, network delay, STB layer delay, STB jitter buffer delay, and MPEG decoders. The time can be mentioned. Among them, the delay time in the conditional access system and process for content protection is high.

On the other hand, such a channel switching time is a phenomenon that appears even when providing a channel guide to the user using the mosaic EPG system.

The Mosaic EPG (Mosaic Electronic Program Guide) system collects and reconstructs the low-quality images required for the composition of a mosaic-type multi-picture screen for each channel at the headend, reconstructs them into one video and audio signal, and transmits them. Display the mosaic EPG. That is, the mosaic EPG service displays a variety of images broadcast on multiple screens on one screen, unlike the conventional EPG, which is provided in text format for easier searching and selection of various broadcasting channels. Provides the ability to select a channel.

1 shows a block configuration of a digital broadcasting system to which a mosaic EPG is applied.

The transmission system 110 for mosaic EPG includes a mosaic screen generator 111, an encoder 113, a mux and modulator 114, and a mosaic information generator 112.

The mosaic EPG screen generator 111 generates a mosaic EPG image in which several broadcast programs provided through various channels are represented by several sub-pictures of a small size in one screen. The generated EPG image is encoded by the encoder 113 into an MPEG data signal suitable for digital broadcasting. The encoded MPEG data signal is output to the mux / modulator 114. The mux / modulator 114 muxes and modulates not only the MPEG data signal but also a signal relating to mosaic information input from the mosaic information generator 112. modulate). Through the transmission system 110, the broadcast signal that has undergone the above encoding, muxing, and modulation process is transmitted in the form of a terrestrial wave or a cable signal.

The digital broadcast reception system 120 receiving the signal transmitted from the transmission system 110 searches for and receives mosaic information provided through the mosaic EPG service for one selected sub-picture among mosaic EPG images for various broadcast channels. For reference, after selecting a broadcast service provided by a corresponding program, an output is displayed as a main screen on the screen of the digital TV 121.

On the other hand, Figure 1 is mainly shown the case using the terrestrial wave and cable, when using a satellite, an antenna, an up-linker (Up-Linker) for transmitting and receiving a signal through a broadcast satellite is further required.

As described above, the system to which the mosaic EPG is applied serves only to help the user to select a channel more easily by providing channel guides for various broadcasts in detail and in detail by using images. Therefore, channel selection time is required and channel switching time is required to switch to the corresponding channel, as is the case of the digital broadcasting system to which the mosaic EPG system is applied.

For this reason, there is a need for an efficient method of reducing channel switching time in a digital broadcasting system supporting mosaic EPG.

In order to solve the above problems, an apparatus and method for reducing digital broadcast channel switching time in a mosaic EPG system for providing a user with a mosaic EPG channel for a time required to restore a high quality original image for channel switching. The purpose is to provide.

According to an aspect of the present invention, there is provided a method for reducing a digital broadcast channel switching time in a mosaic EPG system, wherein the mosaic EPG channel selected by a user for channel switching is enlarged and displayed. A low quality image display step of performing decoding; And displaying a high quality image to display a decoded high quality original image when the decoding is completed.

The displaying of the low quality image may further include performing tuning, demodulation, and demultiplexing on the selected channel.

The magnification of the mosaic EPG channel selected in the low quality image display step is optimized in consideration of the image quality experienced by the user. The magnification of the mosaic EPG channel may also be adjusted to be displayed on the full screen.

The digital broadcasting channel switching time reduction method may further include a user switching to a mosaic EPG mode for channel selection.

The apparatus for reducing digital broadcast channel switching time in a mosaic EPG system according to another aspect of the present invention may enlarge and display a mosaic EPG channel selected by a user for channel switching, perform decoding on the selected channel, and When the decoding is completed, the control unit for displaying the decoded high quality original image.

The apparatus for reducing digital broadcast channel switching time in the mosaic EPG system may further include a decoder for decoding the selected EPG channel under the control of the controller.

The apparatus may further include a graphic module configured to display the mosaic EPG channel and the restored original image according to a command of the controller.

According to another aspect of the present invention, a digital broadcast reception system includes a display of an enlarged mosaic EPG channel selected by a user for channel switching, performing decoding on the selected channel, and upon completion of decoding, Display the original image.

The system is capable of simultaneous processing of image recovery processing for the mosaic EPG channel and the switch selected channel.

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the drawings.

2 shows a block configuration of a digital broadcast reception system according to the present invention.

In Figure 2 is shown mainly to play a major role in the practice of the present invention, in addition to the various functional blocks may be added.

The digital broadcast reception system includes a tuner 110 for tuning a desired channel from a broadcast signal received in an analog form, and a demodulator 120 for demodulating the tuned analog signal into a digital signal. The demodulator 120 transmits the reception restriction related data, that is, the key information and the viewing authority information for each program, to the reception restriction processing unit 160.

When the subscriber selects a program channel, the conditional access system (CAS) 160 checks whether the subscriber has the right to view the corresponding program channel according to the viewing right information for each program, In this case, the encrypted broadcast data is descrambled according to the key information.

The demultiplexer 130, which has received the decoded signal through the reception limit processing unit 160, demultiplexes the broadcast data converted into the digital signal form and converts the broadcast data into the MPEG type broadcast data. At this time, video data of the broadcast data output from the demultiplexer 130 is in the MPEG 2 form, and audio data is in the MPEG 1 form.

The MPEG decoder 140 decompresses the data output from the demultiplexer 130 into a broadcast signal by decompressing it according to the MPEG method, and the graphic module 150 manipulates the converted broadcast signal to be displayed on a digital TV. . The manipulated broadcast signal is converted into an analog signal form by an encoder (not shown) and transmitted to the digital TV.

The controller 170 controls the graphics module 150 to enlarge and display one sub-picture selected by the user among a plurality of low-quality sub-pictures displayed on one screen, and to perform decoding on the selected channel. Control 140.

Here, in the digital broadcast reception system 200 according to the present invention, modules for image restoration such as tuner 210, reception limiter 260, MPEG decoder 240, which are components thereof, are basically selected as a mosaic EPG channel and a transition is selected. It is assumed that simultaneous processing for the channel is possible.

Meanwhile, the digital broadcast reception system may further include a network interface for a function of receiving guide information of a program through a network in addition to the above components. In FIG. 1, only the main role of the present invention is illustrated, and various additional function blocks may be added in addition to those illustrated.

3 shows a TV screen change when channel switching is selected according to the present invention.

As shown in FIG. 3, through a digital broadcasting system provided with a mosaic EPG, a user may check a program being broadcast in various channels in the form of a mosaic EPG on one screen. The number of channels displayed on one screen is variable, which can be changed through the mosaic EPG screen generator and the mosaic EPG information generator in the digital broadcast transmission system described in FIG.

The data constituting the mosaic screen includes information on the number of mosaic channels, the size and position of each screen element in each mosaic, the desired size of the frame cursor, and the movement range of the frame cursor. This data may also include the location (page number and coordinates) of each channel in the mosaic, the PID of the associated soundtrack in the combined audio signal and the channel reference information in the pilot data.

To this end, the digital broadcasting transmission system may provide various pieces of information necessary for switching to a broadcast service corresponding to each sub-picture, that is, various additional information such as service name, service ID, network ID, and RF frequency. Provide in conjunction with.

In the case of FIG. 3, a total of six sub-pictures are displayed on one screen, and the user has selected a third sub-picture. As such, when the user selects one sub-picture by clicking a selection button on the remote controller, the digital broadcasting reception system searches for and refers to mosaic information provided through the mosaic EPG service and provides a program corresponding to the sub-picture. After tuning a broadcast service signal, displaying a program received through the signal is a procedure in the case of using a normal EPG service.

At this time, the broadcast signal selected and tuned by the user must go through demodulation, demultiplexing, MPEG decoding through blocks as shown in FIG. 2, and it takes a certain time to pass through all of these processes. In this case, the user is bored because the time required for channel switching is so large that it cannot be ignored.

Accordingly, in the present invention, while performing tuning, demodulation, demultiplexing, MPEG decoding, and the like on the selected broadcast signal, a small size low quality image provided as an EPG screen is enlarged and provided to the user as it is. Only when the process (tuning, demodulation, demultiplexing, MPEG decoding, etc.) is completed, the original image of the high-quality restored image is displayed on the screen. In the case of mosaic EPG, which displays multiple channels in a mosaic form on one screen, the data allocated to one channel is limited, so that it can be provided as a low quality image, but only during the time required to restore a high quality original image. The purpose is to help resolve the dissatisfaction of viewers by using low quality video.

In temporarily displaying a low quality screen, the size of the screen should be displayed larger than the original size in the mosaic EPG, but it is not necessary to enlarge and display the entire screen, and the user may feel that the enlarged screen quality is good. Finding the right size and displaying it is a better way.

4 is a flowchart illustrating an operation flow of a digital broadcast reception system during channel switching according to the present invention.

When the user generates a switching event to the mosaic EPG mode for channel search while watching TV (S410), the digital broadcasting reception system 200 provides a mosaic image as shown in FIG. 3 on the TV screen. When the user moves the cursor to one sub-picture among a plurality of sub-pictures (S420), a video / audio signal of a program being broadcast is output on a channel corresponding to the sub-picture where the cursor is located (S430).

When the user moves the cursor to search for a channel and finds a desired channel, the user selects a corresponding channel (S440). If the user does not like the channel where the cursor is located, the user continues to move the cursor (S441) and searches for the channel. Whenever the channel where the cursor is located is changed, the video / audio signal for the program being broadcast on the corresponding channel is output. (S430).

If the channel the user wishes to switch to is selected, for example, a channel switching event may be triggered by pressing a button that determines the channel selection, such as 'OK' or 'OK' on the remote control to watch the mosaic EPG channel where the cursor is located. When generated, the low quality image on the mosaic EPG where the cursor is located is enlarged and displayed on the TV screen. At the same time, the selected channel is decoded (S450). As mentioned above, in the enlarged display of a low quality image, the corresponding channel may be enlarged so as to appear on the entire screen, but it is more preferable to adjust the size to an appropriately optimized size in consideration of the degree of image quality felt by the user. Will do.

While decoding is performed, the viewer can watch the selected channel although it is a low quality image, and when the decoding operation for the corresponding channel is completed (S460), the decoded high quality original image is displayed in full screen (S470).

As described above, the present invention provides a method for more efficiently reducing the channel switching time experienced by the user in the digital broadcasting system to which the mosaic EPG system is applied.

The present invention has the advantage of eliminating the boredom that the user feels during the channel switching time by providing the viewer with a low quality mosaic EPG image for the time required for processing for channel switching.

Claims (12)

In the channel switching time reduction method of the digital broadcasting system to which Mosaic EPG (Mosaic Electronic Program Guide) is applied, A low quality image display step of enlarging and displaying a mosaic EPG channel selected by a user for channel switching, and performing decoding on the selected channel; Wow And a high quality image display step of displaying a decoded high quality original image when the decoding is completed. The method of claim 1, The low quality image display step, And performing tuning, demodulation, and demultiplexing on the selected channel. The method of claim 1, The enlarged size of the mosaic EPG channel selected in the low quality image display step is optimized in consideration of the image quality experienced by the user. The method of claim 1, A method for reducing digital broadcast channel switching time in a mosaic EPG system, further comprising the user switching to mosaic EPG mode for channel selection. In the apparatus for reducing the channel switching time of a digital broadcasting system to which a mosaic EPG is applied, A mosaic EPG system including a control unit configured to enlarge and display a mosaic EPG channel selected by a user for channel switching, perform decoding on the selected channel, and display a decoded high quality original image when the decoding is completed Digital broadcast channel switching time reduction device in. The method of claim 5, The enlarged size of the mosaic EPG channel is optimized in consideration of the image quality experienced by the user. The method of claim 5, The enlarged size of the mosaic EPG channel is adjusted to be displayed on the entire screen, the apparatus for reducing digital broadcast channel switching time in the mosaic EPG system. The method of claim 5, And a decoder for decoding the selected EPG channel under the control of the controller. The method of claim 5, And a graphic module for displaying the mosaic EPG channel and the restored original image according to a command of the controller. In a digital broadcast receiving system connected to a digital TV, A digital broadcast reception system for enlarging and displaying a mosaic EPG channel selected by a user for channel switching, performing decoding on the selected channel, and displaying a decoded high quality original image when the decoding is completed. The method of claim 10, And digital image recovery processing for the mosaic EPG channel and the switched selected channel. The method of claim 10, The enlarged size of the mosaic EPG channel is optimized in consideration of the image quality experienced by the user.

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