KR20060015075A - Digital broadcasting receiver and method for searching video information of other channel - Google Patents

Abstract

The present invention relates to an apparatus and a method for enabling retrieval of video information of another channel by using a thumbnail in a digital broadcast receiver. In particular, when the user watches a particular channel broadcast through the main screen, the thumbnail information of the video information for at least one program being broadcast on another channel through the sub-screen without interrupting the viewing of the broadcast displayed on the main screen You can browse at the same time, you can scroll search using a remote control. In addition, by using a thumbnail image as video information of a program being broadcast in another channel, it is possible to minimize the additional burden of hardware for decoding the video data of another channel.

Sub picture, thumbnail video, other channel

Description

Digital broadcasting receiver and method for searching video information of other channel

1 is a block diagram illustrating a digital broadcast receiver according to the present invention.

2 is a flowchart illustrating an embodiment of a decoding / displaying process of a main / subchannel according to the present invention.

3 is a flowchart illustrating an embodiment of a process of generating a thumbnail image for outputting a sub-screen according to the present invention.

4A to 4C illustrate examples of display configurations of a main / subscreen according to the present invention.

Explanation of symbols for main parts of the drawings

101, 104: tuner 102, 105: channel demodulator

103: Demultiplexer 106: Multi Video Decoder

107: thumbnail generation unit 108: display processing unit

The present invention relates to a digital broadcast receiver and a method for retrieving video information of another channel in a digital broadcast receiver. In particular, the present invention relates to an apparatus and a method for enabling retrieval of video information of another channel by using a thumbnail in a digital broadcast receiver.

With the rapid development of digital broadcasting technology and the diversification of services, digital TVs and set-top boxes are more effective and differentiated to accommodate the changing environment and the increasing demands of users in addition to the basic functions of receiving digital broadcasting. This is necessary.

 One such function is to provide a function of effectively viewing information of another channel while fixing a channel currently being viewed.

Representative methods for expressing other channel information in the conventional method include a PIP (Picture In Picture) function and an EPG (Electronic Program Guide) display function. To implement such a function, two receivers are built in, and one receiver is used to receive information broadcast on a channel currently being viewed. After receiving the information broadcasted on the other channel by using the other receiver, the video information of the other channel is shown in the PIP form or the EPG information of the program broadcasted on the other channel is sequentially displayed by using the OSD function. have.

However, in the conventional method, there is a disadvantage in that it is not possible to provide an effective function for displaying the visual information of programs broadcast on a plurality of channels at once when expressing other channel information.

In addition, the conventional method provides a plurality of other channel information in the form of characters such as a broadcast schedule. However, the method of providing other channel broadcasting information in the form of a character has a disadvantage in that it does not provide visual information of the corresponding program.

In addition, the method of providing visual information using the PIP is also inefficient when considering the trend of the rapidly developing broadcast receiving environment. That is, a method of providing one channel information at a time by using one PIP screen in order to show video information of another channel takes too much time to search for a desired program in a number of channels.

In order to solve this problem, programs that are being broadcast on other channels may be displayed through several PIP screens. However, if a plurality of PIPs are used to simultaneously display the screens of several channels using the conventional method, there is a significant hardware burden since the tuner must be secured as many as the number of channels to be displayed.

 Accordingly, in order to solve such a conventional problem and to implement a channel search function suitable for a rapidly changing broadcasting environment, an effective method for minimizing additional burden on hardware and simultaneously displaying video information of multiple channels is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to currently watch video information of a program being broadcast in another channel through one or several sub-screens while minimizing additional hardware burden in the digital broadcasting receiver. An apparatus and method for simultaneously listening to a channel is provided.

Another object of the present invention is to provide an apparatus and method for providing a user with video information on at least one program being broadcast on another channel in the form of thumbnails.

It is still another object of the present invention to provide video information on a sub-screen in the form of thumbnails on at least one program being broadcast on another channel without interrupting viewing of the corresponding program in the course of playing a broadcast or playing a recorded broadcast. And providing a method.

According to an aspect of the present invention, there is provided a digital broadcast receiver comprising: a first tuner and a demodulator for tuning and demodulating a broadcast signal of a main channel to be displayed on a main screen and outputting the transport signal in a transport form; A second tuner and a demodulator for tuning and demodulating a broadcast signal of a sub-channel to be displayed on a sub-screen and outputting it in a transport form; A demultiplexer for separating the video stream from the transport streams of the main and subchannels output from the first and second tuners and the demodulator; A video decoder for performing a complete video decoding on all video streams if the video stream separated by the demultiplexer is for a main picture, and decoding only DC coefficients for a sub picture; A thumbnail generator configured to generate and store a thumbnail image for all subchannels using DC coefficients of the subchannel decoded by the video decoder; And a display processor configured to display a plurality of thumbnail images generated and stored by a thumbnail generator in a main screen on a main screen, and the video of the main channel decoded by the video decoder according to a preset main / subscreen configuration. It is characterized in that the configuration.

The thumbnail generator may sequentially store all the thumbnail images in a predetermined order for all channels when thumbnail image generation for one subchannel is completed.

In the digital broadcast receiver according to the present invention, a video information retrieval method of another channel is provided.

(a) performing full video decoding on all video streams if the incoming video stream is for main picture;

(b) decoding only DC coefficients of an I picture if the input video stream is for a sub picture;

(c) generating and storing a thumbnail image using the DC coefficients of the I picture of step (b); And

and (d) displaying the video of the main screen decoded in step (a) and the thumbnail image generated in step (c) according to the preset main / sub picture configuration. do.

In the step (c), when the generation of the thumbnail image for one subchannel is completed, the process of storing the thumbnail image is sequentially performed for all channels in a predetermined order.

In the step (c), when the generation of a thumbnail image for one subchannel is completed, a process of sequentially storing all the thumbnail images for all channels in a predetermined order is performed periodically to perform thumbnails of each subchannel. The image is periodically updated.

The step (c) further includes determining whether the thumbnail image is valid for representing the video information of the subchannel when the thumbnail image generation for one subchannel is completed.

The step (c) is a step of generating and storing thumbnail images sequentially for all channels in a preset order in a standby mode in which the user does not watch TV, and a plurality of stored thumbnail images as soon as the user turns on the TV. And simultaneously displaying the above-described sub-screen.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, with reference to the accompanying drawings illustrating the configuration and operation of the embodiment of the present invention, the configuration and operation of the present invention shown in the drawings and described by it will be described as at least one embodiment, By the technical spirit of the present invention described above and its core configuration and operation is not limited.

The present invention is characterized by displaying video information of a program being broadcast on another channel as a thumbnail image.                     

1 is a block diagram of a digital broadcast receiver according to the present invention, wherein the first and second channel demodulators 102 and 105 demodulate the broadcast signals tuned by the first and second tuners 101 and 104 and the respective tuners 101 and 104, respectively. ) Is provided. The outputs of the first and second channel demodulators 102 and 105 are output to the demultiplexer 105.

The first and second tuners 101 and 104 tune broadcast signals of a specific channel, and the first and second channel demodulators 102 and 105 demodulate the tuned broadcast signals in reverse of a modulation scheme and demultiplexer in a transport stream form. Output to (103). For example, if the modulation scheme on the transmitting side is the VSB scheme, VSB demodulation. If the QPSK scheme, the QPSK demodulation is performed. In the present invention, the first tuner 101 tunes the main picture broadcast signal, and the second tuner 104 tunes the sub picture broadcast signal. This is one embodiment, and according to the designer, the first tuner 101 may tune the sub picture broadcast signal, and the second tuner 104 may tune the main picture broadcast signal.

The demultiplexer 103 separates an elementary stream such as video / audio / EPG from a transport stream output from the first and second channel demodulators 102 and 105. The video decoder 106 decodes the video ES separated by the demultiplexer 103 into the inverse of the video compression process, and outputs video data for the main picture to the display processor 108, and the DC coefficient for the sub picture is the thumbnail generator 107. ) That is, the video decoder 106 performs a complete video decoding when the input video stream is for the main picture and outputs it to the display processing unit 108. In the case of the sub picture, the video decoder 106 decodes only the DC coefficient of the I picture to generate the thumbnail. Will output                     

The thumbnail generator 107 generates a thumbnail image by using the DC coefficient and outputs the thumbnail image to the display processor 108. The output of the display processor 108 includes a main screen on which a video / EPG of a program broadcast on a channel currently being viewed and at least one subscreen on which a video / EPG of a program broadcasting on another channel is output.

In FIG. 1, the decoding process of the broadcast stream for the main picture output and the driving process of the display apparatus follow a general digital TV reception and output method, and thus are not described in the present invention. In the present invention, it is assumed that the first tuner and the channel demodulators 101 and 102 tune and demodulate the broadcast signal of the main picture.

It is also assumed that the second tuner and the channel demodulators 104 and 105 tune and demodulate the broadcast signals of other channels. That is, the video information of the other channel is output through the sub picture in the form of a thumbnail, and for this purpose, the second tuner 104, the second channel demodulator 105, the demultiplexer 103, the video decoder 106, and the thumbnail generator ( 107).

In addition, in FIG. 1, the demultiplexer 103 and the multi video decoder 106 assume that two streams can be processed at the same time. In other words, it is assumed that the demultiplexer 103 is implemented to enable video / audio / EPG separation for two transport streams at the same time through an algorithm such as a combination of two independent demultiplexers or an appropriate time division. The video decoder 106 also implements the decoding of two video streams at the same time. At this time, the video stream for output to the main picture should be able to decode in full form, and the video stream for output to the sub picture may be simplified to decode only the DC coefficient of the I picture.

Therefore, the multi-video decoder 106 of FIG. 1 is composed of one video decoder and one DC coefficient decoder.

The reason for simplifying the DC coefficient decoder is that an image necessary for outputting a sub picture is composed of thumbnails, and such a thumbnail image can be sufficiently implemented by only DC coefficients of I pictures of a video stream. That is, in order to completely decode all the actual video, it is necessary to decode DC coefficients, AC coefficients, motion vectors, and the like, and then convert the size of the reconstructed frame in order to properly display the sub-pictures. However, when generating a thumbnail image using the DC coefficient, only the DC value is decoded, so that an image necessary for sub-screen output can be more easily obtained.

In addition, since it does not require the parts necessary for decoding AC coefficients and motion vectors and converting the size of the image, a thumbnail image corresponding to 1/64 of the original image can be generated in a relatively simple method while greatly reducing the hardware burden. There is an advantage.

Accordingly, in the present invention, if a thumbnail is generated by decoding only the DC coefficient of an I picture for each channel, an image to be displayed on all subchannels can be obtained more simply and quickly.

A detailed description of the thumbnail generator 107 will be described later.

On the other hand, the display processor 108 in charge of the final video output is responsible for properly controlling the main / sub-screen image input from the video decoder 106 and the thumbnail generator 107 to be divided into the main screen and the sub-screen and outputs it. In charge.

2 is a flowchart illustrating a video decoding and display output process for searching video information of another channel according to the present invention.

In the present invention, for convenience of description, a channel currently being viewed through the main screen is called a main channel, and a channel displayed on the sub screen as a thumbnail image is called a subchannel.

In FIG. 2, it is determined whether the video stream currently being input is output to the main screen or sub-screen (step 201). In the case of the video stream of the channel currently being watched, that is, the video stream of the main channel, the video decoder 106 completely decodes all video data (step 202). Each decoded video frame is output to the display processor 108 (step 203).

On the other hand, if the input video stream is a sub-channel video stream, the video decoder 106 decodes only the DC coefficient of the I picture and outputs it to the thumbnail generator 107 (step 204). The thumbnail generator 107 generates a thumbnail image using the DC coefficient, outputs the thumbnail image to the display processor 108, and simultaneously stores the thumbnail image (step 205).

In other words, the video data of the subchannel for the sub picture output is decoded in the video decoder 106 only for the I pictures except for the P or B pictures, but only the DC coefficients are decoded without decoding all the coefficients of each block. The thumbnail generator 107 generates one thumbnail image for each I picture by using the DC coefficients of the I pictures output from the video decoder 106. That is, since one pixel is extracted per 8x8 block of the original image, the thumbnail image has a size of 1/8 of the original image and a size of 1/64 of the original image, respectively.

When the thumbnail image generation on one subchannel is completed, the image is stored in an accessible volatile or nonvolatile memory so that the video information of the subchannel can be output when requested by the user.

In this case, in the process of storing the thumbnail image, additional information is required to enable proper mapping with a corresponding channel. The additional information is largely composed of channel information and connection information of the corresponding thumbnail image. At this time, the channel information is obtained using the EPG data.

When the generation and storage of the thumbnail image in one subchannel is completed, another subchannel is received through appropriate control of the second tuner 104, and the above process is repeated to display a thumbnail image for a program broadcast in another channel. To be created (step 207). As a result, the thumbnail image is sequentially generated for all video channels by controlling the second tuner 104 for all channels.

The thumbnail image stored through the above-described process may be output to a part of the main screen according to the main / subscreen configuration set in the display processor 108 when the user wants to access video information of another channel through the subscreen. (Step 206).

In this case, the video information displayed on the sub screen may match the video information displayed on the main screen. For example, while watching the news being broadcast on channel 11 as the main screen, you can view a thumbnail image of the news broadcasting on channel 11 as the sub screen.

In the present invention, the thumbnail generation operation is continuously performed sequentially in a predetermined channel order, so that video information of each channel can be continuously updated.

3 is a flowchart illustrating a process of generating a thumbnail image for retrieving video information of another channel according to the present invention.

That is, when video data for outputting the sub-picture is input (step 301), the video decoder 106 first determines the picture type of the corresponding video frame (step 302). If it is a P or B picture, it is ignored, and if it is an I picture, the DC coefficient is decoded and output to the thumbnail generator 107 (step 303). The thumbnail generation unit 107 generates a thumbnail image by using a method of temporarily storing sequentially input DC coefficients in an internal FIFO or the like and then transmitting them to a volatile or nonvolatile memory of the system in a predetermined unit (step 304). In this case, the volatile memory may use a system such as SDRAM or DDR of the system, and the nonvolatile memory may use a ROM or a hard disk.

The validity of the thumbnail generated in step 304 may be checked to determine whether the thumbnail is appropriate for representing video information of the corresponding subchannel (step 305). For this purpose, blank image detection is performed. Since the blank image detection method may use a known technique, detailed description thereof will be omitted.

If it is determined in step 305 that the thumbnail image is valid through the blank image detection method, the thumbnail image is output to the storage and display processor 108. If it is determined in step 305 that the thumbnail image is not valid, the method may be repeated until a valid thumbnail is generated for the corresponding subchannel. Alternatively, when the effective thumbnail image is not generated by repeating the process for a limited number of times, the method may move to the next subchannel and then generate the thumbnail image again when the subchannel returns.

In general, in an MPEG-based broadcast video stream, one I picture is included in one GOP (Group Of Pictue), and the GOP is composed of 15 frames. Therefore, one thumbnail image may be generated at least every 0.5 seconds from a video stream composed of 30 frames per second. Therefore, the time required for generating the thumbnail image for each channel takes a maximum time of 0.5 seconds if there is no blank image. If it is assumed that the number of channels that can be received in a digital TV is M, it takes at least 0.5 x M seconds to prepare video information of all channels in a form that can be output.

 In order to prevent such a delay in advance, when a user does not watch TV, a function of generating thumbnail images for all channels periodically in a standby mode may be implemented. In this case, the user may search video information of other channels at once as soon as the TV is turned on. In addition, this method has a small hardware burden for generating thumbnails, and as a result, the power consumption required for driving the thumbnails is very small.

4 illustrates embodiments of a main / sub picture configuration for a main channel and a plurality of subchannels according to the present invention.

That is, FIG. 4A illustrates an example of displaying a sub screen using an OSD on a portion of the lower right side of the main screen. 4B illustrates an example of simultaneously displaying subscreens for a plurality of subchannels in a horizontal direction at the bottom of the main screen, and FIG. 4C simultaneously displays subscreens for a plurality of subchannels in a vertical direction from the right side of the main screen. An example is shown.

At this time, there is no particular limitation on the number of videos of other channels that can be simultaneously displayed and can be adjusted in a range in which the user can easily acquire video information of other channels. In addition, the sub-screen allows the user to scroll through the remote control. That is, the thumbnail image of the next channel can be viewed through the operation of the arrow keys.

 The present invention relates to an implementation of a function for viewing video information of another channel, and the information displayed through the sub-screen using the corresponding device uses EPG data in addition to the video to use a brief text or graphic about the channel. It may include additional information.

As such, when the user watches a broadcast of a specific channel through the main screen, the present invention thumbnails video information of at least one or more programs being broadcast on other channels through the sub-screen without interrupting the viewing of the broadcast displayed on the main screen. The image can be viewed and searched using a remote controller or the like.

Also, the present invention provides a thumbnail image of video information of at least one program being broadcast on another channel through a sub-screen without interrupting viewing of the broadcast displayed on the main screen when the user plays the broadcast recorded through the main screen. Can be viewed and searched using a remote controller or the like.

In the present invention, a digital TV or set-top box device for receiving digital broadcasts or a PVR for storing and reproducing a broadcast may be used as a digital broadcast receiver.

That is, the present invention provides a digital TV or a set-top box equipped with a digital broadcast reception function when a user wants to view video information of another channel while continuously watching a program currently being watched, or plays a stored program on a device such as a PVR. It is more effective when you want to read the information of the program currently being broadcast.

On the other hand, the terms used in the present invention (terminology) are terms defined in consideration of the functions in the present invention may vary according to the intention or practice of those skilled in the art, the definitions are the overall contents of the present invention It should be based on.

In addition, since the present invention has been described through the preferred embodiment of the present invention, in view of the technical difficulty aspects of the present invention, those having ordinary skill in the art can easily and other embodiments of the present invention. Other variations can be made. Therefore, it is apparent that all of the embodiments and variations cited in the above description belong to the claims of the present invention.

 As described above, according to the digital broadcasting receiver and the video information retrieval method of another channel according to the present invention, when a user watches a specific channel broadcast through the main screen, the sub-screen is not disturbed without being prevented from watching the broadcast displayed on the main screen. Through video information on at least one or more programs that are being broadcast on other channels can be simultaneously viewed as a thumbnail image, scroll search can be performed using a remote control or the like.

In particular, by using a thumbnail image as video information of a program broadcast in another channel, it is possible to minimize the additional burden of hardware for decoding the video data of another channel.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (11)

A first tuner and a demodulator for tuning and demodulating a broadcast signal of a main channel to be displayed on a main screen and outputting the same in a transport form; A second tuner and a demodulator for tuning and demodulating a broadcast signal of a sub-channel to be displayed on a sub-screen and outputting it in a transport form; A demultiplexer for separating the video stream from the transport streams of the main and subchannels output from the first and second tuners and the demodulator; A video decoder for performing a complete video decoding on all video streams if the video stream separated by the demultiplexer is for a main picture, and decoding only DC coefficients for a sub picture; A thumbnail generator configured to generate and store a thumbnail image for all subchannels using DC coefficients of the subchannel decoded by the video decoder; And The main channel image decoded by the video decoder according to a preset main / sub picture configuration includes a display processor configured to display a plurality of thumbnail images generated and stored in a thumbnail generator on a main screen and on a plurality of corresponding sub screens. Digital broadcast receiver, characterized in that. The method of claim 1, wherein the video decoder And decoding only DC coefficients of an I picture when the input video stream is for a sub picture. The method of claim 1, wherein the thumbnail generator And when the generation of the thumbnail image for one subchannel is completed, storing the corresponding thumbnail image sequentially for all channels in a predetermined order. The method of claim 1, wherein the thumbnail generator When the generation of the thumbnail image for one sub-channel is completed to store the thumbnail image is configured by the channel information and the connection information of the thumbnail image to enable mapping between the corresponding channel. (a) performing full video decoding on all video streams if the incoming video stream is for main picture; (b) decoding only DC coefficients of an I picture if the input video stream is for a sub picture; (c) generating and storing a thumbnail image using the DC coefficients of the I picture of step (b); And and (d) displaying the video of the main screen decoded in step (a) and the thumbnail image generated in step (c) according to the preset main / sub picture configuration. Video information retrieval method of other channels in the digital broadcast receiver. The method of claim 5, wherein step (c) The method of retrieving video information of another channel in a digital broadcasting receiver, when the generation of a thumbnail image for one subchannel is completed, sequentially storing all the thumbnail images for all channels in a predetermined order.  The method of claim 5, wherein step (c) When thumbnail image generation for one subchannel is completed, periodically performing the process of sequentially saving all the thumbnail images for all channels in a predetermined order to update the thumbnail images of each subchannel periodically. A method of retrieving video information of another channel in a digital broadcasting receiver. The method of claim 5, wherein step (c) Determining whether or not the thumbnail image is valid for representing video information of the corresponding subchannel when generating the thumbnail image of one subchannel is completed; Storing the thumbnail image when it is determined to be valid in the step; And repeating the process until a valid thumbnail is generated for a corresponding subchannel if it is determined that the information is invalid in the step. The method of claim 5, wherein step (c) Determining whether or not the thumbnail image is valid for representing video information of the corresponding subchannel when generating the thumbnail image of one subchannel is completed; Storing the thumbnail image when it is determined to be valid in the step; If it is determined that it is not valid in this step, the process is repeated for a limited number of times, and if a valid thumbnail image is not generated, the process proceeds to the next subchannel and then generates a thumbnail image when the subchannel sequence returns. A method of retrieving video information of another channel in a digital broadcast receiver comprising a. The method of claim 5, wherein step (c) Generating and storing thumbnail images sequentially for all channels in a preset order in a standby mode in which the user does not watch TV; The user further comprises the step of simultaneously displaying the plurality of stored thumbnail images on the plurality of sub-screens as soon as the TV is turned on. The method of claim 5, wherein step (d) When the user selects a video search for another channel, a plurality of pre-stored thumbnail images are read and displayed on a plurality of preset sub-screen positions, respectively.

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