KR101466981B1 - display for PIP, SoC and DMB using the same - Google Patents

Abstract

According to another aspect of the present invention, there is provided a PIP supporting display apparatus including: a receiver for receiving a transport stream of a plurality of channels; A decoding unit decoding a received transport stream of a plurality of channels and outputting a STC (System Time Clock) for a plurality of image frame information and a main channel transport stream; A frame memory arranged in a number corresponding to the output image frame information and storing the plurality of image frame information for each channel; And an image frame information output unit for outputting image frame information when a CTS (Composition Time Stamp) of the image frame information stored in each sub frame memory satisfies the STC. Thus, in a display device supporting only one PCR, The reliability of the whole product can be improved.

PIP, Split, STC, PCR, CTS, Transport Stream, Video

Description

PIP-enabled display device, system-on-chip and DMB terminal using the same,

[0001] The present invention relates to a PIP-enabled display device, and more particularly, to a display device supporting only a PCR (Program Clock Reference) and a display device supporting a PIP (Picture in Picture) And a system-on-chip and a DMB terminal using the same.

PIP (Picture in Picture) is a screen having a function to display a small screen at the same time as a screen viewed from a television receiver screen. It is similar to a window of a personal computer (PC) PIP) function. In a television having such a function, a background screen is referred to as a parent screen (main screen), and a screen displayed in a smaller size is referred to as a PIP (sub screen). With this feature, you can see the contents of another channel at the same time when you are watching a program, but the disadvantage is that a part of the screen is hidden. It is also a type of PIP that displays a regular screen broadcast with a 4: 3 aspect ratio on a large screen with a 16: 9 aspect ratio as a small screen on the screen.

Such a PIP can provide convenience by simultaneously displaying a plurality of channels to a user in consideration of the current and various future broadcasting channels. In other words, when a user wants to broadcast a desired program in a plurality of channels at the same time, the user can selectively view only one channel of the broadcast program. By providing the channel program of the other lane as a sub-screen, , Which helps improve the reliability of the entire product.

In general, PIP-enabled displays are being applied to medium and large televisions that are not portable, such as in home televisions. In order to support PIP, a plurality of channels must be received and processed at the same time. Therefore, tuners corresponding to the number of PIPs required plus the number of main screens and a corresponding baseband are required, .

In addition, it is necessary to support a PCR (Program Clock Reference) for each transport stream for each channel. This means that a device supporting PCR as many as the number of screens to be displayed must be separately added to the display device.

However, a portable or small display device such as a DMB (Digital Multimedia Broadcasting) terminal does not support a plurality of PCRs. As a result, PIP support in portable or small display is very limited and it is urgent to solve the problem.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to support a smooth PIP function in a display device supporting only one PCR.

Another object of the present invention is to provide a PIP function in a portable or small display device such as a DMB terminal by providing a system-on-chip supporting a smooth PIP function in a display device supporting only one PCR.

According to an aspect of the present invention, there is provided an apparatus for receiving a transport stream of a plurality of channels, A decoding unit decoding a received transport stream of a plurality of channels and outputting a STC (System Time Clock) for a plurality of image frame information and a main channel transport stream; A frame memory arranged in a number corresponding to the output image frame information and storing the plurality of image frame information for each channel; And a picture frame information output unit for outputting picture frame information when a CTS (Composition Time Stamp) of the picture frame information stored in each sub frame memory satisfies the STC, present.

Here, the decoding unit separates the received transport streams of the plurality of channels into selective audio data and a plurality of video data, restores STC as a reference of the system from a PCR (Program Clock Reference) of the main channel transport stream, and outputs the STC A system decoder; A bit stream buffer unit arranged in a number corresponding to the plurality of video data and comprising a sub bit stream buffer for storing the plurality of video data for each channel; And a video decoder for decoding the video data stored in the bitstream buffer unit and outputting image frame information. In this case, the video decoder unit may decode the video data of the bitstream buffer unit when the frame memory unit is empty. It is desirable to load them.

The image frame information output unit may check whether the frame memory unit is stored for each display clock.

On the other hand, the CTS (New_Sub_CTS) of the transport stream (subchannel transport stream) excluding the main channel is expressed by the following equation

New_Sub_CTS = C_Sub_CTS - (F_Sub_CTS - F_STC_Time)

C_Sub_CTS: CTS of data in the current subchannel transport stream

F_Sub_CTS: CTS of data in the first subchannel transport stream

F_STC_Time: STC at the time of applying F_Sub_CTS

. ≪ / RTI >

According to another aspect of the present invention, there is provided a decoding apparatus comprising: a decoding unit decoding a received transport stream and outputting STC for a plurality of image frame information and a main channel transport stream; A frame memory arranged in a number corresponding to the plurality of output image frame information and storing the plurality of image frame information for each channel; And a video frame information output unit for outputting the corresponding video frame information when the CTS of the video frame information stored in each sub frame memory satisfies the STC, to present a PIP supporting system on chip (SoC) do.

A receiver for receiving a plurality of transport streams of the plurality of channels; A decoding unit decoding a received transport stream of a plurality of channels and outputting a plurality of image frame information and a STC for a main channel transport stream; A P frame having a picture frame information output unit for outputting picture frame information when the CTS of the picture frame information stored in each sub frame memory satisfies the STC; Supports System-on-Chip; And a display unit for displaying the output image frame information. The digital multimedia broadcasting (DMB) terminal supports only one PCR.

As described above, the PIP supporting display apparatus according to the present invention and the system on chip and the DMB terminal using the PIP supporting display apparatus can improve the reliability of the entire product by providing a smooth PIP function in a display device supporting only one PCR.

Hereinafter, a method for implementing a PIP in a display device supporting only one PCR will be described in detail.

1 is a block diagram schematically illustrating a configuration of a display device supporting only one PCR.

Referring to FIG. 1, a broadcast signal is received through an antenna, and a specific program or channel is selected through the tuner 11 and transmitted to the system decoder 12 in the form of a transport stream (TS). Since the present invention relates to a PIP function for displaying a plurality of screens on one screen, the tuner 11 comprises at least two or more tuners 11, and a device such as a baseband unit . The number of the tuner and the base band portion is changed according to the number of screens to be displayed by the PIP function. In general, the current PIP supports one main screen as a background and one sub-screen displayed on a part of the main screen, i.e., two screens in total, so that the following description will focus on the implementation of PIP on two screens.

Since the tuner 11 and the baseband (not shown) need to process two broadcast channel transport streams simultaneously, two broadcast channel transport streams must be allocated to each of the two broadcast channel transport streams. The system decoder 12 collects the program guide information from the transport stream TS and filters the audio and video data corresponding to the program selected by the viewer and delivers them to the audio decoder 13 and the video decoder 16, Depending on its speed, it can perform its function at any one time. At this time, the format of data transmitted to the audio decoder 13 and the video decoder 16 includes information useful for decoding such as a time stamp (DTS, CTS in the case of MPEG-4) according to the MPEG version. The system decoder 12 restores the STC (System Time Clock), which is a reference of the system, from the PCR (Program Clock Reference), which is the information stored in the transport stream TS, and outputs it to the audio decoder 13 and the video decoder 16 ). The STC is also used as the driving clock of the STC counter, which is used as a reference for decoding the audio decoder 13 and the video decoder 16 in time stamp matching. However, since it is assumed that the PIP is implemented in two screens in advance, and only one PCR is supported while two channel transport streams are received, only one of the PCRs included in the two transport streams should be selected and used. In general, the STC is restored by using the PCR of the main transport stream applied to the main picture. Processing for the sub-transport stream applied to the sub-picture having no STC will be described later. The audio data output from the system decoder 12 may support only one audio output during the PIP implementation and the output thereof will be the audio output for the main screen (displayed in audio through the speaker 14) However, even when the user requests the audio output for the sub screen instead of the main screen, processing for a sub transport stream to be described later is related.

The video decoder 16 decodes the video data output from the system decoder 12 to output image frame information to be displayed on an actual screen. The output image frame information is stored in the frame memory 17.

The video post-processing unit 18 performs image conversion of the image frame information decoded by the video decoder 16 and stored in the frame memory 17 to fit the screen configuration of the display device 19, do. Examples of image conversion include screen size conversion, aspect ratio conversion, and display scan method conversion.

In the above example, it is assumed that there is only one STC corresponding to the PCR included in the transport stream of the main channel corresponding to the main screen, that is, only one PCR is supported. Referring to FIG.

In FIG. 2, except for audio processing, it is shown only for video processing.

The system decoder 22 separates the transport stream of a plurality of channels (two channels in this embodiment) into audio data and video data, and restores the STC by referring to the PCR of the constant transport stream. Generally, The transport stream including the PCR to be transmitted will be the main transport stream (transport stream of the main channel).

The bit stream buffer 25 stores video data output from the system decoder 22. In this embodiment, main video data corresponding to a main screen (corresponding to a main channel) and a sub screen Are alternately stored in the order of M: 0, S: 0, M: 1, S: 1, and so on. The bit stream buffer 25 manages AUI (Access Unit Information), and the output is performed in an input order by taking a storage method in a queue format. Of course, the manner in which the main video data and the sub video data are alternately stored should be agreed with each other in the system decoder 22 and the video decoder 26 behind.

The video decoder 26 decodes the main video data and the sub video data stored in the bit stream buffer 25 and outputs the generated video frame information. In the present invention, the video data decoded in order to distinguish the video data from the video data passed through the system decoder 22 is referred to as video frame information.

The image frame information is stored in the frame memory 27. Like the bit stream buffer 25, main image frame information for main video data and sub-image frame information for sub video data are alternately stored, And takes the same queue format as the bit stream buffer 25. The main picture frame information stored in the frame memory 27 compares the CTS (Composition Time Stamp) included in the main picture frame information with the STC output from the system decoder 22 and if the CTS satisfies the STC If there is a difference, the difference is delayed by the difference and then output to the display device 29. The comparison of the CTS and the STC is performed by the image frame information output unit 28. [ The image frame information output from the image frame information output unit 28 may be directly displayed through a predetermined display unit, or may be displayed in an adjusted state such as an aspect ratio through a video post-processing unit.

However, in this embodiment, the CTS for the subchannel does not have a STC as a reference to be compared. Therefore, an arbitrary but consistent delay value is given to the subchannel, and the delayed value is outputted after the delay. However, in such a case, not only the sub-picture corresponding to the sub-channel can not be normally output but also the main picture is not outputted at the normal timing, and the lip-sync of the audio-video can not be adjusted. Main picture frame information corresponding to the main picture and sub-picture frame information corresponding to the sub-picture are alternately stored in the single frame memory. If the main picture frame is stored in the picture frame information output unit 28, When the 20 ms delay is applied to the sub-picture frame, the main picture and the sub-picture output to the picture frame information output unit 28 are delayed by 50 ms Is delayed. On the other hand, an audio decoder (not shown) outputs audio data with reference to the STC, and thus outputs an output that is out of sync with the main picture, thereby lowering the reliability of the user. This is also the case when the audio data corresponds to a subchannel. In order to solve this problem, the delay of the output of the audio decoder may be set in consideration of both the delay of the main screen and the delay of the sub screen. However, in this case, there is a time lag which is recognized as a difference from the actual broadcast time, which may be another factor for lowering the reliability of the user, which is not preferable.

Therefore, in order to realize an efficient PIP in a display device supporting only one PCR, the present invention proposes the following method.

FIG. 3 is a block diagram illustrating a PIP supporting display apparatus according to an embodiment of the present invention. Referring to FIG. 3, the PIP supporting display apparatus according to the present embodiment includes a reception unit 110 for receiving a plurality of transport streams of a plurality of channels; A decoding unit (120) for decoding the received transport streams and outputting STC (System Time Clock) for a plurality of image frame information and a main channel transport stream; A frame memory (130) comprising a subframe memory arranged in a number corresponding to the plurality of output image frame information and storing the plurality of image frame information for each channel; And an image frame information output unit 140 for outputting image frame information when a CTS (Composition Time Stamp) of the image frame information stored in each sub frame memory satisfies the STC.

The receiving unit 110 receives a plurality of transport streams and is provided with a tuner (not shown) for receiving a desired number of channels, that is, a number of channels to be displayed on the screen.

The decoding unit 120 filters audio data and video data for each of a plurality of transport streams received through the receiving unit 110, decodes the respective video data, and outputs the decoded video data as image frame information. The STC is restored by referring to the PCR included in the main transport stream which is the transport stream and outputted. The decoding unit 120 is configured to exclude an audio decoder, and detailed description of an audio decoder will be omitted.

The frame memory unit 130 includes a plurality of sets of subframe memories that are provided for the number of the plurality of image frame information output from the decoding unit 120 and in which image frame information of one channel is stored separately from image frame information of other channels to be. Therefore, only the image frame information corresponding to one channel is stored in the sub-frame memory. Each subframe memory is output in the order in which it is input to the memory in the queue format.

The image frame information output unit 140 checks each sub-frame memory of the frame memory unit 130 and, if there is image frame information, outputs the CTS included in the image frame information to the decoding unit 120 And outputs the image frame information when the CTS satisfies the STC as compared with the output STC. The output information is processed directly or after being processed in a video post-processing unit (not shown) Lt; / RTI > If the CTS does not satisfy the STC, the CTS delays and outputs the difference. The STC includes STC for each picture frame information stored in each subframe memory. Since the STC is STC for the main picture, the picture frame information (sub-picture frame information) excluding the CTS of the picture frame information for the main picture, There is no comparison of CTS of. Accordingly, as described with reference to FIG. 2, a consistent delay value is assigned to the CTS of the sub-picture frame information for processing. Since the delay value is a value that does not consider the STC corresponding to the sub-picture frame information, an error of a certain degree with respect to the actual broadcasting time is shown. Unlike in FIG. 2, however, By storing the image frame information corresponding to the channel, the delay value of one channel does not affect the delay value of the other channel. Accordingly, since the main picture is processed irrespective of the delay applied to the other sub-picture, the audio output and the video output are normally performed, and the parallax due to the coherent delay value arbitrarily given only to the sub- do. If audio output is to be performed on the sub screen, the audio output to the main screen is stopped, and the audio decoder outputs the sub audio data corresponding to the sub screen by applying the arbitrarily given coherent delay value, So that the output is made. Of course, in this case, it is not possible to refer to the own STC value, so that there may be a time difference or a cut-off phenomenon with the actual broadcasting.

The image frame information output unit 140 checks whether or not to store the frame memory unit, or more specifically, each sub frame memory. Since the check interval is sufficient for each display clock, It is desirable to maintain the sleeping state to prevent unnecessary power consumption.

As described above, the PIP supporting display apparatus according to the present embodiment includes a plurality of subframe memories corresponding to the respective image frame information of the plurality of channels output from the decoding unit, so that the delay value of one channel is different from that of another channel Do not affect the delay value. In addition, by restoring the STC to be the reference so as to correspond to the main screen, at least the main screen is normally displayed as in a general television. As a result, a display device supporting only one PCR can support a PIP function capable of displaying a normal main channel.

The decoding unit 120 may be configured as shown in FIG. Since the audio decoder is not considered in this embodiment, the decoding unit 120 includes a system decoder 121 for filtering audio data and video data from a transport stream, and a video decoder 125 for decoding the video data . In addition, since the video data input to the video decoder 125 must be performed according to whether there is content stored in the frame memory unit, the bit stream buffer unit 123 for storing the video data output from the system decoder 121 is additionally provided Is required.

The system decoder 121 separates the transport streams of the plurality of channels received through the receiver 110 into selective audio data and a plurality of video data, and extracts the standard of the system from the PCR (Program Clock Reference) And outputs the restored STC. Since the present invention is directed to a display device supporting only one PCR, the STC reconstructed by the system decoder 121 becomes a value corresponding to one PCR, and a transport stream of a main channel among a plurality of transport streams It is preferable to be a target.

The bit stream buffer 123 includes a number of sub bit stream buffers corresponding to the video data output from the system decoder 121 so that video data corresponding to one channel is stored in one sub bit stream buffer . Although the bitstream buffer unit 123 may be formed of one sub-bitstream buffer to store a plurality of channels alternately as shown in FIG. 2, as the number of channels to be implemented by the PIP increases, There is a possibility of occurrence. Therefore, it is desirable to construct a plurality of sub-bit stream buffers, each of which corresponds to the sub-frame memory so as to process the consistent data. For example, in the sub bit stream buffer 0 and the sub frame memory 0, information on the main picture (video data, video frame information) can be stored.

The video decoder 125 decodes the video data stored in the bitstream buffer unit and outputs video frame information. The video decoder unit 125 decodes the video data stored in the bitstream buffer unit 125 when the frame memory unit 130 is empty. And to retrieve the video data of the part (123). Otherwise, an overflow may occur.

In the embodiment of FIG. 4, in the display device supporting only one PCR, a number of sub-storage units (a sub-bit stream buffer, a sub-bit stream buffer, Frame memory) so as to smoothly implement a large number of PIPs.

In the above-described embodiments, a method of assigning a randomly consistent delay value as an alternative to the PCR, i.e., STC, can not be considered for the subchannel has been disclosed. Therefore, even if the PIP implementation is feasible, it is undesirable. Is clear. It is necessary to add a separate component for giving a consistent delay value and the subchannel information does not pass through the video frame information output unit 140 of FIG. need. In this case, even if a sub-channel (sub-picture) having no inconvenience to the user is available, it is inevitable that the broadcast will have parallax with the actual broadcast. In general, by applying a consistent delay value to the CTS, It can be a factor to lower the trust of users in the long term.

Therefore, a solution to this problem is required. In the following, a method of comparing the STC of the main channel with the CTS of the subchannel, that is, the function of the image frame information output unit of FIG. 3, And to enable normal output for subchannels.

Generally, the PCR of a transport stream of a subchannel, that is, a sub-transport stream, has a constant offset from the main transport stream, as shown in FIG. 5, The CTS value of the video data may be adjusted so as to be compared with the restored STC by referring to the PCR of the main transport stream.

That is, CTS (New_Sub_CTS) of the transport stream (subchannel transport stream) excluding the main channel can be compared with the STC of the main channel by defining the CTS (New_Sub_CTS) by the following equation (1).

New_Sub_CTS = C_Sub_CTS - (F_Sub_CTS - F_STC_Time)

C_Sub_CTS: CTS of data in the current subchannel transport stream

F_Sub_CTS: CTS of data in the first subchannel transport stream

F_STC_Time: STC at the time of applying F_Sub_CTS

Even when the initial subchannel transport stream is received, the PCR for the subchannel is not referred to, but the decoder extracts the CTS while decoding the data in the subchannel transport stream. Since the CTS value at this time is close to but not coincident with the sub-STC reconstructed by the PCR of the original sub-channel, when the first sub-channel transport stream is received, the CTS for the sub-channel is extracted and then restored using the main transport stream (= (F_Sub_CTS - F_STC_Time)) for the subchannel as compared with the STC. Subsequently, subtracting the offset from the CTS of the data in the currently received sub-transport stream, the value (New_Sub_CTS) approaches the CTS of the data in the main transport stream. This means that the New_Sub_CTS can be compared with the STC of the main transport stream, and the presence of the STC to be compared enables the display of the sub screen to be normally performed.

The New_Sub_CTS is compared with the STC in the image frame information output unit 140 and outputted and displayed when the STC is satisfied. Therefore, the sub-channel information does not need to avoid the image frame information output unit, and a normal main screen and sub-screen can be output with a simpler structure. Since New_Sub_CTS can be applied to sub audio data of subchannels, even if the user desires audio output of subchannels instead of main channels, screen output including normal audio output becomes possible.

Meanwhile, the embodiments described above can be integrated into one SoC (System on Chip).

A decoding unit decoding a plurality of transport streams of the plurality of channels received by the one-chip system and outputting a plurality of image frame information and an STC of a main channel transport stream; A frame memory arranged in a number corresponding to the output image frame information and storing the plurality of image frame information for each channel; And an image frame information output unit for outputting the image frame information when the CTS of the image frame information stored in each sub frame memory satisfies the STC, thereby improving the convenience of design and reducing the production cost .

At present, there is no way to integrate a plurality of tuners, so the receiver is not added, but it may be added according to the future technology development. Also, in the case of a one-chip system, it is preferable to limit the cost of the one-chip system itself by limiting the number of screens that can be implemented by the PIP to two to four including the main screen. Particularly, in the case of a portable or small display device such as a DMB (Digital Multimedia Broadcasting) terminal, since the screen size is basically small, it is not difficult to recognize the number of divided screens or the PIP if it exceeds the number of divided screens or PIPs. .

In addition, since a portable display device such as a DMB terminal supports only one PCR, it is desirable to arrange the embodiment of FIGS. 3 and 4 or the one-chip system using the same.

That is, there is provided a DMB terminal, comprising: a receiver for receiving a transport stream of a plurality of channels; A decoder for decoding the received transport stream of the plurality of channels and outputting a plurality of image frame information and an STC of a main channel transport stream; And a PIP supporting unit for outputting image frame information when the CTS of the image frame information stored in each of the sub frame memories satisfies the STC, System on chip; And a display unit for displaying the output image frame information, so that it is possible to realize a PIP with a simple structure.

Meanwhile, although the PIP has been mainly discussed above, it is possible to apply the PIP supporting configuration according to the present invention even in the case of a split screen different in concept from the PIP.

It is to be noted that the technical idea of the present invention has been specifically described in accordance with the above preferred embodiment, but the above-mentioned embodiments are intended to be illustrative and not restrictive. In addition, it will be understood by those of ordinary skill in the art that various embodiments are possible within the scope of the technical idea of the present invention.

The present invention can be applied to a case where a PIP or a divided screen is supported in a display device supporting only one PCR, and it is particularly advantageous to apply it to a small or portable display device such as a DMB terminal.

1 is a block diagram schematically showing a configuration of a display device supporting only one PCR.

2 is a block diagram illustrating a PIP implementation in a display device that supports only one PCR.

3 is a block diagram illustrating a PIP-enabled display device according to one preferred embodiment of the present invention.

FIG. 4 is a block diagram specifically showing a decoding unit of FIG. 3;

5 is a graph showing a relationship between a main stream and a sub stream;

Description of the Related Art [0002]

110 ... receiving unit 120 ... decoding unit

130 ... frame memory unit 140 ... image frame information output unit

Claims (7)

A receiver for receiving a transport stream of a plurality of channels; A decoding unit decoding a received transport stream of a plurality of channels and outputting a STC (System Time Clock) for a plurality of image frame information and a main channel transport stream; A frame memory arranged in a number corresponding to the output image frame information and storing the plurality of image frame information for each channel; And And an image frame information output unit for outputting image frame information when a CTS (Composition Time Stamp) of the image frame information stored in each sub frame memory satisfies the STC, The image frame information output unit Wherein the control unit checks whether the frame memory unit is stored for each display clock. A receiver for receiving a transport stream of a plurality of channels; A decoding unit decoding a received transport stream of a plurality of channels and outputting a STC (System Time Clock) for a plurality of image frame information and a main channel transport stream; A frame memory arranged in a number corresponding to the output image frame information and storing the plurality of image frame information for each channel; And And an image frame information output unit for outputting image frame information when a CTS (Composition Time Stamp) of the image frame information stored in each sub frame memory satisfies the STC, The decoding unit A system decoder for separating the received transport streams into selective audio data and a plurality of video data, restoring STC as a reference of the system from a PCR (Program Clock Reference) of the main channel transport stream, and outputting the STC; A bit stream buffer unit arranged in a number corresponding to the plurality of video data and comprising a sub bit stream buffer for storing the plurality of video data for each channel; And And a video decoder for decoding the video data stored in the bit stream buffer and outputting image frame information. The method of claim 2, Wherein the video decoder unit fetches the video data of the bitstream buffer unit when the frame memory unit is empty. The method of claim 2, The image frame information output unit Wherein the control unit checks whether or not the frame memory unit is stored for each display clock. 5. The method according to any one of claims 1 to 4, The CTS (New_Sub_CTS) of the transport stream (subchannel transport stream) excluding the main channel is expressed by the following equation New_Sub_CTS = C_Sub_CTS - (F_Sub_CTS - F_STC_Time) C_Sub_CTS: CTS of data in the current subchannel transport stream F_Sub_CTS: CTS of data in the first subchannel transport stream F_STC_Time: STC at the time of applying F_Sub_CTS Lt; RTI ID = 0.0 > PIP < / RTI > A decoding unit decoding a received transport stream of a plurality of channels to output a plurality of image frame information and an STC for a main channel transport stream; A frame memory arranged in a number corresponding to the output image frame information and storing the plurality of image frame information for each channel; And And an image frame information output unit for outputting image frame information when the CTS of the image frame information stored in each sub frame memory satisfies the STC, The image frame information output unit (PIP) system-on-chip (SoC) according to a display clock. A receiver for receiving a transport stream of a plurality of channels; A decoding unit decoding a received transport stream of a plurality of channels and outputting a plurality of image frame information and a STC for a main channel transport stream; A P frame having a picture frame information output unit for outputting picture frame information when the CTS of the picture frame information stored in each sub frame memory satisfies the STC; Supports System-on-Chip; And And a display unit for displaying the output image frame information, The image frame information output unit Wherein the controller checks whether the frame memory unit is stored for each display clock.

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