WO2012091203A1

WO2012091203A1 - Set top box for switching a broadcast channel, and method of switching same

Info

Publication number: WO2012091203A1
Application number: PCT/KR2010/009575
Authority: WO
Inventors: 박정환
Original assignee: 가온미디어 주식회사
Priority date: 2010-12-30
Filing date: 2010-12-30
Publication date: 2012-07-05

Abstract

The present invention relates to a set top box for switching a broadcast channel, and a method of switching same. To this end, the set top box of the present invention includes: a tuning unit for tuning a signal of a channel selected from a broadcast signal by a user; a demultiplexing unit for separating the tuning signal tuned by the channel tuning unit into a video stream and audio stream; a decoder for decoding the video and audio stream separated by the demultiplexing unit, and then, outputting the decoded video and audio streams to an image output device; and a control unit for capturing the last image screen of a channel, which is being outputted through the decoder, when a user inputs a channel switching command, and then, outputting the captured last image screen of the channel before an image screen of a switched channel corresponding to the channel switching command is outputted through the decoder. According to the present invention, in order to replace the black screen that occurs while a broadcast channel is being switched in a set top box, the last image screen of a currently-outputting channel is captured and outputted before the channel is switched. Thus, a user may experience smooth and fast channel switching.

Description

Set-top box for switching broadcasting channels and method therefor

The present invention relates to a set-top box for switching broadcast channels and a method therefor, and more particularly, to a technique for removing a black screen generated when switching a broadcast channel in the set-top box according to a user's channel switching command.

A set-top box receives a digital broadcast signal transmitted through wired and wireless transmission channels, and displays the received digital broadcast signal on a screen through a video output device such as a television. Converter that converts into a signal.

1 is a view showing a change in the screen output through the image output device when switching channels in a conventional set-top box.

When the user's channel switching command is input, the conventional set-top box stops tuning and decoding (decoding) of the previous channel currently being output and executes tuning and decoding on a new switching channel corresponding to the user's channel switching command.

Therefore, in the conventional set-top box, a delay occurs according to each process of stopping tuning and decoding on a previous channel and executing tuning and decoding on a new switching channel corresponding to a user's channel switching command. During this delay, a black screen as shown in (b) of FIG. 1 is output to the image output device.

In other words, in the process of switching channels in a conventional set-top box, a user may feel a delay due to channel switching through a black screen visually displayed on an image output device. As a result, the user may feel boredness and frustration due to channel switching. Will occur.

An object of the present invention particularly relates to a technology for switching the broadcast channel by capturing and outputting the last video screen of the channel being output before the channel is switched by replacing the black screen generated in the process of switching the broadcast channel in the set-top box. .

In order to achieve this technical problem, the present invention provides a channel tuning unit for tuning a signal of a channel selected by a user from a broadcast signal; A demultiplexer for separating the tune signal tuned by the channel tuner into a video stream and an audio stream; A decoder for decoding a video stream and an audio stream separated from the demultiplexing and outputting the decoded video stream to an image output device; And when the channel switching command is input from the user, the last video screen of the channel being output through the decoder is captured, and the last video screen of the captured channel is output until the video screen of the switching channel corresponding to the channel switching command is output through the decoder. It includes a control unit.

The present invention also provides a method for switching channels in a set-top box, the method comprising: (a) determining whether a channel switching command is received from a user while outputting a broadcast of a channel selected by a user from a broadcast signal; (b) if it is determined in step (a) that a channel switch command is received, capturing the last video screen of the channel being output; (c) stopping decoding while outputting the last image of the captured channel; (d) tuning and decoding the switching channel corresponding to the channel switching command; And (e) outputting the decoded switching channel image by replacing the turned on image.

According to the present invention, by replacing the black screen generated in the process of switching the broadcast channel in the set-top box and captures and outputs the last video screen of the output channel before the channel is switched, the user can feel a natural and fast channel switching It's effective.

2 is a block diagram showing the configuration of a set-top box according to an embodiment of the present invention.

3 is a view showing a change in the screen output through the image output device when switching channels in the set-top box according to an embodiment of the present invention.

4 is a flowchart illustrating a process of switching channels in a set top box according to a first embodiment of the present invention.

5 is a flowchart illustrating a process of switching channels in a set top box according to a second embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Here, in the embodiment of the present invention, for convenience of description, it will be described on the assumption that the image of a channel previously selected by the user in the set top box is output through the image output device 300 such as a TV.

Referring to FIG. 2, the set top box 200 according to an exemplary embodiment of the present invention may include a channel tuning unit 210, a demultiplexer 220, a decoder 230, a key input unit 240, and a controller 250. And a storage unit 260. Here, the set-top box 200 according to an embodiment of the present invention will be described on the assumption that the digital broadcast signal of the MPEG2 TS (Transport Stream) method is input.

The channel tuner 210 tunes a broadcast signal received by wire or wirelessly to a selected channel selected by a user and transmits the broadcast signal to the demultiplexer 220. At this time, the channel tuning unit 210 receives the MPEG2 TS stream corresponding to the selected channel through the tuning process.

The demultiplexer 220 separates a video stream, an audio stream, and various data streams from the MPEG2 TS stream received from the channel tuner 21 and obtains program information of a selected channel.

The decoder 230 decodes (decodes) a video stream, an audio stream, and various data streams received from the demultiplexer 220 into a signal that a user can actually watch through the image output device, and decodes the decoded signal. Output through 300).

The key input unit 240 is configured as a receiver for receiving a command from the keypad or the remote controller 150 implemented outside of the set-top box 200, and controls the channel switching command input by the user through the keypad or the remote controller 150. 250).

When the channel switching command is received from the key input unit 240, the controller 250 captures the last image screen of the current channel currently being output through the decoder 230, and completes tuning to a new switching channel. In addition, the controller 250 outputs the last image screen of the current channel captured until the switching channel corresponding to the channel switching command is output through the decoder 230 after the tuning to the new switching channel is completed. In this case, the last image screen of the current channel captured by the controller 250 is stored in the storage unit 260.

Here, the control unit 250 has two methods of replacing the last video screen of the current channel being output in the channel switching process with the video screen of the switching channel, and the two methods will be described below. do.

In a first method, if the first I-Picture (Intra Picture) image detected first for the switching channel is detected by the decoder 230 while outputting the last image screen of the captured current channel, the controller 250 outputs the current image. The last video screen of the channel is replaced with the first I-Picture video detected by the decoder 230 and outputted to perform a quick channel screen switching. At this time, as soon as the first I-picture is detected, the control unit 250 replaces the last video screen of the current channel with the first I-Picture and outputs it continuously. . Here, the image that can be normally output means an image that the user can normally watch through the image output device 300. As a result, the first method can switch images quickly, but there may be a delay after the first I-Picture is output until a normally outputable image is output. Therefore, the image output may not be smooth after the first I-Picture is output. . Here, the I-Picture image is one of I-Picture, Bi-directionally Predictive Picture (B-Picture), and P-Picture (Unidrectionally Predicted Picture) constituting the video stream from the MPEG2 TS stream, and is referred to by the B-Picture. ).

In a second method, a PTS (Presentation Time Stamp) and a STC (System Time Clock) of an image frame or an audio frame of a switching channel corresponding to a channel switching command are output from the decoder 230 while outputting the last image of the captured current channel. When the sync is completed, the control unit 250 may output the last video screen of the current channel being output, and the decoder 230 may normally output the video detected when the sync of the PTS and STC of the video frame or the audio frame of the switching channel is completed. Replace with At this time, the controller 250 replaces the last video screen of the current channel with a video that can be normally output, and the channel switching proceeds smoothly continuously. However, the delay may be further occurred in the channel switching as compared to the first method described above. Here, PTS means a code for identifying a stream, a size of a packet, time information for synchronous reproduction, STC means a reference time in an MPEG2 system decoder, and the control unit 250 displays an image at the point where the PTS and STC coincide. Will print

Referring to FIG. 3, the set-top box 200 according to the embodiment of the present invention inputs a channel switching command from the user while outputting an image of the user's selected channel according to the passage of time as shown in (a) of FIG. As shown in (b) of FIG. 3, the last video screen of the current channel is output instead of the conventional black screen. Subsequently, if an image of a switching channel is decoded while outputting an image as shown in (b) of FIG. 3, the set-top box 200 outputs a decoded image as shown in (c) of FIG. 3.

Referring to FIG. 4, the controller 250 outputs a broadcast of a selected channel selected by a user through the image output apparatus 300 (S410), and the controller 250 controls a channel from the user through the key input unit 240. It is determined whether a switch command is received (S420).

If it is determined in step S420 that a channel switch command is received from the user, the controller 250 captures the last video screen of the current channel being output through the current decoder 230 and outputs the last video screen of the captured current channel. Output through the device 300 (S430).

Subsequently, the control unit 250 stops decoding the broadcast currently being output through the decoder 230 (S440), and performs tuning for the switching channel corresponding to the channel switching command through the channel tuning unit 210 (S450). ).

Subsequently, the controller 250 separates a video stream, an audio stream, and various data streams from the signal tuned through the demultiplexer 220 (S460).

Subsequently, the controller 250 decodes each stream separated through the decoder 230 (S470) and acquires an I-Picture image, which is the first image screen (S480).

Subsequently, the controller 250 replaces the last video screen of the current channel currently being output with the obtained I-Picture video (S490). Thereafter, the controller 250 outputs a normally outputable image detected after the I-Picture image, which is the first image screen.

Referring to FIG. 5, the control unit 250 outputs a broadcast of a selected channel selected by a user through the image output device 300 (S510), and the control unit 250 transmits a channel from the user through the key input unit 240. It is determined whether a switch command is received (S520).

If it is determined in step S520 that a channel switching command is received from the user, the controller 250 captures the last video screen of the current channel being output through the current decoder 230 and outputs the last video screen of the captured current channel. Output through the device 300 (S530).

Subsequently, the control unit 250 stops decoding of the broadcast currently being output through the decoder 230 (S540), and performs tuning for the switching channel corresponding to the channel switching command through the channel tuning unit 210 (S550). ).

Subsequently, the controller 250 separates a video stream, an audio stream, and various data streams from the signal tuned through the demultiplexer 220 (S560).

Subsequently, the controller 250 decodes each stream separated through the decoder 230 (S570), and the decoder 230 synchronizes the PTS and STC of the video frame or the audio frame of the switching channel corresponding to the channel switching command. It is determined whether is completed (S580).

If it is determined in step S580 that the synchronization of the PTS and STC of the video frame or the audio frame of the switching channel is completed, the control unit 250 displays the last video screen of the current channel currently being output by the decoder 230 in the video frame of the switching channel. Alternatively, the image is detected and output when the sync of the PTS and STC of the audio frame is completed (S590).

Therefore, according to an embodiment of the present invention, by replacing the black screen generated in the process of switching the broadcast channel in the set-top box to capture and output the last video screen of the output channel before the channel is switched, the user is natural and fast Allows you to feel channel switching.

Although the present invention has been described in more detail with reference to the examples, the present invention is not necessarily limited to these examples, and various modifications can be made without departing from the spirit of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims

A channel tuning unit for tuning a signal of a channel selected by the user from the broadcast signal;

A demultiplexer for separating the tuning signal tuned by the channel tuner into a video stream and an audio stream;

A decoder configured to decode the video stream and the audio stream separated from the demultiplexer and output the decoded video stream to an image output device; And

When the channel change command is input from the user, the last video screen of the channel being output through the decoder is captured, and the last of the captured channel is output until the video screen of the switching channel corresponding to the channel change command is output through the decoder. A controller for outputting an image screen;

Set top box comprising a.
The method according to claim 1,

The channel tuning unit,

A set top box that receives a digital broadcast signal of the MPEG2 TS method and tunes a signal of a channel selected by the user.
The method according to claim 2,

The control unit,

And when the first I (Intra) -Picture of the switching channel corresponding to the channel switching command is detected by the decoder, replaces the last video picture of the captured channel with the detected first I-Picture and outputs the replaced I-Picture.
The method according to claim 2,

The control unit,

When the decoder completes the synchronization between the PTS (Presentation Time Stamp) of the video frame or the audio frame of the channel corresponding to the channel switching command and the STC (System Time Clock) of the set-top box, the captured channel image is converted into the channel switching command. The set-top box for outputting by substituting the image of the time point at which the synchronization between the PTS of the video frame or audio frame of the corresponding channel and the STC of the set-top box is completed.
In the method of switching channels in the set-top box,

(a) determining whether a channel switching command is received from the user while outputting a broadcast of a channel selected by the user from a broadcast signal;

(b) if it is determined in step (a) that the channel switch command is received, capturing the last video screen of the channel being output;

c) stopping decoding while outputting the last image of the captured channel;

(d) tuning and decoding a switching channel corresponding to the channel switching command; And

(e) outputting an image of the decoded switching channel by replacing the turned on image;

Channel switching method in the set-top box comprising a.
The method according to claim 5,

In step (a),

The broadcast signal is a channel switching method in a set-top box which is a digital broadcast signal of the MPEG2 TS system.
The method according to claim 6,

In step (e) above,

And a first I-Picture (Intra Picture) image of the channel corresponding to the channel switching command is detected and the last I-Picture of the captured channel is replaced with the detected first I-Picture image.
The method according to claim 6,

In step (e) above,

When the synchronization between the PTS (Presentation Time Stamp) of the video frame or the audio frame of the channel corresponding to the channel switching command and the STC (System Time Clock) of the set-top box is completed, the captured channel image corresponding to the channel switching command A channel switching method in a set-top box that replaces and outputs an image of a point in time at which a sync between a PTS and an STC of an audio frame or an image frame is completed.