KR102150685B1 - Method and Apparatus for Switching Media Service Channel - Google Patents

Abstract

In this embodiment, when switching channels in an IPTV set-top box, a caching server is used to minimize the time required to detect the first I frame for the switching channel, while the feature information of the initial data information of the switching channel is converted to the switching channel information. In addition, the present invention relates to a method and apparatus for switching a media service channel, which is provided to a caching server together with the caching server so that the caching server can transmit only exactly necessary caching stream data so that broadcast data of a switch channel can be processed more quickly.

Description

Method and Apparatus for Switching Media Service Channel {Method and Apparatus for Switching Media Service Channel}

The present embodiment relates to a method and apparatus for switching a media service channel. More specifically, it relates to a method and apparatus for optimally controlling a channel switching time when switching between service channels in an IP-based media service such as IPTV.

The content described in this section merely provides background information on the present embodiment and does not constitute the prior art.

In recent years, Internet Protocol TV (IPTV) broadcasting service has begun. IPTV broadcasting is also called'Internet multimedia broadcasting', and it is a generic term for broadcasting services provided through an IP (Internet Protocol) network regardless of its name.

Users can use the IPTV service by manipulating the IPTV set-top box through a remote control, similar to the conventional broadcast service method. The IPTV set-top box can be integrated with the TV receiver or configured as an independent device to interlock with the TV receiver.

1 is an exemplary diagram illustrating a process of channel switching in an IPTV set-top box. In general, IPTV channel switching procedure is, for the first time, when the channel switching signal is received (T1), the screen of the existing channel (existing channel) is stopped (T2), and the first screen of the target channel (conversion channel) is displayed. The first screen is displayed (T3) when the conversion channel starts to be received after maintaining the stop status until (T2~T3), and when the play is complete for the conversion channel such as audio/video synchronization, PCR/PTS alignment, etc. It consists of a procedural time interval that starts (T4).

In general, a process of receiving a switch channel stream by requesting a switch channel from a time point T2 is entered, and when the first I frame for the switch channel is received, a corresponding I frame image may be displayed at T3. Even if the I frame of the video for the switching channel is found, in order to start playing the stream, audio-video synchronization must be completed with a data packet having the display time information (PTS) in the same time zone, and the display time information of the video and audio is PCR (Program Clock Reference: Program reference time) It should be aligned after the reference time. The time period for synchronizing audio/video and time information for this changeover channel play is T3 to T4, and when the play is ready, the changeover channel is played at time T4, and the channel changeover procedure is completed.

As described above, in the case of the conventional IPTV set-top box channel switching method, there is an inconvenience in that a user must wait for a certain time after switching channels to watch a broadcast program of a new channel. To this end, a new technology is required to complete the reception of switched channel data in a minimum time in each section of the channel switching procedure, particularly in the T2 to T3 section.

In this embodiment, when switching channels in an IPTV set-top box, a caching server is used to minimize the time required to detect the first I frame for the switching channel, while the feature information of the initial data information of the switching channel is converted to the switching channel information. The purpose of this is to provide the caching server in addition to the caching server so that the caching server can transmit only the caching stream data that is exactly necessary, so that the broadcast data of the switching channel can be processed more quickly.

The present embodiment includes the steps of transmitting a service request signal for connection to the channel to be switched to an IPTV service device when a switch request signal to the channel to be switched is received; Receiving broadcast data of the conversion target channel from the IPTV service device in response to the service request signal; Transmitting a caching information request signal including packet information on the broadcast data and channel information on the conversion target channel to a caching server device; Receiving the packet information and caching stream data corresponding to the channel information from the caching server device in response to the caching information request signal; And a step of processing the caching stream data to output an image. It provides a channel switching method of an IPTV set-top box.

In addition, according to another aspect of the present embodiment, there is provided a process of receiving a caching information request signal including channel information on a switched channel and packet information on broadcast data of the switched channel from an IPTV set-top box; Selecting stream data corresponding to the switching channel based on the channel information; Selecting data up to a specific location section in the stream data as caching stream data for the switching channel based on the packet information; And transmitting the caching stream data to the IPTV set-top box.

In addition, according to another aspect of the present embodiment, a service request signal for access to a channel to be switched is transmitted to an IPTV service device, and broadcast data of the channel to be switched is received in response to the service request signal from the IPTV service device. A service request unit; Transmitting a caching information request signal including packet information for the broadcast data and channel information for the channel to be switched to a caching server device, and receiving caching stream data corresponding to the packet information and the channel information from the caching server device A data processing unit; And an image processor configured to output an image by processing the caching stream data.

In addition, according to another aspect of the present embodiment, there is provided a data receiver for receiving a caching information request signal including channel information for a switched channel and packet information for broadcast data of the switched channel from an IPTV set-top box; A data selection unit that selects stream data corresponding to the switching channel based on the channel information; A data selector for selecting data up to a specific location section in the stream data as caching stream data for the switching channel based on the packet information; And a data transmission unit transmitting the caching stream data to the IPTV set-top box.

In addition, according to another aspect of the present embodiment, when a switch request signal to a channel to be switched is received by being combined with hardware, transmitting a service request signal for access to the channel to be switched to an IPTV service device; Receiving broadcast data of the conversion target channel from the IPTV service device in response to the service request signal; Transmitting a caching information request signal including packet information on the broadcast data and channel information on the conversion target channel to a caching server device; Receiving the packet information and caching stream data corresponding to the channel information from the caching server device in response to the caching information request signal; And a computer program stored in a computer-readable recording medium to execute a process of processing the caching stream data and outputting an image.

According to this embodiment, when switching channels in an IPTV set-top box, a caching server is used to minimize the time required to detect the first I frame for the switching channel, while also switching characteristic information of the initial data information of the switching channel. The channel information is additionally provided to the caching server so that the caching server can transmit only exactly necessary caching stream data, thereby making it possible to process the broadcast data of the switching channel more quickly.

1 is a diagram illustrating a procedure for channel switching in a general IP-based media service.
2 is a block diagram schematically illustrating an IPTV system for switching a media service channel according to the present embodiment.
3 is a block diagram schematically showing an IPTV set-top box according to the present embodiment.
4 is a block diagram schematically showing a caching server apparatus according to the present embodiment.
5 is a flow chart illustrating a method of switching a media service channel of an IPTV set-top box according to the present embodiment.
6 is a flowchart illustrating a method of switching a media service channel of a caching server device according to the present embodiment.
7 to 8 are exemplary diagrams illustrating a method of switching a media service channel according to the present embodiment.

Hereinafter, this embodiment will be described in detail with reference to the accompanying drawings.

In general, in order to receive data on a switching channel in an IPTV system, request stream data for a multicast channel of an IPTV service device through a network device of an IPTV set-top box, and start playing first when the requested stream data starts to be received. The work of finding the audio data of the same display time period as the I frame video data for is performed. Thereafter, when the audio stream synchronized with the first I frame and the respective display times are synchronized with the reference time, play on the switching channel starts.

At this time, in order to minimize the time required to detect the first I frame from the received stream data, a caching server device is used in this embodiment. That is, in the case of the IPTV system according to the present embodiment, when a channel switching signal is generated, in the process of requesting data for a multicast channel of the IPTV service apparatus through the network device of the IPTV set-top box, Requests the latest stream data from the caching server device. Thereafter, when the requested stream data starts to be received from the caching server device, the stream starting from the I frame data of the corresponding time zone is received, and the I frame data is detected at a shorter time than the stream data received from the media service network. Replay play begins.

In this embodiment, a method of reducing the delay time due to channel switching is proposed by enabling the reception of switching channel data to be processed more quickly in the channel switching process using the caching server device.

2 is a block diagram schematically illustrating an IPTV system for switching a media service channel according to the present embodiment.

As shown in FIG. 2, the IPTV system 200 according to the present embodiment includes an IPTV service device 210, an IPTV set-top box 220, a caching server device 230, and a terminal 240.

Hereinafter, in describing the functions of each component of the IPTV system 200, an operation for completing the reception of switching channel data in a minimum time will be mainly described.

The IPTV service device 210 is a device that receives a plurality of broadcast content information from a content provider, transmits the received content information to devices such as the IPTV set-top box 220 and the terminal 240, and provides it to an IPTV subscriber. That is, the IPTV service device 210 receives a plurality of broadcast content information transmitted from a content provider, distributes the received broadcast content information to the IPTV set-top box 220 and the terminal 240 to provide real-time broadcasting and VOD to IPTV subscribers. Provides services such as (Video On Demand).

The IPTV service device 210 according to the present embodiment additionally provides broadcast data corresponding to each service target channel to the caching server device 230 in advance. The caching server device 230 stores broadcast data of service target channels for a predetermined period of time, and provides broadcast data of a channel suitable for a purpose when necessary.

On the other hand, to explain the broadcast data for each channel, video data for each channel is compression-encoded into I frame, P frame, and B frame, and then formed into a PES (Packetized Elementary Stream). It is processed in units of Group Of Pictures (GOP) including P frames and a plurality of B frames. Audio data is also compression-encoded to form an element stream (ES), and then PES. Video PES and audio PES are multiplexed, converted into a transport stream (TS), and then transmitted through a network.

The IPTV set-top box 220 basically connects to a network network through a router, processes broadcast data received from the network network, and outputs it to the terminal 240.

When a channel switching signal according to a user's remote control operation is received, the IPTV set-top box 220 performs a channel switching operation such as ending an existing channel and acquiring information on the switching channel. That is, when the IPTV set-top box 220 generates a channel switching signal, the IPTV set-top box 220 requests the IPTV service apparatus 210 for broadcast data for the switching channel through the network device.

The IPTV set-top box 220 according to the present embodiment transmits the switching channel information to the caching server device 230 when information on the initial data of the switching channel is received from the IPTV service device 210 to provide caching information for the corresponding channel. Request more. In this case, the IPTV set-top box 220 according to the present embodiment additionally provides packet information of the initial data of the switching channel to the caching server apparatus 230 together with the switching channel information. This causes the caching server device 230 to be able to transmit only exactly necessary caching stream data, thereby minimizing the amount of transmission data for channel switching.

Thereafter, the IPTV set-top box 220 detects the most advanced I frame by using the caching stream data received from the caching server device 230, and expresses this in step T3 of the IPTV channel switching procedure, and then in step T4. It works to be played. A detailed operation for the play of the switching channel of the IPTV set-top box 220, for example, a procedure for synchronizing audio/video and time information is the same as in the prior art, and thus a detailed description thereof will be omitted.

The caching server device 230 receives broadcast data of service target channels from the IPTV service device 210, stores it for a certain period of time, and provides broadcast data of a channel suitable for a purpose when necessary.

The caching server apparatus 230 according to the present embodiment receives a request signal for caching information of a corresponding channel from the IPTV set-top box 220 when channel switching for a service target channel occurs.

The caching server device 230 calculates stream data corresponding to the switching channel based on the channel information included in the request signal.

Meanwhile, in the present embodiment, packet information of initial data of the switching channel may be additionally included in the request signal received from the IPTV set-top box 220 by the caching server device 230. The characteristic information is preferably collected at the time when the IPTV set-top box 220 receives broadcast data of the switching channel from the IPTV service device 210, and may be included in the request signal.

The caching server apparatus 230 according to the present embodiment includes only the minimum data required by the IPTV set-top box 220 in the actual channel switching process among stream data corresponding to the switching channel based on the packet information. To be transmitted to the box 220.

The caching server device 230 extracts, as caching stream data, data up to a specific location section determined based on packet information among stream data corresponding to the channel information, and transmits it to the IPTV set-top box 220. For example, the caching server device 230 determines the end position of the transmitted image using packet information transmitted from the IPTV set-top box 220, and transmits only exactly necessary caching stream data to the IPTV set-top box 220 based on this. It works so that it can be.

On the other hand, for a detailed operation of calculating the optimum caching stream data for transmission to the IPTV set-top box 220 by the caching server device 230 according to the present embodiment, a process of describing FIGS. 3 and 4 It will be described later.

3 is a block diagram schematically showing an IPTV set-top box according to the present embodiment.

As shown in FIG. 3, the IPTV set-top box 220 according to the present embodiment includes a service request unit 300, a data processing unit 310, and an image processing unit 320. Here, the components included in the IPTV set-top box 220 according to the present embodiment are not necessarily limited thereto. That is, in the case of FIG. 3, only essential components for completing the reception of the switching channel data in the minimum time in the interval T2 to T3 in the channel switching process described in FIG. 1 are exemplarily illustrated. It should be recognized that the set-top box 220 may have more or less components than those shown or configurations of different components for implementing other functions.

The service request unit 300 communicates with the IPTV service device 210 to transmit and receive broadcast data for a service target channel.

The service requesting unit 300 according to the present embodiment, when a request for switching from a currently connected channel to another channel is recognized, sends a service request signal for access to another channel (= a channel to be switched) to the IPTV service apparatus 210 Transfer to.

The service request unit 300 receives broadcast data of a switch channel from the IPTV service device 210 in response to a service request signal.

The data processing unit 310 communicates with the caching server device 230 and performs a function of receiving caching stream data for a switching channel.

The data processing unit 310 transmits a caching information request signal including channel information for the switching channel to the caching server device 230, and in response to the caching information request signal from the caching server device 230, caching corresponding to the switching channel Receive stream data.

The data processing unit 310 according to the present embodiment may provide only switching channel information when transmitting a caching information request signal to the caching server device 230, but also provides packet information for broadcast data of the switching channel as additional information. can do.

In the present embodiment, the packet information for the broadcast data is data initially received at the time when broadcast data of the switching channel is received from the IPTV service device 210 in response to a service request signal from the service request unit 300. Packet information or corresponding feature information may be included. For example, in the present embodiment, as packet information on broadcast data, first N bytes of broadcast data received from the IPTV service device 210 through the service request unit 300, feature information of the first received packet data, and Some or all of the packet connection number information may be included.

Meanwhile, in consideration of its efficiency, the data processing unit 310 immediately retrieves the packet information of the broadcast data at the time when the broadcast data of the switched channel is received from the IPTV service device 210 through the service request unit 300. It is preferable to transmit the included caching information request signal to the caching server device 230, but is not limited thereto.

In this embodiment, packet information on broadcast data is used to optimize the amount of caching data to be transmitted by accurately indicating the end position of the caching data to be provided to the IPTV set-top box 220 to the caching server device 230 Can be used as That is, in the case of the present embodiment, the caching server apparatus 230 allows the caching server device 230 to transmit only exactly necessary caching stream data, thereby causing the effect of more rapidly processing the broadcast data of the switching channel.

In more detail, the data processing unit 310 receives data from the caching server device 230 to a specific location section determined based on the packet information of broadcast data among stream data corresponding to the channel information of the switching channel as caching stream data. .

That is, in the present embodiment, the data processing unit 310 stores caching stream data having the same packet as the packet information of the broadcast data among stream data corresponding to the channel information of the switching channel from the caching server device 230 as an end position. Receive.

In addition, the data processing unit 310 starts from the caching server device 230 to the immediately previous I frame based on the same packet or N (N≥1) number of I frames prior to the previous I frame. Receives caching stream data with as.

Meanwhile, a detailed method of receiving the caching stream data from the caching server apparatus 230 by the data processing unit 310 will be described in more detail in the process of describing the operation of each component of the caching server apparatus 230.

The image processing unit 320 completes channel switching to the switching channel based on broadcast data and caching stream data for the switching channel received through the service request unit 300 and the data processing unit 310. Since the operation of the image processing unit 320 is the same as in the related art, a detailed description thereof will be omitted.

4 is a block diagram schematically showing a caching server apparatus according to the present embodiment.

As shown in FIG. 4, the caching server apparatus 230 according to the present embodiment includes a data receiving unit 400, a data selecting unit 410, a data selecting unit 420, and a data transmitting unit 430. Here, components included in the caching server device 230 according to the present embodiment are not necessarily limited thereto.

The data receiver 400 receives a caching information request signal corresponding to the switching channel from the IPTV set-top box 220. In this case, the caching information request signal received from the IPTV set-top box 220 by the data receiving unit 400 may include channel information for a switch channel and packet information for broadcast data of the switch channel.

The data selection unit 410 selects stream data corresponding to the switching channel from among the previously collected broadcast data for each service target channel, based on channel information on the switching channel included in the caching information request signal.

Based on the packet information included in the caching information request signal, the data selection unit 420 converts data up to a specific location section in the stream data previously selected by the data selection unit 410 into the caching stream data for the switching channel. It is selected as

Hereinafter, a method of selecting caching stream data for a switching channel by using the information included in the caching information request signal by the data selection unit 420 will be described.

The data selector 420 detects the same packet as the packet information from among stream data corresponding to the channel information of the switching channel, and determines an end position of the caching stream data based on the same packet. For example, the data selector 420 may determine the end position of the caching stream data up to the data end section of the same packet.

The data selector 420 determines the start position of the caching stream data based on the nearest I frame of the time before the determined end position data. For example, the data selection unit 420 may determine the immediately previous I frame as the start position of the caching stream data based on the same packet.

In another embodiment, in order to increase the play stability for the switching channel in the IPTV set-top box 220, the data selection unit 420 is a number of N (N≥1) previous I frames of the same packet. The I frame can be determined as the start position of the caching stream data.

The data transmission unit 430 transmits the determined caching stream data to the IPTV set-top box 220.

5 is a flow chart illustrating a method of switching a media service channel of an IPTV set-top box according to the present embodiment.

The IPTV set-top box 220 transmits a service request signal for access to another channel (=switched channel) to the IPTV service device 210 when the request for switching from the currently connected channel to another channel is recognized (S502). .

The IPTV set-top box 220 receives broadcast data of the switched channel in response to the service request signal of step S502 from the IPTV service device 210 (S504).

The IPTV set-top box 220 transmits, to the caching server apparatus 230, a caching information request signal including packet information for broadcast data and channel information for a switching channel received in step S504 (S506). In step S506, the IPTV set-top box 220 may transmit a caching information request signal to the caching server device 230 immediately at a point in time when broadcast data of the switching channel is received in step S504.

In response to the caching information request signal of step S506, the IPTV set-top box 220 caches data from the caching server device 230 to a specific location section determined based on the packet information among stream data corresponding to the switching channel. It is received as (S508). In step S508, the IPTV set-top box 220 has the same packet as the packet information of the stream data corresponding to the switching channel as an end position, and the immediately preceding I frame or the immediately preceding I frame based on the same packet. As a reference, caching stream data having I frames before N (N≥1) number as a start position is received.

The IPTV set-top box 220 completes channel switching to the switching channel based on the broadcast data in step S504 and the caching stream data in step S508 (S510).

6 is a flowchart illustrating a method of switching a media service channel of a caching server device according to the present embodiment.

The caching server device 230 receives a caching information request signal corresponding to the switching channel from the IPTV set-top box 220 (S602). In step S602, the caching server device 230 receives a caching information request signal from the IPTV set-top box 220, which includes channel information for the switch channel and packet information for broadcast data of the switch channel.

The caching server apparatus 230 selects stream data corresponding to the switching channel based on the channel information in the caching information request signal in step S602 (S604).

The caching server apparatus 230 selects data up to a specific location section in the stream data in step S604 as caching stream data for the switching channel based on the packet information in the caching information request signal in step S602 (S606). In step S606, the caching server device 230 determines the end position of the caching stream data up to the same packet as the packet information from among the stream data corresponding to the switching channel, and the previous I frame or the immediate previous I frame based on the same packet. Based on the previous I frame, the number of I frames before N (N≥1) is determined as the start position of the caching stream data.

The caching server device 230 transmits the caching stream data of step S606 to the IPTV set-top box 220 (S608).

Here, steps S502 to S510 and steps S602 to S608 correspond to the operations of the components of the IPTV set-top box 220 and the caching server device 230 described above, and thus further detailed descriptions are omitted.

In FIGS. 5 and 6, it is described that each process is sequentially executed, but is not limited thereto. In other words, since the process described in FIGS. 5 and 6 may be changed and executed or one or more processes may be executed in parallel, FIGS. 5 and 6 are not limited to a time series order.

As described above, the media service channel switching method illustrated in FIGS. 5 and 6 is implemented as a program and can be read using software of a computer (CD-ROM, RAM, ROM, memory card, hard disk, magneto-optical disk). , Storage devices, etc.).

7 to 8 are exemplary diagrams illustrating a method of switching a media service channel according to the present embodiment. Meanwhile, FIG. 7 illustrates a method for switching a media service channel according to a first embodiment of the present invention, and FIG. 8 illustrates a method for switching a media service channel according to a second embodiment of the present invention.

First, referring to FIGS. 7 and 8, in the case of the media service channel switching method according to the present embodiment, when a channel switching signal is received (T1), an operation for terminating an existing channel and obtaining information on a switching channel, etc. As a result, the existing viewing channel is stopped at the time point T2, and a task for receiving the switched channel stream data from the IPTV service apparatus is performed (Z0) using the acquired switching channel information.

As shown in FIG. 7, in the case of the media service channel switching method according to the first embodiment of the present invention, a switching channel is requested from the IPTV service device 210 by using information on the switching channel at a time point Z0. , Start receiving the corresponding service channel at point Z1.

The IPTV set-top box 220 transmits the information on the switching channel at C0 and the initial packet information or corresponding feature information of the data received at Z1 to the caching server apparatus 230 together.

The caching server device 230 finds the same packet as the initial packet information from caching information for a channel corresponding to the switching channel information received from the IPTV set-top box 220, and provides caching stream data to the IPTV set-top box 220 It is determined by the end position of.

The caching server device 230 determines the closest I frame (I(0)) of the time before the determined end position data as the start position of the caching stream data. That is, from the nearest I frame (I(0)) from the packet identical to the initial packet information or feature information to the first packet information or the packet identical to the feature information, determined as caching stream data and transmitted to the IPTV set-top box 220 do.

At this time, when the caching server device 230 determines the end position of the caching data stream using the initial packet information received together with the switching channel information or the corresponding characteristic information, if the corresponding initial packet information or data matching the corresponding characteristic information If is not cached, it is possible to set a specific time, wait for the data to be cached, and then determine the end position when caching is performed within a predetermined time.

In addition, the caching server device 230 may transmit the caching stream data determined as the start and end positions as it is to the IPTV set-top box 220, or PAT (Program Associate Table) and PMI (Precoding Matrix indicator) included in the corresponding channel stream. PSI (Program Specific Information) information such as) may be added and transmitted.

As shown in FIG. 8, in the case of the media service channel switching method according to the second embodiment of the present invention, the step of determining the end position of the caching stream data to be provided to the IPTV set-top box 220 is performed according to the present invention. It is the same as the media service channel switching method according to the second embodiment, and there is a difference in the method of determining the start position of the caching stream data. In the case of the media service channel switching method according to the first embodiment, there is an advantage in that the play stability of the switching channel in the IPTV set-top box 220 can be improved.

The caching server apparatus 230 determines the I frame (I(-1)) immediately preceding the nearest I frame (I(0)) of the determined end position data previous time as the caching stream data start position. That is, caching from the I frame (I(-1)) immediately preceding the closest I frame (I(0)) from the first packet information or the same packet as the corresponding feature information to the first packet information or the same packet as the corresponding feature information. It is determined as stream data and transmitted to the IPTV set-top box 220.

On the other hand, the start position of the caching stream data is I frame (I(-1)) or I(-2) or I frame (I(-k)) before a certain number before it, depending on the format of the stream, structure timing configuration, etc. May be. The K value is an integer value, may be set manually, and the caching server device 230 analyzes the stream of the corresponding channel, determines timing information, audio video packet configuration, etc., and then automatically applies it.

The above description is merely illustrative of the technical idea of the present embodiment, and those of ordinary skill in the technical field to which the present embodiment belongs will be able to make various modifications and variations without departing from the essential characteristics of the present embodiment. Accordingly, the present exemplary embodiments are not intended to limit the technical idea of the present exemplary embodiment, but are illustrative, and the scope of the technical idea of the present exemplary embodiment is not limited by these exemplary embodiments. The scope of protection of this embodiment should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present embodiment.

200: IPTV system 210: IPTV service device
220: IPTV set-top box 230: caching server device
240: terminal 300: service request unit
310: data processing unit 320: image processing unit
400: data receiving unit 410: data selecting unit
420: data selection unit 430: data transmission unit

Claims (12)

Transmitting a service request signal for connection to the channel to be switched to an IPTV service device when a switch request signal to the channel to be switched is received;
Receiving broadcast data of the conversion target channel from the IPTV service device in response to the service request signal;
Transmitting a caching information request signal including packet information of first received data for the broadcast data and channel information for the channel to be switched to a caching server device;
Receiving the packet information and caching stream data corresponding to the channel information from the caching server device in response to the caching information request signal; And
Process of processing the caching stream data and outputting an image
Channel switching method of an IPTV set-top box comprising a. The method of claim 1,
The process of transmitting to the caching server device,
And transmitting the caching information request signal to the caching server device at a time when broadcast data of the channel to be switched from the IPTV service device starts to be received. The method of claim 1,
Packet information for the broadcast data,
The channel switching method of an IPTV set-top box, comprising some or all of first N bytes of broadcast data received from the IPTV service device, feature information of first received packet data, and packet connection number information. The method of claim 1,
The process of receiving the caching stream data,
And receiving the caching stream data having the same packet as the packet information as an end position among stream data corresponding to the channel information from the caching server device. The method of claim 4,
The process of receiving the caching stream data,
Receiving the caching stream data having the immediately preceding I frame based on the same packet or N (N≥1) number of I frames as a starting position based on the immediately previous I frame from the caching server device IPTV set-top box channel switching method characterized by. Receiving a caching information request signal from an IPTV set-top box including channel information for a switched channel and packet information of initially received data for broadcast data of the switched channel;
Selecting stream data corresponding to the switching channel based on the channel information;
Selecting data up to a specific location section in the stream data as caching stream data for the switching channel based on the packet information; And
Transmitting the caching stream data to the IPTV set-top box
Channel switching method of a caching server device comprising a. The method of claim 6,
The process of selecting,
And detecting the same packet as the packet information among stream data corresponding to the channel information, and determining an end position of the caching stream data based on the same packet. The method of claim 7,
The process of selecting,
The caching server apparatus, characterized in that, based on the same packet, the immediately preceding I frame or the immediately preceding I frame by N (N≥1) number of previous I frames is determined as a start position of the caching stream data. Channel switching method. The method of claim 8,
The process of selecting,
And determining the value of N differently based on some or all of the format, structure and timing configuration information of the stream data corresponding to the channel information. A service request unit which transmits a service request signal for access to a conversion target channel to an IPTV service device, and receives broadcast data of the conversion target channel in response to the service request signal from the IPTV service device;
Caching corresponding to the packet information and the channel information from the caching server device by transmitting a caching information request signal including packet information of the first received data for the broadcast data and channel information on the channel to be switched to a caching server device A data processing unit for receiving stream data; And
An image processing unit that processes the caching stream data and outputs an image
IPTV set-top box comprising a. A data receiver configured to receive a caching information request signal including channel information on a switched channel and packet information of initially received data on broadcast data of the switched channel from the IPTV set-top box;
A data selection unit that selects stream data corresponding to the switching channel based on the channel information;
A data selector for selecting data up to a specific location section in the stream data as caching stream data for the switching channel based on the packet information; And
Data transmission unit for transmitting the caching stream data to the IPTV set-top box
Caching server device comprising a. Combined with hardware,
Transmitting a service request signal for connection to the channel to be switched to an IPTV service device when a switch request signal to the channel to be switched is received;
Receiving broadcast data of the conversion target channel from the IPTV service device in response to the service request signal;
Transmitting a caching information request signal including packet information of first received data for the broadcast data and channel information for the channel to be switched to a caching server device;
Receiving the packet information and caching stream data corresponding to the channel information from the caching server device in response to the caching information request signal; And
Process of processing the caching stream data and outputting an image
A computer program stored in a recording medium that can be read by a computer to run.

Images