KR101759964B1 - Method of providing Audio/Video seamless handover of TDMB broadcasting - Google Patents

Abstract

The present invention provides a seamless AV handover technology in which a viewer can not recognize the fact of moving a receiving region by accurately synchronizing the same broadcasting service while maintaining the same broadcasting service in a mobile receiving environment of a TDMB broadcasting. Quality TDMB broadcasting reception environment, and minimizes key operation during operation, thereby contributing to safe driving. The present invention can be preferably applied to an apparatus for moving and receiving a TDMB broadcast, such as a TDMB receiver for a vehicle or an AVN system for a vehicle. According to the present invention, even if a broadcasting service area is moved by a vehicle, viewers can not recognize the change, The stability of the city hall can be enhanced and the driver of the vehicle can minimize the operation of operating the broadcasting receiver in the process of moving the service area, thereby contributing to safe driving.

Description

[0001] The present invention relates to a method for processing AV seamless seamless handover for TDMB broadcasting,

TECHNICAL FIELD [0001] The present invention relates generally to AV seamless handover processing techniques implemented in a TDMB broadcast receiving apparatus.

More particularly, the present invention provides a seamless AV handover technique in which a viewer can not recognize the fact of moving a receiving region by accurately synchronizing the same broadcasting service while synchronizing with a service area in a mobile receiving environment of TDMB broadcasting Quality TDMB broadcast reception environment which improves the stability of broadcasting viewing, and also contributes to safe driving by minimizing key operation during operation.

In the course of broadcasting technology, TDMB (Terrestrial Digital Multimedia Broadcasting) technology has been introduced for the purpose of providing digital multimedia broadcasting service in a mobile broadcasting receiving environment such as a car or a railroad.

In the TDMB broadcasting, a plurality of transmission antennas are installed for each region, and a broadcasting signal is transmitted at a frequency of a terrestrial wave band allocated in advance for each broadcasting company. A coverage area, that is, a reception area, is formed around the respective transmission antennas to effectively receive broadcasting signals transmitted from the corresponding antennas.

1 is a diagram showing an example of a TDMB broadcast receiving environment, which shows a transmitting station of the metropolitan area covering the metropolitan area and a transmitting station of the Chungcheong region covering the Chungcheong area, and the TDMB broadcasting receiving device is connected to the vehicle 30 running on the Kyungbu Expressway It is implemented as a mounted TDMB receiver.

As the vehicle 30 travels, the TDMB broadcasting receiver moves from the service area of the metropolitan area transmission station to the service area of the Chungcheong area transmission station. In this specification, when the service area is crossed, the TDMB broadcast receiving apparatus calls the service area, which is the existing service area, as the 'current domain 10', and the TDMB broadcast receiving apparatus receives the newly registered service domain as' .

In the conventional technology, as the vehicle 30 moves beyond the service area, the TDMB service (hereinafter, referred to as 'broadcast viewing service') that was previously viewed in the current area 10 is not normally reproduced from any moment. In such a case, it is general that the vehicle driver manually operates the TDMB receiver to rediscover the broadcast channel. Alternatively, the TDMB receiver may be configured to automatically re-search the channel. At this time, the service immediately before the channel list is reproduced after the channel search regardless of the existing broadcasting viewing service. In the present specification, 'service' means a broadcast program or broadcast content.

As described above, the prior art does not provide a user-friendly TDMB broadcasting viewing environment. In the present TDMB broadcasting related technical standard, there is no standard protocol about how to switch the service when the service area is moved, and there is no provision for service handover. Conventionally, a method of selecting and playing back a desired service after the user directly reselects the service for each zone in moving the service area is generally used.

Accordingly, there is a need for a technique for eliminating the inconvenience and realizing a user-friendly TDMB broadcasting viewing environment.

An object of the present invention is to provide an AV seamless handover processing technique generally performed in a TDMB broadcast receiving apparatus.

In particular, in the mobile reception environment of the TDMB broadcasting, when the service area is crossed, the same broadcasting service is maintained and the synchronization is precisely adjusted, thereby providing seamless AV handover technology so that the viewer can not recognize the reception area movement, The present invention provides an AV seamless handover processing technique capable of realizing a high quality TDMB broadcasting reception environment that improves the stability of viewing, minimizing key operation during operation and contributing to safe driving.

According to another aspect of the present invention, there is provided a method for processing AV seamless handover for TDMB broadcasting, comprising: receiving a TDMB broadcast stream for a specific broadcast viewing service from a current domain through a current TDMB tuner; A first step of storing video data and audio data subjected to audio-video decoding in a current video buffer (130) and a current audio buffer (140), respectively; The TDMB broadcasting stream for the broadcast viewing service is received at the next region 20 through the next TDMB tuner 210 and the video data and the audio data for performing the audio video decoding are transmitted to the next video buffer 230 and the next audio buffer 240, Respectively; A handover event information generator for generating TDMB broadcast handover event information from the current domain 10 to the next domain 20 based on the strength of the TDMB broadcast signal received by the current TDMB tuner 110 and the next TDMB tuner 210, Step 3; A synchronous control corresponding to the PTS offset between the current TDMB tuner 110 and the next TDMB tuner 210 for the broadcast viewing service by comparing patterns of the audio data stored in the current audio buffer 140 and the next audio buffer 240 A fourth step of generating information; The audio video reproduction path of the AV output unit 330 is switched from the current video buffer 130 and the current audio buffer 140 to the next video buffer 230 and the next audio buffer 240 in response to the handover event information, And a fifth step of shifting the audio-video playback time according to the PTS offset in response to the control information.

At this time, the AV seamless handover processing method according to the present invention includes: detecting a lock-off interval (hereinafter, referred to as a current lock-off interval) due to a broadcast reception failure of the current TDMB tuner 110; Inserting audio null data into the current audio buffer 140 in response to a current lock off interval to uniformize the buffered state of the current audio buffer 140; Detecting a lock-off period (hereinafter referred to as 'next lock-off interval') in accordance with a broadcast reception failure of the next TDMB tuner 210; Inserting audio null data into the next audio buffer 240 in response to the next lock off interval to manage the buffered state of the next audio buffer 240 in a uniform manner.

In this case, the fifth step includes: switching the audio reproduction path of the AV output unit 330 from the current audio buffer 140 to the next audio buffer 240 in response to the handover event information; Switching the video playback path of the AV output unit 330 from the current video buffer 130 to the next video buffer 230 in response to the handover event information; Adjusting the audio synchronization of the handover by setting the playback pointer of the next audio buffer 240 in accordance with the value of the PTS offset in comparison with the current audio buffer 140 in response to the synchronization control information; And adjusting the video synchronization of the handover by setting the playback pointer of the next video buffer 230 to correspond to the playback timing of the next audio buffer 240. [

According to another aspect of the present invention, there is provided a TDMB broadcast receiving apparatus for AV seamless handover, comprising: a current TDMB tuner (110) for receiving a TDMB broadcast stream for a specific broadcast viewing service in a current domain; A current AV decoder 120 for audio-video decoding a TDMB broadcast stream received by the current TDMB tuner 110; A current video buffer 130 for storing video data output by the current AV decoder 120; A current audio buffer 140 for storing audio data output from the current AV decoder 120; A NeXT TDMB tuner 210 for receiving a TDMB broadcast stream for a broadcast viewing service at a next region 20; A Next AV decoder 220 for audio-video decoding the TDMB broadcast stream received by the NeXT TDMB tuner 210; A Next video buffer 230 for storing video data output from the Next AV decoder 220; A next audio buffer 240 for storing audio data output from the next AV decoder 220; A QoS for generating handover event information of TDMB broadcast reception from the current domain 10 to the next domain 20 based on the strength of the TDMB broadcast signal received from the current TDMB tuner 110 and the next TDMB tuner 210, A monitoring unit 320; A synchronous control corresponding to the PTS offset between the current TDMB tuner 110 and the next TDMB tuner 210 for the broadcast viewing service by comparing patterns of the audio data stored in the current audio buffer 140 and the next audio buffer 240 An audio synchronization detecting unit 340 for generating information; The audio video reproduction path is switched from the current video buffer 130 and the current audio buffer 140 to the next video buffer 230 and the next audio buffer 240 in accordance with the handover event information, And an AV output unit 330 for shifting the audio-video playback time according to the PTS offset in response to the information.

At this time, the TDMB broadcasting receiver according to the present invention detects a lock-off period in response to a broadcast reception failure of the current TDMB tuner 110, inserts audio null data into the current audio buffer 140, A current lock-off processing unit 150 for uniformly managing the buffering state of the buffer 140; The NeXT TDMB tuner 210 detects a lock-off period in accordance with a broadcast reception failure and inserts audio null data into the NeXT audio buffer 240 to correspond to the NeXT audio buffer 240, Off processing unit 250 according to an embodiment of the present invention.

At this time, the AV output unit 330 shifts the reproduction pointer of the next audio buffer 240 in accordance with the value of the PTS (Presentation Time Stamp) offset in comparison with the current audio buffer 140 in response to the synchronization control information, And to set the playback pointer of the next video buffer 230 in synchronization with the playback timing of the next audio buffer 240. [

Meanwhile, a computer-readable nonvolatile recording medium according to the present invention records a program for causing a computer to execute an AV seamless handover processing method for TDMB broadcasting.

The present invention can be preferably applied to an apparatus for moving and receiving a TDMB broadcast, such as a TDMB receiver for a vehicle or an AVN system for a vehicle. According to the present invention, even if a broadcasting service area is moved by a vehicle, viewers can not recognize the change, The stability of the city hall can be enhanced and the driver of the vehicle can minimize the operation of operating the broadcasting receiver in the process of moving the service area, thereby contributing to safe driving.

FIG. 1 is a diagram illustrating an example of a TDMB broadcast receiving environment; FIG.
2 is a block diagram illustrating a basic structure of an internal functional configuration of a TDMB broadcast receiving apparatus according to the present invention;
3 is a block diagram illustrating an operation of a QoS monitoring unit in a TDMB broadcast receiving apparatus according to the present invention;
4 is a block diagram illustrating an operation of an audio synchronization detecting unit in a TDMB broadcast receiving apparatus according to the present invention.
5 is a diagram showing the concept of audio synchronization detection in the present invention.
6 is a block diagram illustrating an operation of a lock-down processing unit in a TDMB broadcast receiving apparatus according to the present invention;
FIG. 7 is a flowchart illustrating an overall process of an AV seamless handover method for TDMB broadcasting according to the present invention; FIG.
FIG. 8 is a flowchart illustrating a lock-off process for an audio buffer according to the present invention. FIG.
FIG. 9 is a flowchart illustrating a seamless switching process of an audio-video playback path in the present invention. FIG.

Hereinafter, the present invention will be described in detail with reference to the drawings.

2 is a block diagram illustrating a basic structure of an internal functional configuration of a TDMB broadcast receiving apparatus according to the present invention.

Referring to FIG. 2, the TDMB broadcasting receiving apparatus according to the present invention includes a functional block capable of receiving TDMB broadcasting and processing audio / video data in the current domain 10 and the next domain 20, respectively, And outputs the selected one to the LCD screen 350 and the speaker 360.

First, the current TDMB tuner 110 receives a TDMB broadcast stream for a specific broadcast viewing service in the current domain 10. Referring to FIG. 1, in the current domain 10, a TDMB broadcast receiving apparatus is reproducing a specific broadcast program (broadcast content) in a specific channel in response to a user's operation. Accordingly, the current TDMB tuner 110 receives a TDMB broadcast stream for a specific broadcast viewing service according to a user operation in the current domain 10.

The NeXT TDMB tuner 210 is a component for receiving a TDMB broadcast stream for the broadcast viewing service at the next region 20. Referring to FIG. 1, the TDMB broadcast receiving apparatus is moving from the current domain 10 to the next domain 20. The NeXT TDMB tuner 210 receives a TDMB broadcast stream corresponding to the broadcast viewing service that the TDMB broadcast receiving apparatus has reproduced in the current domain 10, at the next domain 20.

The TS decoder 310 demultiplexes the TDMB broadcast stream provided by the current TDMB tuner 110 and the next TDMB tuner 210, thereby outputting audio data and video data for a specific broadcast viewing service. At this time, the audio data and the video data outputted by the TS decoder 310 are compressed type. For example, the audio data is compressed by AAC (Advanced Audio Coding) and the video data is compressed by H.264.

The current AV decoder 120 performs audio-video decoding processing on the TDMB broadcast stream (audio data, video data) received and provided by the current TDMB tuner 110 in the current domain 10 according to, for example, the AAC and H.264 standards, And outputs compressed audio data and video data.

The current video buffer 130 and the current audio buffer 140 buffer and store the uncompressed video data and audio data output from the current AV decoder 120, respectively.

The next AV decoder 220 performs audio video decoding on the TDMB broadcast stream (audio data, video data) received and provided by the next TDMB tuner 210 in the next region 20 according to, for example, the AAC and H.264 standards, And outputs compressed audio data and video data.

The NeXT video buffer 230 and the NeXT audio buffer 240 buffer and store the uncompressed video data and audio data output from the Next AV decoder 220, respectively.

The AV output unit 330 receives audio data and video data for a specific broadcast viewing service that the user is currently watching from the current region 10 from the current video buffer 130 and the current audio buffer 140, And outputs it to the screen 350 and the speaker 360 to provide it to the viewer. The AV output unit 330 receives the audio data and the video data obtained in the next region 20 from the next video buffer 230 and the next audio buffer 240,

The AV output unit 330 switches the audio / video reproduction path from the current region 10 to the next region 20 in response to the identification of the fact that the service area has been exceeded, that is, the handover event information. The audio data and the video data transmitted from the current video buffer 130 and the current audio buffer 140 are output and the audio data and the video data transmitted from the next video buffer 230 and the next audio buffer 240 are output .

At this time, the AV output unit 330 according to the present invention adjusts the sync before and after the switching in the switching process of the audio-video reproduction path. That is, the position of the playback pointer for the next video buffer 230 and the next audio buffer 240 is precisely controlled so that the viewer does not feel a screen break phenomenon or an audio break phenomenon during the handover process. This will be described in detail later with reference to [Figure 4] and [Figure 5].

3 is a block diagram illustrating an operation of the QoS monitoring unit 320 in the TDMB broadcast receiving apparatus of the present invention.

In the present invention, the QoS monitoring unit 320 performs a function of identifying an event that the TDMB broadcast receiving apparatus goes beyond the service area. Referring to FIG. 1, as the vehicle 30 travels in the direction of the arrow, the QoS monitoring unit 320 moves the service area from the current area 10 to the next area 20 somewhere in a section where the service area overlaps It is to identify that it went.

The QoS monitoring unit 320 monitors the strength of the TDMB broadcast reception signal of the current domain 10 received through the current TDMB tuner 110 and the next TDMB tuner 210 and the TDMB broadcast reception signal of the next domain 20 To compare the strengths of the two. And generates handover event information indicating that the TDMB broadcast reception service area has been crossed from the current domain 10 to the next domain 20 based on the comparison result.

The AV output unit 330 outputs the broadcast viewing service to the LCD screen 350 and the speaker 360 in the current domain 10 and then receives the handover event information from the QoS monitoring unit 320, Switches the path of the output buffer from the service of the next zone 20 to the service of the next zone 20. At this time, as described later with reference to FIG. 4 and FIG. 5, if the service switching is performed while the audio / video synchronization is secured by utilizing the PTS offset value between the two services acquired by the audio synchronization detecting unit 340 The viewers are able to watch TDMB broadcasting in a seamless manner.

In the present invention, the TDMB broadcast receiving apparatus is discriminated from the service area, and the TDMB broadcast stream corresponding to the service (broadcast viewing service) currently being watched in the current domain 10 is transmitted to the next domain 20, And a description of the process of receiving and searching in FIG.

1, when the vehicle 30 travels in the direction of the arrow and enters the overlapping region with the next region 20 which is the edge of the current region 10, the QoS monitoring unit 320 monitors the TDMB front end it is discriminated at the front end that the TDMB broadcast reception signal of the current domain 10 is weakening.

Accordingly, the TDMB broadcast receiving apparatus performs channel search of the adjacent region in the overlapping region. At this time, if the position of the TDMB broadcast receiving apparatus is geographically located at the boundary of the zone through the GPS module, the channel search time of the adjacent region can be shortened. If the TDMB broadcast receiving apparatus does not have a GPS module or the GPS reception state is poor, the channel search of the adjacent region can be performed through the TDMB nationwide search.

Among the channels thus searched, a service which is the same as the service label or has been watched in the current domain 10 based on the code system of the service ID, i.e., the broadcast viewing service and the hand- Service can be linked to create a handover database (DB) list. The handover target service identified through the above process is decoded through the NeXT TMDB tuner 210, the TS decoder 310, and the Next AV decoder 220, thereby making it possible to perform seamless handover processing.

FIG. 4 is a block diagram illustrating an operation of the audio synchronization detector 340 in the TDMB broadcasting receiver of the present invention. FIG. 5 is a diagram illustrating the concept of audio synchronization detection in the present invention.

The audio synchronization detecting unit 340 detects uncompressed audio data received from the current audio buffer 140 and the next audio buffer 240 for a specific broadcast viewing service in the current area 10 and the next area 20, (Pulse Code Modulation) data and NeXT PCM data.

Then, the audio synchronization detecting unit 340 compares the sequence of the current PCM data with the sequence of the next PCM data to search for a matching portion, thereby determining a PTS offset (PTS offset) between the current region 10 and the next region 20 , The PTS difference value is obtained. At this time, the PTS (Program Time Stamp) is a reference time that is generated in order to synchronize the reproduction motions of the audio and the video when the moving picture is reproduced. The PTS offset identified and obtained by the audio synchronization detector 340 corresponds to synchronization control information for synchronizing audio synchronization between the current TDMB tuner 110 and the next TDMB tuner 210 for the corresponding broadcast viewing service.

In response to the handover event information, the AV output unit 330 switches the reproduction pointer of the next audio buffer 240 to the current audio information in response to the synchronization control information generated by the audio synchronization detector 340 in the process of switching the TDMB broadcast reproduction path. The buffer 140 is shifted according to the value of the PTS offset, thereby achieving audio synchronization in the handover process.

In addition, the AV output unit 330 sets a reproduction pointer of the next video buffer 230 to correspond to the reproduction timing of the next audio buffer 240, thereby achieving video synchronization in the handover process. That is, the PTS of the synchronization point is secured in the handover target broadcast through audio synchronization, and video synchronization is achieved through the synchronization point between video and audio corresponding thereto.

As described above, when the PTS difference value between the two services acquired by the audio synchronization detecting unit 340 is used, the AV output unit 330 can perform service switching while ensuring synchronization, thereby enabling seamless viewing of the broadcasts.

This process will be described in detail with reference to FIG. 5, a PTS value of a broadcast currently being viewed in the current domain 10 is indexed by m on the basis of a specific time point with respect to a specific broadcast viewing service, and a PTS value of a handover target broadcast is indexed by n Respectively.

When the current PCM data is compared with the NeXT PCM data and the matching part is searched, it can be seen that the audio synchronization interval of the two broadcasts is the n-2 point in the handover target broadcast. That is, the handover target broadcast has a time delay of about -2 at the same point in time for the broadcast currently being viewed. The audio synchronization detecting unit 340 identifies the PTS offset by comparing the current PCM data and the next PCM data And generates synchronization control information.

The AV output unit 330 receives the synchronization control information and shifts the PTS value from the current time point to -2 in the handover process. That is, the handover does not proceed from the 'A' point of the current PCM data to the 'B' point of the next PCM data through the handover but shifts by -2 and proceeds to the 'C' point. As the AV output unit 330 performs handover while shifting the PTS value, the viewer can view the service while maintaining audio synchronization.

On the other hand, in the present invention, the audio synchronization detecting unit 340 retrieves audio synchronization from audio data in an uncompressed state.

Generally, even if the same service (broadcast content) is used when the service area is different, the broadcast signal actually transmitted through the transmitting station according to the service area may have different audio and video encoding rates. Accordingly, even if the same service is provided, there is a high possibility that data in a compressed form before audio-video decoding is completely different from each other. That is, as the audio data in the compressed form, the correlation between the audio of the broadcast currently being watched and the audio of the handover target broadcast is not performed, so that the synchronization section can not be found.

In addition, since the audio PCM data, which is decompressed and decompressed after decoding, is the actual audio data generated by sampling from the analog signal, it is possible to search for the synchronization section using the existing verified frequency band synchronization and time band synchronization algorithm Do.

6 is a block diagram illustrating operations of a current lock-off processing unit 150 and a next lock-off processing unit 250 in a TDMB broadcast receiving apparatus according to the present invention.

First, the current lock-off processing unit 150 detects a lock-off period corresponding to a broadcast reception failure of the current TDMB tuner 110 and inserts audio null data into the current audio buffer 140 in response to the lock- So that the buffered state of the current audio buffer 140 can be maintained uniformly.

The next lock-off processing unit 250 detects the lock-off period of the next TDMB tuner 210 in response to a broadcast reception failure and inserts audio null data into the next audio buffer 240 in response to the lock- ) Can be maintained in a uniform state.

In the present invention, it is important to manage the audio buffers 140 and 240 in order to precisely grasp the time of audio synchronization in two services before and after the handover. Since the terrestrial broadcasting environment is poor, the lock-off phenomenon occasionally occurs. However, the area where the handover occurs corresponds to the edge of the service area, and thus the reception environment is particularly poor.

When a lock-off phenomenon occurs, broadcast data is not input from the TDMB tuners 110 and 210 in the service area, and audio data is not output from the AV decoders 120 and 220 as a result. If such a state is left unchanged, the time corresponding to the lock-off section disappears in the audio buffers 140 and 240, and thus the time flow of the audio buffers 140 and 240 is distorted. Since the lock-off phenomenon occurs independently for each service area, time-current distortion in the current audio buffer 140 and the next audio buffer 240 is completely different.

In the case where the time flows of the audio buffers 140 and 240 are distorted in different forms, the pattern comparison becomes difficult in [FIG. 5], so that the time synchronization can not be properly adjusted and it seems that a PTS offset for synchronizing at a certain point is found There is a problem that the synchronization is immediately turned off when the lockoff zone 10 or the next zone 20 encounters a lockoff zone.

Accordingly, in the present invention, when a lock-off interval is identified, null data is inserted into the audio buffers 140 and 240 of the path where the lock-off occurred, It is necessary to make the audio data constantly in the audio buffers 140 and 240 and constantly exhausted so that the flow remains constant, i. E., Over time.

7 is a flowchart illustrating an overall process of an AV seamless handover method for TDMB broadcasting according to the present invention.

The AV seamless handover processing technology according to the present invention searches for the same service as that currently being watched when the service area is moved in the TDMB mobile reception environment in the next region 20 and seamlessly performs handover through audio synchronization detection Technology.

Since the service for transmitting national broadcasting such as KBS broadcasts the same contents in the same time zone, it is possible to provide a seamless high quality viewing environment to the user by using the present invention.

In step S110, the TDMB broadcast receiving apparatus receives a TDMB broadcast (broadcast content) of a specific broadcast viewing service (broadcast content) that the viewer has selected and watched in the current domain 10 through the current TDMB tuner 110, Video data and audio data that have been subjected to audio-video decoding such as AAC and H.264 through the current AV decoder 120 are stored in the current video buffer 130 and the current audio buffer 140, respectively .

The TDMB broadcast receiving apparatus receives the TDMB broadcast stream corresponding to the corresponding broadcast viewing service in the next region 20 through the next TDMB tuner 210 and transmits the TDMB broadcast stream to the AAC And H.264, respectively, in the next video buffer 230 and the next audio buffer 240, respectively.

Step S130: The QoS monitoring unit 320 determines whether or not the current status of the Neighbor TDMB tuner 110 and the Neighbor TDMB tuner 210 in the current domain 10 is " And generates handover event information of TDMB broadcast reception in the area 20. The process of generating the handover event information by the QoS monitoring unit 320 has been described in detail with reference to FIG.

Step S140: The audio synchronization detector 340 compares the sequence of the audio data in the uncompressed form stored in the current audio buffer 140 and the next audio buffer 240 to generate a current TDMB tuner 110 And a Neighbor TDMB tuner 210. The synchronous control information includes a synchronous control information and a synchronous control information. The process of generating synchronization control information by the audio synchronization detecting unit 340 has been described in detail with reference to FIGS. 4 and 5. FIG.

In step S150, the AV output unit 330 outputs an audio-video playback path from the current video buffer 130 and the current audio buffer 140 to the next video buffer 130 in response to the handover event information provided by the QoS monitoring unit 320, (230) and the next audio buffer (240). The TDMB broadcasting signal received at the next region 20 is more advantageous than the TDMB broadcasting signal received from the current region 10, so that handover is performed to the next region 20.

At this time, the AV output unit 330 determines the reproduction time point of the video data and the audio data obtained from the next video buffer 230 and the next audio buffer 240 according to the synchronization control information provided by the audio synchronization detecting unit 340, Shift according to the offset. The process of the AV output unit 330 using the PTS offset included in the synchronization control information to achieve synchronization of audio video in the handover process has been described in detail with reference to FIG. 4 and FIG.

8 is a flowchart illustrating a lock-off process performed by the current lock-off processing unit 150 and the next lock-off processing unit 250 for the current audio buffer 140 and the next audio buffer 240 in the present invention.

As described above with reference to FIG. 6, the lock-off phenomenon frequently occurs independently in the current domain 10 and the next domain 20 in the process of going beyond the service domain. At this time, if the audio buffers 140 and 240 of the path where the lock-off occurs are not specifically managed, distortion of time flow occurs, thereby making it difficult to achieve a seamless handover.

The configuration in which the lock-off processing units 150 and 250 insert null data into the audio buffers 140 and 240 corresponding to the lock-off phenomenon by the lock-off interval is described in detail in FIG. 6 . Hereinafter, the processing process will be briefly described.

Steps S210 and S220: First, the current lock-off processing unit 150 detects a lock-off period (hereinafter, referred to as a current lock-off period) due to a broadcast reception failure of the current TDMB tuner 110. When detecting the lock-off, the current lock-off processing unit 150 inserts the audio null data into the current audio buffer 140 corresponding to the current lock-off interval, thereby buffering the current audio buffer 140 To be maintained.

Steps S230 and S240: Similarly, the next lock-off processing unit 250 detects a lock-off period (hereinafter referred to as a 'next lock-off period') caused by a broadcast reception failure of the next TDMB tuner 210. If the lock-off is detected, the next lock-off processing unit 250 inserts audio null data into the next audio buffer 240 corresponding to the next lock-off period, thereby buffering the buffer state of the next audio buffer 240 To be maintained.

9 is a flowchart specifically illustrating a process of seamlessly switching the audio-video playback path of the TDMB broadcast between the current domain 10 and the next domain 20 in accordance with the present invention. The flowchart of FIG. 9 corresponds to step S150 in the flowchart of FIG. 7, and the technical structure for implementing the same is described in detail with reference to FIG. 3 to FIG.

Step S310: First, the AV output unit 330 switches the audio reproduction path from the current audio buffer 140 to the next audio buffer 240 in response to the handover event information provided by the QoS monitoring unit 320 . The TDMB broadcasting signal received at the next region 20 is more advantageous than the TDMB broadcasting signal received from the current region 10, so that handover is performed to the next region 20.

Step S320: Similarly, in response to the handover event information provided by the QoS monitoring unit 320, the video reproduction path of the AV output unit 330 is switched from the current video buffer 130 to the next video buffer 230 . The TDMB broadcast signal received at the next domain 20 is more advantageous than the current domain 10, so that handover is performed to the next domain 20.

The AV output unit 330 outputs the reproduction pointer of the next audio buffer 240 to the value of the PTS offset in comparison with the current audio buffer 140 in accordance with the synchronization control information provided by the audio synchronization detection unit 340 Set the shift accordingly. The audio output point in FIG. 5 corresponds to the process of moving from the 'B' point to the 'C' point in the next PCM data. Thus, the audio sound output to the speaker 360 is seamlessly connected to the 'C' point of the next PCM data at the 'A' point of the current PCM data before and after the handover.

Step S340: The AV output unit 330 sets the reproduction pointer of the next video buffer 230 to correspond to the reproduction timing of the next audio buffer 240, thereby achieving video synchronization in the handover process. Through the audio synchronization, the PTS of the synchronization point is secured in the handover target broadcast, and video synchronization is achieved through the synchronization point between the video and audio corresponding thereto.

As described above, when the PTS difference value between the two services acquired by the audio synchronization detecting unit 340 is used, the AV output unit 330 can perform service switching while ensuring synchronization, thereby enabling seamless viewing of the broadcasts.

Meanwhile, the present invention can be embodied in the form of computer readable code on a computer-readable non-volatile recording medium. Such a non-volatile recording medium includes all kinds of storage devices for storing computer-readable data such as a hard disk, an SSD, a CD-ROM, a NAS, a magnetic tape, a web disk, a cloud disk, The code may be distributed and stored in the storage device of the computer.

110: Current TDMB tuner
120: Current AV decoder
130: Current video buffer
140: Current audio buffer
150: Current lock-off processing unit
210: NeXT TDMB tuner
220: Next AV decoder
230: NeXT video buffer
240: Next audio buffer
250: Neckstop Processor
310: Play TS
320: QoS monitoring unit
330: AV output section
340: Audio sync detection unit
350: LCD screen
360: Speaker

Claims (8)

CLAIMS 1. A method for processing AV seamless handover while receiving a TDMB broadcast while a TDMB broadcast receiving apparatus is moving,
The current TDMB broadcasting stream is received from the current domain 10 through the current TDMB tuner 110 and the video data and audio data which have been subjected to the audio video decoding are transmitted to the current video buffer 130 and the current audio buffer 140), respectively;
The TDMB broadcast stream corresponding to the broadcast viewing service is received from the next region 20 through the next TDMB tuner 210 and the video data and audio data which have been subjected to the audio video decoding are transmitted to the next video buffer 230 and the next audio buffer 240), respectively;
Off period according to a broadcast reception failure of the current TDMB tuner 110 (hereinafter, referred to as 'current lock-off interval'), the current audio buffer 140 stores audio null data A third step of managing the buffered state of the current audio buffer 140 by uniformly inserting the current audio buffer 140;
(Hereinafter, referred to as a 'next lock-off interval') in accordance with a broadcast reception failure of the next TDMB tuner 210, audio null data A fourth step of managing the buffered state of the next audio buffer 240 by uniformly inserting the buffered state of the next audio buffer 240;
The handover event information of the TDMB broadcast reception from the current domain 10 to the next domain 20 based on the strength of the TDMB broadcast signal received from the current TDMB tuner 110 and the next TDMB tuner 210, ;
The sequence of the current PCM data stored in the current audio buffer 140 is compared with the sequence of the next PCM data stored in the next audio buffer 240 to search for a matching portion of the current PCM data, A sixth step of identifying a PTS offset which is a PTS difference value between the first TDMB tuner 210 and the next TDMB tuner 210;
Video playback path of the AV output unit 330 from the current video buffer 130 and the current audio buffer 140 in correspondence with the handover event information to the next video buffer 230 and the next audio buffer 240 );
An eighth step of adjusting audio synchronization before and after handover by setting a reproduction pointer of the next audio buffer 240 to be shifted according to a value of the PTS offset as compared with the current audio buffer 140;
And the AV seamless handover processing method for TDMB broadcasting.
delete The method according to claim 1,
In the seventh step,
Switching an audio reproduction path of the AV output unit 330 from the current audio buffer 140 to the next audio buffer 240 in response to the handover event information;
Switching the video playback path of the AV output unit 330 from the current video buffer 130 to the next video buffer 230 in response to the handover event information;
Wherein the AV seamless handover processing method comprises the steps of:
The method according to claim 1,
The method of claim 1,
A ninth step of adjusting the video synchronization of the handover by setting the reproduction pointer of the next video buffer 230 to correspond to the reproduction timing of the next audio buffer 240;
Wherein the AV seamless handover processing method further comprises:
delete delete delete A computer readable nonvolatile recording medium storing a program for causing a computer to execute a method of processing an AV seamless handover for TDMB broadcasting according to any one of claims 1, 3 and 4.

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