JP2009118136A - Television receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid break off of video images and sound when broadcast for fixed reception and broadcast for mobile reception are switched. <P>SOLUTION: This television receiver includes: a common data detection part which detects common (the same) data between the broadcast for fixed reception and the broadcast for mobile reception; a broadcast for fixed reception analysis part which analyzes the common data about the broadcast for fixed reception; a broadcast for mobile reception analysis part which analyzes the common data about the broadcast for mobile reception; a delay time difference detection part which calculates delay time difference between the broadcast for fixed reception and the broadcast for mobile reception from results obtained by analysis of each analysis part; and a delay processing part which delays the broadcast for fixed reception by delay time detected by the delay time difference detection part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mobile phone such as a mobile phone that receives a digital TV broadcast, a television receiver such as a portable device or an in-vehicle device.

  Terrestrial digital broadcasting started in December 3, 2003 in the three major areas of Kanto, Kinki, and Chukyo became available in December 2006 at the prefectural offices nationwide.

  Currently, in terrestrial digital broadcasting, broadcasting for fixed reception and broadcasting for mobile reception are performed. In broadcasting for fixed reception, it is possible to view high bit rate video and audio compressed by MPEG2. On the other hand, in broadcasting for mobile reception, H.264 is used. H.264 compressed video and audio can be viewed at a low bit rate.

  Here, in a television receiver that switches between viewing for fixed reception broadcasting and broadcasting for mobile reception, video and audio are interrupted when switching. Usually, a fixed reception broadcast and a mobile reception broadcast cause a delay time difference depending on the encoding method at the time of transmission and the decoding method at the time of reception. Broadcasting for mobile reception uses H.264 with a high compression rate. Since H.264 is employed, both the compression processing and the decoding processing have a larger delay amount than the fixed reception broadcasting employing MPEG2.

  Therefore, when such two types of digital broadcasts are switched and received, the video and audio are interrupted. As a method for avoiding the video and audio, there is the following document.

The invention described in Patent Document 1 is a digital broadcast receiving device mounted on a mobile body, and switches to mobile reception broadcasting if it is in a state in which fixed reception broadcasting cannot be properly received. In order to eliminate the difference in the delay amount at the time of switching, the output timing on the side with the smaller delay amount is delayed by the delay amount and output.
JP 2004-166173 A

  However, in the conventional configuration, the delay amount is calculated by comparing (frequency comparison) audio signals for a certain period of time between broadcast for fixed reception and broadcast for mobile reception, so in terms of signal processing load and accuracy There are challenges.

  The present invention solves the above-described conventional problems, calculates a delay amount between a fixed reception broadcast and a mobile reception broadcast with high accuracy with a relatively small signal processing load, and The purpose is to provide uninterrupted video and audio when switching between fixed reception broadcasting and mobile reception broadcasting by delaying by the amount of delay.

In order to solve the above-described conventional problems, a television receiver according to the present invention includes an antenna unit that receives broadcast for fixed reception and broadcast for mobile reception, and a tuner unit that performs demodulation processing of broadcast for fixed reception and broadcast for mobile reception A fixed reception AV signal processing unit that outputs video and audio from the demodulated fixed reception broadcast; a mobile reception AV signal processing unit that outputs video and audio from the demodulated mobile reception broadcast;
A reception state monitoring unit that monitors reception states of the fixed reception broadcast and the mobile reception broadcast, and the fixed reception broadcast and the mobile reception broadcast according to the reception state detected by the reception state monitoring unit. An output signal switching control unit for switching, a video display unit for displaying a video switched by the output signal switching control unit, and an audio output unit for outputting audio.

  With this configuration, when the received signal strength decreases, the broadcast can be switched from the fixed reception broadcast to the mobile reception broadcast and viewed.

  Furthermore, the television receiver of the present invention includes a common data detection unit that detects whether the broadcast is for the fixed reception and the broadcast for the mobile reception common (identical) data, so that it is a simulcast, and the fixed reception When the broadcast for mobile and the broadcast for mobile reception are simulcast, the broadcast analysis unit for fixed reception that analyzes the data of the common fixed reception broadcast and the broadcast for mobile reception that analyzes the data of the common mobile reception broadcast An analysis unit, a delay time difference detection unit that calculates a delay time difference between the fixed reception broadcast and the mobile reception broadcast, and a delay time detected by the delay time difference detection unit, from the results analyzed by the respective analysis units And a delay processing unit that delays the fixed reception broadcast.

  With this configuration, when the fixed reception broadcast and the mobile reception broadcast are simultaneous broadcasts, the delay amount between the fixed reception broadcast and the mobile reception broadcast is calculated, and the fixed reception broadcast is delayed by that amount. Thus, it is possible to avoid interruption of video and audio when the broadcast for fixed reception and the broadcast for mobile reception are switched.

  According to the television receiver of the present invention, the delay time difference between the broadcast for fixed reception and the broadcast for mobile reception can be easily and accurately grasped using subtitle data. When switching, seamless switching without time difference can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIG. 2, the present invention is mounted on a mobile body such as an in-vehicle type television receiver 202, a portable type television receiver 203, and a mobile type television receiver 204, and fixed reception transmitted from a broadcasting station 201. It can be used with a TV receiver that can switch between one of the broadcast for mobile use and the broadcast for mobile reception.

  FIG. 1 is a functional block diagram of the television receiver according to Embodiment 1 of the present invention. A solid line indicates the flow of the stream, and a broken line indicates a control signal or control data.

  The fixed reception broadcast and the mobile reception broadcast input from the antenna 101 are demodulated by the tuner unit 102. At this time, the reception state monitoring unit 112 monitors whether it can be demodulated normally by using an index such as a bit error rate, and when the reception state becomes worse than the threshold value, the output signal switching control unit 113 performs the video signal switching unit 110. And the audio signal switching unit 111 are instructed to switch the output from the broadcast for fixed reception to the broadcast for mobile reception.

  The common data detection unit 103 detects whether the fixed reception broadcast and the mobile reception broadcast are simultaneous broadcasts by detecting common (identical) caption data of the fixed reception broadcast and the mobile reception broadcast. Can be detected. When the broadcast for fixed reception and the broadcast for mobile reception are simultaneous broadcasts, the common subtitle data is analyzed by the fixed reception subtitle data analysis unit 104 and the mobile reception subtitle data analysis unit 105.

  Hereinafter, the method of calculating the delay time difference between the fixed reception broadcast and the mobile reception broadcast from the analysis of the caption data and the analysis result will be described with reference to FIG.

  In S001, the common data detection unit 103 detects caption data common to the fixed reception broadcast and the mobile reception broadcast.

  Next, in S002, the common data detection unit 103 performs PTS1 (Presentation Time Stamp), which is the display time in the common fixed reception broadcast caption data, and TOT1 (Time Offset Table), which is the real time information, in the subsequent stage. To the fixed reception subtitle data analysis unit 104 of the received data. Similarly, the mobile reception subtitle data analysis unit 105 in the subsequent stage is notified of the values of the display time PTS2 and the real-time information TOT2 in the common subtitle data for mobile reception broadcasting.

  Next, in S003, the fixed reception caption data analysis unit 104 recognizes how many more clocks (x clocks) the caption data is to be displayed from the notified value of PTS1. In step S005, x is converted to a time unit, and x 'is calculated. Next, in S007, the fixed reception subtitle data analysis unit 104 calculates the actual time X of the x ′ using the TOT1. Note that the caption data display time Y in broadcasting for mobile reception is similarly calculated in S004, S006, and S008. In S009, the delay time difference detection unit 106 calculates the delay time difference between the fixed reception broadcast and the mobile reception broadcast from the difference between X and Y.

  The delay time difference calculated in this way is notified to the delay processing unit 107. The delay processing unit 107 repeatedly outputs the fixed reception broadcast by delaying by the delay time difference. According to such a configuration, it is possible to synchronize the broadcast for fixed reception and the broadcast for mobile reception. Therefore, it is possible to avoid interruption of video and audio when switching from broadcast for fixed reception to broadcast for mobile reception. In addition, since the caption data has a data amount of about several hundred kbps at most, the signal processing load for analyzing the data is relatively light. Since the display timing of the caption data is synchronized with the video, the delay time can be accurately grasped.

  The delayed broadcast for fixed reception is separated into video and audio by the fixed reception AV signal processing unit 108 and output to the video display unit 114 and the audio output unit 115. Similarly, the mobile reception broadcast is also separated into video and audio by the mobile reception AV signal processing unit 109 and output to the video display unit 114 and the audio output unit 115.

  When the common data detection unit 103 detects that the broadcast for fixed reception and the broadcast for mobile reception are not simultaneous broadcasts, the common data detection unit 103 and the fixed reception subtitle data analysis unit 104 and the mobile The received subtitle data analysis unit 105 is instructed not to analyze subtitle data. In addition, the delay time difference detection unit 106 instructs the delay processing unit 107 not to perform the delay processing.

  If the reception state is determined to be good by the reception state monitoring unit 112, it may be switched to the fixed reception broadcast while viewing the mobile reception broadcast. Since the broadcast for fixed reception and the broadcast for mobile reception are synchronized, video and audio are not interrupted at the time of switching.

  The video signal switching unit 110 and the audio signal switching unit 111 can be automatically switched by an instruction from the output signal switching control unit 113. On the other hand, the user can make a determination manually based on the video on the video display unit 114 or the audio on the audio output unit 115, and switch manually. In this case, the reception state monitoring unit 112 and the output signal switching control unit 113 are not necessary.

  In the block diagram of FIG. 1, the tuner unit 102 has a built-in filter for separating the fixed reception broadcast and the mobile reception broadcast. However, the tuner unit 102 and the filter may be arranged separately. The antenna 101 and the tuner unit 102 may also be prepared for each of the fixed reception broadcast and the mobile reception broadcast.

  In the present embodiment, the switching between two digital broadcasts, that is, the broadcast for fixed reception and the broadcast for mobile reception has been described. However, the switching of three or more digital broadcasts can be realized by the same method.

  The television receiver according to the present invention has means for analyzing common subtitle data and calculating a delay time difference when a fixed reception broadcast such as 12 segments and a broadcast for mobile reception such as 1 segment are simultaneous broadcasts. Therefore, it is useful for mobile devices such as mobile phones, portable devices, and in-vehicle devices that switch between viewing for fixed reception and broadcasting for mobile reception.

Functional block diagram of the television receiver in Embodiment 1 of the present invention The figure which shows the utilization scene of this invention The flowchart which calculates the delay time difference in Embodiment 1 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Antenna 102 Tuner part 103 Common data detection part 104 Fixed reception subtitle data analysis part 105 Mobile reception subtitle data analysis part 106 Delay time difference detection part 107 Delay processing part 108 Fixed reception AV signal processing part 109 Mobile reception AV signal processing part 110 Video signal Switching unit 111 Audio signal switching unit 112 Reception state monitoring unit 113 Output signal switching control unit 114 Video display unit 115 Audio output unit 201 Broadcast station 202 Car-mounted type television receiver 203 Portable type television receiver 204 Mobile type television receiver

Claims (9)

A television receiver mounted on a mobile body such as a mobile phone, a portable device or an in-vehicle device,
An antenna unit for receiving broadcast for fixed reception and broadcast for mobile reception;
A tuner unit that performs demodulation processing of fixed reception broadcasting and mobile reception broadcasting;
A fixed reception AV signal processing unit for outputting video and audio from the demodulated broadcast for fixed reception;
A mobile reception AV signal processing unit for outputting video and audio from the demodulated mobile reception broadcast;
A reception state monitoring unit that monitors reception states of the fixed reception broadcast and the mobile reception broadcast;
An output signal switching control unit that switches between the fixed reception broadcast and the mobile reception broadcast according to the reception state detected by the reception state monitoring unit;
A video display unit for displaying the video switched by the output signal switching control unit;
An audio output unit for outputting audio switched by the output signal switching control unit;
A common data detection unit for detecting whether the broadcast is for fixed reception and the broadcast for mobile reception is the same (same) data, or whether it is a simulcast,
When the broadcast for fixed reception and the broadcast for mobile reception are simultaneous broadcasts, a broadcast analysis unit for fixed reception that analyzes data of the common fixed reception broadcast;
A mobile reception broadcast analysis unit for analyzing the data of the common mobile reception broadcast;
From the results analyzed by the broadcast analysis unit for fixed reception and the broadcast analysis unit for mobile reception, a delay time difference detection unit that calculates a delay time difference between the broadcast for fixed reception and the broadcast for mobile reception;
A television receiver, comprising: a delay processing unit that delays broadcasting for fixed reception by a delay time detected by the delay time difference detection unit. The fixed reception broadcast analysis unit analyzes the common caption data detected by the common data detection unit, and detects a display time value in the common fixed reception broadcast caption data. Item 2. A television receiver according to item 1. The mobile reception broadcast analysis unit analyzes the common caption data detected by the common data detection unit, and detects a display time value in the common mobile reception broadcast caption data. Item 2. A television receiver according to item 1. 3. The fixed reception broadcast analysis unit corrects the detected display time value of the fixed reception broadcast caption data with real time information, and calculates the real time caption data display time. A television receiver as described in 1. 4. The mobile reception broadcast analysis unit corrects the detected display time value of caption data of mobile reception broadcast with real time information, and calculates real time caption data display time. A television receiver as described in 1. The television receiver according to claim 4, wherein the real-time information is TOT (Time Offset Table). 6. The television receiver according to claim 5, wherein the real-time information is TOT (Time Offset Table). The delay time difference detection unit is configured to calculate a delay time difference between the fixed reception broadcast and the mobile reception broadcast from a difference between real time caption data display time of the fixed reception broadcast and subtitle data display time of the mobile reception broadcast. The television receiver according to claim 1, wherein the television receiver is detected. 2. The television receiver according to claim 1, wherein the common data detection unit compares the subtitle data of the fixed reception broadcast and the mobile reception broadcast to detect whether the broadcast is a simultaneous broadcast.

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