JP2008011254A - Terrestrial digital broadcasting receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent video display from being interrupted momentarily (1-4 seconds) when changing the video presentation of broadcasting for fixed receivers to that of broadcasting for portable receivers. <P>SOLUTION: A demultiplexer 2 divides a transport stream outputted from a tuner 1 into MPEG2 video and audio streams, and H. 264 video and audio streams. The MPEG2 video stream and the H. 264 video stream are supplied to a video decoder 3 for MPEG 2 and a video decoder 4 for H. 264, respectively. Video data outputted from the video decoders 3, 4 each are supplied to a selection section 6. The selection section 6 selects one video data by the manual operation of the user or automatic selection based on an error rate. The selected video data are supplied to a video processing section 7. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a terrestrial digital broadcast receiving apparatus that receives terrestrial digital broadcasts.

A receiving apparatus that receives terrestrial digital broadcasting includes a tuner that demodulates a transport stream (TS) from received radio waves, separates packets from the transport stream, and outputs video and audio by decoding the packets by a decoder. . And in terrestrial digital broadcasting, one of 13 segments is used for broadcasting for portable receivers, and a unique service is transmitted in this one segment (one-segment broadcasting), and 12 segments are broadcasting services for fixed receivers. Operation to be used for provision is possible (see Patent Document 1).
JP 2005-277873 A

  In the one-segment broadcasting, the video is H.264. H.264 is encoded, and in the broadcast for fixed receivers, the video is encoded by MPEG2. The decoder of the broadcast receiving apparatus is composed of a digital signal processor (DSP). It functions as an H.264 decoder or an MPEG2 decoder.

  However, said H.I. In the video generation processing according to H.264, when the video format information is transmitted at intervals of about 2 seconds, the video presentation is performed when switching from the video presentation state of the broadcast for the fixed receiver to the video presentation of the broadcast for the portable receiver. There is a momentary break (1 to 4 seconds).

  In view of the above circumstances, the present invention can switch between video presentation for broadcasting to a fixed receiver and video presentation for broadcasting to a portable receiver, and can prevent a situation in which video display is momentarily interrupted during this switching. An object of the present invention is to provide a terrestrial digital broadcast receiver.

  In order to solve the above problems, a terrestrial digital broadcast receiving apparatus of the present invention receives a terrestrial digital broadcast and outputs a transport stream, a demultiplexer that separates packets from the transport stream, and the transformer A first video decoder for decoding a fixed receiver broadcast video packet separated from a port stream; a second video decoder for decoding a non-fixed receiver broadcast video packet separated from the transport stream; A selection unit that selects one of the video data output from both video decoders and a display unit that displays a video based on the selected video data are provided.

  With the above configuration, one video data is selected from the video data output from both the first video decoder and the second video decoder, and the other video has been decoded at the time of video switching. Therefore, it is possible to prevent a situation where the video display is interrupted for an instant (1 to 4 seconds) when switching between the video presentation for the fixed receiver and the video presentation for the portable receiver.

  In the terrestrial digital broadcast receiving apparatus having the above-described configuration, the selection unit may select one video data in accordance with a user's manual operation.

  In the terrestrial digital broadcast receiving apparatus having these configurations, the determination unit for determining the reception quality, and when the reception quality is equal to or higher than a predetermined threshold, the selection unit selects the video data output from the first video decoder, and the reception quality is And a control unit that causes the selection unit to select video data output from the second video decoder when less than a predetermined threshold.

  In the terrestrial digital broadcast receiver having these configurations, the determination unit determines both the reception quality of the broadcast for the fixed receiver and the reception quality of the broadcast for the non-fixed receiver, and the display unit selects the selected video or the other video. It is good also as displaying the information regarding the reception quality of.

  According to the present invention, it is possible to prevent a situation in which video display is interrupted for a moment (1 to 4 seconds) when switching between video presentation for broadcasting to a fixed receiver and video presentation for broadcasting to a portable receiver. Play.

  Hereinafter, an in-vehicle terrestrial digital broadcast receiving apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  The antenna in the terrestrial digital broadcast receiving apparatus 30 receives a digital broadcast signal transmitted from a terrestrial broadcast station. The terrestrial digital tuner 1 extracts a signal having a specific frequency from the high-frequency digital modulation signal including video / audio data. Further, the tuner 1 includes an OFDM (Orthogonal Frequency Multiplexing) demodulation circuit, a deinterleave circuit, an error correction circuit, and the like, thereby demodulating the selected digital modulation signal and outputting a transport stream (TS). When the radio wave reception status (broadcast reception quality) is poor, packet correction by the error correction circuit may become impossible (reception error or packet loss), and the error rate (packet loss rate) as a monitoring result is The tuner 1 is notified to the microcomputer 13. In this embodiment, packet errors are monitored for each segment (for each layer) of one segment for so-called one-seg broadcasting (broadcast for portable receivers) and the other 12 segments (broadcast for fixed receivers). Is notified to the microcomputer 13.

  The DEMUX (demultiplexer) 2 converts the transport stream output from the tuner 1 into an MPEG2 (Moving Picture Experts Group 2) video stream and audio stream; H.264 video stream and audio stream. Then, the MPEG2 video stream is supplied to the video decoder 3 (for MPEG2). The H.264 video stream is supplied to the video decoder (for H.264) 4. The audio decoder 5 receives an audio stream of the selected service. The audio decoder 5 is, for example, a high-order decoder for both broadcasting for portable receivers and broadcasting for fixed receivers. In addition, the demultiplexer 2 supplies PSI / SI (Program Specific Information / Service Information) separated from the transport stream to the microcomputer 13. There are PSI / SI that exists in broadcasts for portable receivers and those that exist in broadcasts for fixed receivers. The microcomputer 13 stores EPG information extracted from each PSI / SI in memory. 14.

  The video data respectively output from the video decoders 3 and 4 is supplied to the selection unit 6. The selection unit 6 is controlled by the microcomputer 13 and selects one video data by manual operation by the user or automatic selection based on the error rate.

  The selected video data is supplied to the video processing unit 7. The audio data output from the audio decoder 5 is output to the audio processing unit 8. The video processing unit 7 receives the selected video data, performs D / A conversion, and generates a video signal. Note that the video processing unit 7 has a scaler function, can enlarge the broadcast video for portable receivers, and can display the video on the entire screen in the same manner as the broadcast video for fixed receivers. The video processing unit 7 has an OSD (on-screen display function), and superimposes video based on character information and image information output from the microcomputer 13 on the video data. The audio processing unit 8 receives the audio data output from the audio decoder 5 and generates audio data.

  Upon receiving the video signal, the driver 9 drives a display (for example, a liquid crystal display panel) 10. The audio data is converted into an analog signal through the D / A conversion amplifier 11 and input to the speaker 12.

  The memory (RAM, EEPROM, flash memory, ROM, etc.) 14 stores various programs and data. When the terrestrial digital broadcast receiving apparatus 30 is turned on, the microcomputer 13 develops the program and data stored in the ROM in the RAM and executes the program on the RAM. When a key of the operation unit 15 is operated, a signal indicating a command corresponding to the key is supplied to the microcomputer 13.

  When the microcomputer 13 detects that the video switch key provided in the operation unit 15 is pressed, the microcomputer 13 gives a command to the selection unit 6 to select a video that is not the currently selected video. That is, when the video switching key is pressed in a state where a broadcast video for a fixed receiver is being presented, the video is switched to presentation of a broadcast video for a portable receiver, and a broadcast video for a portable receiver is presented. When the video switch key is pressed in the state, the display is switched to presentation of a broadcast video for the fixed receiver. Note that the user can select the automatic switching mode on the menu screen, for example. The microcomputer 13 performs video selection processing based on the error rate (broadcast reception quality) when the automatic switching mode is selected. For example, when the error rate of a broadcast packet for a fixed receiver is below a predetermined level, the selection unit 6 is made to select video data output from the video decoder 3, and when the error rate exceeds a predetermined level, the selection unit 6 causes the video data output by the video decoder 4 to be selected. In determining the reception state (broadcast reception quality), information such as the reception field strength of radio waves, the bit error rate, and the occurrence status of block noise may be used instead of the error rate. Broadcasts for portable receivers are strong and broadcasts for fixed receivers are often weak, and broadcasts for portable receivers can be seen even if broadcasts for fixed receivers are not seen.

  2 and 3 are flowcharts showing the processing contents of the microcomputer 13. For example, the last channel is selected when the television is turned on. Further, when the TV is turned on, the user can select a desired service on the EPG screen, or can select a desired service with the channel UP / DOWN key (step S1). The microcomputer 13 determines whether or not a transport stream change (broadcast station change) has occurred to acquire the selected service (step S2). When the transport stream is changed, a frequency setting process is performed on the tuner 1 (step S3), and it is determined whether or not a baseband signal can be extracted (step S4). If “YES” in the step S4, the PSI / SI for the fixed receiver broadcast and the PSI / SI for the portable receiver broadcast are acquired (step S5), and the process proceeds to the step S6. Also, when it is determined in step S2 that the transport stream has not been changed, the process proceeds to step S6.

  In step S6, it is determined whether or not the selected service is a service for a fixed receiver. If the selected service is a service for a fixed receiver, a packet of one selected service of a broadcast for a fixed receiver in the transport stream is determined based on a PMT (program map table) in the PSI / SI. In addition to the acquisition, a packet of one predetermined service for broadcasting to the portable receiver in the transport stream is acquired (step S7). On the other hand, if the selected service is a service for a portable receiver, the packet of one selected service of the broadcast for the portable receiver in the transport stream is acquired based on the PMT in the PSI / SI. Then, a packet of one predetermined service for broadcasting to the fixed receiver in the transport stream is acquired (step S8).

  Each video packet is decoded by the first and second video decoders 3 and 4 (step S9), the video of the selected service is presented, and the audio packet of the selected service is decoded by the audio decoder 5. Then, audio output is performed (step S10).

  Here, the predetermined one service described above will be described. For convenience of explanation, three services (channels) “021”, “022”, and “023” exist as broadcasts for a fixed receiver in one transport stream. Assume that there are two services (channels) “621” and “622”. An example of the transition of service selection is shown below.

(1) When the transport stream is changed due to the user selecting “021”, the receiving apparatus 30 acquires and decodes the packet constituting the service “021”, and the video and audio Make a presentation. For broadcasts for portable receivers, for example, a video packet constituting a service “621” having the smallest channel number by default is acquired and decoded.

(2) When the automatic switching mode is selected and the radio wave reception state deteriorates in the state of (1) above, the receiving device 30 continues to acquire and decode the video packet of the service “021”. The video / audio to be presented is switched to the video / audio based on the service “621”.

(3) When the channel UP operation is performed in the state of (2) above, the receiving device 30 continues to acquire and decode the video packet of the service “021”, but about the broadcast for the portable receiver. , The packet constituting the service “622” is acquired, and the video / audio to be presented is switched to the video / audio based on the service “622”.

(4) When the automatic switching mode is selected, when the radio wave reception state becomes good in the state of (3) above, the receiving device 30 continues to acquire and decode the video packet of the service “622”. Also, the video / audio to be presented is switched to video / audio based on the service “021”.

(5) When the channel UP operation is performed in the state of (4) above, the receiving device 30 continues to acquire and decode the video packet of the service “622”, but for the broadcast to the fixed receiver. , The packet constituting the service “022” is acquired, and the video / audio to be presented is switched to the video / audio based on the service “022”.

(6) When the automatic switching mode is selected, if the radio wave reception state deteriorates in the state of (5) above, the receiving device 30 continues to acquire and decode the video packet of the service “022”. The video / audio to be presented is switched to the video / audio based on the service “622”.

(7) When the channel UP is operated in the state of (6) above, the receiving device 30 performs processing for acquiring another transport stream (another broadcasting station). For example, the receiver 30 presents the video and audio of the service having the smallest channel number for broadcasting to the fixed receiver by default, while the service for the portable receiver constitutes the service having the smallest channel number by default, for example. The received video packet is acquired and decoded.

  Of course, as described above, manual video switching (fixed → mobile, mobile → fixed) is possible by pressing the video switching key. In addition, when switching the video, for example, when switching from the video presentation state of the broadcast for portable receivers to the video presentation of the broadcast for fixed receivers, the reception status of the broadcast for fixed receivers is not good (the error rate is predetermined). When the level is exceeded), a message such as “There is a possibility that the message cannot be received. Are you sure? YES NO” may be displayed, and the video may be switched when the user selects YES.

  In the above example, only one audio decoder is used. However, two audio decoders for broadcasting for portable receivers and broadcasting for fixed receivers are provided, and audio data output from one is provided. You may provide the selection part which selects. In addition, in the video presentation state for broadcasting to a fixed receiver, the own (fixed) radio wave reception status (error rate, etc.) or the other (mobile) radio wave reception status (error rate, etc.) is displayed on a pictograph or the like. It is also possible to display the radio wave reception status (error rate, etc.) of itself (mobile phone) or the other (fixed) radio wave reception status (error rate, etc.) with a pictograph or the like in the broadcast video presentation state for portable receivers. It is good as well.

  In the example described above, an in-vehicle terrestrial digital broadcast receiving apparatus is shown, but an apparatus with car navigation can also be used. Also, a portable terrestrial digital broadcast receiving apparatus can be provided.

1 is a block diagram showing a terrestrial digital broadcast receiver according to an embodiment of the present invention. It is the flowchart which showed the processing content of embodiment of this invention. It is the flowchart which showed the processing content of embodiment of this invention.

Explanation of symbols

1 tuner 2 demultiplex 3 video decoder (for MPEG2)
4 Video decoder (for H.264)
5 Audio decoder 13 Microcomputer

Claims (4)

A tuner that receives a terrestrial digital broadcast and outputs a transport stream; a demultiplexer that separates packets from the transport stream; and a first video decoder that decodes broadcast video packets for fixed receivers separated from the transport stream. A video decoder, a second video decoder for decoding a broadcast video packet for a non-fixed receiver separated from the transport stream, and selecting one video data from the video data output from both video decoders A terrestrial digital broadcast receiving apparatus comprising: a selection unit; and a display unit that displays a video based on the selected video data. 2. The terrestrial digital broadcast receiving apparatus according to claim 1, wherein the selection unit selects one video data in accordance with a manual operation by a user. 3. The digital terrestrial broadcasting receiver according to claim 1 or 2, wherein the determination unit for determining reception quality and the video data output by the first video decoder to the selection unit when the reception quality is equal to or higher than a predetermined threshold value. A terrestrial digital broadcast receiving apparatus comprising: a control unit that causes the selection unit to select video data output from the second video decoder when the reception quality is less than a predetermined threshold value. The terrestrial digital broadcast receiver according to any one of claims 1 to 3, wherein the determination unit determines both reception quality of a broadcast for a fixed receiver and reception quality of a broadcast for a non-fixed receiver, The display unit displays information relating to the reception quality of the selected video or the other video, and is a terrestrial digital broadcast receiver.

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