JP4845610B2 - Terrestrial digital broadcast receiver - Google Patents

Description

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

A receiving device that receives digital terrestrial 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 mobile receivers, and a unique service is transmitted in this one segment (one-segment broadcasting: broadcasting for mobile receivers), and 12 segments are fixedly received. Operation to be used for providing services for a machine 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.

  By the way, one-segment broadcasting is often a strong layer and broadcasting for a fixed receiver is often a weak layer, and even if the broadcasting for a fixed receiver is not seen, the one-segment broadcasting may be seen. Therefore, it is conceivable to have an automatic switching mode that automatically switches between the video / audio presentation of the broadcast for the fixed receiver and the video / audio presentation of the one-segment broadcasting according to the reception state (reception quality) of the broadcast. If the state selection based on the operation of the switching key for manually switching the video is not appropriate, there is a possibility that an undesired state for the user is selected.

  In view of the above circumstances, the present invention provides a terrestrial digital broadcast receiver capable of appropriately changing the state when a switching key for manually switching video is operated in a state where the automatic switching mode is selected. The purpose is to provide.

  In order to solve the above problems, a terrestrial digital broadcast receiver according to the present invention receives a terrestrial digital broadcast and outputs a transport stream, a demultiplexer that separates packets from the transport stream, and the packets And a video / audio presentation unit for presenting video / audio based on the video / audio data obtained by the decoding, according to the broadcast reception quality, It has an automatic switching mode that automatically switches between video and audio presentation of broadcasting for non-fixed receivers. When the automatic switching mode is not selected, it is fixed when a manually operated switching key is operated. The switching key operation repeats between the video / audio presentation of the broadcast for the receiver and the video / audio presentation of the broadcast for the non-fixed receiver. On the other hand, when the automatic switching mode is selected, when the manually operated switching key is operated, the video / audio presentation of the broadcast for the fixed receiver and the broadcast for the non-fixed receiver are performed. The video / audio presentation of the broadcast and the video / audio presentation of the broadcast selected in the automatic switching mode are selected in order by repeating the operation of the switching key.

  With the above configuration, when the automatic switching mode is selected, when a manually operated switching key is operated, video / audio presentation of a broadcast for a fixed receiver and video of a broadcast for a non-fixed receiver Since audio presentation and video / audio presentation of the broadcast selected in the automatic switching mode are selected sequentially by repeating the operation of the switching key, the video is manually switched in a state where the automatic switching mode is selected. When the switching key is operated, the state can be appropriately changed.

  In the digital terrestrial broadcast receiving apparatus having the above configuration, the decoder includes a first video decoder for decoding a video packet for broadcasting to a fixed receiver separated from the transport stream, and a non-fixed reception separated from the same transport stream. And a second video decoder that decodes video packets for broadcasts to the machine. With this 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 is already decoded when switching the video. Therefore, it is possible to prevent a situation where the video display is momentarily interrupted 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 these configurations, both the reception quality of the broadcast for the fixed receiver and the reception quality of the broadcast for the non-fixed receiver are determined, and information on the reception quality of the selected video or the other video is displayed. Also good.

  According to the present invention, there is an effect that the state can be appropriately changed when the switching key for manually switching the video is operated in the state where the automatic switching mode is selected.

  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). Note that when the radio wave reception condition 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 from the tuner 1 to the microcomputer. 13 is notified. 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 broadcasting for portable receivers and that that exists in broadcasting for fixed receivers, and the microcomputer 13 stores EPG information extracted from each PSI / SI in the 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 (reception quality).

  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. The video processing unit 7 has a scaler function, and can enlarge the broadcast video for portable receivers and display the broadcast video for portable receivers on the entire screen in the same manner as the fixed receiver broadcast video. . 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.

  Further, 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 when the automatic switching mode is selected. For example, when the error rate of the fixed receiver packet is equal to or lower than a predetermined level, the selection unit 6 is caused to select the video data output from the video decoder 3, and when the error rate exceeds a predetermined level, the selection unit 6 is selected. The video data output from the video decoder 4 is selected. In determining the 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 of the packet. 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.

  The video switching is also performed when the video switching key is pressed while the automatic switching mode is selected. The details will be described later.

  In the terrestrial digital broadcast receiver 30, for example, the last channel is selected when the television is initially turned on. Further, when the television 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. When the transport stream change (broadcast station change) occurs to acquire the selected service, the microcomputer 13 performs frequency setting processing on the tuner 1, and broadcast PSI for the fixed receiver. / SI and PSI / SI of the broadcast for portable receivers are acquired.

  If the selected service is a service for the fixed receiver, the microcomputer 13 selects the broadcast for the fixed receiver in the transport stream based on the PMT (program map table) in the PSI / SI. A packet for one service is acquired, and a packet for a predetermined one service for broadcasting to a portable receiver in the transport stream is acquired. 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 a predetermined service for broadcasting to the fixed receiver in the transport stream is acquired.

  Then, each video packet is decoded by the first and second video decoders 3 and 4, respectively, and the video of the selected service is presented, and the audio packet of the selected service is decoded by the audio decoder 5 for audio output. I do.

  Next, an example of the transition of service selection in the automatic switching mode will be shown based on FIG. 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”.

(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 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”, while the video and audio to be presented is “621”. Switch to video and audio based on the service.

(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 radio wave reception state becomes good in the state of (3) above, the receiving apparatus 30 continues to acquire and decode the video packet of the service “622”, while displaying the video / audio to be presented “021”. Switch to video and audio based on the service.

(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 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”, but the video / audio to be presented is “622”. Switch to video and audio based on the service.

(7) When the channel UP operation is performed in the state of (6) above, the receiving apparatus 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.

  Next, processing when the video switching key is pressed in the selection state of the automatic switching mode described above will be described. When the video switching key is pressed in a state where the automatic switching mode is not selected, as shown in FIG. 4, the video / audio presentation of the broadcast for the fixed receiver, the video / audio presentation of the broadcast for the portable receiver, Are alternately selected by repeating the operation of the video switching key.

  When the video switching key is pressed in the selection state of the automatic switching mode, as shown in FIG. 3, the video / audio presentation of the broadcast for the fixed receiver, the video / audio presentation of the broadcast for the portable receiver, and the automatic switching mode The video / audio presentation of the broadcast selected in (1) is selected in order by repeating the operation of the video switch key. 3 and 4, for simplification of explanation, one service (channel) “081” exists as a broadcast for a fixed receiver in one transport stream, and a broadcast for a portable receiver. It is assumed that there is one service (channel) “681”. In addition, the video / audio presentation of the broadcast for the fixed receiver → the video / audio presentation of the broadcast for the portable receiver → the video / audio presentation of the broadcast selected in the automatic switching mode → the video / audio presentation of the broadcast for the fixed receiver may be used. Then, the video / audio presentation of the broadcast for the portable receiver → the video / audio presentation of the broadcast for the fixed receiver → the presentation of the video / audio of the broadcast selected in the automatic switching mode → the presentation of the video / audio of the broadcast for the portable receiver may be used. .

  According to the above switching process, when the video switching key is pressed when the automatic switching mode is selected, instead of alternately switching between the broadcasting for the fixed receiver and the broadcasting for the portable receiver, the switching is performed sequentially through the automatic switching mode. Therefore, there may be a case where switching from broadcasting for a fixed receiver to broadcasting for a portable receiver or switching from broadcasting for a portable receiver to broadcasting for a fixed receiver is not immediately performed. For this reason, even in the automatic switching mode, it is conceivable to adopt the idea that the automatic switching mode is canceled when the video switching key is pressed. Similar to the operation described above, it is possible to immediately switch from one broadcast to the other. However, this makes it impossible to switch sequentially through the automatic switching mode. In this application, although it is not possible to immediately switch from one broadcast to the other broadcast, it respects the will of the user who has selected the automatic switching mode and switches in order via the automatic switching mode. Consider switching.

  When manual video switching is performed, for example, when switching from a video presentation state of a broadcast for a portable receiver to a video presentation of a broadcast for a fixed receiver, the reception status of the broadcast for the fixed receiver is not good (the error rate is When a predetermined level is exceeded), a message such as “May not be received. Are you sure? YES NO” may be displayed, and the video may be switched when the user selects YES.

  In addition, in the video presentation state of a broadcast for 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.) on a pictograph or the like in the video presentation state for mobile receivers. It is good as well.

  In the above example, the two video decoders 3 and 4 are provided. However, the two video decoders are not necessarily provided. By providing one decoder composed of a digital signal processor (DSP) and changing the microcode loaded into the decoder, It may be configured to function as an H.264 decoder or an MPEG2 decoder. Further, although the in-vehicle terrestrial digital broadcast receiving apparatus is shown, it can be a car navigation system. 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 explanatory drawing of the channel transition (automatic switching mode) of embodiment of this invention. It is explanatory drawing of the channel transition (switching via automatic switching mode) of embodiment of this invention. It is explanatory drawing of the channel transition (non-automatic switching mode) 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 (3)

A tuner that receives terrestrial digital broadcasting and outputs a transport stream, a demultiplexer that separates packets from the transport stream, a decoder that decodes the packets, and a video based on video and audio data obtained by the decoding An audio / video presentation unit that presents audio;
According to the broadcast reception quality, it has an automatic switching mode that automatically switches between the video / audio presentation of the broadcast for the fixed receiver and the video / audio presentation of the broadcast for the non-fixed receiver,
When the automatic switching mode is not selected, when the manually operated switching key is operated, the video / audio presentation of the broadcast for the fixed receiver and the video / audio presentation of the broadcast for the non-fixed receiver are switched. While alternately selected by repeated key operations,
When the automatic switching mode is selected, when a manually operated switching key is operated, a video / audio presentation of a broadcast for a fixed receiver, a video / audio presentation of a broadcast for a non-fixed receiver, and the automatic switching The video / audio presentation of the broadcast selected in the mode is selected in order by repeating the operation of the switching key. 2. The terrestrial digital broadcast receiving apparatus according to claim 1, wherein the decoder is separated from the same transport stream as the first video decoder for decoding a video packet for broadcasting to a fixed receiver separated from the transport stream. A terrestrial digital broadcast receiver comprising: a second video decoder for decoding a broadcast video packet for a non-fixed receiver. 3. The terrestrial digital broadcast receiver according to claim 1 or 2, wherein both the reception quality of the broadcast for the fixed receiver and the reception quality of the broadcast for the non-fixed receiver are determined, and the reception quality of the selected video or the other video A terrestrial digital broadcast receiver characterized by displaying information on

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