JP5127112B2 - Digital broadcast receiver - Google Patents

Description

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

Conventionally, there has been proposed a digital broadcast receiving apparatus that includes two tuners for digital terrestrial broadcasting so that broadcast reception can be continued even if the reception area is changed (see Patent Document 1).
JP 2004-64590 A

  By the way, in the digital terrestrial broadcasting service, a one-segment service for a mobile body such as a mobile phone is planned. As a video encoding system for this one segment service, MPEG AVC / H. H.264 will be adopted. In this encoding method, IDR frames necessary for video decoding are inserted at intervals of 2 to 5 seconds, so even if two tuners are provided, it takes time to start video display after switching. This is expected.

  In view of the above circumstances, an object of the present invention is to provide a digital broadcast receiving apparatus that can smoothly display an image when switching between two tuners or when switching tuner frequencies.

  In order to solve the above problems, the digital broadcast receiving apparatus of the present invention generates a stream by demodulating the received terrestrial digital broadcast wave, and refers to the independent frame that can be decoded by itself and the independent frame. In the digital broadcast receiving apparatus including a receiving unit that generates a group of accompanying frames that can be decoded and generates video data by decoding the frame, the receiving unit includes a plurality of receiving units, and one receiving unit receives The other receiving means monitors the broadcast of another frequency in the same series as the broadcast and tries to receive the broadcast of the other frequency, and the video is displayed on the monitor based on the video data generated by the one receiving means. The other receiving means is also generating the video data in the state where is displayed, and the reception by the one receiving means is performed under a predetermined condition. Characterized in that it consists of displaying the status of the image to switch to display the status of the received image according to another receiving unit operable to generate the image data.

  With the above configuration, when the display state of the received video by the one receiving unit is switched to the display state of the received video by the other receiving unit that generates the video data, the other receiving unit also displays the video. Since the data is generated, the video is displayed smoothly without interruption even if such switching is performed.

  In the digital broadcast receiving apparatus having the above-described configuration, the other receiving unit executes video data generation only for the independent frame, and decodes all frames when switching to video display by the other receiving unit. It may be configured to do. With such a configuration, the processing burden on other receiving means is reduced.

  Also, the digital broadcast receiving apparatus of the present invention generates a stream by demodulating the received terrestrial digital broadcast wave, and an independent frame that can be decoded by itself from this stream and an associated frame that can be decoded in consideration of the independent frame In a digital broadcast receiving apparatus including a receiving unit that generates a frame group and decodes the frame to generate video data, an auxiliary receiving unit is provided in addition to the receiving unit, and the broadcast received by the receiving unit The auxiliary receiving means monitors broadcasts of other frequencies in the same series and tries to receive broadcasts of other frequencies, and displays video on the monitor based on the video data generated by the receiving means. The auxiliary receiving means performs a process of generating an independent frame and holding the latest independent frame under a predetermined condition. The reception frequency of the reception means is switched to the other frequency, and the auxiliary reception means supplies the latest independent frame to the reception means, and the reception means uses the received independent frame to receive the received frame. It is configured to perform decoding.

  With the above configuration, the reception frequency of the reception unit is switched to the other frequency, the auxiliary reception unit supplies the latest independent frame to the reception unit, and the reception unit receives the received independent frame. Since the received frame is decoded using the video, the video is displayed smoothly without interruption even if such frequency switching is performed. Further, since the auxiliary receiving means does not need to include a decoder, the configuration can be simplified.

  Also, the digital broadcast receiving apparatus of the present invention generates a stream by demodulating the received terrestrial digital broadcast wave, and an independent frame that can be decoded by itself from this stream and an associated frame that can be decoded in consideration of the independent frame In a digital broadcast receiving apparatus including a receiving unit that generates a frame group and decodes the frame to generate video data, an auxiliary receiving unit is provided in addition to the receiving unit, and the broadcast received by the receiving unit The auxiliary receiving means monitors broadcasts of other frequencies in the same series and tries to receive broadcasts of other frequencies, and displays video on the monitor based on the video data generated by the receiving means. In such a state, the auxiliary receiving means retains video data by generating an independent frame and decoding the latest independent frame. The reception frequency of the reception means is switched to the other frequency under a predetermined condition, and the auxiliary reception means supplies video data obtained by decoding the latest independent frame to the reception means, and the reception The means is configured to decode the received frame using the received video data.

  With the above configuration, the reception frequency of the reception unit is switched to the other frequency, the auxiliary reception unit supplies video data obtained by decoding the latest independent frame to the reception unit, and the reception unit receives Since the received frame is decoded using the video data, the video is displayed smoothly without interruption even when such frequency switching is performed. Further, since the auxiliary receiving means only needs to be able to decode independent frames, the configuration can be simplified.

  In the digital broadcast receiving apparatus having these configurations, the independent frame has an encoding method of MPEG4 AVC / H. It is preferable that the IDR frame is H.264.

  In the digital broadcast receiving apparatus configured as described above, the predetermined condition may be when a predetermined operation is performed by a user. Alternatively, the predetermined condition may be when the reception quality of the receiving means generating the video displayed on the monitor falls below a predetermined value. Alternatively, the predetermined condition may be when the reception quality of the receiving means generating the video displayed on the monitor is lower than a predetermined value and a predetermined operation is performed by the user.

  Further, in the digital broadcast receiving apparatus having these configurations, the predetermined condition is not satisfied when the reception quality of the receiving means or the auxiliary receiving means generating the video not displayed on the monitor is below a predetermined value. May be.

  According to the present invention, it is possible to smoothly display an image when switching between the two tuners or when switching the tuner frequency.

  A digital broadcast receiver according to an embodiment of the present invention will be described below with reference to FIGS. Here, a digital terrestrial broadcast receiver configured as a mobile phone with a TV is illustrated.

  FIG. 1 is a block diagram showing a mobile phone 10 with a TV. The mobile phone with TV 10 includes a telephone function unit 30 and a digital broadcast receiving unit 20. The telephone function unit 30 includes a radio circuit 31, a signal processing circuit 32, an A / D / D / A conversion unit 33, a microphone 34, and a speaker 35. The radio circuit 31 performs voice and data transmission / reception processing and predetermined protocol processing (transmission time processing and reception time processing) with the base station. The signal received in the normal telephone processing is given to the speaker 35 via the radio circuit 31, the signal processing circuit 32, and the D / A conversion unit, while the voice uttered by the user is converted into an audio signal by the microphone 34. The data is transmitted through the conversion unit, the signal processing circuit 32, and the wireless circuit 31.

  The CPU 1 controls both the telephone function unit 30 and the digital broadcast receiving unit 20. When the TV function activation key of the operation key unit 2 is turned on, the CPU 1 sets the channel number to a process for giving an ON command to the digital broadcast receiving unit 20 or when the numeric keypad of the operation key unit 2 is operated. A process such as giving a channel selection command to the digital broadcast receiving unit 20 is performed. The power supply circuit 5 supplies power obtained from the battery 4 to the telephone function unit 30 and the digital broadcast receiving unit 20.

  Next, the digital broadcast receiving unit 20 will be described. The first terrestrial antenna 21A and the second terrestrial antenna 21B apply the received signals to the first terrestrial digital tuner 22A and the second terrestrial digital tuner 22B. Each terrestrial digital tuner 22 extracts a signal of a specific frequency from a high frequency digital modulation signal including video / audio data. Each terrestrial digital tuner 22 includes a demodulation circuit, a deinterleave circuit, an error correction circuit, etc., demodulates the selected digital modulation signal, outputs a transport stream, and outputs the transport stream to the first demultiplexer. The data is supplied to the multiplexer (DEMUX) 23A and the second demultiplexer (DEMUX) 23B.

  Each demultiplexer (DEMUX) 23 sends the transport stream to the H.264 standard in IEEE. H.264 video stream, audio stream, PSI / SI (Program Specific Information / Service Information), broadcast information (region identifier, service type, broadcast station identification, service number, remote control key ID), etc. Each demultiplexer 23 converts the video stream and the audio stream into the first H.D. H.264 decoder 24A and second H.264 decoder 24A. The PSI / SI, broadcast information, and the like (this information is called program information) are supplied to the table management unit 25. In addition, when a channel list including frequency, stationed / unstationed information, etc. is created by executing channel scan (search), this channel list is stored in the table management unit 25.

  Each H. The H.264 decoder 24 includes a video decoder that decodes the video stream. The video decoder decodes the input encoded signal to obtain a quantization coefficient and a motion vector, and performs video compensation by performing inverse DCT transformation, motion compensation control based on the motion vector, and the like.

  The sequence switch 26 is a signal from the first tuner system (first ground antenna 21A, first demultiplexer 23A, first H.264 decoder 24A) or second tuner system (second ground antenna 21B, second demultiplexer 23B). , Any one of the signals from the second H.264 decoder 24B) is selected for supply to the liquid crystal monitor 27. This selection is executed by a command from the CPU 1. In the following description, the selected tuner system may be referred to as a viewing tuner system, and the other tuner system may be referred to as a monitoring tuner system. The video data of the viewing tuner system selected by the series switch 26 is supplied to the liquid crystal monitor 27 and converted into, for example, RGB data and displayed. Also, the audio stream of the viewing tuner system selected by the sequence switch 26 is converted into an audio signal by the AAC decoder 28 and supplied to the speaker 29.

  Each tuner system supplies the CPU 1 with information useful for determining reception quality. Examples of the information include received radio wave intensity, C / N ratio, and error correction information. The CPU 1 uses the information for tuner system switching (control of the system switch 26).

  In terrestrial digital broadcasting, as described above, broadcast data is composed of a transport stream (Transport Stream) made up of fixed-length data called a transport stream packet (Transport Stream Packet). Each TS packet is assigned a PID by data such as video data and audio data, and the demultiplexer 23 separates each data by the PID. In terrestrial digital broadcasting for mobile phones, the video encoding method is IEEE H.264. H.264 is adopted. H. H.264 includes an IDR frame (independent frame) and a non_IDR frame (accompanying frame). It is guaranteed that decoding can be performed normally when decoding from the IDR frame, and the IDR frame must be reliably decoded. become.

  FIG. 2 shows an image diagram of the terrestrial digital broadcasting form. First, consider moving from region A to region C. When in the area A, it is assumed that the viewing tuner system receives a broadcast of the frequency f1. At this time, since three frequencies are described in the NIT (network information table), the broadcast at the frequency f2 can be monitored by the monitoring tuner system while receiving the broadcast at the frequency f1 by the viewing tuner system. When the reception status of the frequency f1 deteriorates due to the movement to the region C, the broadcast of the frequency f2 can be received and viewed by switching the monitoring tuner system to the viewing tuner system.

  Next, consider moving from region B to region C. Although only one frequency is described in the NIT of the region B, since the broadcast station a is described as the affiliated broadcast station in the BIT (broadcast information table), the broadcast of the frequency f1 is received by the viewing tuner system. However, the broadcast station a can be searched and monitored by the monitoring tuner system. When the reception status of the frequency f1 deteriorates due to the movement to the region C, the broadcast of the frequency f2 can be received and viewed by switching the monitoring tuner system to the viewing tuner system.

  Next, processing contents during viewing will be described based on the flowchart of FIG. When starting viewing, the CPU 1 checks whether or not the channel list is stored in the table management unit 25 (step S1). If there is no channel list (NO in step S1), a channel scan is executed in the viewing tuner system (step S2), and a channel list is created (step S3). If there is a channel list (YES in step S1), the frequency of the channel to be selected is set in the tuner of the viewing tuner system, and broadcast wave reception is started (step S4). If reception is not possible or the reception quality is below a predetermined value (NO in step S5), an error message is displayed on the monitor 27 (step S6). This error message is generated by an OSD (On Screen Display) circuit (not shown). On the other hand, if reception can be performed satisfactorily (YES in step S5), it is determined whether the table management unit 25 has created a table made up of PSI / SI, broadcast information, etc. (steps S7 and S8). If the table is not properly created (NO in step S8), an error message is displayed (step S6).

  On the other hand, when the table is properly created, as shown in the flowchart of FIG. 4, the setting for decoding all frames (IDR frame and non_IDR frame group) is performed in the viewing tuner system (step S11). Then, processing for acquiring video data and audio data is executed in the viewing tuner system (step S12). If the IDR frame has been decoded in this process (YES in step S13), presentation of video and audio is started immediately (step S15). If the IDR frame has not been decoded, it is determined whether or not the received frame is an IDR frame (step S14). If the IDR frame is an IDR frame, it is decoded and the process proceeds to step S15. If the received frame is not an IDR frame, the process returns to step S12.

  Next, as shown in the flowchart of FIG. 5, the CPU 1 determines whether there is a broadcast of the same series as the broadcast received by the viewing tuner system based on the information in the table management unit 25 (step S21). If it exists, the broadcast frequency is set in the tuner of the monitoring tuner system, and broadcast wave reception is started (step S22). If reception is not possible or the reception quality is below a predetermined value (NO in step S23), an error message is displayed on the monitor 27 (step S24). On the other hand, if reception can be performed satisfactorily (YES in step S23), the table management unit 25 determines whether a table including PSI / SI of the monitoring tuner system, broadcast information, etc. has been created (step S25). , Step S26). If the table is not properly created (NO in step S26), an error message is displayed (step S24). On the other hand, if the table is properly created, the monitoring tuner system is set to decode the IDR frame (step S27). Then, video data is acquired in the monitoring tuner system (step S28).

  For viewing switching, as shown in the flowchart of FIG. 6, the CPU 1 monitors the reception status in the viewing tuner system. If the reception status deteriorates (YES in step S31), the CPU 1 monitors the reception status. It is determined whether it is in the middle (step S32). If monitoring is in progress (YES in step S32), the reception status of the monitoring tuner system is checked (step S33). If the reception status of the monitoring tuner system is good (YES in step S34), notification is sent to the sequence switch 26, the monitoring tuner system is the viewing tuner system, and the viewing tuner system is the monitoring tuner system. Switching processing is performed (step S35).

  When such a switching process is performed, the monitoring tuner system is in a state where the IDR frame of the broadcast of the same series as the broadcast received by the viewing tuner system is being decoded. When switching to the viewing tuner system, the video can be displayed smoothly without interruption.

  In the above embodiment, the monitoring tuner system and the viewing tuner system are switched, but the present invention is not limited to this. That is, the main tuner system and the auxiliary tuner system are configured, and when the main tuner system performs broadcast reception and video display, the IDR frame obtained by monitoring the series broadcast and receiving the series broadcast in the auxiliary tuner system. Decode. When broadcast reception in the main tuner system is deteriorated, reception of a series broadcast having a different frequency is performed in the main tuner system, and the latest IDR frame acquired by the auxiliary tuner system at the time of frequency switching is obtained. The main tuner system acquires the video data obtained by decoding the video. Even if the main tuner system can only receive the non_IDR frame from the broadcast wave after frequency switching, it can decode the non_IDR frame using the video data and display the video smoothly without interruption. . When such a configuration is adopted, the auxiliary tuner system only needs to be able to decode the IDR frame, and it is not necessary to have a configuration for decoding the non_IDR frame. Also, it is not necessary to decode the audio. Further, the series switch 26 is not required.

  Further, the configuration including the main tuner system and the auxiliary tuner system is the same as the above configuration, but the auxiliary tuner system may be configured without a decoder. That is, when broadcasting is being received by the main tuner system, the auxiliary tuner system acquires the monitoring of the affiliated broadcast and the IDR frame of the affiliated broadcast, and holds the latest IDR frame in the memory. When broadcast reception in the main tuner system is deteriorated, reception of a series broadcast having a different frequency is performed in the main tuner system, and the latest IDR frame acquired by the auxiliary tuner system at the time of frequency switching is obtained. Is acquired by the main tuner system, and the main tuner system acquires the video data by decoding the IDR frame. Even if the main tuner system can only receive the non_IDR frame from the broadcast wave after frequency switching, the non-IDR frame can be decoded using the IDR frame, and the video can be displayed smoothly without interruption. . When such a configuration is adopted, the auxiliary tuner system does not have to decode the IDR frame, so that the decoding can be omitted. Further, the series switch 26 is not required.

  In the above embodiment, broadcast reception (or frequency switching in the main tuner system) is automatically performed by the monitoring tuner system when the reception quality of the viewing tuner system deteriorates. However, the present invention is not limited to this. The condition for switching may be that a predetermined operation (for example, pressing of a switching key, etc.) is performed by the user in such a state that reception quality is deteriorated. Further, it may be configured such that the switching is simply performed by a user operation.

  In the above example, a mobile phone with a TV function has been described. However, a mobile or mobile terrestrial digital broadcast receiver may be configured.

1 is a block diagram showing a mobile phone with a TV function (digital broadcast receiver) according to an embodiment of the present invention. It is an image figure of a terrestrial digital broadcasting form. 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. 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 CPU
10 Mobile phone with TV function 20 Digital broadcast receiver 22A First tuner 22B Second tuner

Claims (8)

The received digital terrestrial broadcast wave is demodulated to generate a stream, and an independent frame that can be decoded by itself and an accompanying frame group that can be decoded in consideration of the independent frame are generated, and the frame is decoded. In a digital broadcast receiving apparatus having receiving means for generating video data,
A plurality of receiving means are provided, and based on the affiliated broadcast station information in the received information, the other receiving means monitors the broadcast of another frequency in the same series as the broadcast received by one receiving means, and the other receiving means At the same time as trying to receive the broadcast of the frequency of the other, while the video is displayed on the monitor based on the video data generated by the one receiving means, the other receiving means also generate the video data And
Even if the other receiving means monitors the other frequency broadcast of the same series and tries to receive the other frequency broadcast, the other frequency broadcast cannot be received or the reception quality is below a predetermined value. If you have a display controller that displays error messages,
Under predetermined conditions, it will switch the display state of the received image by the one receiver means for displaying the status of the received image according to another receiving unit operable to generate the image data,
The other receiving unit executes video data generation only for the independent frame, and is configured to decode all frames when switching to video display by the other receiving unit. A digital broadcast receiver. The received digital terrestrial broadcast wave is demodulated to generate a stream, and an independent frame that can be decoded by itself and an accompanying frame group that can be decoded in consideration of the independent frame are generated, and the frame is decoded. In a digital broadcast receiving apparatus having receiving means for generating video data,
Auxiliary receiving means is provided in addition to the receiving means, and the auxiliary receiving means transmits broadcasts of other frequencies in the same series as the broadcast received by the receiving means based on the affiliated broadcast station information in the received information. While monitoring and trying to receive the broadcast of the other frequency, the auxiliary receiving means generates an independent frame and displays the video on the monitor based on the video data generated by the receiving means. Processing to keep the latest independent frame,
When the auxiliary receiving means monitors broadcasts of other frequencies of the same series and tries to receive broadcasts of other frequencies, or when the broadcasts of other frequencies cannot be received or the reception quality is below a predetermined value Has a display controller that displays error messages,
Under a predetermined condition, the reception frequency of the reception unit is switched to the other frequency, the auxiliary reception unit supplies the latest independent frame to the reception unit, and the reception unit uses the received independent frame. A digital broadcast receiving apparatus configured to decode a received frame. The received digital terrestrial broadcast wave is demodulated to generate a stream, and an independent frame that can be decoded by itself and an accompanying frame group that can be decoded in consideration of the independent frame are generated, and the frame is decoded. In a digital broadcast receiving apparatus having receiving means for generating video data,
Auxiliary receiving means is provided in addition to the receiving means, and the auxiliary receiving means transmits broadcasts of other frequencies in the same series as the broadcast received by the receiving means based on the affiliated broadcast station information in the received information. While monitoring and trying to receive the broadcast of the other frequency, the auxiliary receiving means generates an independent frame and displays the video on the monitor based on the video data generated by the receiving means. Processing to hold video data by decoding the latest independent frame,
When the auxiliary receiving means monitors broadcasts of other frequencies of the same series and tries to receive broadcasts of other frequencies, or when the broadcasts of other frequencies cannot be received or the reception quality is below a predetermined value Has a display controller that displays error messages,
Under a predetermined condition, the reception frequency of the reception unit is switched to the other frequency, the auxiliary reception unit supplies video data obtained by decoding the latest independent frame to the reception unit, and the reception unit receives the received data. A digital broadcast receiving apparatus configured to decode a received frame by using video data. In the digital broadcast receiving apparatus according to any one of claims 1 to 3, wherein the independent frame, the encoding scheme is MPEG4AVC / H. A digital broadcast receiver characterized by being an IDR frame for H.264. In the digital broadcast receiving apparatus according to any one of claims 1 to 4, wherein the predetermined condition, the digital broadcast receiving apparatus is characterized in that when a predetermined operation is performed by the user. It in a digital broadcast reception device according to any one of claims 1 to 4, wherein the predetermined condition is when the reception quality of receiving means is generating the image displayed on the monitor is below a predetermined value A digital broadcast receiver characterized by the above. In the digital broadcast receiving apparatus according to any one of claims 1 to 4, wherein the predetermined condition, the reception quality of the receiving means is generating the image displayed on the monitor is in a predetermined by and user below the predetermined value A digital broadcast receiver characterized in that an operation is performed. In the digital broadcast receiving apparatus according to any one of claims 1 to 7, when the reception quality of the receiving means or the auxiliary receiving means is generating a video image not displayed on the monitor is below a predetermined value, the predetermined condition A digital broadcast receiver characterized in that is not satisfied.

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