JP2009171141A - Digital broadcast receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control useless power consumption and useless capacity of a recording medium by performing recording reservation, viewing reservation cancellation, recording and viewing stop when reception conditions are bad.
A recording reservation unit for setting a recording reservation for a received signal, an error rate detecting unit for detecting an error rate of the received signal before the recording start time set by the recording reservation unit, and the error And control means 20 for determining whether or not to cancel the recording reservation set by the recording reservation means based on the detection result of the rate detection means.
[Selection] Figure 1

Description

  The present invention relates to a digital broadcast receiving apparatus suitable for receiving an interleaved digital broadcast signal.

  In recent years, digital broadcasting that transmits and receives digitally has been started. In Japanese digital broadcasting, the ISDB-T system is adopted. In the ISDB-T system, signal processing such as error correction coding, interleave coding, digital modulation, and the like is performed on TS (transport stream) defined by the Moving Picture Expert Group (MPEG) 2 standard. (Orthogonal Frequency Division Multiplexing) modulated and output.

  Also, terrestrial digital broadcasting employs a relatively long time interleaving. Dispersing noise and facilitating error correction by interleaving makes it easy to decode even if a poor reception state due to amplitude fluctuations due to fading occurs.

  However, error correction is not always possible depending on the reception area, antenna installation status, weather, and the like. For example, the reception state may deteriorate due to worsening weather, and certain error correction may not be possible in a certain time zone. If so, the image quality may deteriorate and the video may be difficult to view.

  Therefore, Patent Document 1 discloses a technique for monitoring the broadcast reception status prior to the start time of digital broadcast recording and viewing, and determining a mode (high hierarchy mode and low hierarchy mode) after the start of recording and viewing. Has been. When the reception situation deteriorates, it is possible to obtain a video that is easy to view by performing reception viewing in the low hierarchy mode.

However, even in the low hierarchy mode, it may not be possible to display with sufficient image quality depending on reception conditions. In addition, some users may not like viewing and recording in the low hierarchy mode. Even in such a case, the technique disclosed in Patent Document 1 is used for viewing and recording, and wasteful power consumption and recording medium capacity are consumed. Further, according to Patent Document 1, once recording and viewing are started, there is a problem in that recording and viewing are continued even if the reception state deteriorates thereafter.
Japanese Patent No. 3,856,681

  The present invention provides a digital broadcast receiving apparatus capable of suppressing power consumption and consumption of a recording medium capacity accompanying recording by canceling recording and viewing depending on reception conditions before and after the start of recording and viewing. The purpose is to provide.

A digital broadcast receiving apparatus according to an aspect of the present invention includes a recording reservation unit that sets a recording reservation for a received signal, and an error rate that detects an error rate of the received signal before the recording start time set by the recording reservation unit. Detection means and control means for determining whether or not to cancel the recording reservation set by the recording reservation means based on the detection result of the error rate detection means,
A digital broadcast receiving apparatus according to another aspect of the present invention is based on a recording processing means for recording a received signal by a recording apparatus, an error rate detecting means for detecting an error rate of the received signal, and a detection result of the error rate detecting means. And a control means for controlling the recording processing means to stop recording by the recording device,
According to another aspect of the present invention, there is provided a digital broadcast receiving apparatus including a video signal processing unit that performs video signal processing on a received signal, an error rate detecting unit that detects an error rate of the received signal, and a detection by the error rate detecting unit. Control means for controlling the video signal processing means based on the result to perform image quality improvement processing on the received signal,
According to another aspect of the present invention, there is provided a digital broadcast receiving apparatus comprising: a recording reservation unit that sets a recording reservation for a received signal; a video signal processing unit that performs video signal processing on the received signal; and the recording reservation unit Prior to the recording start time, an error rate detecting means for detecting an error rate of the received signal, and a detection result of the error rate detecting means is compared with a first set value, and the recording reservation means is set based on the comparison result Control means for canceling recording reservation, comparing the detection result of the error rate detection means with a second set value, and controlling the video signal processing means to perform image quality improvement processing on the received signal based on the comparison result; It is characterized by comprising.

  According to the present invention, it is possible to suppress power consumption and the consumption of the capacity of a recording medium accompanying recording by canceling recording and viewing depending on reception conditions before and after the start of recording and viewing. Have.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a digital broadcast receiving apparatus according to an embodiment of the present invention.

  In FIG. 1, a high frequency signal of digital broadcasting is induced in the antenna 11. This high frequency signal is given to the tuner 12 of the digital broadcast receiver 10. The tuner 12 selects a signal in a predetermined band from the input high frequency signal and outputs it to the demodulator 13. The digital broadcast signal is obtained by orthogonally modulating an OFDM signal. The demodulator 13 performs quadrature detection on the input signal, removes the guard interval from the obtained baseband OFDM signal, and then converts the time-domain OFDM signal to the frequency-domain OFDM symbol by FFT (Fast Fourier Transform) processing. Convert to Further, the demodulator 13 performs demodulation processing on the OFDM symbol to restore the data before the modulation processing on the broadcast station side. For example, each subcarrier of the OFDM symbol is modulated by a modulation scheme such as PSK modulation or QAM modulation, and the demodulator 13 restores the data before the modulation processing by demodulation processing corresponding to these modulation schemes. Further, the demodulating unit 13 performs de-interleaving processing corresponding to the interleaving processing on the broadcasting station side on the demodulated data, and then outputs the data to the error correcting unit 14.

  The error correction unit 14 corrects data errors by error correction processing using an error correction code. For example, the error correction unit 14 performs a decoding process for an inner encoding process and an outer encoding process, which are error correction processes performed on the transmission side. Note that, as the inner encoding process and the outer encoding process, a convolutional encoding process, an RS encoding process, and the like are employed. The error correction unit 14 outputs a signal subjected to error correction processing, for example, a transport stream, to the TS separation / decoding unit 15.

  The TS separation / decoding unit 15 separates and decodes the input transport stream into video data, audio data, section data, and the like. In addition, the TS separation / decoding unit 15 can perform predetermined video signal processing on the video signal obtained by decoding. For example, the TS separation / decoding unit 15 can perform image quality improvement processing such as interpolation processing and scanning line conversion processing as video signal processing. Furthermore, the TS separation / decoding unit 15 can perform image quality improvement processing such as blurring processing on an image whose image quality is relatively deteriorated. The TS separation / decoding unit 15 can output the video signal and the audio signal thus obtained to the monitor 26 and the recording device 27.

  In the present embodiment, the output of the error correction unit 14 is also given to the BER detection unit 16. The BER detection unit 16 detects the bit error rate (error rate) after the error correction processing of the error correction unit 14 and outputs the detection result to the memory 17. The memory 17 stores sequentially inputted bit error rates.

  The comparison processing unit 18 is controlled by the control unit 20 to determine the reception status based on the comparison between the bit error rate stored in the memory 17 and a predetermined set value. For example, the comparison processing unit 18 compares the average value of the bit error rate in the period specified by the control unit 20 with the set value, and if the average value of the bit error rate is high, the reception situation deteriorates. Judge that there is. For example, the comparison processing unit 18 compares the peak value of the bit error rate with the set value in the period specified by the control unit 20, and the peak value of the bit error rate exceeds the set value by the set number of times. It may be determined that the reception status has deteriorated. The determination result of the comparison processing unit 18 is given to the control unit 20.

  The control unit 20 controls each unit of the digital broadcast receiving apparatus 10. The user I / F 19 includes keys, switches, and the like (not shown), and outputs a signal based on a user operation to the control unit 20. The control unit 20 determines a setting value used for comparison with the bit error rate based on a user operation signal from the user I / F 19. The control unit 20 provides the setting value to the setting value memory 21 for storage, and also supplies it to the comparison processing unit 18.

  The recording unit 22 is controlled by the control unit 20 to perform recording reservation processing for recording in the recording device 27 and to control recording of the recording device 27. The recording unit 22 includes a timer 23, a recording processing unit 24, and a memory 25, and the recording processing unit 24 stores the recording reservation information specified by the control unit 20 in the memory 25. Further, the recording unit 22 controls the recording device 27 based on the recording reservation information to perform recording. That is, the recording processing unit 24 grasps the recording start and end times and the recording channel on the basis of the recording reservation information stored in the memory 25 and the time information of the timer 23. A request to select a recording channel is generated, and the recording device 27 is caused to start recording video signals and audio signals from the TS separation / decoding unit 15.

  In the present embodiment, the control unit 20 controls recording reservation and recording processing in the recording unit 22. For example, when the comparison processing unit 18 determines that the reception status is deteriorated, the control unit 20 cancels the recording reservation before the recording time and performs recording by the recording device 27 after the recording time. It is supposed to stop. Moreover, the control part 20 may stop the output by the monitor 26, when the comparison process part 18 determines with the receiving condition getting worse.

  For example, when notified from the recording processing unit 24 that there is a recording reservation that reaches a predetermined time before the recording start time, the control unit 20 selects the same channel as the recording reservation channel for the tuner 12. Let When the current reception status is deteriorated from the determination result of the comparison processing unit 18 for the received channel, the control unit 20 sends a signal for canceling the recording reservation to the recording processing unit. 24. Accordingly, the recording processing unit 24 deletes the recording reservation information stored in the memory 25 and cancels the recording reservation.

  If a channel other than the recording reservation channel has already been selected by the tuner 12 during the reception status confirmation period, the tuner 12 determines the reception status for the channel currently being received, and the recording reservation is determined based on this determination result. You may decide to cancel.

  In addition, when the determination result of the comparison processing unit 18 indicates that the current reception status is deteriorated, the control unit 20 controls the recording processing unit 24 to record the program currently being recorded. Stop. In this case, the control unit 20 stops the output of the TS separation / decoding unit 15 to the recording device 27, and the recording processing unit 24 stops the recording operation of the recording device 27.

  In addition, when the determination result of the comparison processing unit 18 indicates that the current reception status is deteriorated, the control unit 20 stops the viewing of the program currently being recorded or viewed. Also good. For example, the control unit 20 stops the output of the TS separation / decoding unit 15 to the monitor 26. In this case, the control unit 20 may stop the output of the error correction unit 14 and stop the operation of the TS separation / decoding unit 15. In addition, the operation of the comparison processing unit 18 may be stopped.

  In addition, when the comparison processing unit 18 determines that the reception status has deteriorated, the control unit 20 causes the TS separation / decoding unit 15 to perform image quality improvement processing so that an easy-to-see image is displayed. It has become.

  Setting values serving as determination criteria such as cancellation of recording / viewing reservation, stop of recording / viewing, and execution of image quality improvement processing can be set by the user. The user can freely set the reception status (image quality) as a reference for deciding whether to cancel recording reservation, stop recording, etc. and perform image quality improvement processing by setting a setting value with the user I / F 19 It is.

  Next, the operation of the embodiment configured as described above will be described with reference to FIGS. 2 to 6 are flowcharts for explaining the operation of this embodiment.

  FIG. 2 shows an operation when there is a recording reservation or a viewing reservation. Even when the main power supply (not shown) of the digital broadcast receiving apparatus 10 is off, the control unit 20 and the like are operating by the standby power supply. When the control unit 20 is notified in step S1 that the recording processing unit 24 has reached a predetermined time before the recording start time of the recording reservation or viewing reservation program, the control unit 20 performs error correction processing of the broadcast signal and The power of the circuit portion necessary for the reception status determination process is turned on, and the tuner 12 is selected for the channel reserved for recording.

  The tuner 12 selects a recording reservation channel signal from the transmission signal. The selected signal is given to the demodulator 13 and demodulated. The output of the demodulation unit 13 is supplied to the error correction unit 14 and subjected to error correction processing.

  The output of the error correction unit 14 is given to the BER detection unit 16. The BER detector 16 detects the bit error rate from the reception signal of the recording reservation channel. The BER detector 16 detects the bit error rate and sequentially stores it in the memory 17 (step S2). The comparison processing unit 18 sequentially reads out the bit error rates from the memory 17 and totals them (step S3).

  The comparison processing unit 18 is given a set value from the control unit 20. When the recording / viewing reservation start time is reached (step S4), the comparison processing unit 18 compares the bit error rate count result with the set value (step S5). For example, the comparison processing unit 18 obtains an average of the bit error rates and compares the average value with the set value. If the set value is larger than the average value of the bit error rate, in step S7, recording or viewing is performed according to recording reservation or viewing reservation.

  That is, in this case, the output of the error correction unit 14 is given to the TS separation / decoding unit 15. When a digital broadcast signal conforming to the ISDB-T standard is received, the output of the error correction unit 14 is a transport stream. The TS separation / decoding unit 15 decodes the transport stream to obtain a video signal and an audio signal. When the viewing reservation is made, the video signal and the audio signal from the TS separation / decoding unit 15 are given to the monitor 26 and displayed on the monitor 26 and also outputted as sound. When the recording reservation is made, the video signal and the audio signal from the TS separation / decoding unit 15 are given to the storage device 27. The recording processing unit 24 controls the recording device 27 to record the program from the TS separation / decoding unit 15.

  On the other hand, when the average value of the bit error rate is larger than the set value, the control unit 20 cancels the recording / viewing in step S6. That is, when a viewing reservation is made, the viewing reservation is canceled from a memory storing viewing reservation information (not shown). If the recording reservation is made, the control unit 20 controls the recording processing unit 24 to delete the recording reservation information stored in the memory 25 and cancel the recording. In this case, the control unit 20 stops supplying the output of the error correction unit 14 to the TS separation / decoding unit 15. Thereby, the power supply of the TS separation / decoding unit 15 can be stopped, and the power consumption can be further suppressed. Further, the control unit 20 may stop power supply to the previous stage of the error correction unit 14, for example, the demodulation unit 13.

  FIG. 3 shows an operation when image quality improvement processing is performed instead of canceling a recording reservation or a viewing reservation. In the example of FIG. 3, image quality improvement processing is performed instead of the recording reservation or viewing reservation cancellation processing in step S6. That is, if it is determined in step S5 that the average bit error rate is larger than the set value, the control unit 20 causes the TS separation / decoding unit 15 to perform image quality improvement processing in step S8. .

  The TS separation / decoding unit 15 performs blurring processing as image quality improvement processing. Generally, the image quality slightly deteriorates due to the blurring process. However, when the reception condition is bad, the image displayed on the monitor 26 is in a state of poor image quality. In such a case, the image quality may be improved by the blurring process, and the image may be easier to see. By such image quality improvement processing, it is possible to record a relatively easy-to-view image even when the reception situation is bad.

  FIG. 4 shows the operation during viewing or recording. When notified from the recording processing unit 24 in step S11 that the recording is being performed, the control unit 20 starts collecting error data at a predetermined timing (step S12).

  The output of the error correction unit 14 is supplied not only to the TS separation / decoding unit 15 but also to the BER detection unit 16. The BER detector 16 detects the bit error rate from the received signal of the channel being recorded. The BER detection unit 16 detects the bit error rate and sequentially stores it in the memory 17. The comparison processing unit 18 sequentially reads out the bit error rates from the memory 17 and totals them (step S3).

  When the set time has elapsed since the start of error data aggregation (step S14), the comparison processing unit 18 compares the bit error rate aggregation result with the set value (step S15). For example, the comparison processing unit 18 obtains an average value of the bit error rate and compares this average value with a set value. If the set value is larger than the average value of the bit error rate, it is determined that the reception status is good, and recording is continued in step S17.

  On the other hand, when the average value of the bit error rate is larger than the set value, it is determined that the reception status is bad, and in step S16, the control unit 20 stops the recording. That is, the control unit 20 controls the TS separation / decoding unit 15 to stop the output to the recording device 27. The control unit 20 also controls the recording processing unit 24 to stop recording by the recording device 27. Further, the control unit 20 may stop power supply to the previous stage of the error correction unit 14, for example, the demodulation unit 13.

  In the example of FIG. 4, an example is shown in which recording is stopped when the reception situation is bad. However, it is obvious that viewing may be stopped when the reception situation is bad.

  FIG. 5 shows an operation when image quality improvement processing is performed instead of recording stop processing. In the example of FIG. 5, image quality improvement processing is performed instead of the recording stop processing in step S16. That is, if it is determined in step S15 that the average bit error rate is greater than the set value, the control unit 20 causes the TS separation / decoding unit 15 to perform image quality improvement processing in step S18. .

  The TS separation / decoding unit 15 performs blurring processing as image quality improvement processing. This blurring process improves the image quality and makes it easier to see the image. By such image quality improvement processing, it is possible to record a relatively easy-to-view image even when the reception situation is bad.

  In the example of FIG. 5, an example in which the image quality improvement process is automatically performed when the reception condition is bad at the time of recording has been described. Obviously, it may be applied.

  Further, in the example of FIG. 6, the setting value for determining whether or not the image quality improvement processing is automatically performed, the recording reservation canceling and the recording stopping are automatically performed in the example of FIG. 2 and FIG. In this example, two types of setting values are used, ie, a setting value for determining whether or not to perform the setting. In the example of FIG. 6, instead of step S5, step S5 'for comparing with the first set value and step S5 "for comparing with the second set value are added.

  The first setting value is for determining whether or not to cancel the recording reservation and viewing reservation, and the second setting value is for determining whether or not to perform image quality improvement processing. 1 set value> second set value. In step S5 ′, when the average value of the bit error rate is larger than the first set value or when a reference (for example, peak value) other than the average value is large, the control unit 20 has an extremely poor reception situation and performs image quality improvement processing. Therefore, it is determined that sufficient image quality cannot be obtained, and the recording reservation or viewing reservation is canceled (step S6).

  In step S5 ″, if the average value of the bit error rate is larger than the second set value, the control unit 20 determines that a certain level of image quality improvement can be obtained by the image quality improvement processing although the reception status is poor. Then, the image quality improvement process is performed (step S8). If the average value of the bit error rate is smaller than the second set value in step S5 ″, the control unit 20 assumes that the reception status is good. Judging, recording and viewing are performed (step S7).

  Although FIG. 6 shows an example applied to the recording reservation or viewing reservation, it is obvious that the present invention can also be applied to the recording time shown in FIGS.

  As described above, in the present embodiment, for a program reserved for recording or viewing, the bit error rate of the received signal is detected before the recording or viewing start time, and the reception status is determined by comparison with the set value. To do. If the reception situation is bad, the recording reservation or viewing reservation is canceled to prevent viewing or recording a video that is difficult to see. Accordingly, it is possible to prevent power from being consumed unnecessarily and the storage area of the medium from being used unnecessarily.

  In the present embodiment, the bit error rate of the received signal is detected during recording, and the reception status is determined by comparison with the set value. Then, when the reception situation is bad, the recording is stopped to suppress the recording of a video that is difficult to see. As a result, it is possible to prevent power from being consumed unnecessarily and the storage area of the medium from being used unnecessarily.

  In the present embodiment, when the reception condition is poor, image quality improvement processing such as blurring processing is performed, and it is possible to automatically view or record a relatively easy-to-view image.

1 is a block diagram showing a digital broadcast receiving apparatus according to an embodiment of the present invention. 6 is a flowchart for explaining the operation of the embodiment. 6 is a flowchart for explaining the operation of the embodiment. 6 is a flowchart for explaining the operation of the embodiment. 6 is a flowchart for explaining the operation of the embodiment. 6 is a flowchart for explaining the operation of the embodiment.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 10 ... Digital broadcast receiver, 14 ... Error correction part, 15 ... TS separation / decoding part, 16 ... BER detection part, 18 ... Comparison processing part, 20 ... Control part, 22 ... Recording part, 24 ... Recording processing part, 26 ... monitor, 27 ... recording device.

Claims (5)

A recording reservation means for setting a recording reservation for the received signal;
An error rate detecting means for detecting an error rate of a received signal before the recording start time set by the recording reservation means;
A digital broadcast receiving apparatus comprising: control means for canceling a recording reservation set by the recording reservation means based on a detection result of the error rate detection means. The error rate detection means starts detecting the error rate of the received signal from a time before a predetermined time of the recording start time,
2. The control unit according to claim 1, wherein the control unit determines whether or not to cancel the recording reservation based on a total result of error rate detection results by the error rate detection unit during the predetermined time. Digital broadcast receiver. Recording processing means for recording a received signal by a recording device;
An error rate detection means for detecting an error rate of the received signal;
A digital broadcast receiving apparatus comprising: control means for controlling the recording processing means based on the detection result of the error rate detecting means to stop recording by the recording device. Video signal processing means for performing video signal processing on the received signal;
An error rate detection means for detecting an error rate of the received signal;
A digital broadcast receiving apparatus comprising: control means for controlling the video signal processing means to perform image quality improvement processing on the received signal based on a detection result of the error rate detecting means. A recording reservation means for setting a recording reservation for the received signal;
Video signal processing means for performing video signal processing on the received signal;
An error rate detecting means for detecting an error rate of a received signal before the recording start time set by the recording reservation means;
The detection result of the error rate detection unit is compared with a first set value, and based on the comparison result, the recording reservation set by the recording reservation unit is canceled, and the detection result of the error rate detection unit is compared with a second set value. And a control means for controlling the video signal processing means to perform image quality improvement processing on the received signal based on the comparison result.

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