JP2007005960A - Digital broadcast receiver and digital broadcast reproducing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital broadcast receiver for receiving a broadcast signal by hierarchical transmissions that can attain automatic switching of a hierarchical layer even when the broadcast program is recorded once to a recording medium and later reproduced, suppress frequent switching of hierarchical layers, and skip video images of low hierarchical layers in response to the preference of a user. <P>SOLUTION: The receiver judges reception quality and records also reception quality information to a HDD in the case of recording a received broadcast signal to the HDD. In the case of reproducing a program from the HDD, the receiver references the recorded reception quality information to automatically select a proper hierarchical layer. However, if the reception quality denoted by the reception quality information frequently changes within a prescribed temporal length, the receiver does not frequently select a hierarchical layer corresponding to the change. Further, the receiver skips program parts receptible at low hierarchical layers only and reproduces only program parts receptible at high hierarchical layers in the case of the presence of a user's instruction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a digital broadcast receiving apparatus capable of recording and / or reproducing a digital broadcast using hierarchical transmission, and a digital broadcast reproduction method.

In certain types of digital broadcasting, for example, BS (Broadcast satellite) digital broadcasting in Japan, “hierarchical transmission” that enables switching and use of a plurality of transmission schemes (hierarchies) is employed. Hierarchical transmission allows high-quality video to be received through a large-capacity transmission method, but if the radio wave condition deteriorates due to rain attenuation or other reasons, the required C / N (Carrier to noise ratio) It is possible to receive a low-quality image by switching to a transmission method having a low noise power ratio. As the former transmission method, for example, a method of transmitting data with a transmission capacity of about 52 Mbps using TC8PSK (Trellis coded 8 phase shift keying) is adopted, and as the latter transmission method, for example, QPSK A method using modulation such as (Quadrature phase shift keying: four-phase phase modulation) or BPSK (Binary phase shift keying) is adopted. Regarding this hierarchical transmission, Patent Document 1 discloses that a digital broadcast receiving apparatus automatically receives a hierarchy (transmission method) as the reception quality (C / N value, etc.) of currently received radio waves changes. That is, a technique for switching video quality) is disclosed.
JP 2000-165766 A

  According to the technique disclosed in Patent Document 1, the reception quality of a broadcast signal is determined from the level, C / N value or BER (Bit Error Rate) of the received broadcast signal of each layer, and the determination The layer to be automatically received is selected and switched according to the received reception quality. Therefore, it is possible to automatically switch to a lower layer (low image quality) image in response to deterioration of the image quality of the higher layer (high image quality).

  However, when recording TS (Transport Stream) on a recording medium such as HDD (Hard Disk Drive), and then reading and playing from it, the reception quality of the broadcast signal is ascertained. It is impossible to perform the above-described automatic hierarchy switching.

  In addition, when the reception quality of the broadcast signal fluctuates near the threshold for determination, the hierarchy is frequently switched by automatic hierarchy switching, and the effect appears in the playback video, and the comfortable video viewing is hindered. There is a risk.

  Further, some users do not want to see a low quality image when a low quality video is selected.

  Accordingly, an object of the present invention is to solve the above-described problems in digital broadcasting using hierarchical transmission.

  That is, one purpose is to enable automatic layer switching even when broadcast information is once recorded on a recording medium and then read and reproduced therefrom.

  Another purpose is to prevent frequent hierarchy switching.

  Another object is to provide a user who does not want to view reproduction information from a specific hierarchy with options that satisfy the desire.

  According to one aspect of the present invention, a digital broadcast receiving apparatus that receives a broadcast signal including a plurality of layers includes a receiving / demodulating unit that receives and demodulates the broadcast signal, and a receiving / demodulating unit at the time of receiving the broadcast signal. Determining means for determining reception quality; recording means for recording the demodulated broadcast signal on a recording medium; and recording reception quality information indicating the determined reception quality on the recording medium in association with the recorded broadcast signal; A selection means for selecting a hierarchy based on reception quality information recorded on the recording medium so that the hierarchy is switched according to a change in reception quality; and a hierarchy selected from the broadcast signal recorded on the recording medium And reproducing means for reproducing source information from the extracted hierarchy.

  According to this digital broadcast receiver, when a broadcast signal is recorded on a recording medium, information indicating the reception quality of the broadcast signal is also recorded in association with the recorded broadcast signal, and video and / or from the broadcast signal is recorded. When source information such as audio is reproduced, the reception quality information recorded in association with it is referred to, and the reception quality information is automatically switched.

  In one embodiment, when the reception quality indicated by the reception quality information recorded on the recording medium is changed once and the time length until the next change is equal to or shorter than a predetermined set time, the reception quality changes. The corresponding hierarchy is not switched. Thereby, frequent switching of hierarchies is suppressed.

  In another embodiment, if the time length until the next change after the reception quality determined at the time of reception is changed is equal to or shorter than a predetermined set time, the change in the reception quality is received quality information. Is not recorded as. This also suppresses frequent hierarchy switching.

  In yet another embodiment, the user can set a skip setting that indicates whether or not to skip a specific layer (for example, when there are two layers of high and low, a low layer with low video quality). Then, when a hierarchy is selected based on the reception quality information, if the hierarchy is the same as the specific hierarchy designated by the skip setting, the hierarchy is skipped and not selected, and the subsequent specific hierarchy Different hierarchies are selected. For the skipped hierarchy, the source information from the hierarchy may not be reproduced at all, or the source information may be fast-forwarded and reproduced from the hierarchy. This provides a user who does not want to view a specific level with the convenience of automatically skipping that level.

  According to the present invention, even when broadcast information is once recorded on a recording medium and then read and reproduced from the recording medium, automatic hierarchy switching can be performed.

  In addition, according to one embodiment of the present invention, frequent hierarchy switching is prevented.

  Further, according to another embodiment of the present invention, it is possible to provide a user who does not want to view a specific hierarchy with options that satisfy the desire.

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

1. First Embodiment FIG. 1 shows a block configuration of a digital broadcast receiving apparatus for receiving and playing back a digital broadcast using hierarchical transmission according to a first embodiment of the present invention.

  As shown in FIG. 1, a digital broadcast receiver 1 includes a channel selection unit 2, a transmission path decoding unit 3, a demultiplexing unit (for example, a demultiplexer) 4, a source information decoding unit (for example, an MPEG decoder) 5, a user interface unit (for example, The input device is a remote controller, a keyboard or a mouse, and the output device is a display device or speaker device using CRT, liquid crystal or PDP, etc.) 6, control unit (for example, CPU) 7, reception quality analysis unit 8, list A generation unit 9, a writing unit 10, a recording medium (for example, hard disk, DVD or D-VHS) 11, a reading unit 12, a list analysis unit 13, a separation selection unit 14, and a system bus 15 are provided.

  A feature of the digital broadcast receiving apparatus 1 is that when a received TS (transport stream) is recorded on the recording medium 11, information indicating the reception quality can be recorded on the recording medium 11 in association with the TS. And, when a TS is read out from the recording medium 11 and reproduced, information on reception quality associated with the TS can also be read out and the layer can be switched based on the information. Hereinafter, the functions and operations of each part of the digital broadcast receiving apparatus 1 will be described focusing on this characteristic function.

  First, the function and operation for recording the received TS together with the received quality information on the recording medium 11 will be described.

  The digital broadcast signal input to the digital broadcast receiving apparatus 1 includes broadcast signals of a plurality of CH (channel) frequencies, and each CH broadcast signal includes a plurality of hierarchies in accordance with a hierarchical transmission scheme. Broadcast signals, for example, high-quality video transmitted by a large-capacity transmission system, low-quality video transmitted by a transmission system having a low required C / N, and the like.

  In the digital broadcast receiving apparatus 1, a signal having a frequency corresponding to the selected CH (channel) is extracted by the channel selection unit 2 from the input digital broadcast signal. The channel selected here is a CH designated by the user using the user interface unit 6, the designated CH is notified from the user interface unit 6 to the control unit 7, and the control unit 7 controls the channel selection unit 2. To select the specified channel.

  The broadcast signal of the selected CH output from the channel selection unit 2 is input to the transmission path decoding unit 3. The transmission path decoding unit 3 performs error correction such as demodulation of modulation such as QPSK (Quadrature Phase Shift Keying) and 64QAM (Quadrature Amplitude Modulation) and decoding of Reed-Solomon code on the input broadcast signal, TS packets (such as MPEG-TS, hereinafter simply referred to as TS) included in the broadcast signal are extracted, and the extracted TS is sent to the separation unit 4. At the same time, the transmission path decoding unit 3 uses the received broadcast signal as a reference for reception quality such as C / N (Carrier to Noise ratio) and BER (Bit Error Rate). Is measured (hereinafter referred to as reception quality basic value), and the measured reception quality basic value, the number of layers existing in the extracted TS, and the time when the reception quality basic value is measured are shown. Time information is notified to the reception quality analysis unit 8.

  The separation unit 4 disassembles the TS received from the transmission path decoding unit 3 and extracts program specific information (PSI) therefrom. The separation unit 4 then performs video and / or audio of the CH number designated by the control unit 7 based on the association between the CH number described in the program identification information and the video and / or audio ES (Elementary Stream). ES is extracted from TS and transmitted to source information decoding unit 5.

  On the other hand, the received broadcast signal generally includes time information, and the time information acquired from the broadcast signal is notified to the control unit 7. As a method for acquiring time information, not only a method of acquiring from a broadcast signal, but also a method of using an internal clock or a method of acquiring from an external input signal other than a broadcast signal can be adopted.

  The source information decoding unit 5 decodes the video and / or audio ES extracted from the TS by the separation unit 4 and sends the decoded video and / or audio information as source information to the user interface unit 6. The user interface unit 6 includes a device (for example, a display device or a speaker device) that outputs video and / or audio, and outputs the requested CH video and audio to the user.

  The reception quality analysis unit 8 acquires the reception quality basic value, the number of layers, and the time information described above from the transmission path decoding unit 3, and determines reception quality (for example, a receivable layer number) based on the reception quality basic value. Then, the received reception quality, the number of layers, and the time information are notified to the list generation unit 9. The list generation unit 9 creates a list of layers that can be received at a specific time (hereinafter referred to as a layer information list) from the reception quality, the number of layers, and the time information, and transmits the list to the writing unit 10. The writing unit 10 associates the hierarchical information list received from the list generation unit 9 with the TS received from the separation unit 4 and records both on the recording medium 11.

  FIG. 2 shows an example of the hierarchical information list.

  As shown in FIG. 2, the hierarchical information list 21 records a plurality of different time information and reception quality at the time indicated by each time information. Here, each time information in the hierarchy information list 21 indicates a time when the transmission path decoding unit 3 described above measured the reception quality basic value, and in particular, a reception quality basic value that causes switching of a receivable hierarchy. Indicates the time when the change occurred. In this embodiment, an STC (System Time Clock) counter value in the digital broadcast receiving apparatus 1 is used as time information. Alternatively, as a modification, PTS (Presentation Time Stamp), time information included in the TS, TS packets processed from the recording start time, the number of I frames, and the like may be used as the time information.

  The reception quality associated with each time information in the hierarchy information list 21 indicates a hierarchy that can be received at the time indicated by the time information. In the illustrated example, when there are two hierarchies, a high hierarchy and a low hierarchy (for example, high-quality video and low-quality video), the reception quality value “0” is a reception quality basic value (for example, a C / N value). ) Is very low, so that no layer can be received. The value "1" indicates that the reception quality base value is considerably low and only the low layer can be received, and the value "2" The reception quality basic value is sufficiently high, and thus represents a state where both the high layer and the low layer can be received.

  Therefore, each time information in the hierarchical information list 21 and the reception quality associated therewith are the same as the reception quality from the time indicated by the time information to immediately before the time indicated by the next time information in the list 21. It means that the corresponding layer was receivable. Therefore, when reading the TS recorded on the recording medium 11 and reproducing the video and audio, according to each time information and each reception quality in the hierarchical information list 21 recorded on the recording medium 11 in association with the TS, It is possible to automatically determine the time to switch the hierarchy and the switching destination hierarchy.

  Refer to FIG. 1 again. As described above, the writing unit 10 records the hierarchical information list from the list generation unit 9 and the TS from the separation unit 4 on the recording medium 11 in association with each other. In this way, the received TS and the reception quality at the time of receiving the TS are simultaneously recorded on the recording medium 11.

  Next, a function and operation for automatically switching the hierarchy according to the reception quality at the time of reception of the TS when the TS recorded on the recording medium 11 is reproduced will be described.

  With reference to FIG. 1, first, a reproduction request for a certain program recorded on the recording medium 11 is input from the user to the user interface unit 6, and the reproduction request is notified to the control unit 7. The reading unit 12 is controlled in response to the reproduction request. The reading unit 12 reads the TS of the designated program and the hierarchical information list associated with the TS from the recording medium 11 according to the instruction from the control unit 7. The reading unit 12 transmits the read TS to the separation unit 4 and transmits the read hierarchical information list to the list analysis unit 13.

  The list analysis unit 13 refers to the current STC counter value and the hierarchy information list to determine which hierarchy should be separated from the current TS, and notifies the separation selection unit 14 of the hierarchy. . The separation selection unit 14 determines the video and / or audio ES to be separated from the TS at the current time point based on the hierarchy designation notification from the list analysis unit 13, and separates the video and / or audio ES from the TS. Then, the separated video and / or audio ES is transmitted to the source information decoding unit 5.

  The source information decoding unit 5 decodes the video and / or audio ES from the separation unit 4 and sends the decoded video and / or audio information to the user interface unit 6. The user interface unit 6 includes a device (for example, a display device or a speaker device) that outputs video and / or audio, and outputs the requested CH video and audio to the user.

  As described above, not only when the received TS is played back immediately, but also when the received TS is recorded on the recording medium 11 and played back later, the reception quality at the time of receiving the TS is improved. In response, an appropriate layer of video and / or audio is automatically selected.

  FIG. 3 shows an algorithm for selecting a hierarchy to be separated from the current TS based on the current STC counter value and the hierarchy information list by the list analysis unit 13.

  As shown in FIG. 3, the list analysis unit 13 that has received the hierarchical information list first acquires the current time information C (in this case, the STC counter value) (S1), and refers to the hierarchical information list to obtain the time information C. The reception quality at the point in time is acquired, and this is held as the previous reception quality Q0 (S2). Here, the acquisition method of the reception quality in the time information C is, for example, as follows. That is, two pieces of time information C1 and C2 satisfying C1 <C <C2 are acquired from a plurality of pieces of time information existing in the hierarchical information list, and the reception quality corresponding to the earlier time information C1 is obtained. The reception quality in time information C is acquired from the hierarchical information list.

  Next, after waiting for a predetermined interval (t1 second) (S3), the current time information (STC counter value) C is acquired again (S4), and the reception quality Q1 at the time of the current time information C is described above. Acquired from the hierarchy information list by the method (S5). Then, the current reception quality Q1 is compared with the previously held previous reception quality Q0, and if both are the same value (yes in S6), the TS currently processing the previous reception quality Q0 Is notified to the separation selection unit 14 (S9).

  On the other hand, if the current reception quality Q1 and the previous reception quality Q0 are different (no in S6), within a predetermined reception quality setting time (T seconds) from the current time (in STC counter, for example, a predetermined stable count value CT Check if there is a change in the reception quality within the later), if there is no change (No in S7), update the previous reception quality Q0 with the current reception quality Q1 value, and then update The previous reception quality Q0 is held (S8), and the updated previous reception quality Q0 (that is, the current reception quality Q1) is notified to the separation selector 14 (S9).

  If there is a change in the reception quality within the reception quality setting time (T seconds) from the current time on the hierarchical information list (yes in S7), the previous reception quality Q0 is not updated and the separation selection unit 14 is directly updated. Notify the previous reception quality Q0.

  The separation selection unit 14 receives the notification of the reception quality (that is, hierarchy designation) Q0 or Q1 from the list analysis unit 13, determines the video and / or audio ES to be currently separated from the TS based on the notification, and the video and / or audio The ES is separated from the TS and transmitted to the source information decoding unit 5.

  In this way, based on the reception quality information recorded on the recording medium 11 in association with the TS recorded on the recording medium 11, the hierarchy when reproducing the TS is automatically set according to the reception quality. Is switched to. At this time, since a change in reception quality in a short time within the above-described stable time (T seconds) is ignored, frequent switching of hierarchies is suppressed.

2. Second Embodiment Next, a digital broadcast receiving apparatus according to a second embodiment of the present invention will be described. The block configuration of this digital broadcast receiving apparatus is basically the same as that of the first embodiment shown in FIG. However, this digital broadcast receiving apparatus differs from the first embodiment described above in the operation for suppressing frequent switching of hierarchies. That is, this digital broadcast receiving apparatus suppresses frequent switching of layers by controlling the recording operation of layer information instead of controlling the operation of selecting layers during reproduction. This control is mainly performed by the reception quality analysis unit 8.

  FIG. 4 shows an algorithm for controlling the recording of layer information by the reception quality analysis unit 8.

  The routine shown in FIG. 4 is started regarding the recording operation of the hierarchical information associated with the TS at the same time as the recording of the received TS on the recording medium 11 is started. When this routine is started, the reception quality analysis unit 8 first initializes the previous reception quality Q0 and the reception quality holding period t, which are storage values, to 0 (S11). Next, the current reception quality Q is acquired from the transmission path decoding unit 3 (S12). Received reception quality Q and reception quality threshold N1 for determining whether or not the lower layer is receivable (This means that if reception quality Q is N1 or higher, lower layer reception is possible. When the acquired reception quality Q is lower than the threshold value N1 (S13: no), the current reception quality Q1 is set to 0 (S14).

  If the acquired reception quality Q is a value greater than or equal to N1 (yes in S13), then the acquired reception quality Q and a reception quality threshold value N2 for determining whether or not a higher layer can be received (this is If the reception quality Q is N2 or higher, it means that higher layer reception is possible). When the acquired reception quality Q is lower than the threshold value N2 (no in S15), the current reception quality Q1 is set to 1 (S16). If the acquired reception quality Q is a value equal to or greater than the threshold value N2 (yes in S15), the current reception quality Q1 is set to 2 (S17).

  After determining the current reception quality Q1 in this way, it is compared with the previous reception quality Q0. When the current reception quality Q1 is equal to the previous reception quality Q0 (yes in S18), a predetermined interval time t1 is added to the reception quality holding period t (S19). When the current reception quality Q1 and the previous reception quality Q0 are not equal (no in S18), the current reception quality Q1 is substituted for the previous reception quality Q0, and 0 is substituted for the reception quality holding period t (this is This means that the duration of the current reception quality Q1 is initialized to 0) (S20).

  When the reception quality holding period t becomes equal to the predetermined reception quality setting time T (yes in S21), the list generation unit 9 uses the held previous reception quality Q0 as the reception quality t seconds before the current time. Is notified (S22). When the reception quality holding period t is not equal to the reception quality setting time T (no in S21), the list generation unit 9 is not notified.

  As a modification, the condition determination in step S21 may be determined as a case where the reception quality holding period t is longer than the reception quality setting time T. In this case, when the reception quality does not change, it is desirable not to notify the list generation unit 9 of the reception quality a plurality of times.

  After waiting for the predetermined interval time t1 after performing the above processing (S23), if the current TS recording operation is still continued (yes in S24), the control returns to step S1 and again the same The routine is repeated. If the current TS recording operation has ended (S24: no), this control ends.

  By the above control, only when it is determined that the same hierarchy can be received continuously for a certain time during program recording, the hierarchy is frequently switched by notifying the list generation unit 9 of the hierarchy switching. Hierarchical information is not recorded in the hierarchical information list.

3. Third Embodiment Finally, a digital broadcast receiving apparatus according to a third embodiment of the present invention will be described. The block configuration of this digital broadcast receiving apparatus is basically the same as that of the first embodiment shown in FIG. However, this digital broadcast receiving apparatus is equipped with a low hierarchy skip function in addition to the functions of the first embodiment. This low hierarchy skip function automatically skips playback (not playback) of program parts in the time zone in which only the low hierarchy was received, and automatically only program parts in the time zone that could be received in the high hierarchy. This is a function of selecting and reproducing only a high hierarchy, and is convenient for a user who does not want to watch a low hierarchy (low image quality) program.

  In order to realize this low hierarchy skip function, in this digital broadcast receiving apparatus, the user interface unit 6 allows the user to perform low hierarchy skip setting (setting to turn ON or OFF the low hierarchy skip function). The setting is notified to the list analysis unit 9 through the control unit 7. When the program recorded on the recording medium 11 is played back, the list analysis unit 9 controls the user reading unit 12 to automatically skip the low layer if the low layer skip setting is ON. Under the control of the list analysis unit 9, the user reading unit 12 reads an arbitrary time section portion of the TS recorded on the recording medium 11 so as to automatically skip the lower layer and reproduce only the higher layer. It can be put out.

  FIG. 5 shows a hierarchy selection and low hierarchy skip control algorithm performed by the list analysis unit 9 in the digital broadcast receiving apparatus.

  In the control algorithm shown in FIG. 5, the difference from that in the first embodiment shown in FIG. 3 is that step S25 is added after step S7, and steps S26 and S27 are taken as branches from step S25. This process is added.

  As shown in FIG. 5, the processing from step S1 to S7 is performed in the same manner as in the first embodiment described above. In step S6, it is determined that the current reception quality Q1 is different from the previous reception quality Q0 (no in S6), and in step S7, the reception quality is changed within a predetermined stable time (T seconds) from the current time. If it is confirmed from the hierarchical information list that there is no (No in S7), the control proceeds to step S25. In step S25, whether or not the current reception quality Q1 is a layer other than a high layer (for example, Q1 <2 when the number of layers is 2), and the low layer skip setting set in advance by the user is ON. It is judged whether or not. As a result, when the current reception quality Q1 is other than the high hierarchy and the low hierarchy skip setting is ON (yes in S25), the time when the current time (STC counter value) is switched to the next higher hierarchy Is searched from the hierarchical information list (S26) (for example, the reception quality of the time information in the hierarchical information list after the current STC counter value is sequentially checked in ascending order of the time information, and the reception quality first becomes higher hierarchy. Find the time). Next, a request is made to the reading unit 12 via the control unit 7 so as to reproduce the TS from that time (S27). The reading unit 12 jumps to a location at a specified time in the TS recorded on the recording medium 11 and reads out the subsequent TS portion from that location and plays it back, or in the recorded TS The TS portion before reaching the designated time portion is subjected to thinning readout and fast-forward playback is performed, and the TS portion after the designated time portion is normally read and normal reproduction is resumed. Thereafter, as long as the program playback operation is continued, the control returns to step S3, and the same routine is repeated. As a result, the program portion that can be received only at the lower hierarchy is automatically skipped or fast-forwarded and only the program portion that can be received at the higher hierarchy is selected and normally reproduced.

  FIG. 6 shows an example of a screen display for performing the low hierarchy skip setting displayed by the user interface unit 6.

  In FIG. 6, reference numeral 61 indicates the entire display screen. When the user operates a button (not shown) such as a “setting menu” on the remote control or the display screen via the remote control or the like provided in the user interface unit 6, a display screen 61 shown in FIG. 6 is displayed. There are buttons such as “Playback setting menu” and “Low layer skip setting”. On this ideographic screen 61, when the user operates the remote controller or the like and selects ON of “low hierarchy skip setting”, the low hierarchy skip setting is set to ON. With this setting, when the user does not want to view the lower hierarchy, it is possible to automatically skip to the portion where the next higher hierarchy can be received and perform playback.

  As mentioned above, although embodiment of this invention was described, this embodiment is only the illustration for description of this invention, and is not the meaning which limits the scope of the present invention only to this embodiment. The present invention can be implemented in various other modes without departing from the gist thereof. For example, the present invention can be applied not only to a digital broadcast receiver fixed on the ground but also to a mobile-mounted or portable digital broadcast receiver. The broadcast transmission form is not limited to wireless broadcast, but may be cable broadcast, broadcast or multicast over the Internet, or communication between devices via a cable such as IEEE1394. The present invention can be implemented by measuring the reception quality at the time of input.

1 is a block diagram showing a configuration of a digital broadcast receiving apparatus according to a first embodiment of the present invention. The figure which shows an example of a hierarchy information list. The flowchart which shows the algorithm of the control of the hierarchy selection which the list analysis part 13 in 1st Embodiment performs. The flowchart which shows the algorithm of the control of the hierarchy information recording which the reception quality analysis part 8 in 2nd Embodiment performs. The flowchart which shows the algorithm of the control of the hierarchy selection and the low hierarchy skip which the list analysis part 13 in 3rd Embodiment performs. The figure which shows the example of a screen display for the low hierarchy skip setting in 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital broadcast receiver 2 Channel selection part 3 Transmission path decoding part 4 Separation part 5 Source information decoding part 6 User interface part 7 Control part 8 Reception quality analysis part 9 List generation part 10 Writing part 11 Recording medium 12 Reading part 13 List analysis part 14 Separation / Selection Unit 15 System Bus Unit 21 Hierarchical Information List 61 Screen Display for Low-Layer Skip Setting

Claims (7)

In a digital broadcast receiver that receives a broadcast signal including a plurality of layers,
Receiving / demodulating means for receiving and demodulating the broadcast signal;
Determination means for determining reception quality at the time of reception of the broadcast signal in the reception / demodulation means;
Recording means for recording the demodulated broadcast signal on a recording medium and recording reception quality information indicating the determined reception quality on the recording medium in association with the recorded broadcast signal;
Selection means for selecting a hierarchy based on reception quality information recorded on the recording medium so that the hierarchy is switched according to a change in the reception quality;
A digital broadcast receiving apparatus comprising: reproduction means for extracting the selected hierarchy from the broadcast signal recorded on the recording medium and reproducing the source information from the extracted hierarchy. In the digital broadcast receiver according to claim 1,
When the selection means reads the reception quality information recorded on the recording medium and the time length until the next change after the reception quality indicated by the reception quality information changes is less than or equal to a predetermined set time 2. The digital broadcast receiving apparatus according to claim 1, wherein the hierarchy is not switched according to a change in the reception quality. In the digital broadcast receiver according to claim 1,
When the recording means determines that the time length until the next change after the reception quality determined by the determination means changes is less than or equal to a predetermined set time, the change in the reception quality determined is recorded on the recording medium. A digital broadcast receiver which is not reflected in the reception quality information recorded in The digital broadcast receiver according to claim 1, wherein
It further comprises setting means for performing a skip setting instructing whether or not to skip a specific hierarchy by user input,
Among the layers to be selected based on the reception quality information recorded on the recording medium, the selection unit skips the same layer as the specific layer instructed by the skip setting, and Digital broadcast receiver that selects a layer different from the layer The digital broadcast receiver according to claim 4, wherein
Digital broadcast receiving apparatus in which the reproduction means does not reproduce the source information from the skipped hierarchy and normally reproduces the source information from the selected hierarchy The digital broadcast receiver according to claim 4, wherein
A digital broadcast receiving apparatus in which the reproduction means fast-forwards and reproduces the source information from the skipped hierarchy and normally reproduces the source information from the selected hierarchy. In a digital broadcast reproduction method for reproducing source information from a broadcast signal including a plurality of received layers,
Determining the reception quality of the received broadcast signal;
Recording the received broadcast signal;
Recording reception quality information indicating the determined reception quality in association with the recorded broadcast signal;
Selecting a hierarchy based on the recorded reception quality information so that the hierarchy is switched according to a change in the reception quality;
Extracting the selected hierarchy from the recorded broadcast signal, and reproducing the source information from the extracted hierarchy.

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