WO2009119031A1

WO2009119031A1 - Digital television broadcast reception device

Info

Publication number: WO2009119031A1
Application number: PCT/JP2009/001142
Authority: WO
Inventors: 田中和久
Original assignee: パナソニック株式会社
Priority date: 2008-03-25
Filing date: 2009-03-13
Publication date: 2009-10-01

Abstract

In a digital television broadcast reception device, a broadband processing unit (40) decodes a content from a stream transmitted in a broadband. A narrowband processing unit (50) decodes a content from a stream transmitted in a narrowband. A delay control unit (70) outputs the decoded content to the broadband processing unit or the narrowband processing unit with a delay. A buffer (80) temporarily stores the decoded content until the delayed output.

Description

Digital television broadcast receiver

The present invention relates to a digital television broadcast receiver, and more particularly to a digital television broadcast receiver that receives broadcast content that is simultaneously broadcast in a wide band and a narrow band.

Recently, TV broadcasting has shifted to so-called digital TV using digital technology. In digital television, by transmitting video and audio as digital signals, it is possible to efficiently use the band of broadcast radio waves compared to conventional analog broadcasting. With this efficiency improvement, a lot of data can be broadcast with a small bandwidth, and it is used for additional broadcasting such as high image quality, multi-channel, data broadcasting and the like.

Broadband and low-bandwidth simultaneous broadcasts are one of its uses. This means that when the radio wave reception is good and the broadcast can be reliably received, a wideband broadcast is received, and when the radio wave reception is poor, the same program can be viewed by receiving the narrowband broadcast. The former can view high-quality, high-resolution video and audio by utilizing the ability to receive a wide band. In the latter case, the quality and resolution of video and audio is lower than that of broadband broadcasting, but the lower limit of radio wave conditions that can be received from broadband broadcasting is low even in places with poor reception conditions (far from the transmitting antenna, in shadows, in buildings, etc.). It is common.

In Japan, terrestrial digital broadcasting adopts this method, and uses a technology called ISDB-T (Integrated Services Services Digital Broadcasting-Terrestrial) to divide one channel into 13 segments, of which 12 segments are high-quality broadband. There is an example of broadcasting (normal high-definition broadcasting) and low-quality narrow-band broadcasting (one-segment broadcasting) in the remaining one segment.

As digital television broadcasts become more widespread, reception by mobile objects has become common. An in-vehicle receiver (car TV), a mobile phone with a TV broadcast receiving function, a portable TV, a receiver as an option of a notebook computer, and the like. In these mobile units, it is necessary to assume that the radio wave state changes, unlike a stationary television. That is, the reception state may improve or deteriorate during movement. Simple mobile digital broadcast receivers have only the function of receiving narrow-band broadcasts so that they can be received even when the radio wave condition deteriorates. However, mobile digital broadcast receivers equipped with high-definition monitors can be used. For example, it has a function capable of receiving broadband high-quality broadcasts. However, if the reception condition deteriorates due to movement as it is, the broadcast cannot be received. Therefore, the mobile digital broadcast receiver capable of receiving a wide band has a function of receiving a narrow band and the radio wave condition is low. An increasing number of broadcasters have a function of receiving wideband broadcasting in good places and narrowband broadcasting in bad places.

By the way, simulcast broadcasts the same program simultaneously in wideband broadcast and narrowband broadcast, but when it is simultaneously received by a conventional general receiver, even if it is live broadcast, its video and audio are They are not synchronized at all (when both are viewed at the same time, they appear to be moving at the same time or the sounds match). This is because the broadcast data processing speed on the broadcast station side and the data processing speed on the receiver side are different between the wideband broadcast and the narrowband broadcast. Normally, it is not necessary to view both wideband and narrowband broadcasts at the same time. If the radio wave condition is good, only the wideband is received and viewed. If the radio wave condition is bad, only the narrowband broadcast is received and viewed. Therefore, even if the wideband broadcast and the narrowband broadcast are not synchronized, it is not a problem at the time of normal reception, and the viewer is hardly aware of the deviation.

On the other hand, the situation is different in a mobile digital broadcast receiver whose reception state changes from moment to moment. Since the receiver moves, even when the broadband broadcast is received and viewed, if the radio wave condition deteriorates during the movement, the broadband broadcast cannot be received. In that case, it is conceivable to switch to reception of narrow-band broadcasting that can be received even if the radio wave condition is bad and continue to watch. That is, the radio wave condition is monitored during reception of the broadband broadcast, and if the radio wave condition deteriorates, switching to narrow band broadcast reception is performed manually or automatically (see, for example, Patent Document 1).
JP 2007-174043 A

Although the same content is transmitted in wideband and narrowband in simulcast, it is broadcast in wideband due to differences in broadcast data processing speed on the broadcasting station side and reception data processing speed on the receiving device side. There is a slight time lag between the playback timing of content to be broadcast and content broadcast in a narrow band. Therefore, even if broadband and narrowband broadcasts received on the receiving device side are processed independently, when these broadcasts are switched, the content is reproduced repeatedly (from the broadcast with the faster processing to the broadcast with the slower processing). Switching) and omissions (when switching from a slower broadcast to a faster broadcast) occurs. In view of this problem, an object of the present invention is to enable smooth switching between wideband broadcasting and narrowband broadcasting so that video and audio are continuous.

In order to solve the above problems, the present invention has taken the following measures. That is, a digital television broadcast receiving apparatus that receives broadcast content that is simultaneously broadcast in a wide band and a narrow band, and a broadband processing unit that decodes content from a stream that is transmitted in a wide band, and a content that is transmitted from a stream that is transmitted in a narrow band A narrowband processing unit for decoding, a delay control unit for delaying output of the decoded content to at least one of the wideband processing unit and the narrowband processing unit, and temporarily storing the decoded content until delayed output And a buffer. According to this, it is possible to synchronize the reproduction timing between the wideband broadcast and the narrowband broadcast, and it is possible to smoothly switch between the wideband broadcast and the narrowband broadcast so that video and audio are continuous.

Preferably, the digital television broadcast receiver further includes a data characteristic extraction unit that extracts data characteristics of the content decoded by each of the wideband processing unit and the narrowband processing unit. The delay control unit compares the data characteristics extracted for each of the wideband processing unit and the narrowband processing unit, detects a time lag related to the decoding process between the wideband processing unit and the narrowband processing unit, and Based on the above, the delay output for at least one of the wideband processing unit and the narrowband processing unit is controlled. According to this, it is possible to automatically match the reproduction timing between the wideband broadcast and the narrowband broadcast.

An apparatus for receiving a digital television broadcast wave in which encoded content is simultaneously broadcast in a wide band and a narrow band, a storage device for storing the stream, and a receiver for transmitting the received stream in a wide band A demultiplexer that separates and stores the data in a storage device, a wideband processor that decodes content from a wideband stream that is stored in the storage device, and a narrowband that is stored in the storage device A narrowband processing unit that decodes content from a stream sent in a delay control unit, and a delay control unit that instructs rewriting of time information contained in at least one of a stream sent in a wideband and a stream sent in a narrowband to a demultiplexing unit; It shall be equipped with. According to this, it is possible to match the reproduction timing between the wideband broadcast and the narrowband broadcast by using the storage device in which the stream is accumulated without providing a dedicated buffer for delay output.

According to the present invention, it is possible to synchronize the playback timing between the wideband broadcast and the narrowband broadcast, and it is possible to smoothly switch between the wideband broadcast and the narrowband broadcast so that video and audio are continuous.

FIG. 1 is a configuration diagram of a digital television broadcast receiving apparatus according to the first embodiment. FIG. 2 is an internal configuration diagram of the delay control unit shown in FIG. FIG. 3 is a configuration diagram of a digital television broadcast receiver according to the second embodiment. FIG. 4 is an internal block diagram of the delay control unit shown in FIG. FIG. 5 is a configuration diagram of a digital television broadcast receiving apparatus according to the third embodiment.

Explanation of symbols

30 Demultiplexer 40 Wideband processor 44 Data characteristic extractor 50 Narrowband processor 54 Data characteristic extractor 60 Output controller 70 Delay controller 80 Buffer 90 Storage device

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows the configuration of a digital television broadcast receiver according to the first embodiment. The antenna unit 10 receives broadcast radio waves. The demodulator 20 demodulates the received signal to generate a transport stream (TS) packet. The demultiplexing unit 30 selects TS packets necessary for video and audio output based on the TS packet header and other demultiplexing information. The broadband processing unit 40 decodes content from a stream transmitted in a wide band (for example, 12 segments). The narrowband processing unit 50 decodes content from a stream sent in a narrowband (for example, 1 segment). A TS packet appropriately selected by the demultiplexing unit 30 is input to the wideband processing unit 40 and the narrowband processing unit 50. In the case of scrambled broadcasting, the scrambled TS packet is decoded by the demultiplexing unit 30, elementary

stream extraction units

41 and 51, which will be described later, and the like.

In the wideband processing unit 40 and the narrowband processing unit 50, elementary

stream processing units

41 and 51 generate video and audio elementary streams (ES) from the input TS packets. The

AV decoding units

42 and 52 restore video and audio data from the generated ES. The

AV processing units

43 and 53 perform image quality correction, size conversion, OSD (On Screen Display) superimposition, sound quality and volume correction, and the like as necessary. The playback control unit 60 controls output switching of the content decrypted by the wideband processing unit 40 and the narrowband processing unit 50. Alternatively, the playback control unit 60 simultaneously displays wideband broadcast and narrowband broadcast video on two screens, or simultaneously plays back the broadband broadcast and narrowband broadcast audio. When video image quality correction or the like is unnecessary, the

AV processing units

43 and 53 serve only as an interface between the reproduction control unit 60 and a buffer 80 described later.

The delay control unit 70 delays and outputs the decrypted content to at least one of the wideband processing unit 40 and the narrowband processing unit 50. The buffer 80 temporarily stores the decrypted content until delayed output.

Hereinafter, the delay output control by the delay control unit 70 will be described in detail. FIG. 2 shows an internal configuration of the delay control unit 70. The output delay control unit 71 outputs a control signal for content switching to the reproduction control unit 60 in accordance with a user operation or automatically. Thereby, the user can confirm the presence or absence of the delay of both by confirming the video or audio | voice of a broadband broadcast and a narrowband broadcast alternately.

When the delay between the broadband broadcast and the narrowband broadcast is confirmed, the user operates a switch or the like (not shown) so that the delay is reduced. The delay amount receiving unit 72 receives an instruction input by a user operation, and receives at least one of the wideband processing unit 40 and the narrowband processing unit 50 via the wideband delay amount control interface 73 and the narrowband delay amount control interface 74. On the other hand, the decrypted content is delayed and output.

For example, when neither the wideband processing unit 40 nor the narrowband processing unit 50 receives the information that the playback timing of the content of the broadband broadcast is earlier than that of the narrowband broadcast when the delay output control is not performed, The delay amount accepting unit 72 instructs the AV processing unit 43 to delay the output of the broadband broadcast content via the broadband delay amount control interface 73. Upon receiving the instruction, the AV processing unit 43 temporarily outputs the content by writing the decrypted content in the buffer 80 once. On the other hand, when the playback timing of the narrowband broadcast content is earlier than that of the wideband broadcast, the delayed output of the narrowband broadcast content is instructed via the narrowband delay amount control interface 74, and the AV processing unit 53 Then, the decrypted content is temporarily written in the buffer 80 to delay output the content.

(Second Embodiment)
FIG. 3 shows a configuration of a digital television broadcast receiver according to the second embodiment. In the digital television broadcast receiver according to the present embodiment, the delay amount between the wideband broadcast and the narrowband broadcast is automatically detected. Only differences from the first embodiment will be described below.

Although it is possible to know whether there is a delay in these broadcasts by comparing the video for broadband broadcasting and the video for narrowband broadcasting, since the resolutions of these videos are different from each other, it is significant even if they are simply compared. No result is obtained. Therefore, the characteristics of video data are extracted for wideband broadcasting and narrowband broadcasting, and the characteristics are compared. For example, in the same bright scene, a bright scene should be output for both wideband and narrowband broadcasts. Therefore, with respect to each of the wideband broadcast and the narrowband broadcast, it is possible to determine the presence or absence of delay by extracting the luminance information of the entire one frame video at a certain moment and comparing it. Data

characteristic extraction units

44 and 54 in the wideband processing unit 40 and the narrowband processing unit 50 extract the above-described video data features for the wideband broadcast and the narrowband broadcast, respectively.

FIG. 4 shows the internal configuration of the delay control unit 70. The data characteristic comparison unit 75 compares the data characteristics extracted by the data

characteristic extraction units

44 and 54 to detect a delay between the wideband broadcast and the narrowband broadcast, and controls the wideband delay amount so as to eliminate the delay. Via the interface 73 and the narrowband delay amount control interface 74, at least one of the wideband processing unit 40 and the narrowband processing unit 50 delays and outputs the decrypted content.

Even if the scenes are different, the brightness of the entire 1-frame video may be the same, so there is a risk of erroneously recognizing the scene to be compared only with the video at a certain moment. Moreover, there is a possibility that a highly accurate delay detection cannot be performed for a scene whose luminance does not change so much. Therefore, the data characteristic comparison unit 75 detects the delay by tracking and comparing the magnitude of luminance and its change for a certain period of time.

Rather than extracting only the luminance of the entire one frame video, for example, by dividing the frame into four and extracting the luminance of each block, the delay between the wideband broadcast and the narrowband broadcast is more accurately recognized, It is conceivable that the time required to synchronize both broadcasts can be shortened. However, since narrow-band broadcasting has low image quality and there is little video data, it should be noted that if the frame is divided very finely, it cannot be compared with video data of wide-band broadcasting.

A similar function can be realized by averaging not only the brightness but also all the data characteristics related to the video, such as the saturation, on a screen or divided block basis. By using a plurality of data characteristics, it is possible to improve the accuracy of delay detection and shorten the time until synchronization can be achieved. Needless to say, functions similar to those described above can be realized using audio data.

There may be cases where different programs are broadcast for broadband and narrowband broadcasting. For example, a commercial broadcast in the middle of a program may be different between a broadband broadcast and a narrowband broadcast. In this case, although it is impossible to match the playback timings of the wideband broadcast and the narrowband broadcast, if the attempt is made forcibly, the system will break down in an attempt to temporarily store the content exceeding the capacity of the buffer 80. There is a fear. Therefore, an upper limit value (fixed value or variable value) of the delay amount is provided, and the delay control unit 70 controls the delay output when the delay between the wideband broadcast and the narrowband broadcast is larger than the upper limit value. It is preferable to stop. In actual simulcasting, the amount of delay between wideband broadcasting and narrowband broadcasting can be roughly estimated, so such a mechanism is effective. Also, if the data characteristics extracted from both wideband and narrowband broadcasts and the degree of change are significantly different, it is effective to determine that they are broadcasting different programs and automatically stop synchronization. It is.

(Third embodiment)
FIG. 5 shows a configuration of a digital television broadcast receiver according to the third embodiment. Only differences from the first embodiment will be described below.

The storage device 90 is a memory card interface, a hard disk device, an optical disk device, or the like. For example, a small card such as a mobile phone or a portable TV is equipped with a memory card interface, a small hard disk device, or the like. The demultiplexing unit 30 records the TS packet generated by the demodulation unit 20 in the storage device 90, and reads the TS packet from the storage device 90 as necessary. By recording the broadcast program in the recording device 90, the user can reproduce the recorded content at a desired time. Also, according to the TS packet format, content can be recorded with a smaller capacity without degrading image quality.

Some of the TS packets have PCR (Program Clock Reference) added as time information. The PCR can be identified by an adaptation field bit in the header of the TS packet. The demultiplexing unit 30 determines video and audio output timings in synchronization with the broadcast station clock based on the PCR. Here, the demultiplexing unit 30 rewrites the PCR included in at least one of the wideband TS packet and the narrowband TS packet according to the instruction of the delay control unit 60 and then records the TS packet in the storage device 90. . Then, the TS packet is read based on the rewritten PCR from the storage device 90 and supplied to the wideband processing unit 40 and the narrowband processing unit 50.

For example, when receiving information from the user that the playback timing of the broadband broadcast content is earlier than that of the narrowband broadcast, the delay control unit 60 transmits the PCR of the TS packet related to the wideband broadcast to the demultiplexing unit 30. An instruction to rewrite at a time later than the value of is issued. In accordance with this instruction, the demultiplexing unit 30 rewrites the PCR of the TS packet related to the broadband broadcast and records it in the storage device 90. In the subsequent reproduction process, the output timing of the video and audio related to the broadband broadcast is adjusted based on the rewritten PCR, so that the content of the broadband broadcast is delayed and output.

In the current Japanese terrestrial digital broadcasting, even in the case of simulcasting, broadband and narrowband broadcasting are assigned PCR independently of each other. That is, since PCR does not represent absolute time, it is not possible to determine whether there is a delay between the two by simply comparing the PCRs of the broadband broadcast and narrowband broadcast. If the broadband broadcast and narrowband broadcast PCRs are matched in the broadcasting station, the presence or absence of a delay between the two can be detected by comparing the PCRs, and the playback timing can be matched in the receiving apparatus.

The digital television broadcast receiver according to the present invention can be smoothly switched between wideband broadcast and narrowband broadcast so that video and audio are continuous. It is.

Claims

A digital television broadcast receiver for receiving broadcast content that is broadcast simultaneously in a wide band and a narrow band,
A wideband processing unit for decoding content from a stream sent in a wideband;
A narrowband processing unit for decoding content from a stream sent in a narrowband;
A delay control unit that delays and outputs the decoded content to at least one of the wideband processing unit and the narrowband processing unit;
A digital television broadcast receiver comprising: a buffer for temporarily storing the decrypted content until delayed output.
The digital television broadcast receiver according to claim 1, wherein
The digital television broadcast receiving apparatus, wherein the delay control unit delays and outputs the decoded content by an instructed delay amount.
The digital television broadcast receiver according to claim 1, wherein
A data characteristic extraction unit that extracts data characteristics of content decrypted by each of the wideband processing unit and the narrowband processing unit;
The delay control unit detects a time lag related to a decoding process between the wideband processing unit and the narrowband processing unit by comparing the data characteristics extracted for each of the wideband processing unit and the narrowband processing unit. A digital television broadcast receiver that controls delay output for at least one of the wideband processing unit and the narrowband processing unit based on the time lag.
In the digital television broadcast receiver of claim 3,
The delay control unit stops the control of the delay output when the time lag is larger than a predetermined value.
In the digital television broadcast receiver of claim 4,
The digital television broadcast receiving apparatus, wherein the delay control unit has a function of adjusting a time width of the predetermined value.
The digital television broadcast receiver according to claim 1, wherein
A digital television broadcast receiving apparatus, comprising: a reproduction control unit that simultaneously reproduces content output from each of the wideband processing unit and the narrowband processing unit.
The digital television broadcast receiver according to claim 1, wherein
A storage device for storing the received stream;
The digital television broadcast receiving apparatus, wherein the wideband processing unit and the narrowband processing unit process a stream read from the storage device.
An apparatus for receiving a digital television broadcast wave in which encoded content is simulcast in a wide band and a narrow band,
A storage device for storing the stream;
A demultiplexer that separates the received stream into one that is sent in a wide band and one that is sent in a narrow band, and stores the separated stream in the storage device;
A wideband processing unit for decoding content from the wideband stream stored in the storage device;
A narrowband processing unit for decoding content from the stream transmitted in the narrowband stored in the storage device;
A digital television broadcast, comprising: a delay control unit that instructs rewriting of time information included in at least one of the stream transmitted in the wide band and the stream transmitted in the narrow band to the demultiplexing unit Receiver device.