JP2000069454A - Digital broadcasting receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of concern that a limited reception broadcasting cannot be received even if a transport stream from a broadcasting signal is viewed after a transport stream from DSM(digital storage media) is viewed without missing necessary information from the broadcasting signal. SOLUTION: A packet identifier filter 6 fetches the packet of necessary information of the limited reception information. A transport stream multiplexer 8 inserts the packet of necessary information into the gap of the packets of a transport stream TS-c from DSM. Thus, a demultiplexer 3 can obtain necessary information for receiving the limited reception broadcasting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcast receiver for receiving a digital broadcast, and more particularly to a digital storage medium such as a digital tape recorder (digital VTR) capable of storing a digital stream based on a digital broadcast signal. The present invention relates to a digital broadcast receiver having a data input / output interface.

[0002]

2. Description of the Related Art In digital broadcasting currently performed in CS broadcasting, video and audio digital data of a plurality of programs compressed by the MPEG2 system are multiplexed together with program information, limited reception information and the like in the form of a transport stream (TS). And transmitted.

A digital storage medium (hereinafter referred to as DSM) capable of recording the compressed video / audio digital data as it is in a digital stream such as a digital VTR.
(Abbreviated as “.”), It is possible to record more efficiently and without deteriorating the image quality than when recording the decoded signal using an analog VTR. Also, since additional information such as program information can be recorded at the same time, the information can be used at the time of reproduction.

The data rate of a digital stream that can be recorded on a DSM is often smaller than the rate of data (TS) transmitted by one transponder of digital broadcasting. Therefore, a digital broadcast receiver having a digital interface for outputting a digital stream to the DSM has a function of selecting and outputting information related to a specific program in order to reduce the transmission rate of the output digital stream. May have. FIG. 5 shows a configuration of a conventional digital broadcast receiver having a function of selecting and outputting information related to such a specific program.

In FIG. 5, a network interface module (NIM) 1 performs signal processing of a transmission system such as a tuner, digital demodulation, and error correction, and the output of the NIM 1 is a transport stream. The descrambler 2 descrambles a specific transport packet in the input transport stream according to an instruction from the host controller 5.

[0006] The transport stream TS-a of the broadcast signal output from the descrambler 2 includes compressed video and audio signals of a plurality of programs and additional information such as program names in FIG.
As shown in (A), the data is multiplexed in units of 188-byte transport packets. More specifically, packets (Vn, Vn, Vn) generated from video and audio elementary streams (ES) of a certain program n (n = 1, 2,...)
An) and a program association table (PA)
Program specific information (PSI: Program Specific Information) such as T: Program Association Table, PMT: Program Map Table, and program sequence information (SI: Service Information) are time-division multiplexed.

[0007] The transport stream TS-a output from the descrambler 2 is input to an MPEG demultiplexer (hereinafter, demultiplexer) 3 via a PID filter 6 and a stream selector 7. The operation of the PID filter 6 will be described later. The transport stream TS-c input from the external DSM is also input to the demultiplexer 3 via the stream selector 7. The stream selector 7 is for selecting the transport stream TS-a output from the descrambler 2 and the transport stream TS-c input from the DSM and inputting them to the demultiplexer 3.

[0008] The demultiplexer 3 extracts PAT, PMT, and the like included in the input transport stream TS, and in accordance with an instruction from the host controller 5 on the basis of the information, converts a video / audio stream related to a predetermined program. The port packet is specified and input to the MPEG decoder 4. The MPEG decoder 4 decodes the input video / audio stream, and outputs a video signal and an audio signal.

FIG. 7 is a block diagram showing an example of a specific configuration of the demultiplexer 3 in FIG. A 13-bit packet identifier (PID:
Packet Identification), which allows the attributes of the packet to be specified. Also, PSI,
The SI and the like have a data structure called a section, and are stored in a payload portion of a transport packet.

In FIG. 7, a PID filter 31
A desired packet is selected using the ID and input to the section filter 32. The section filter 32 extracts a section of program identification information such as PAT or program arrangement information from the input packet, and inputs the section to the memory 33 in a form that the host controller 5 can refer to. The memory 33 is composed of a plurality of buffers, and stores information on video packets and audio packets output from the PID filter 31 and information on sections output from the section filter 32. Note that signal lines indicated by broken lines from the PID filter 31 and the section filter 32 indicate signal lines when a plurality of video packets and audio packets are output and other information is output. Therefore, the number of buffers in the memory 33 is appropriately increased or decreased according to the presence or absence of such data.

The host controller 5 reads information stored in the memory 33 via the memory controller 34 and performs appropriate processing such as physical channel selection, program selection, and presentation of service information. The packet including the video and audio elementary streams is specified by the information in the above section, and its transport packet (or ES packet) is specified.
Alternatively, only the stream called PES generated from the ES) is input to the MPEG decoder 4. This operation allows the user to select one desired program from the transport stream TS in which a plurality of programs are multiplexed.

Returning to FIG. 5, when the transport stream TS is output to the DSM, the PID filter 6 uses the program identification information obtained from the demultiplexer 3 together with the program selection information from the user. According to an instruction from the host controller 5, a transport packet of a video / audio stream related to one or a plurality of programs is selected, and the transport stream TS-b is selected.
Output as This processing can be considered as a part of the function of the demultiplexer 3. Therefore, it is also possible to use a function of the demultiplexer 3 to output the transport stream TS-b to the DSM.

In this transport stream TS-b, not only one program is selected, but also auxiliary information such as PSI is output at the same time. FIG. 6B shows an example of the transport stream TS-b. When only a specific program is selected from the transport stream TS shown in FIG. 6A to be the transport stream TS-b shown in FIG. 6B, the form of the transport stream TS-b is as follows. PSI and the like are changed so as not to violate the rules of MPEG. SI is a selection information table (SIT: Selection Information Tabl).
e) Only the specific packet referred to as e) is transmitted. FIG.
A packet indicated by a broken line in (B) indicates a packet obtained by changing the packet illustrated in FIG.

In the example shown in FIG. 6, programs (A) and (Video packets V1, V2 and audio packets A1,
A2) selects a video / audio packet (V1, A1) of the program 1 from the multiplexed transport stream TS, and deletes information about the unselected program from the PAT and PMT1 accordingly. PMT1
Has changed. The SI outputs only information on the selected program in a SIT packet. In addition,
These change processes may be performed by the host controller 5.

With the above configuration, the digital broadcast receiver shown in FIG. 5 selects and decodes the transport stream TS-a obtained from the broadcast signal and the transport stream TS-c input from the DSM. And a transport stream TS-b of one or more programs can be output to the DSM.

[0016]

By the way, in a broadcast signal, in addition to a video and audio signal, for example, conditional access information for enabling a scrambled broadcast signal to be received only by a specific receiver, There is information that must be constantly received and monitored even when the user is not actually watching the broadcast, such as an emergency broadcast signal (hereinafter referred to as essential information).
However, in the above-described conventional digital broadcast receiver, the stream selector 7 selects the transport stream TS-c input from the DSM, and
When the decoder is decoding, the above essential information cannot be monitored.

Therefore, for example, when viewing of the transport stream TS-a input from the DSM is completed and the user intends to view the transport stream TS-a obtained from the broadcast signal, the essential information can be received. Otherwise, if the essential information is limited reception information, a problem may occur that the program cannot be viewed. Assuming that such essential information is transmitted at predetermined time intervals, it means that a conditional access broadcast (scramble broadcast) cannot be received until the essential information is received next time.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and without failing to receive essential information from a broadcast signal, for example, after viewing a transport stream from a DSM, a transport stream from the broadcast signal is converted. It is an object of the present invention to provide a digital broadcast receiver which does not cause a problem that a conditional access broadcast cannot be received even when viewing.

[0019]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention provides a digital broadcast receiver for receiving a digital broadcast. A packet output unit (6) for extracting a specific packet from packets constituting the first transport stream obtained from the output of the reception demodulation unit, and a gap between packets of the second transport stream input from outside And a demultiplexer (3) for demultiplexing the second transport stream including the specific packet output from the insertion unit, wherein the insertion unit (8) inserts the specific packet into the second transport stream.
And a decoder (4) for decoding the output of the demultiplexer.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A digital broadcast receiver according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of a digital broadcast receiver according to the present invention;
FIG. 2 is a block diagram showing a configuration example of the TS multiplexer 8 in FIG. 1, FIG. 3 is a block diagram showing another configuration example of the TS multiplexer 8 in FIG. 1, and FIG. 4 is a TS multiplexer 8 in FIG. It is a block diagram showing an example of a peripheral part. In FIG. 1, the same portions as those in FIG. 5 are denoted by the same reference numerals, and description of the common portions may be omitted as appropriate.

In FIG. 1, a network interface module (NIM) 1 performs signal processing of a transmission system such as a tuner, digital demodulation, and error correction, and the output of the NIM 1 is a transport stream. The descrambler 2 descrambles a specific transport packet in the input transport stream according to an instruction from the host controller 5.

The transport stream TS-a of the broadcast signal output from the descrambler 2 includes compressed video / audio signals of a plurality of programs and additional information such as program names in FIG.
As described in (A), they are multiplexed in units of 188-byte transport packets.

The transport stream TS-a output from the descrambler 2 is input to a PID filter 6 and a TS multiplexer 8 newly provided according to the present invention. The transport stream TS-b output from the PID filter 6 is input to the TS multiplexer 8. The transport stream TS-c input from the external DSM is also input to the TS multiplexer 8. The output of the TS multiplexer 8 is input to an MPEG demultiplexer (hereinafter, demultiplexer) 3. P
The operations of the ID filter 6 and the TS multiplexer 8 will be described later.

The TS multiplexer 8 provided in place of the stream selector 7 selects the transport stream TS-a output from the descrambler 2 and the transport stream TS-c input from the DSM, and demultiplexes the TS-a. And transport packets specific to the transport stream TS-c,
That is, it is for multiplexing a specific packet including the above essential information.

In order to view the transport stream TS-c input from the DSM, the host controller 5
When the TS multiplexer 8 selects the transport stream TS-c according to the instruction from the PID filter 6, the PID filter 6 extracts the specific packet including the above essential information and supplies the packet to the TS multiplexer 8.

The demultiplexer 3 extracts PAT, PMT and the like included in the input transport stream TS, and, based on the information, instructs the host controller 5 to convert a video / audio stream related to a predetermined program. The port packet is specified and input to the MPEG decoder 4. The MPEG decoder 4 decodes the input video / audio stream, and outputs a video signal and an audio signal.

The specific configuration and operation of the demultiplexer 3 in FIG. 1 are as described with reference to FIG.

When outputting the transport stream TS to the DSM, the PID filter 6 uses the program identification information obtained from the demultiplexer 3 together with the program selection information from the user, and the host controller 5.
Selects a transport packet of a video / audio stream related to one or a plurality of programs and outputs the transport packet as a transport stream TS-b. This processing can be considered as a part of the function of the demultiplexer 3. Therefore, using the function of the demultiplexer 3, the transport stream T
A configuration for outputting Sb is also possible.

In the transport stream TS-b, not only one program is selected, but also auxiliary information such as PSI is output at the same time. An example of the transport stream TS-b is as described with reference to FIG.

Here, a specific configuration of the TS multiplexer 8 in FIG. 1 will be described. FIG. 2 is an example of a specific configuration of the TS multiplexer 8. In FIG. 2, the transport stream T output from the descrambler 2
Sa is input to the selector 81. The specific packet including the above essential information extracted by the PID filter 6 is input to the buffer 82 and stored. The packet once stored by the buffer 82 is
Is input to

Transport stream T from DSM
S-c is input to the TS gap detector 83 and the selector 84. The TS gap detector 83 detects a gap between packets into which a specific packet including the above essential information extracted by the PID filter 6 can be inserted. As shown in FIG. 6 (B), since there is a gap without a packet in the transport stream TS-c from the DSM, a specific packet including essential information can be inserted. When the TS gap detector 83 detects a packet gap, the selector 8
4 selects the output of the buffer 82 and inserts a specific packet containing essential information into the transport stream TS-c.

As described above, by multiplexing the transport stream TS-c and the specific packet including the essential information, the transport stream TS-c into which the specific packet including the essential information is inserted is selected by the selector 81. Is input to The selector 81 transmits a transport stream TS-a of a broadcast signal output from the descrambler 2 according to an instruction from the host controller 5,
The transport stream TS-c from the DSM is selectively output.

The T based on the presence or absence of packets of the transport streams TS-a and TS-c from the NIM1 or DSM.
When the S enable signal is input, the TS multiplexer 8 may be configured as shown in FIG. In FIG. 3, the transport stream TS-a output from the descrambler 2 is input to the selector 85. The TS enable signal of the transport stream TS-a is input to the selector 86.

The specific packet containing the essential information extracted by the PID filter 6 and its TS enable signal are input to the buffer 87 and stored. The packet once stored in the buffer 87 is
Is input to T once stored by buffer 87
The S enable signal is input to the AND circuit 89.

Transport stream T from DSM
S-c is input to the selector 88. The TS enable signal of the transport stream TS-c is supplied to the selector 8
8 and inputted to the AND circuit 89. The selector 88 multiplexes the transport stream TS-c and the buffer 87 in response to the TS enable signal of the transport stream TS-c, thereby multiplexing a specific packet including essential information in the transport stream TS-c. insert.

The output of the selector 88 is input to the selector 85. The OR output from the AND circuit 89 is output to the selector 8
6 is input. The selectors 85 and 86, under the direction of the host controller 5, transmit the transport stream TS-a of the broadcast signal output from the descrambler 2 and its TS enable signal, and the transport stream TS-c from the DSM and its TS enable signal. And are selectively output.

FIG. 2 and FIG. 3 show an example of the configuration of the TS multiplexer 8 alone.
The multiplexer 8 may be configured integrally with the demultiplexer 3. FIG. 4 shows the TS multiplexer 8 shown in FIG.
Is shown. It should be noted that in FIG.
The selector 84 in the multiplexer 8 is deleted, and the selector 81 also functions as the selector 84. Although the transport stream TS-b is output from the PID filter 6 in the configuration of FIG. 1, the transport stream TS-b may be output from a subsequent stage of the buffer 82 in the TS multiplexer 8 as shown in FIG. 3 may be output from the subsequent stage of the PID filter 31.

With the above configuration and operation, in the digital broadcast receiver of the present invention, even while watching the transport stream TS-c from the DSM, the essential information required by the digital broadcast receiver can be obtained. It is possible to acquire the transport stream TS-a of the broadcast signal as if it had always been received.

When the viewing of the transport stream TS-c input from the DSM is completed and the user wishes to view the transport stream TS-a obtained from the broadcast signal, the demultiplexer 3 supplies the transport stream from the DSM to the transport stream TS-a. Since the essential information is input even while watching the TS-c, the transport stream TS-a after the switching is used as the conditional access broadcast (scramble broadcast).
, The demultiplexer 3 can obtain the essential information for enabling the reception of the conditional access broadcast.
This essential information is input to the host controller 5, and the descrambler 2 descrambles according to an instruction from the host controller 5. As a result, the above problem does not occur.

With the above configuration, the digital broadcast receiver of the present invention shown in FIG. 1 selects the transport stream TS-a obtained from the broadcast signal and the transport stream TS-c input from the DSM. It can decode, and can output one or more program transport streams TS-b to the DSM. In addition, when viewing the transport stream TS-c input from the DSM, essential information such as limited reception information or an emergency broadcast signal transmitted from a broadcast signal is not missed.

[0041]

As described in detail above, the digital broadcast receiver according to the present invention receives and demodulates a digital broadcast, and a first demodulation unit (NIM) obtained from the output of the reception demodulation unit. A packet output unit (PID) for extracting a specific packet from the packets constituting the transport stream
Filter), an insertion unit (TS multiplexer) for inserting the specific packet into the gap between the packets of the second transport stream input from the outside, and a second unit including the specific packet output from the insertion unit. Since the apparatus is provided with the demultiplexer for demultiplexing the transport stream and the decoder for decoding the output of the demultiplexer, it does not miss the essential information from the broadcast signal. For example, when viewing a transport stream from a broadcast signal after viewing a transport stream from a digital storage medium such as a digital VTR, there is no problem that a conditional access broadcast cannot be received.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a TS multiplexer 8 in FIG.

FIG. 3 is a block diagram showing another configuration example of the TS multiplexer 8 in FIG. 1;

FIG. 4 is a block diagram showing an example of a TS multiplexer 8 and its peripheral portion in FIG.

FIG. 5 is a block diagram showing a conventional example.

FIG. 6 is a diagram for explaining a transport stream.

FIG. 7 is a block diagram showing an example of a specific configuration of a demultiplexer 3 in FIGS. 1 and 5;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Network interface module (reception demodulation part) 2 Descrambler 3 MPEG demultiplexer 4 MPEG decoder 5 Host controller 6 PID filter (packet output part) 8 TS multiplexer (insertion part)

Claims (2)

[Claims] 1. A digital broadcast receiver for receiving a digital broadcast, comprising: a receiving / demodulating unit for receiving and demodulating a digital broadcast; and a packet constituting a first transport stream obtained from an output of the receiving / demodulating unit. A packet output unit that extracts the packet of the second transport stream, an insertion unit that inserts the specific packet into a gap between the packets of the second transport stream input from the outside, and the specific packet that is output from the insertion unit. A digital broadcast receiver, comprising: a demultiplexer that demultiplexes the second transport stream; and a decoder that decodes an output of the demultiplexer. 2. The apparatus according to claim 1, further comprising a descrambler for descrambling an output of the reception demodulation unit, wherein the specific packet is a packet of limited reception information necessary for the descrambler to descramble the output of the reception demodulation unit. The digital broadcast receiver according to claim 1, wherein: