JP3587341B2 - Digital signal processing method and digital signal processing device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a digital signal processing method and digital signal processing for selecting and displaying only EPG (Electrical Program Guide) information relating to a program recorded on a recording medium in a digital recording / reproducing apparatus or the like having a built-in digital broadcast receiver. Equipment related.
[0002]
[Prior art]
Conventionally, when viewing a broadcast program (program) using, for example, a television receiver, a viewer finds a desired program from a television program column published in a newspaper or the like, and sets the broadcast time of the program to the desired program. In order to receive a broadcast channel of a program, a television receiver or a remote controller for controlling the television receiver has been operated.
[0003]
In addition, when newspapers are not at hand, or even when newspapers are at hand, it is troublesome to watch them, by operating the television receiver or remote controller to sequentially change the reception channel. , To select a program to be displayed on the screen.
[0004]
Therefore, in order to obtain information on a desired program, it is necessary to watch a newspaper or perform an operation for sequentially changing the receiving channel, which is troublesome.
[0005]
Therefore, for example, via a satellite or the like, information on each channel (each broadcast station) (for example, information corresponding to information described in a television program column of a newspaper, such as a broadcast channel, a broadcast start time of a program, a program title, and the like) ) Has been developed, which distributes an EPG (Electric Program Guide: electronic program guide) and displays the EPG on the receiving side. Therefore, the viewer can obtain desired program information by looking at the EPG.
[0006]
Information such as the above-mentioned EPG is multiplexed and distributed in a broadcast signal in digital broadcasting. First, multiplexing of a transmission signal in digital broadcasting will be described with reference to FIG. Assuming that a digital broadcast signal is transmitted as an MPEG transport stream, first, a video signal and an audio signal of a certain program (for example, program 1) are compressed according to the compression format of MPEG2, and are called PES (Packetized Elementary Stream) packets. A variable-length packet is formed and time-division multiplexed with a PES packet of a data signal such as character multiplexing.
[0007]
The PES packet includes two types of time stamps, a PTS (Presentation Time Stamp) for giving presentation times of audio and video, and a DTS (Decoding Time Stamp) for giving a decoding start time, and a control signal for scrambling in PES packet units. , A PES header including information such as a flag indicating the presence or absence of a copyright and a CRC (Cyclic Redundancy Check), and a PES payload of a data portion.
[0008]
Next, the signal obtained in this way is multiplexed with information of another program or information of encryption and transmitted to a TS (Transport Stream) packet. The TS packet is a fixed-length packet of 188 bytes, and includes a 4-byte fixed-length TS header, a variable-length adaptation field following the TS header, and a payload.
[0009]
FIG. 3 shows the configuration of the PES packet and the TS packet described above. According to the figure, a PES packet is divided and inserted into a payload portion of a TS packet and transmitted. A 13-bit identifier called PID (Packet ID) is inserted in the header of the TS packet, and the PES packet is divided into a plurality of TS packet payloads having the same PID number and transmitted. The program is distinguished by the PID number of the TS packet. Here, when the program is to be subjected to conditional access, the signal of the program is scrambled with the scramble key Ks as shown in FIG. 2 before the signal of the program is loaded on the payload of the TS packet. After the scramble key Ks and the attribute information of the program are encrypted by the work key Kw as ECM (Entitlement Control Message), they are TS packetized and multiplexed. PES packets are similarly formed for other programs (here, program 2... Program k), and after being converted into TS packets, time-division multiplexed with information on other programs. The work key Kw is transmitted together with other contract information as an EMM (Entitlement Management Message) as a TS packet having a predetermined PID. FIG. 4 shows the specific contents of the ECM and the EMM and the number of bits constituting them. Others that are multiplexed as TS packets having a predetermined PID include program list information for EPG and information uniquely set by a broadcaster.
[0010]
Next, reception and recording of the digital broadcast will be described. FIG. 5 is a block diagram showing a digital recording / reproducing device with a built-in digital satellite broadcast receiver. In the figure, a digital broadcast signal coming from an antenna 201 is subjected to processing such as frequency conversion, demodulation, and error correction in a front end 202 to become a baseband digital signal, which is supplied to a switch 203. At this time, the movable section of the switch 203 is set to the a side. Although a plurality of programs are time-division multiplexed on the output signal from the switch 203, a signal relating to a desired program is extracted from the output signal by the demultiplexer 204.
[0011]
As described above, a video signal, an audio signal, and a data signal constituting one program are encoded using a video / audio encoding standard of MPEG2 and a standard such as JPEG, and become an ES (Elementary Stream) signal. Next, these signals are modulated into PES based on the MPEG2 system standard, multiplexed into TS signals, modulated, and broadcast. According to the MPEG2 system standard, information necessary for separating and decoding these multiplexed signals at a receiver and information such as a program name are stored in a table such as a PAT (Program Association Table) signal or a PMT (Program Map Table). Multiplexed with the TS signal and transmitted.
[0012]
FIG. 6 is a block diagram showing the function of the demultiplexer 204. First, a PAT (Program Association Table) signal whose PID is fixed to a predetermined value is extracted from the input TS signal by detecting the predetermined PID (for example, “0”). It is stored in the area (here, area 1). The PAT signal includes a PMT (Program Map Table) PID list for each program number (16 bits). By analyzing the contents of the PAT signal, any PID of the PMT of a desired program can be received. It is possible to know whether to extract the packet. The above-described extraction and analysis of the PAT signal is performed by the PAT extraction / analysis means 103.
[0013]
In the PMT of a desired program obtained by extracting the PAT signal, a PID list of a packet in which a stream of video, audio, data, and the like constituting the program is transmitted is described. The PMT is extracted from the TS signal by the PAT extraction / analysis means 104 and stored in a predetermined area (here, area 2) in the memory 107. Also, by analyzing the PAT signal, data such as video and audio of a desired program can be extracted.
[0014]
Information (viewing enablement information) necessary for conditional access such as an EMM is obtained by extracting a packet having a predetermined PID and stored in a predetermined area (here, area 4) in the memory 107.
[0015]
The extraction and decoding of the EMM are performed by the EMM extraction / decoding means 101. The extraction of the EMM is performed by extracting a packet having a predetermined PID in the TS signal, and the decryption of the EMM is decrypted by the master key Km stored in the receiving device. The EMM is transmitted at intervals of several days to one month, for example, and is not always transmitted. However, the latest work key Kw stored in the area 4 of the memory 107 is used.
[0016]
If the extracted data such as video and audio is scrambled, it is released. For that purpose, it is necessary to obtain the scramble key Ks. Since the scramble key Ks is transmitted by the ECM, the ECM extracting / decoding means 102 extracts the ECM from the TS signal based on the PID of the ECM of the program described in the PMT.
[0017]
Since the ECM is encrypted using the scramble key Ks, the ECM extraction / decryption unit 102 uses the work key Kw described in the EMM to decrypt and decrypt the ECM. Then, it is stored in a predetermined area (here, area 3) in the memory 107.
[0018]
The video signal and the audio signal among the signals related to the desired program, which are extracted and descrambled by the packet extraction / descrambler 105 of the demultiplexer 204, are compressed by, for example, the MPEG2 compression method. This compression is decoded by a video / audio decoder 206 and further converted into an analog signal by a D / A converter (not shown). Then, the signal is output as a standard TV signal such as an NTSC signal or a PAL signal by the NTSC / PAL encoder 207.
[0019]
When recording the received digital broadcast signal on a recording medium, a signal to be recorded is extracted by the packet extracting / descrambler 105 of the demultiplexer 204, and the PAT information and PMT information which are recorded simultaneously are demultiplexed. The PAT / PMT rewriting means 106 rewrites the contents to those related to the signals to be recorded. The video signal and the audio signal are multiplexed with the rewritten PAT and PMT by the multiplexing unit 108 and recorded by the recording / reproducing unit 205.
[0020]
When reproducing the signal recorded on the recording medium, the movable section of the switch 203 is set to the b side, and the digital signal reproduced by the demultiplexer 204 is used for restoring a signal such as a video signal and an audio signal relating to a desired program. Necessary information is extracted and processed in the same manner as when receiving a broadcast.
[0021]
[Problems to be solved by the invention]
In the recording / reproducing apparatus integrated with the digital broadcast receiver as described above, a part of the program is recorded in the received digital broadcast signal, but the EPG information transmitted in the digital broadcast is recorded and reproduced as it is and displayed. Then, there is a problem in that information regarding a program that has not been recorded is also included in the EPG list, and confusion arises when selecting a program during reproduction. If the EPG information is not recorded in order to avoid this, the recorded program can be reproduced without confusion in the case of a single program. However, when a plurality of programs are recorded, the program cannot be selected by the EPG. It is necessary to select a program by some method. At this time, if a program selection mechanism other than the EPG is provided, a different program selection system is required at the time of broadcast reception and at the time of reproduction, and there is a problem that the apparatus becomes complicated. Further, even when a single program is recorded, if no EPG information is recorded, additional information such as a genre related to the program to be recorded is lost, which causes inconvenience in use.
[0022]
[Means for Solving the Problems]
In order to solve the above problems, in the digital signal processing method according to the present invention, information of a plurality of programs and program list information forming list information of the plurality of programs are multiplexed and transmitted in a packet form. Receiving a digital signal, extracting the program list information from the digital signal, and extracting only a packet containing information constituting a part of the plurality of programs to provide for recording, New program list information in which information of programs other than the above-mentioned part programs is deleted from the contents of the program list information is generated, and the extracted packet and the new program list information are multiplexed and transmitted. It is characterized by the following.
Also, in the digital signal processing method according to the present invention, the digital signal is transmitted in the form of an MPEG transport stream including a PAT and a PMT, extracts a packet including information constituting the portion of the program In this case, the information in the PAT and PMT is rewritten along with the extraction.
In addition, digital signal processing method according to the present invention, wherein the plurality of programs of packet and the packet of the program list information are added different packet ID, during extraction of the program list information, the packet ID Is used to extract the program list information.
Also, the digital signal processing apparatus according to the present invention includes a plurality of program information, reception and program list information forming the list information of the plurality of programs receives a digital signal that is transmitted by multiplexing a packet form Means, program list information extracting means for extracting the program list information from the digital signal, and extracting only packets including information constituting a part of the plurality of programs for recording. Program extracting means, program list information generating means for generating new program list information by deleting information of programs other than the partial program from the contents of the program list information, and the extracted packet and the new program list Transmission means for multiplexing information and transmitting the multiplexed information .
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a block diagram showing one embodiment of a digital signal processing method and a digital signal processing device according to the present invention. The same components as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted. The digital broadcast signal coming from the antenna 201 is subjected to processing such as frequency conversion, demodulation, and error correction in the front end 202, becomes a baseband digital signal, and is supplied to the switch 203. At this time, the movable section of the switch 203 is set to the a side. Although a plurality of programs are time-division multiplexed on the output signal from the switch 203, a signal relating to a desired program is extracted from the output signal by the demultiplexer 204.
[0024]
Among the signals related to the desired program extracted and descrambled by the demultiplexer 204, the video signal and the audio signal are compressed by, for example, an MPEG2 compression method. This compression is decoded by a video / audio decoder 206 and further converted into an analog signal by a D / A converter (not shown). Then, the signal is output as a standard TV signal such as an NTSC signal or a PAL signal by the NTSC / PAL encoder 207.
[0025]
Since EPG data is sent as a packet having a predetermined PID, EPG information is extracted by extracting a packet having a predetermined PID from the TS signal by the EPG extracting means 1.
[0026]
When receiving a broadcast, the extracted EPG information is stored in the EPG information memory 3 and displayed on the screen by the EPG screen creation circuit 4 as necessary. The viewer can select a program or make a program reservation by performing a predetermined operation using the program selection processing means 5. However, when a desired program is recorded on a recording medium, the EPG information extracted from the TS signal is used. Among them, only the program relating to the program to be recorded is selectively extracted by the EPG extracting / rewriting means 2, and information indicating that these programs are recorded on the recording medium is added. For this purpose, there is a method of allocating and identifying a specific bit for additional information. In time information such as a start time and an end time, an actual time such as “32 days” or “25:00” is represented. For this purpose, a value that is not used may be used to indicate that these programs are recorded on a recording medium.
[0027]
The EPG information rewritten in this way is multiplexed by the multiplexing means 108 together with a packet representing information such as video and audio, and a PAT and PMT rewritten into information relating to a program to be recorded. Recorded on a recording medium.
[0028]
When reproducing a recording medium on which a program is recorded, the movable contact of the switch 203 is switched to the b side, and EPG information is extracted from the reproduced TS signal and processed in the same manner as when receiving a broadcast. At the time of recording, the content of the EPG information is rewritten to the information of only the program to be recorded. Therefore, when the viewer displays the EPG during reproduction, only the content relating to the recorded program is displayed. In addition, as described above, since the information that the program is recorded on the recording medium is included as additional information, the information that the program is recorded is displayed on the screen using characters, symbols, color coding, or the like using this information. May be displayed.
[0029]
One program is automatically selected when one program is recorded. However, when a plurality of programs are recorded, the recorded program is selected in the same manner as when a broadcast program is selected by EPG information. A specific program can be selected from among them, and additional information such as a genre and a performer included in the EPG information can be displayed by the same operation as at the time of receiving a broadcast.
[0030]
As another method, the PAT information and the PMT information are rewritten to the contents limited to the program to be recorded, but the EPG information is recorded as it is without rewriting, and the EPG information is extracted from the reproduction signal at the time of reproduction. By comparing the PAT information and / or PMT information with the program information in the EPG information, a program not described in the PAT information and / or PMT information can be regarded as a program not recorded. In this way, the programs described in the EPG information are classified into those that have been recorded and those that have not been recorded, and when the EPG is displayed, it is displayed so that this distinction can be made. When selecting a program, selection of a program that has not been recorded may not be accepted, or when an EPG is displayed, a program that has not been recorded may not be displayed.
[0031]
The recording / reproducing apparatus has been described above. However, the present invention is not limited to this. The digital broadcasting is received, some programs are selected from the digital broadcasting, and transmitted to other devices through a digital transmission path instead of recording. The present invention can also be applied to an apparatus or an apparatus that receives and processes a signal selectively transmitted as described above instead of a reproduced signal from a recording medium.
[0032]
【The invention's effect】
According to the digital signal processing method and the digital signal processing device according to the present invention, only the information related to the program recorded by the recording / reproducing device is displayed from the information of each program included in the EPG information. Can be selected.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of a digital signal processing method and a digital signal processing device according to the present invention.
FIG. 2 is a diagram illustrating multiplexing of a transmission signal in digital broadcasting.
FIG. 3 is a diagram showing a configuration of a PES packet and a TS packet.
FIG. 4 is a diagram showing the contents and the number of constituent bits of an ECM and an EMM.
FIG. 5 is a block diagram illustrating an example of a conventional digital signal processing method and digital signal processing apparatus.
FIG. 6 is a diagram showing a demultiplexer used in a conventional digital signal processing device.
[Explanation of symbols]
1 EPG information extraction means 2 Extraction / rewriting means 3 EPG information memory 4 EPG screen creation means 5 Program selection processing means 101 EMM extraction / decoding means 102 ECM extraction / decoding means 103 PAT extraction / analysis means 104 PMT extraction / analysis means 105 Packet extraction / descrambling means 106 PAT, PMT rewriting means 107 Memory 108 Multiplexing means 201 Antenna 202 Front end 203 Switch 204 Demultiplexer 205 Recording / reproducing unit 206 Video / audio decoder 207 NTSC / PAL encoder

Claims (4)

Receiving a digital signal in which information of a plurality of programs and program list information forming the list information of the plurality of programs are multiplexed and transmitted in a packet form;
Extracting the program list information from the digital signal,
In order to provide for recording, only packets including information constituting a part of the plurality of programs are extracted, and information of programs other than the part of the programs is deleted from the contents of the program list information. Generated new program list information,
A digital signal processing method, wherein the extracted packet and the new program list information are multiplexed and transmitted. The digital signal is transmitted in the form of an MPEG transport stream including PAT and PMT,
When extracting a packet including information constituting the part of the program, according to claim 1 Symbol placement of the digital signal, characterized in that as in accordance with this extract rewrites the information in the PAT and PMT Processing method. Different packet IDs are added to the packets of the plurality of programs and the packets of the program list information, respectively.
Wherein at the time of extracting the program list information, the digital signal processing method according to claim 1 or 2, wherein the program list information using the packet ID are extracted. Receiving means for receiving a digital signal in which information of a plurality of programs and program list information forming the list information of the plurality of programs are multiplexed and transmitted in a packet form,
Program list information extracting means for extracting the program list information from the digital signal,
Program extraction means for extracting only a packet containing information constituting a part of the plurality of programs for recording,
Program list information generating means for generating new program list information by deleting information of programs other than the partial program from the contents of the program list information,
A digital signal processing device comprising: a transmission unit that multiplexes the extracted packet and the new program list information and transmits the multiplexed information.

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