JP2001054031A - Digital broadcast reception device and its semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously decode a plurality of channels multiplexed with an MPEG(moving picture expert group) stream and to selectively or simultaneously display individual screens. SOLUTION: A plurality of channels are multiplexed with an MPEG stream received by a station selection/demodulation means 2. A packet separation means 4 separates the encoding data (encoding video data and encoding sound data) of the channels at every data A in a byte unit. Data A is supplied to a channel information addition means 5 together with PID information showing the channel to which data belongs. Channel information is added at every data A on the basis of PID information. Data B obtained by adding channel information to data A is supplied to an MPEG decoder 8. The MPEG decoder 8 is provided with decoders for the respective channels and data B is decoded by the pertinent decoder on the basis of channel information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcast receiving apparatus and a semiconductor device thereof, and more particularly to a method for simultaneously extracting a plurality of video signals from a stream in which a plurality of video signals are multiplexed or a plurality of video signals from a plurality of streams. The present invention relates to a digital broadcast receiving apparatus for separating and decoding a video signal and a semiconductor device thereof.

[0002]

2. Description of the Related Art MPEG (Moving P) which is an international standard
audio and video information encoded using digital compression encoding technology represented by
Digital broadcasting, in which various other information is multiplexed and broadcast in one bit stream, has begun, and a digital broadcasting receiver has been spreading along with this. In such digital broadcasting, the MPEG2 system standard (ISO / IE
Video data and audio data encoded according to C 13818-1) are multiplexed, and the encoded data is transport stream packets (hereinafter, TS packets) having the configuration shown in FIG. ), And the TS packets are multiplexed into a transport stream (hereinafter, referred to as an MPEG stream).
Is sent out.

[0003] In Japan, BS (satellite) digital broadcasting using the MPEG standard is scheduled to start in 2000, and digitalization is also planned for terrestrial broadcasting. The center of such digital broadcasting is high-definition HDTV (High Definition Television).
levision) broadcast. However, from the viewpoint of transmitting many programs at the same time, a standard resolution SD that can transmit about four programs at a transmission rate required for one HDTV program is used.
TV (Standard Definition Television) broadcasting and HDT
A plan of combining V broadcasts (for example, performing SDTV broadcasting of four programs from morning to evening and performing HDTV broadcasting from evening) is being studied. For example, in a program such as a sports broadcast, It is considered that a plurality of SDTV video data viewed from different directions are multiplexed into one MPEG stream and transmitted, so that the viewer can select and view a video from a desired angle.

[0004] In the following, when a plurality of different videos are transmitted simultaneously in one program, it is said that each video is transmitted on a different channel, and this program is a program of a plurality of channels. Of course, when one program has one video signal, this program is a one-channel program.

[0005]

As described above, it is possible to simultaneously transmit the video of the same program on a plurality of channels, and it is possible for a viewer to select and watch one of these channels. However, in the conventional digital broadcast receiving apparatus, it is assumed that only one channel is separated from a received MPEG stream, and a decoder that decodes the separated coded video signal is assumed to decode only one channel. Not. Therefore, even if a plurality of videos of the same program are transmitted as separate channels, the plurality of videos cannot be viewed simultaneously. When one program is transmitted on multiple channels as in the case of a sports program as described above, it is preferable for a viewer to be able to view these channels simultaneously,
This is not possible with the conventional digital broadcast receiver.

The present invention has been made in view of this point, and has as its object to provide a digital broadcast receiving apparatus and a digital broadcast receiving apparatus capable of simultaneously viewing a plurality of channels multiplexed in a received stream. It is to provide a semiconductor device.

Another object of the present invention is to provide a digital broadcast receiving apparatus and a semiconductor device thereof, which enable simultaneous viewing of programs of a plurality of received streams.

[0008]

In order to achieve the first object, a semiconductor device according to the present invention is characterized in that a packet is formed by adding first identification data to each of coded data of a plurality of channels, A packet separation unit for extracting the coded data of the channel from the received stream, wherein the packet separation unit is used in a digital broadcast receiving apparatus for receiving a stream formed by multiplexing the packets; Means for sequentially extracting and outputting the encoded data of each of the channels from the stream based on data set from outside and the first identification data, and, together with the extracted encoded data, It is configured to output the second packet identification data according to the first identification data.

A digital broadcast receiving apparatus according to the present invention receives a stream in which coded data of a plurality of channels is packetized and multiplexed, and selects and streams the stream. Station / decoding means, packet separation means for extracting encoded data of each channel from the selected / decoded stream, and for each extracted encoded data, a channel to which the encoded data belongs. Channel information adding means for adding channel information, and decoding means for judging the channel to which the encoded data belongs based on the channel information and simultaneously decoding the encoded data of each channel separated by the packet separating means. And a configuration including:

In order to achieve the second object, in a semiconductor device according to the present invention, a packet is formed by adding first identification data to each encoded data, and the packet is formed by multiplexing the packets. A digital broadcast receiving apparatus for receiving a plurality of streams, the apparatus comprising packet separating means for extracting the coded data of the channel from the received stream, the packet separating means capable of simultaneously inputting a plurality of streams. And sequentially extracting and outputting the encoded data from the plurality of streams, respectively, based on the data set from the outside and the first identification data, and together with the extracted encoded data, First
Is configured to output the second packet identification data according to the identification data.

A digital broadcast receiving apparatus according to the present invention receives a plurality of streams in which encoded data is packetized and multiplexed, and extracts a encoded data for each of the received streams. Separating means, for each of the extracted coded data, stream information adding means for adding stream information indicating a stream to which the coded data belonged, and to which the coded data belonged based on the stream information. Decoding means for judging a stream and simultaneously decoding the encoded data of each stream separated by the packet separating means.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a first embodiment of a digital broadcast receiving apparatus according to the present invention, wherein 1 is an antenna, 2 is a channel selection / demodulation means, 3 is an error correction means, and 4 is a packet separation means. 5 is channel information adding means, 6 is a memory, 7 is a register group, 8 is an MPEG decoder, 9 is an OSD (On Screen Display) circuit, 10 is a video encoder, 11 is a D / A (digital / analog) converter, 12 Is a control means, 13 is a video processing circuit, 14 is an audio processing circuit, 15 is a video display means, 16 is a speaker, 17
Is a user input means.

In FIG. 1, a digital broadcast wave transmitted from an artificial satellite (not shown) is received by an antenna 1,
The MPEG stream of the digital broadcast program desired by the user is selected and demodulated by the tuning / demodulation means 2.
The user input unit 17 is, for example, a remote controller, and a user can designate a desired digital broadcast program by operating the remote controller.

The demodulated signal (MPE) from the channel selection / demodulation means 2
The G stream) is subjected to error correction based on the error correction code added to the demodulated signal by the error correction means 3 and then supplied to the packet separation means 4 to provide the code of the digital broadcast program desired by the user to view. The encoded audio data, the encoded video data, and the additional data are separated. The coded audio data and the coded video data separated by the packet separating means 4 are supplied to the channel information adding means 5 for each data A in byte units, and after the channel information is added thereto, M
It is supplied to the PEG decoder 8 and decoded. The additional data separated by the packet separating means 4 is temporarily stored in the memory 6.
Is stored. The additional data is read by the control unit 12 through the register group 7 including a plurality of registers.

Here, one or more channels are multiplexed in each of a plurality of MPEG streams of a digital broadcast program received by the antenna 1, and in an MPEG stream in which a plurality of channels are multiplexed, each channel is multiplexed. May be from separate digital broadcast programs, or some or all of those channels may be from the same digital broadcast program. One MP
The fact that the plurality of channels included in the EG stream are of the same digital broadcast program means that, for example, as described above, a sports program and a plurality of videos for a plurality of videos when watching the sport simultaneously from different directions. There is a channel.

The channel selecting / demodulating means 2 is for selecting and demodulating one MPEG stream including a digital broadcast program desired by the user from a plurality of MPEG streams received by the antenna 1, and a packet separating means. 4: separating TS packets of all channels of a digital broadcast program desired by the user from the demodulated MPEG stream, and extracting coded video data, coded audio data, and additional data from the separated TS packets. Can be.

The MPEG decoder 8 is composed of, for example, a channel discriminator and a plurality of decoders, each of which is assigned to a different channel. When coded audio data (hereinafter collectively referred to as coded data) is extracted, these are decoded by a corresponding decoder so that the coded data of these channels can be simultaneously decoded. Since the encoded data output from the packet separating means 4 has no information such as a header, it cannot be distinguished to which channel it belongs. For this purpose, in this embodiment, channel information adding means 5 is provided, and thereby, channel information indicating the channel to which the data belongs is added to the encoded data extracted by the packet separating means 4. In the MPEG decoder 8, the channel discriminator specifies a decoder for decoding the encoded data from the channel information added to the supplied encoded data.

In the MPEG decoder 8, one M
The maximum number of channels multiplexed in the PEG stream is N
(Where N is an integer of 2 or more), N decoders are provided, and these decoders
2,..., N. Therefore, the channel i (where i = 1, 2,...,
When the encoded data of N) is extracted, the channel data adding means 5 adds the encoded data to the channel i.
Is added to the MPEG decoder 8, and the corresponding decoder is designated by the channel information according to the channel information, and the encoded data is decoded by the designated decoder.

As described above, the decoder itself is the same as the conventional decoder, and can decode only one channel of coded data. Thus, encoded data of a plurality of channels multiplexed on the same MPEG stream can be decoded simultaneously.

The packet separating means 4 is integrated into an IC to form a semiconductor device as one device.

Next, the structure of an MPEG stream and the addition of channel information will be described with reference to FIG.

The MPEG stream is obtained by multiplexing TS packets having the above-described encoded video data, encoded audio data, and additional data as packet data. The TS packets are shown in FIG. As described above, the payload for storing the packet data and the type of the stored packet data (that is, the data of the channel, the encoded video data, the encoded audio data, and the additional data) ), And a header to which information (PID (Packet Identification: packet identification) information) is added, and an error correction check bit for correcting an error occurring during transmission. Have been. Hereinafter, a TS packet in which coded video data is packet data is referred to as a video packet, and similarly, TS packets of coded audio data and additional data are referred to as an audio packet and an additional data packet, respectively.

The TS packets having such a configuration are multiplexed as shown in FIG. 2B to form an MPEG stream. In an MPEG stream including a plurality of channels, video packets, audio packets, and additional data packets of each channel are multiplexed.

As shown in FIG. 2C, the packet data stored in the TS packet pen load is a byte (8 bytes).
It consists of multiple bytes as a bit) unit. Here, the data in byte units is A, and as shown in the figure, the data A stored in the pen load is data A1, A2, A3,... Of course, the data A1, A2, A3,.
It is the same type of encoded data on the same channel.

The channel information adding means 5 (FIG. 1) adds channel information for each data A in byte units. FIG. 2D shows data A to which channel information is added. Here, this channel additional information is 2
It is a bit. This channel information is added to the head of data A in byte units as shown in the figure. Therefore, the data A to which the channel information is added becomes 10-bit data, which is referred to as channel information additional data B.

In this case, since the channel information is 2 bits, a maximum of 4 channels can be multiplexed in one MPEG stream.

The packet separating means 4 shown in FIG. 1 uses the PID information added to the header (FIG. 2) of the TS packet from the supplied MPEG stream to output each channel of the digital broadcast program desired by the user. Are separated. FIG. 3 is a diagram schematically showing a main part of the packet separating means 4 and the channel information adding means 5, wherein 4a is an input terminal, 4b is a coincidence detecting section, and FIG.
Are given the same reference numerals.

In the figure, the demodulated signal S of the MPEG stream output from the error correction means 3 (FIG. 1) is input to the packet separation means 4 from the input terminal 4a and supplied to the coincidence detection unit 4b. Here, in the demodulated signal S, the digital broadcast program desired by the user is 4 to 4 of channels 1 to 4.
It shall consist of channels. The PID information of each of these channels is channel 1: CPID0 channel 2: CPID1 channel 3: CPID2 channel 4: CPID3. When the user designates this digital broadcast program by the user input means 17 (FIG. 1), the PID information of all the channels 1 to 4 of this digital broadcast program is set as search information in the match detection unit 4b. Even if the channel is the same, the PID information is different for each video packet and audio packet, and the PID is set for each audio packet and video packet. However, for simplicity of description, the PID information is set in the coincidence detection unit 4b. Each of the above-mentioned CPIDs 0 to 3 is the same for video packets and audio packets.

Therefore, the coincidence detecting section 4b compares, for each TS packet of the supplied demodulated signal S, the PID information added to the header (FIG. 2) with the set search information CPID0 to CPID3. If the PID information in the header matches one of the search information CPIDs 0 to 3, the packet data following the header is extracted and sent to the channel information adding means 5. In this case, the PID information at this time is also sent to the channel adding means 5 for each data A (FIG. 2) in byte units constituting the extracted packet data.

When the data A is supplied from the packet separating means 4, the channel information adding means 5 determines which channel the data A belongs to from the PID information supplied at the same time. The corresponding channel information is added to the data A as described with reference to FIG. That is, channel information is added for each data A in byte units.

FIG. 2E shows a specific example of the relationship between the PID information and the channel information, in which CPD0 → 00 CPD1 → 01 CPD2 → 10 CPD3 → 11. A conversion table indicating this relationship is provided in the channel information adding means 5, and channel information is selected from this table according to the supplied PID information and added to the data A. This channel information is MPE
The decoder in the G decoder 8 (FIG. 1) is designated.

Note that PID information differs for each digital broadcast program. For this reason, the PID information of each channel of the digital broadcast program desired by the user is also set as search information in the coincidence detecting unit 4b. A conversion table as shown in FIG.

The MPEG2 standard defines that a list of PID information of each TS packet constituting the stream is added to the MPEG stream. By setting specific search information in the packet separating means 4, this list can be extracted. Therefore, in FIG.
A user input means 17 for inputting a digital broadcast program desired by the user
Is selected, the MP containing this digital broadcast program
When the EG stream is selected, first, the control unit 12
However, the list is separated by the packet separating means 4, and the list is set as search information in the match detection unit 4b (FIG. 3).
In this way, even if the user changes the desired digital broadcast program, the T
S packets can be extracted.

In FIG. 1, all the channels of the digital broadcast program desired by the user can be simultaneously decoded as described above, and the decoded video signal of each channel can be decoded by the OSD means 9 as necessary. OSD (On Screen Display) information such as characters and graphics is added to the video encoder 10 (in response to an instruction from the user through the user input means 17). In the video encoder 10, under the control of the control unit 12 based on the user's instruction from the user input unit 17, when the decoded video signals of a plurality of channels are supplied, one of them is selected. A process such as synthesizing a decoded video signal of a channel designated by a user is performed to generate a decoded video signal of one channel, and this decoded video signal or only a decoded video signal of one channel is output from the MPEG decoder 8. At times, each of the decoded video signals is converted into an analog video signal.
After a process such as adding a synchronization signal is performed, it is supplied to the video processing circuit 13. In this video processing circuit, the analog video signal is processed so as to be suitable for video display and supplied to the video display means 15.

Therefore, according to the user's instruction, for example,
As shown in FIG. 4A, the images A, B, C, and D of the four channels of the same digital broadcast program can be appropriately switched and displayed. ) And (c), the video of the channel desired by the user can be displayed simultaneously.

In FIG. 1, the MPEG decoder 8
Is converted into an analog audio signal by the D / A converter 11, processed by the audio processing circuit 14, and supplied to the speaker 16.

In the above description, the MPEG decoder 8 is composed of a plurality of decoders. However, the MPEG decoder 8 may be composed of a single decoder. A memory area for storing data A for each channel may be set, and a memory area for writing supplied data A and reading data for decoding processing may be selected according to channel information. However, in the following embodiments, M is used to simplify the description.
It is assumed that the PEG decoder 8 includes a plurality of decoders.

FIG. 5 is a block diagram showing a main part of a second embodiment of the digital broadcast receiving apparatus according to the present invention.
Reference numeral 8 denotes a channel information generating means, and portions corresponding to those in FIGS. 1 and 3 are denoted by the same reference numerals. FIG. 6 is a timing chart showing the operation of the channel information generating means 18.

The second embodiment has the same overall configuration as the first embodiment shown in FIG. 1, but instead of the channel information adding means 5 in FIG. 1, as shown in FIG. The channel information generating means 18 is used to supply the generated channel information to the MPEG decoder 8 (FIG. 1) without adding it to the data A.

In FIG. 5, the packet separating means 4 is
This is the same as the specific example shown in FIG. Therefore, from the packet separating means 4, the coincidence detecting section 4 b outputs
Data A in byte units of the TS packet described in (c)
Is output, PID information for identifying the channel to which it belongs is also output. The PID information of the data A extracted from the same TS packet is the same.

When the PID information is supplied, the channel information generating means 18 generates channel information represented by the PID information, and supplies this to the MPEG decoder 8 (FIG. 1).

Here, the packet data of the channels 1, 2, 3, and 4 extracted by the coincidence detecting section 4a is
CH2, CH3, CH4, and channels 1, 2, 3,
Channel information of ch1, ch2, ch3, c, respectively.
h4. Therefore, as shown in FIG.
Packet separating means 4 in the order of 1, CH2, CH3, CH4
Assuming that the packet data is separated and output from the PID information, the channel information generation means 18 sets the period channel information ch1 of the packet data CH1 of the channel 1 to “H” (high) according to the supplied PID information as shown in FIG. Level), the period channel information ch2 of the packet CH2 of the next channel 1 is set to “H”, and the period channel information ch of the packet data CH3 of the next channel 3 is set to “H”.
3 is set to “H”, and the packet C of the next channel 4 is further set.
The period channel information ch4 of H4 is set to “H”. That is, only the channel information for the packet data of the channel output from the packet separating means 4 becomes “H”.

The MPEG decoder 8 (FIG. 1) supplies the packet data supplied from the packet separating means 4 to a decoder corresponding to the "H" channel information at that time.
Decode this.

As described above, also in the second embodiment, a plurality of channels multiplexed in the MPEG stream can be separated and decoded at the same time, and the same effect as in the first embodiment can be obtained. .

In the above description, a plurality of channels of the same digital broadcast program are simultaneously separated and decoded. However, the present invention is not limited to this. A different digital broadcast program is included in the selected MPEG stream. In some cases, by setting the PID for each digital broadcast program as search information in the coincidence detecting section 4b of the packet separating means 4, the TS packets of these digital broadcast programs can be separated and decoded at the same time. However, in this case, it is necessary to make channel information added to these digital broadcast programs different. For example, when two digital broadcast programs 1 and 2 are individually selected, the MPEG decoder is used when the channel 1 of the digital broadcast program 1 is selected and when the channel 1 of the digital broadcast program 2 is selected. 8, the same decoder may be used in some cases. However, when such channels of digital broadcast programs 1 and 2 are simultaneously selected, the control means (not shown) of the channel addition means 5 In accordance with an instruction from the control means 12, the channel information to be added to one of the digital broadcast programs 1 and 2 is made different from the value registered in the conversion table as shown in FIG. As a result, the respective digital broadcast programs are normally simultaneously decoded.

[0047] Figure 7 is a block diagram showing a third embodiment of a digital broadcast receiving apparatus according to the present invention, ₂₁ to ₂₄
Tuning and demodulation means 3 ₁ to 3 ₄ error correction means, 5 'stream information adding means, 19 is a packet separating means, a redundant description with the same reference numerals corresponding to FIG. 1 Omitted.

The first and second embodiments described above have the following features.
In the third embodiment, TS packets of a plurality of channels are simultaneously extracted from one MPEG stream, and the encoded data are simultaneously decoded.
The TS packets of the PEG stream can be simultaneously extracted and decoded at the same time, and the digital broadcast programs of the MPEG stream can be selected or simultaneously displayed and viewed.

[0049] In FIG. 7, MPEG stream for each digital broadcasting program received by the antenna 1 is supplied to the tuning and demodulation means ₂₁ to _24. Now, the user wants to view four digital broadcast programs by the user input means 17,
When these digital broadcasting program is assumed to be multiplexed to each different MPEG streams, the control unit 12 controls the tuning and demodulation means ₂₁ to _24, is demodulated by selecting a different MPEG streams respectively. After MPEG stream demodulated by these (demodulated signals _{S 1, S 2, S 3} , S 4) are each, the processing of the error correction by the error correction means 3 ₁ to 3 ₄ is made, is supplied to the packet separating unit 19 You. The packet separating means 19 separates the TS packet of the digital broadcast program desired by the user from the supplied demodulated signals S ₁ , S ₂ , S ₃ and S ₄ under the control of the control means 12. The encoded data is multiplexed, and together with the PID information,
It is supplied to the stream information adding means 5 '. Subsequent processing is the same as in the first embodiment shown in FIG.

The stream information adding means 5 'can have the same configuration as the channel information adding means 5 shown in FIGS. 1 and 5, and the information to be handled here indicates which received stream it represents. The only difference is that the type of information is different from that of the channel information adding means 5.

FIG. 8 shows the packet separating means 19 in FIG.
A block diagram showing a specific example of, 20 ₁ to 20 ₄ match detecting section, 21 ₁ to 21 ₄ are memory, 22 and 23 selector, 24 is a PLL (Phase Locked Loop) circuit, 24
a is a counter, 24b is a subtractor, 24c is a D / A (digital / analog) converter, 24d is an LPF (low pass filter), and 24e is a VCO (Voltage Controlled O).
scilater: voltage-controlled oscillator), 25 is a multiplier, and portions corresponding to FIG. 7 are denoted by the same reference numerals.

[0052] In the figure, the demodulated signals S ₁ of each stream _{supplied, S 2, S 3, S} 4 are each match detecting unit 20 _1,
20 ₂ , 20 ₃ , and 20 ₄ . These coincidence detection unit 20 _1, 20 _2, 20 _3, 20 ₄ are each, 3 or 5
In the same manner as the coincidence detection unit 4b shown in FIG. 7, the TS packet of the digital broadcast program desired by the user is separated using the PID information, and the packet data (encoded data) included therein is separated by the above-described byte-unit data A. The time information multiplexed in the MPEG stream (in the MPEG2 standard, PCR (Program Cloc
k Reference: program time reference value) information) is also separated. Coincidence detecting unit 20 _1, 20 _2, 20 _3, 20 ₄ data A output from the respective memories 21 _1, 21 _2, 21 _3,
It is supplied to the 21 _4.

[0053] coincidence detecting unit 20 _1, 20 _2, 20 _3, 20 time information extracted by ₄ is supplied to the selector 23, one of the time information in accordance with information set in the register group 7 by the control unit 12 Is selected and supplied to the PLL circuit 24.

In the PLL circuit 24, the clock φ ₁ is generated and output by the VCO 24e. This clock φ ₁ is counted by the counter 24a, and the count value is time information (STC (Syst
em Time Clock: Output as basic synchronization information)). A difference value between the time information and the time information selected by the selector 23 is detected by a subtractor 24b, converted into an analog value by a D / A converter 24c, and averaged by an LPF 24d. The output of the LPF 24d controls the oscillation frequency of the VCO 24e as a control voltage.

When the reception of the digital broadcast program starts,
The time information first output from the selector 23 is also loaded into the counter 24a. Therefore, the subtracter 2 at this time
4b becomes 0, and thereafter, the counter 24a counts the VCO2 from the value of the loaded time information.
Counts clock phi ₁ from 4e, each time the time information from the selector 23 is supplied, a difference value between the count value of the time information and the counter 24a (time information) subtractor 2
4b, and the VCO 24e is set so that the difference value becomes zero.
Is controlled. For this reason, the frequency of the clock φ ₁ becomes equal to the clock frequency of the received MPEG stream. That is, this clock φ ₁ is a system clock required for MPEG decoding, and the system clock φ ₁ is reproduced by using the PLL circuit 24 with time information extracted from the MPEG stream.

The time information (STC information) obtained by the counter 24a serves as a reference when decoding coded video data and coded audio data, and is generated by the PLL circuit 24 in the MPEG decoder 8. with operating the system clock phi ₁ was to determine the output timing of the video signal and audio signal decoded by referring to the count value of the counter 24a.

The system clock φ ₁ thus obtained is used as a clock for the MPEG decoder 8 (FIG. 7) and as a write clock for the memories 21 _{1 to} 21 ₄ . Also, this system clock φ ₁
Is supplied to multiplier 25, where, since it is capable of receiving four MPEG stream 4 are multiplied, the multiplied clock phi ₂ of 4 times the frequency of the system clock phi ₁ is generated. The multiplied clock φ ₂ is supplied to the channel information adding means 5 and the MPEG decoder 8 (FIG. 7), and is also used as a read clock for the memories 21 ₁ , 21 ₂ , 21 ₃ and 21 ₄ .

[0058] Therefore, the coincidence detection unit 20 _1, 20 _2, 2
0 _3, 20 ₄ data A byte output from respectively written to the system clock phi ₁ to the memory 21 _1, 21 _2, 21 _3, 21 ₄ as a write clock, the multiplication clock phi ₂ as a read clock , These memories 21 ₁ , 21
_2, 21 _3, 21 ₄ are read out at approximately four times the speed at the time of writing from. Therefore, the read data A in byte units
Is time-axis-compressed almost １ ／ times that at the time of writing. The data A thus read is supplied to the stream information adding means 5 ', and like the first embodiment described with reference to FIG. 1, like the channel information adding means 5 described with reference to FIGS. The 2-bit stream information is added to form 10-bit stream information additional data B ′. The time length of the 10-bit stream information additional data B ′ is the byte-length data A before the time axis compression.
時間 times the time length of Of course, instead of adding the stream information to the data A by the stream information adding means 5 ', the channel information generating means 1 shown in FIG.
8, the data may be supplied to the MPEG decoder 8 without being added to the data A. However, in this case, since the stream information is not added, the memories 21 ₁ , 21 ₂ , 2
1 _3, 21 data A time base compressed bytes to be read from the _4, may be a fourth of the time length of the previous data A writing.

The read timings from the memories 21 ₁ , 21 ₂ , 21 ₃ , and 21 ₄ are set so that the time-axis-compressed data A in byte units read from these memories do not overlap in time. The selector 22 includes the memories 21 ₁ , 21 ₂ ,
The memory from which reading is started is selected from 21 ₃ and 21 ₄ , and time-axis-compressed data A read from the memory is output. Therefore, as shown in FIG.
If there is almost no time difference between the writing start timings of the data A in byte units at 11 ₁ , 21 ₂ , 21 ₃ , and 21 ₄ , for example, the order of the memories 21 ₁ , 21 ₂ , 21 ₃ , and 21 _{4 is} as follows. Are read out in a fixed order. For example, as shown in FIGS. 9B and 9C, the memories 21 ₁ and 2
1 _2, 21 _3, when there is a shift in the write start timing of data A byte at 21 ₄ to read from written early memory. Coincidence detecting unit 20 _1,
Since the extraction timing of the byte data of the coded data in 20 ₂ , 20 ₃ , and 20 ₄ can be detected by the header of the TS packet, the control means 12 uses the detection results to store the memories 21 ₁ , 21 ₂ , 21 ₃ , 21 The reading timing of ₄ may be set. Then, the selector 22 is controlled to select a memory from which the reading is started.

[0060] In this way, the memory 21 _1, 21 _2, 21 _3, 21 data A byte read from ₄ is output after being multiplexed from the selector 22, in FIG. 7, the stream information adding means 5 '. Even in this case, the time-axis-compressed PID information is also supplied to the channel information adding means 5 'for each time-axis-compressed data A. To obtain this time axis compressed PID information to PID information, the memory 21 ₁ in FIG. 8, 2
1 _2, 21 _3, 21 ₄ or may be provided the same apparatus as the selector 22. Also, it goes without saying that the bit rate of the stream information added by the stream information adding means 5 'is equal to the bit rate of the data A to which the stream information is added.

The MPEG decoder 8 in FIG. 7 separates each of the received MPEG streams from the supplied multiplexed signal of the data A in units of bytes using the stream information added thereto. Using the multiplied clock φ ₂ generated by the multiplier 25 in FIG. 8, writing to the built-in memory, and reading from this memory and subsequent decoding processing are performed by the system clock generated by the PLL circuit 24 in FIG. to make use of the φ _1.

As described above, in this embodiment, the encoded data of each digital broadcast program can be simultaneously extracted from a plurality of streams using a single packet separating means, and can be decoded simultaneously. Digital broadcast programs of a plurality of streams can be selected or viewed simultaneously on the same screen.

In the third embodiment, the time information multiplexed on any one of a plurality of streams is used for the PLL circuit 24 shown in FIG. Is generally sent on the premise that the output timing is determined using the same clock as when encoding, and time information is extracted and set in the PLL circuit 24 before multiplexing a plurality of streams. Therefore, time management at the time of decoding can be performed without any problem.

In the above description, a digital broadcast program is selected from four streams simultaneously.
Obviously, the number of streams is not limited to this.

[0065]

As described above, according to the present invention,
Since a plurality of channels can be separated from one stream and these can be decoded simultaneously, and since digital broadcast programs of a plurality of streams can be separated and decoded simultaneously, a plurality of channels or program screens can be displayed. Can be displayed selectively or simultaneously.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a digital broadcast receiving apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the structure of an MPEG stream and the addition of channel information.

FIG. 3 is a block diagram showing a specific example of a packet separating unit and a channel information adding unit in FIG. 1;

FIG. 4 is a diagram showing a video display mode in the embodiment shown in FIG.

FIG. 5 is a block diagram showing a main part of a second embodiment of the digital broadcast receiving apparatus according to the present invention.

FIG. 6 is a diagram showing the operation of the channel information adding means shown in FIG.

FIG. 7 is a block diagram showing a configuration of a third embodiment of a digital broadcast receiving apparatus according to the present invention.

FIG. 8 is a block diagram showing a specific example of a packet separating unit in FIG. 7;

FIG. 9 is a diagram showing the operation of the packet separating means shown in FIG.

[Explanation of symbols]

1 antenna 2,2 ₂₁ to ₂₄ channel-selection-demodulation means 4 packet separating means 4b coincidence detecting unit 5 channel information adding means 5 'stream information adding means 8 MPEG decoder 9 OSD circuit 10 video encoder 11 D / A converter 12 control means 17 user input means 18 channel information generating unit 19 packet separating means 20 ₁ to 20 ₄ match detecting unit 21 ₁ to 21 ₄ memories 22 and 23 the selector 24 PLL circuit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // H04N 5/445 (72) Inventor Keisuke Inada 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi, Ltd. In-house Digital Media Development Division (72) Inventor Hironori Komi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture In-house Digital Media Development Division Hitachi, Ltd. (72) Inventor Koichi Terui 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Address Digital Media Development Division, Hitachi, Ltd. (72) Inventor Satoshi Iimuro 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Digital Media Development Division, Hitachi, Ltd. (72) Inventor Yuji Yamamoto Totsuka, Yokohama-shi, Kanagawa Prefecture 292 Yoshida-cho, Ward Hitachi Digital Media Development Co., Ltd. The internal F-term (reference) 5C025 AA23 BA25 BA27 BA28 BA30 CA06 CA09 DA01 DA04 5C063 AA20 AB03 AB07 AC01 AC05 CA09 CA12 CA23 CA40

Claims (9)

[Claims] 1. A digital broadcast receiving apparatus for forming a packet by adding first identification data to encoded data of a plurality of channels and receiving a stream formed by multiplexing the packet. A semiconductor device provided with packet separating means for extracting the encoded data of the channel from the received stream, wherein the packet separating means separates the externally set data and the first identification data from each other. Sequentially extracting and outputting the encoded data of each channel from the stream, and outputting second packet identification data corresponding to the first identification data together with the extracted encoded data. A semiconductor device characterized by the above-mentioned. 2. A digital broadcast receiving apparatus for receiving a stream in which coded data of a plurality of channels are packetized and multiplexed, wherein the station selects and decodes the stream, A packet separating means for extracting encoded data of each channel from the selected and decoded stream; and a channel for adding channel information indicating a channel to which the encoded data belongs for each extracted encoded data. Information adding means, and decoding means for judging a channel to which the encoded data belongs based on the channel information, and simultaneously decoding the encoded data of each channel separated by the packet separating means. Digital broadcast receiver characterized by the above-mentioned. 3. The stream selected and demodulated by the tuning and demodulating means according to claim 2, wherein packet identification data for identifying a channel for each packet of the encoded data is added. The packet separating unit extracts the encoded data of the packet of the desired channel based on the packet identification data, and outputs the packet identification data together with the extracted encoded data; A digital broadcast receiving apparatus for adding the channel information corresponding to the packet identification data from the packet means to the encoded data. 4. The apparatus according to claim 2, wherein the decoding means selects one or more of the decoded video signals of each channel, or synthesizes two or more of the decoded video signals, and displays a video by the decoded image signal output from the means. And a means for performing the operation. 5. A digital broadcast receiving apparatus for forming a packet by adding first identification data to each encoded data and receiving a plurality of streams formed by multiplexing the packets. A packet separating means for extracting the coded data of the channel from the received stream, wherein the packet separating means is capable of simultaneously inputting a plurality of streams, A second packet corresponding to the first identification data, the extracted data being sequentially extracted from the plurality of streams based on the first identification data; A semiconductor device for outputting identification data. 6. The semiconductor device according to claim 5, wherein the packet separating unit multiplexes the encoded data extracted from the plurality of streams and outputs the multiplexed data as one stream. 7. The stream according to claim 6, wherein time information for managing a decoding time of the encoded data is multiplexed on each of the plurality of streams, and Time information extracting means for extracting the time information; clock reproducing means for reproducing a system clock for decoding based on the extracted time information; multiplying means for multiplying the system clock; A plurality of memory means for writing the extracted coded data for each stream, using the system clock as a write clock, and reading a clock from the multiplying means as a read clock; and the code read from the plurality of memory means Multiplexing means for multiplexing multiplexed data into one stream. Device. 8. A digital broadcast receiving apparatus for receiving a plurality of streams in which coded data is packetized and multiplexed, comprising: a packet separating means for extracting coded data for each of the received streams; Stream information adding means for adding stream information indicating a stream to which the encoded data belongs, for each of the encoded data, determining a stream to which the encoded data belongs based on the stream information; A digital broadcast receiving apparatus comprising: decoding means for simultaneously decoding encoded data of each stream separated by the packet separating means. 9. The means according to claim 8, wherein said decoding means selects one or more of the decoded video signals of each channel, or synthesizes two or more of the decoded video signals, and displays the video with the decoded image signal output from said means. And a digital broadcast receiving device comprising: