JP2005117679A - Digital broadcast receiver and its semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simultaneously decode a plurality of channels multiplexed on an MPEG stream and to selectively or simultaneously display each of pictures. <P>SOLUTION: A plurality of channels are multiplexed on an MPEG stream received by a tuning/demodulating means 2, and a packet separating means 4 uses PID information to separate encoded data (encoded video data or encoded audio data) of the channels into data A of the unit of a byte. The data A are supplied to a channel information adding means 5 together with the PID information representing a channel to which the data A belong, and channel information is added to each of the data A on the basis of the PID information. Data B obtained by thus adding the channel information to the data A are supplied to an MPEG decoder 8. The MPEG decoder 8 comprises a decoder for each channel, for example, and decodes the data B using a corresponding decoder on the basis of the channel information. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a digital broadcast receiving apparatus and a semiconductor device thereof, and more particularly to extracting a plurality of video signals simultaneously from a stream in which a plurality of video signals are multiplexed, or separating a plurality of video signals simultaneously from a plurality of streams. The present invention relates to a digital broadcast receiving apparatus for decoding and a semiconductor device thereof.

  Digital that multiplexes and broadcasts audio information, video information, and various other information into a single bitstream, encoded using digital compression encoding technology such as MPEG (Moving Picture Experts Group), an international standard. Broadcasting has begun, and along with this, digital broadcast receivers are becoming widespread. In such digital broadcasting, video data, audio data, etc. encoded in accordance with the MPEG2 system standard (ISO / IEC 13818-1) are multiplexed. The encoded data is shown in FIG. It is stored in the payload of a transport stream packet (hereinafter referred to as a TS packet) having the structure shown, and the TS packets are multiplexed and transmitted as a transport stream (hereinafter referred to as an MPEG stream).

  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 heart of such digital broadcasting is high-definition HDTV (High Definition Television) broadcasting. However, from the viewpoint of simultaneously sending many programs, a standard resolution SDTV (Standard Definition Television) broadcast capable of transmitting about four programs at a transmission rate required for one HDTV program and a combination of HDTV broadcasts are proposed. (For example, SDTV broadcasting of four programs is performed from morning to evening, and HDTV broadcasting is performed from evening.) For example, in a program such as a sports broadcast, a plurality of SDTVs viewed from different directions are considered. It is considered that the video data can be multiplexed and transmitted in one MPEG stream, and the viewer can select the video from the desired angle.

  In the following, when a plurality of different videos are simultaneously transmitted in one program as described above, it is said that each video is transmitted through different channels, 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.

  As described above, it is possible to simultaneously transmit the video of the same program through a plurality of channels, and the viewer can select and view one of these channels. However, it is assumed that only one channel is separated from the received MPEG stream, and only one channel decoding is assumed for a decoder that decodes the separated encoded video signal. For this reason, even if a plurality of videos of the same program are transmitted as separate channels, the plurality of videos cannot be viewed simultaneously. When a single program is transmitted in multiple channels as described above, such as a sports program, it is preferable for viewers to be able to view these channels at the same time. However, conventional digital broadcast receivers can do this. There wasn't.

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

  Another object of the present invention is to provide a digital broadcast receiving apparatus and a semiconductor device thereof capable of simultaneously viewing a plurality of received stream programs.

  In order to achieve the first object, a semiconductor device according to the present invention is formed by adding first identification data to encoded data of a plurality of channels to form a packet, and multiplexing the packet. Data that is used in a digital broadcast receiving apparatus that receives a stream, and that includes packet separation means for extracting the encoded data of the channel from the received stream, the packet separation means being data set from the outside And the encoded data of each channel are sequentially extracted from the stream and output based on the first identification data and the first identification data together with the extracted encoded data and the first identification data corresponding to the first identification data. 2 packet identification data is output.

  The digital broadcast receiving apparatus according to the present invention receives a stream in which encoded data of a plurality of channels are packetized and multiplexed, and selects and decodes the stream. Means, packet separating means for extracting encoded data of each channel from the selected and demodulated stream, and channel information representing the channel to which the encoded data belongs for each of the extracted encoded data. Channel information adding means for adding, and decoding means for determining 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 The configuration is as follows.

  In order to achieve the second object, a semiconductor device according to the present invention adds a first identification data to each encoded data to form a packet, and multiplexes a plurality of streams formed by multiplexing the packet. Used in a receiving digital broadcast receiving apparatus, comprising packet separation means for extracting the encoded data of the channel from the received stream, wherein the packet separation means is capable of simultaneous input of a plurality of streams. , Based on data set from the outside and the first identification data, sequentially extract and output the encoded data from the plurality of streams, and together with the extracted encoded data, the first The second packet identification data corresponding to the identification data is output.

  The digital broadcast receiving apparatus according to the present invention receives a plurality of streams in which encoded data is packetized and multiplexed, and includes packet separation means for extracting encoded data for each received stream. Stream information adding means for adding stream information representing the stream to which the encoded data belongs for each extracted encoded data, and determining the stream to which the encoded data belongs based on the stream information And a decoding means for simultaneously decoding the encoded data of each stream separated by the packet separation means.

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

  Hereinafter, embodiments of the present invention will be described 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, 4 is a packet separation means, Channel information adding means, 6 a memory, 7 a register group, 8 an MPEG decoder, 9 an OSD (On Screen Display) circuit, 10 a video encoder, 11 a D / A (digital / analog) converter, and 12 a control means , 13 is a video processing circuit, 14 is an audio processing circuit, 15 is video display means, 16 is a speaker, and 17 is user input means.

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

  The demodulated signal (MPEG stream) from the channel selection / demodulation means 2 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. Thus, the encoded audio data, the encoded video data, and the additional data of the digital broadcast program desired by the user are separated. The encoded audio data and the encoded video data separated by the packet separating means 4 are supplied to the channel information adding means 5 for each byte A of data A, channel information is added, and then supplied to the MPEG decoder 8. Is decrypted. Further, the additional data separated by the packet separation means 4 is temporarily stored in the memory 6. This additional data is read by the control means 12 through the register group 7 composed of a plurality of registers.

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

  The channel selection / demodulation means 2 selects and demodulates one MPEG stream including a digital broadcast program desired by the user from a plurality of MPEG streams received by the antenna 1, but the packet separation means 4 From this demodulated MPEG stream, TS packets of all channels of a digital broadcast program desired by the user can be separated, and encoded video data, encoded audio data, and additional data can be extracted from the separated TS packets.

  The MPEG decoder 8 is composed of, for example, a channel discriminator and a plurality of decoders, and each decoder is assigned to a different channel, and the packet separating means 4 encodes the encoded video data and encoded audio of the plurality of channels. When data (hereinafter collectively referred to as encoded data) is extracted, these are decoded by the corresponding decoder so that the encoded data of these channels can be decoded simultaneously. Since the encoded data output from the means 4 excludes information such as a header, it cannot be distinguished which channel it is. For this purpose, in this embodiment, channel information adding means 5 is provided, whereby channel information representing the channel to which it belongs is added to the encoded data extracted by the packet separating means 4. In the MPEG decoder 8, the channel discriminator designates a decoder that decodes the encoded data from the channel information added to the supplied encoded data.

  In the MPEG decoder 8, if the maximum number of channels multiplexed in one MPEG stream is N (where N is an integer of 2 or more), N decoders are provided. Channels 1, 2,..., N are assigned in order. Therefore, when the encoded data of channel i (where i = 1, 2,..., N) is extracted by the packet separating means 4, the channel information adding means 5 indicates the channel i. When channel information is added and supplied to the MPEG decoder 8, a decoder corresponding to the channel discriminator is designated by the channel information, and the coded data is decoded by the designated decoder.

  In this way, the decoder itself is the same as the conventional decoder and can only decode the encoded data of one channel. By configuring as described above, the same MPEG can be obtained. The encoded data of a plurality of channels multiplexed in the stream can be decoded simultaneously.

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

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

  An MPEG stream is obtained by multiplexing TS packets having the above-described encoded video data, encoded audio data, and additional data as packet data. As shown in FIG. What type of data is the payload for storing packet data and the stored packet data (that is, which channel data is encoded video data, encoded audio data, or additional data) Or the like (PID (Packet Identification) information) added to the header and an error correction check bit portion for correcting an error occurring during transmission. . In the following, TS packets that use encoded video data as packet data are referred to as video packets, and similarly, encoded audio data and additional data TS packets are referred to as audio packets and additional data packets, respectively.

  The TS packet having such a configuration is 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.

  The packet data stored in the pen load of the TS packet is composed of a plurality of bytes as a byte (8 bits) unit as shown in FIG. Here, the data in bytes is A, and the data A stored in the pen load is data A1, A2, A3,. Of course, the data A1, A2, A3,... In the same TS packet are the same kind of encoded data of the same channel.

  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 bits. 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 channel information is added becomes 10-bit data, which is called 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 in FIG. 1 uses the PID information added to the header (FIG. 2) of the TS packet from the supplied MPEG stream, and the TS packet of each channel of the digital broadcast program desired by the user. Isolate. FIG. 3 is a diagram schematically showing the main part of the packet separating means 4 and the channel information adding means 5. 4a is an input terminal, 4b is a coincidence detecting part, and the same parts as in FIG. A sign is attached.

In this figure, the MPEG stream demodulated signal S 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 section 4b. Here, in this demodulated signal S, the digital broadcast program desired by the user is assumed to be composed of four channels 1 to 4. Also, the PID information for each of these channels is
Channel 1: CPID0
Channel 2: CPID1
Channel 3: CPID2
Channel 4: CPID3
And When the user designates this digital broadcast program by the user input means 17 (FIG. 1), the PID information of all these channels 1 to 4 of this digital broadcast program is set as search information in the coincidence 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, in order to simplify the description, it is set in the coincidence detection unit 4b. Each of the above-mentioned CPID 0 to 3 is assumed to be the same for the video packet and the audio packet.

  Therefore, the coincidence detection unit 4b compares the PID information added to the header (FIG. 2) with the set search information CPID0 to 3 for each TS packet of the demodulated signal S supplied, If the PID information matches any one of the search information CPID 0 to 3, the packet data following this 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 byte-unit data A (FIG. 2) 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 is from the PID information supplied at the same time, and the channel corresponding to the determination result Information is added to data A as described with reference to FIG. That is, channel information is added for each data A in byte units.

FIG. 2 (e) shows a specific example of the relationship between PID information and channel information.
CPD0 → 00
CPD1 → 01
CPD2 → 10
CPD3 → 11
It is said. 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 designates a decoder in the MPEG decoder 8 (FIG. 1).

  Note that the PID information is different for each digital broadcast program. For this reason, the coincidence detection unit 4b also sets the PID information of each channel of the digital broadcast program desired by the user as search information, but the channel information adding means 5 also receives each digital broadcast program that can be received. A conversion table as shown in FIG. 2 (e) is set.

  Further, the MPEG2 standard stipulates that a list of PID information of each TS packet constituting the MPEG stream is added to the MPEG stream. This list can be extracted by setting specific search information in the packet separation means 4. Therefore, in FIG. 1, when the user selects a desired digital broadcast program by the user input unit 17, when an MPEG stream including the digital broadcast program is selected, first, the control unit 12 uses the packet separation unit 4. This list is separated and set as search information in the coincidence detection unit 4b (FIG. 3). In this way, even if the digital broadcast program desired by the user is changed, it is possible to extract TS packets of each channel of the digital broadcast program.

  In FIG. 1, as described above, all the channels of the digital broadcast program desired by the user can be decoded at the same time, but the decoded video signal of each channel is obtained by the OSD means 9 as necessary (ie, OSD (On Screen Display) information such as characters and figures is added to the video encoder 10 after the user input means 17 instructs the user. In the video encoder 10, when decoded video signals of a plurality of channels are supplied under the control of the control unit 12 based on a user instruction from the user input unit 17, one of these is selected. Then, a process such as synthesizing the decoded video signal of the channel specified by the user is performed to obtain a decoded video signal of one channel, and this decoded video signal or only the decoded video signal of one channel is output from the MPEG decoder 8. In some cases, the decoded video signal is converted into an analog video signal, and a process such as adding a synchronization signal is performed, and then 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 may be appropriately switched and displayed. Alternatively, for example, as shown in FIGS. 4B and 4C, the video of the channel desired by the user can be displayed simultaneously.

  In FIG. 1, the digital audio signal decoded by 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 one decoder. In this case, for example, each decoder is provided with each decoder. A memory area for storing data A may be set, and a memory area for reading data for writing or decoding of data A supplied according to channel information may be selected. However, also in the following embodiments, the MPEG decoder 8 is composed of a plurality of decoders in order to simplify the description.

FIG. 5 is a block diagram showing the main part of the second embodiment of the digital broadcast receiving apparatus according to the present invention, wherein 18 is channel information generating means, and the same reference numerals are given to the parts corresponding to FIGS. I'm wearing it.
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 that of the first embodiment shown in FIG. 1, but instead of the channel information adding means 5 in FIG. 1, as shown in FIG. The means 18 is used to supply the channel information generated here to the MPEG decoder 8 (FIG. 1) without adding it to the data A.

  In FIG. 5, the packet separation means 4 is the same as the specific example shown in FIG. Therefore, each time the data A in byte units of the TS packet described with reference to FIGS. 2A to 2C is output from the packet separation unit 4 by the coincidence detection unit 4b, the channel to which the packet belongs is identified. PID information is also output. The PID information of 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 it to the MPEG decoder 8 (FIG. 1).

Here, the packet data of channels 1, 2, 3, and 4 extracted by the coincidence detection unit 4a are CH1, CH2, CH3, and CH4, respectively, and the channel information of channels 1, 2, 3, and 4 are respectively ch1, ch2, and ch4. ch3 and ch4. Therefore, as shown in FIG. 6, assuming that packet data is separated and output from the packet separation means 4 in the order of CH1, CH2, CH3, and CH4, the channel information generation means 18 uses the supplied PID information. 6, the period channel information ch1 of the packet data CH1 of the channel 1 is set to “H” (high level), the period channel information ch2 of the packet CH2 of the next channel 1 is set to “H”, and the next The period channel information ch3 of the packet data CH3 of the channel 3 is set to “H”, and the period channel information ch4 of the packet CH4 of the next channel 4 is set to “H”. That is, only the channel information for the packet data of the channel output from the packet separator 4 is “H”.

  In the MPEG decoder 8 (FIG. 1), the packet data supplied from the packet separation means 4 is supplied to a decoder corresponding to the channel information of “H” at that time, and is decoded.

  Thus, 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, and when the selected MPEG stream includes different digital broadcast programs, respectively. By setting the PID for the digital broadcast program as search information in the coincidence detection unit 4b of the packet separation means 4, the TS packets of these digital broadcast programs can be separated and decoded simultaneously. 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, an MPEG decoder is selected when channel 1 of digital broadcast program 1 is selected and when channel 1 of digital broadcast program 2 is selected. 8, the same decoder may be used. However, when the channels of the digital broadcast programs 1 and 2 are selected at the same time, the control means (not shown) of the channel adding means 5 The channel information added to one of the channels of the digital broadcast programs 1 and 2 is made different from the value registered in the conversion table as shown in FIG. Thereby, each digital broadcast program is normally decoded simultaneously.

  FIG. 7 is a block diagram showing a third embodiment of the digital broadcast receiving apparatus according to the present invention, in which 21 to 24 are channel selection / demodulation means, 31 to 34 are error correction means, 5 'is stream information addition means, Reference numeral 19 denotes packet separation means, and the same reference numerals are given to the portions corresponding to those in FIG.

  In the first and second embodiments described above, TS packets of a plurality of channels are simultaneously extracted from one MPEG stream, and the encoded data is simultaneously decoded. This third embodiment In this configuration, TS packets of a plurality of MPEG streams can be simultaneously extracted and decoded simultaneously, and digital broadcast programs of these MPEG streams can be selected or simultaneously displayed and viewed.

  In FIG. 7, the MPEG stream of each digital broadcast program received by the antenna 1 is supplied to the channel selection / demodulation means 21 to 24. If the user desires to view four digital broadcast programs by the user input means 17 and these digital broadcast programs are multiplexed in different MPEG streams, the control means 12 selects the channel selection / demodulation means 21 to 24. , And select and demodulate different MPEG streams. The demodulated MPEG streams (demodulated signals S1, S2, S3, S4) are subjected to error correction processing by the error correction means 31 to 34, and then supplied to the packet separation means 19. Under the control of the control means 12, the packet separation means 19 separates TS packets of the digital broadcast program desired by the user from the supplied demodulated signals S 1, S 2, S 3, S 4. It is multiplexed and supplied to the stream information adding means 5 ′ together with the PID information. The subsequent processing is the same as that of 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 FIG. 1 and FIG. 5, and the information handled here indicates which received stream represents information. Is different from the case of the channel information adding means 5.

  FIG. 8 is a block diagram showing a specific example of the packet separating means 19 in FIG. 7, in which 201 to 204 are coincidence detection units, 211 to 214 are memories, 22 and 23 are selectors, and 24 is a PLL (Phase Locked Loop). Circuit, 24a is a counter, 24b is a subtractor, 24c is a D / A (digital / analog) converter, 24d is an LPF (low pass filter), 24e is a VCO (Voltage Controlled Oscilater), and 25 is a multiplier. The parts corresponding to those in FIG.

  In the figure, the supplied demodulated signals S1, S2, S3 and S4 are supplied to coincidence detectors 201, 202, 203 and 204, respectively. Similar to the coincidence detection unit 4b shown in FIG. 3 or FIG. 5, these coincidence detection units 201, 202, 203, and 204 separate the TS packets of the digital broadcast program desired by the user using the PID information. The packet data (encoded data) included in the data is output for each byte A of data A. At the same time, time information multiplexed in the MPEG stream (in the MPEG2 standard, PCR (Program Clock Reference: The program time base reference value) information) is also separated. Data A output from the coincidence detectors 201, 202, 203, 204 is supplied to memories 211, 212, 213, 214, respectively.

  The time information extracted by the coincidence detectors 201, 202, 203, and 204 is supplied to the selector 23, and any time information is selected by the control means 12 according to the information set in the register group 7, and the PLL circuit 24 is selected. To be supplied.

  In the PLL circuit 24, the clock φ1 is generated and output by the VCO 24e. This clock φ1 is counted by the counter 24a, and the count value is time information (STC (System Time Clock: basic in the MPEG2 standard). Synchronous information)) is output. A difference value between the time information and the time information selected by the selector 23 is detected by the subtractor 24b, converted into an analog value by the D / A converter 24c, and then averaged by the 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 is started, the time information first output from the selector 23 is also loaded into the counter 24a. Accordingly, the difference value obtained by the subtractor 24b at this time is 0. Thereafter, the counter 24a counts the clock φ1 from the VCO 24e from the loaded time information value, and the time information is supplied from the selector 23. Each time, the difference value between the time information and the count value (time information) of the counter 24a is obtained by the subtractor 24b, and the VCO 24e is controlled so that the difference value becomes zero. For this reason, the frequency of this clock φ1 is equal to the clock frequency of the received MPEG stream. That is, the clock φ1 is a system clock required for MPEG decoding, and the system clock φ1 is reproduced by using the time information extracted from the MPEG stream in the PLL circuit 24.

  The time information (STC information) obtained by the counter 24a serves as a reference when decoding the encoded video data or the encoded audio data. In the MPEG decoder 8, the system clock generated by the PLL circuit 24 is used. In addition to operating by φ1, the output timing of the decoded video signal and audio signal is determined with reference to the count value of the counter 24a.

  The system clock .phi.1 obtained in this way is used as a clock for the MPEG decoder 8 (FIG. 7) and as a write clock for the memories 211 to 214. Further, this system clock φ1 is supplied to the multiplier 25. Here, since four MPEG streams can be received, the system clock φ1 is multiplied by four to generate a multiplied clock φ2 having a frequency four times that of the system clock φ1. The This multiplied clock φ2 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 211, 212, 213 and 214.

  Therefore, the byte-unit data A output from the coincidence detectors 201, 202, 203, and 204 is written to the memories 211, 212, 213, and 214 using the system clock φ1 as a write clock, and the multiplied clock φ2 as a read clock. Are read out from these memories 21 1, 21 2, 21 3, and 21 4 at a speed almost four times that at the time of writing. Therefore, the read byte-unit data A is time-axis-compressed approximately ¼ times that at the time of writing. The data A read out in this way is supplied to the stream information adding means 5 ′, and like the channel information adding means 5 explained in FIG. 2 and FIG. 3, as in the first embodiment explained in FIG. The 2-bit stream information is added to become 10-bit stream information additional data B ′. The time length of the 10-bit stream information additional data B ′ is the time of the data A in bytes before time axis compression. Try to be 1/4 times the length. Of course, instead of adding the stream information to the data A by the stream information adding means 5 ′, the stream information may be supplied to the MPEG decoder 8 without being added to the data A as in the channel information generating means 18 shown in FIG. In this case, since stream information is not added, the time-axis-compressed byte-unit data A read from the memories 21 1, 21 2, 213, and 214 is 1/4 times as long as the data A before writing. It only needs to be long.

  The read timing from the memories 211, 212, 213, and 214 is set so that the time-axis-compressed byte-unit data A read from these does not overlap in time. The selector 22 selects a memory to start reading from among the memories 211, 212, 213, and 214, and outputs time-axis compressed data A read from the selected memory. Therefore, as shown in FIG. 9A, when there is almost no time difference in the write start timing of the data A in byte units in the memories 211, 212, 213, 214, for example, the memories 211, 212, 213, 214 For example, as shown in FIGS. 9B and 9C, writing of data A in units of bytes in the memories 211, 212, 213, and 214 is started. When there is a difference in timing, the data is read from the memory written earlier. Since the extraction timing of the byte data of the encoded data in the coincidence detectors 201, 202, 203, and 204 can be detected by the header of the TS packet, the control means 12 determines whether the memories 211, 212, 213, and 214 are based on the detection result. The reading timing may be set. Then, the selector 22 is controlled to select a memory for starting the reading.

In this way, the selector 22 outputs the data A in byte units read from the memories 21 1, 21 2, 21 3, and 214 in a multiplexed manner and supplies it to the stream information adding means 5 ′ in FIG. Even in this case, for each data A compressed in time axis, PID information compressed in time axis is also supplied to the channel information adding means 5 ′. In order to obtain the time-compressed PID information, a device similar to the memories 21 1, 21 2, 21 3, and 214 and the selector 22 shown in FIG. Needless to say, the bit rate of the stream information added by the stream information adding means 5 'is also equal to the bit rate of the data A to which it is added.

  In addition, the MPEG decoder 8 in FIG. 7 separates each received MPEG stream from the supplied multiplexed signal of data A in byte units using the stream information added thereto, 8 is written in the built-in memory using the multiplied clock φ2 generated by the multiplier 25, and the system clock φ1 generated by the PLL circuit 24 in FIG. 8 is used for reading from this memory and subsequent decoding processing. To.

  In this way, in this embodiment, it is possible to simultaneously extract the encoded data of each digital broadcast program from a plurality of streams using a single packet separation means, and to decode them simultaneously. The digital broadcast program can be selected or viewed simultaneously on the same screen.

  In the third embodiment, the time information multiplexed on any one of the plurality of streams is used in the PLL circuit 24 shown in FIG. 8, but the time information is encoded. In general, it is sent on the assumption that the output timing is determined using the same clock as that at the time, 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 at the same time, but it is obvious that the number of streams is not limited to this.

It is a block diagram which shows the structure of 1st Embodiment of the digital broadcast receiver by this invention. It is a figure which shows the structure of an MPEG stream, and addition of channel information. It is a block diagram which shows a specific example of the packet separation means and channel information addition means in FIG. It is a figure which shows the video display mode in embodiment shown in FIG. It is a block diagram which shows the principal part of 2nd Embodiment of the digital broadcast receiver by this invention. It is a figure which shows the operation | movement of the channel information addition means shown in FIG. It is a block diagram which shows the structure of 3rd Embodiment of the digital broadcast receiver by this invention. It is a block diagram which shows one specific example of the packet separation means in FIG. It is a figure which shows the operation | movement of the packet separation means shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antenna 2, 21 ~ 2 4 Channel selection / demodulation means 4 Packet separation means 4b Match detection part 5 Channel information addition means 5 'Stream information addition means 8 MPEG decoder 9 OSD circuit 10 Video encoder 11 D / A converter 12 Control means 17 User Input means 18 Channel information generation means 19 Packet separation means 201-204 Match detection section 211-214 Memory 22, 23 Selector 24 PLL circuit

Claims (9)

A packet is formed by adding first identification data to encoded data of a plurality of channels, and is used in a digital broadcast receiving apparatus that receives a stream formed by multiplexing the packets. In a semiconductor device comprising packet separation means for extracting the encoded data of the channel from the stream,
The packet separation means sequentially extracts and outputs the encoded data of each channel from the stream based on data set from the outside and the first identification data, and the extracted encoded data And a second packet identification data corresponding to the first identification data. A digital broadcast receiving apparatus for receiving a stream in which encoded data of a plurality of channels is packetized and multiplexed,
Channel selection / demodulation means for selecting and decoding the stream;
Packet separation means for extracting encoded data of each channel from the selected and demodulated stream;
Channel information adding means for adding channel information representing a channel to which the encoded data belongs, for each extracted encoded data;
Digital broadcasting comprising: decoding means for determining 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 separation means Receiver device. In claim 2,
Packet identification data for identifying a channel for each packet of each encoded data is added to the stream selected and demodulated by the channel selection / demodulation means, and the packet separation means The encoded data of the packet of the desired channel is extracted based on the identification data, the packet identification data is output together with the extracted encoded data, and the channel information adding unit is configured to output the packet identification data from the packet unit. The digital broadcast receiving apparatus is characterized in that the channel information according to the above is added to the encoded data. In claim 2 or 3,
Digital broadcasting comprising: means for selecting one or more decoded video signals of each channel from the decoding means, or synthesizing two or more; and means for displaying a video with the decoded image signal output from the means Receiver device. The first identification data is added to each encoded data to form a packet, and is used in a digital broadcast receiving apparatus that receives a plurality of streams formed by multiplexing the packets, and the received stream In a semiconductor device comprising packet separation means for extracting the encoded data of the channel from
The packet separation means can simultaneously input a plurality of streams, and sequentially extracts and outputs the encoded data from the plurality of streams based on data set from the outside and the first identification data. And outputting the second packet identification data corresponding to the first identification data together with the extracted encoded data. In claim 5,
The semiconductor device, wherein the packet separation unit multiplexes the encoded data extracted from the plurality of streams and outputs the multiplexed data as one stream. In claim 6,
Each of the plurality of streams is multiplexed with time information for managing the decoding time of the encoded data,
The packet separation means extracts time information extraction means for extracting the time information from the received stream;
Clock recovery means for recovering a system clock for decoding based on the extracted time information;
A multiplication means for multiplying the system clock;
A plurality of memory means for writing the encoded data extracted from the respective streams for each stream, using the system clock as a writing clock and reading out the clock from the multiplication means as a reading clock;
A semiconductor device comprising: multiplexing means for multiplexing the encoded data read from the plurality of memory means into one stream. A digital broadcast receiving apparatus that receives a plurality of streams in which encoded data is packetized and multiplexed,
Packet separation means for extracting encoded data for each received stream;
Stream information adding means for adding stream information representing the stream to which the encoded data belongs for each extracted encoded data;
Digital broadcasting comprising: decoding means for determining a stream to which the encoded data belongs based on the stream information and simultaneously decoding the encoded data of each stream separated by the packet separation means Receiver device. In claim 8,
Means for selecting one or more decoded video signals of each channel from the decoding means, or combining two or more;
A digital broadcast receiving apparatus comprising: means for displaying an image with a decoded image signal output from the means.

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