JP2004222307A - Digital signal receiving device, digital signal processing device, and program recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce and divide a plurality of programs selected on a receiver side into one screen in a digital signal receiving apparatus which receives a transport stream standardized by MPEG2 as an input.
SOLUTION: PID filter means 11 for selecting a desired packet identification number from a signal composed of a program identified by a plurality of packet identification numbers, and stream ID reassigning means 12 for assigning a plurality of stream IDs to a selected signal. And a video decoding means 14 capable of performing decoding processing for each stream ID, and a display processor 16 for reducing the output of the video decoding means and arranging the video decoding means at an arbitrary position. Display is enabled.
[Selection diagram] Fig. 1

Description

  The present invention relates to a digital signal receiving apparatus that receives, decodes, and displays a bit stream encoded based on MPEG2.

  In recent years, a transmission / reception system using digital high-efficiency coding has been put into practical use due to international standardization (registered in ISO / IEC 13818) of MPEG2 (Moving Picture Experts Group phase 2). By using the MPEG2 coding method, it is possible to increase the number of channels under a certain transmission band, but at the same time, the number of channels of a broadcast program exceeds 100, and from among such a large number of broadcast programs, It is virtually difficult for a user to instantly select a program desired to be viewed.

  One method for solving this problem is to use a multi-screen for reducing, arranging and displaying a plurality of program videos on one screen. The multi-screen allows the user to visually select a desired program.

  Hereinafter, a conventional multi-screen display method will be described. FIG. 7 is a block diagram showing a configuration of a conventional multi-screen display system.

  In FIG. 7, reference numeral 91 denotes PID filter means for dividing a transport stream defined by MPEG2 for each packet identification number (hereinafter, referred to as PID); 92, a buffer memory for temporarily storing the output of the PID filter means; , A decoding memory 94 used by the video decoding means, and a control means 95 for controlling the PID filter means 91 and the video decoding means 93. A signal 900 is an input transport stream, signals 901 and 902 are packetized elementary streams (hereinafter referred to as PES) obtained by removing headers from transport packets, a signal 903 is a data request signal from video decoding means, A signal 904 indicates a decode result output.

  The operation of the conventional multi-screen display system configured as described above will be described below. First, the program receiver notifies the control means 95 of the intention of calling the multi-screen by, for example, pressing a button on the remote controller. The control means 95 sets the PID of the transport stream 900 on which the multi-channel is broadcast in the PID filter means 91. An output 901 of the PID filter means 91 outputs PES data 902 via the buffer memory 92 in accordance with a data request signal 903 from the video decoding means.

  The video decoding means 93 performs video decoding using the decoding memory 94 in accordance with the rules of MPEG2, and outputs a baseband video signal 904. Since the video signal 904 is composed of a screen in which one screen is multi-channeled into, for example, 16 divisions on the transmission side, the user can view the multi-channel screen.

  The multi-screen display method according to the prior art is as described above. However, in such a configuration, the multi-screen includes only a specific program determined by the transmitter side, and such a multi-screen is used. The screen does not always include the program expected by the receiver.

  Further, visually, a maximum of one screen is divided into about 16 divisions, and displaying more than one simultaneous program does not make sense. Therefore, in the current broadcasting mode exceeding 100 channels, the number of programs that can be multi-displayed simultaneously is limited. There is a problem that.

  The present invention has been made in view of the problems of the multi-screen display system according to the conventional technology as described above, and it is possible to selectively display only a plurality of programs desired by a receiver on one screen at the same time. To provide a digital signal receiving device, a digital signal processing device, and a program recording medium.

  In order to achieve the above object, a first aspect of the present invention is to receive a transport stream obtained by multiplexing a plurality of programs identified by a packet identification number (PID) in accordance with a high efficiency coding scheme, PID filter means for separating all or a part of the plurality of programs for each PID from the transport stream and outputting it as payload data, and different stream identification for each of the payload data according to the PID Stream identification number assigning means for generating one packetized elementary stream (PES) by assigning numbers, and decoding for independently decoding the PES for each stream identification number included therein Means and a decoding result for each of the individual stream identification numbers. A digital signal receiving apparatus characterized by comprising a display processor to cause disposed on one screen.

  According to a second aspect of the present invention, in the digital signal receiving apparatus according to the first aspect, the display processor reduces the decoding result for each stream identification number at a predetermined reduction rate. is there.

  Further, the third invention is the digital signal receiving apparatus according to the first or second invention, wherein the high-efficiency encoding is based on MPEG2.

  Further, the fourth invention is the digital signal receiving apparatus according to the first or second invention, wherein the decoding means decodes only the I picture specified by MPEG2 from the PES.

  In a fifth aspect of the present invention, the decoding means decodes the PES data such that the decoding result is reduced at a predetermined reduction rate. It is any one of the digital signal receiving apparatuses of the present invention.

  A sixth aspect of the present invention is the digital signal receiving apparatus according to the fifth aspect of the present invention, wherein the decoding means calculates only a low frequency component when performing the inverse DCT calculation.

  According to a seventh aspect of the present invention, there is provided a digital signal receiver according to any one of the first to sixth aspects, wherein a program for causing a computer to execute all or a part of the functions of each unit or each unit is recorded. It is a program recording medium characterized by the following.

  As is apparent from the above description, according to the present invention, by arranging the decode output at an arbitrary position on the screen, it becomes possible to simultaneously display a plurality of programs set on the receiving side. There is an effect that a signal receiving device, a digital signal processing device, and a program recording medium can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a block diagram illustrating a configuration of a digital signal receiving device according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 11 denotes a PID filter unit for dividing a transport packet for each PID, 12 denotes a stream ID replacement unit for newly reassigning a stream ID to a plurality of signals after PID filtering, and 13 denotes a stream ID replacement unit. A buffer memory for temporarily storing the output of the means, 14 a video decoding means for receiving the output of the buffer memory and decoding a video signal in accordance with MPEG2, 15 a decoding memory used by the video decoding means 14, and 16 an output of the video decoding means Is a display processor for reducing the size of the image and arranging it at an arbitrary position on the screen. Reference numeral 17 denotes control means for controlling the entire functional block constituted by these means, and is generally realized by a device-incorporated control microcomputer or the like.

  In the figure, a signal 100 is an input transport stream, 101 is a plurality of PES signals after PID filtering, 102 and 103 are PES data which are input signals to the buffer memory and output signals from the buffer memory 13, respectively. Denotes a data request signal from the video decoding means 14 to the buffer memory 13, 105 denotes a video decoding result output signal, and 106 denotes a video baseband signal forming a multi-screen constituted by a display processor.

  Next, FIG. 2 to FIG. 4 are explanatory diagrams showing the definition of the bit stream sequence of the PES signal defined by MPEG2. In the figure, the bit stream sequence is represented as a program function, but each “row” corresponds to a physical bit sequence, and indicates a hardware bit stream state.

  The digital signal receiving apparatus according to Embodiment 1 of the present invention configured as described above will be described with reference to FIGS.

  First, for simplicity, in FIG. 1, the input transport stream 100 is one transport stream in which four video signals having packet identification signals (PIDs) of PID1, PID2, PID3, and PID4 are multiplexed. Assume. Further, in order to represent a hexadecimal number, it is expressed as 0xAA in the future. 0xAA represents “1010 1010” in binary and “170” in decimal.

  The control unit 17 detects, from a user input or the like, that the four video signals (programs) of PID1, PID2, PID3, and PID4 are to be multi-displayed from the input transport stream 100 from a user input or the like. The transport stream (TS) packet to which PID3 and PID4 are assigned is set to be filtered.

  Upon receiving the input transport stream 100, the PID filter means 11 filters the four types of TS packets of PID 1, PID 2, PID 3, and PID 4 and outputs them as PES signals 101 to the stream ID changing means 12.

  Upon receiving the four PES signals 101, the stream ID reassigning means 12 reassigns the stream IDs contained in each of the PES signals to stream IDs = 0xE0, 0xE1, 0xE2, and 0xE3, and converts them into one PES format. Output a stream.

  At this time, the stream ID changing means 12 converts the data into a PES data format to which a PES header is added for each information amount corresponding to one transport stream (TS) packet. In other words, the PES data 102 output from the stream ID changing means 12 includes packet start code prefix (24 bits), stream id (8 bits), PES packet length (16 bits), and bit information shown in FIGS. The stream id is composed of PES packet data bytes, and the stream id takes a value of 0xE0 to 0xE3. However, if the TS packets constituting the input transport stream 100 originally include a PES header, the PES header information, which was originally included therein, is preserved, and only the stream id is converted. It is assumed that the output is performed.

  Next, the PES data 102 output from the stream ID reassigning means 12 is temporarily stored in the buffer memory 13 and input to the video decoding means 14 in accordance with the data request signal 104 from the video decoding means 14. Upon receiving the input of the PES data 102, the video decoding means 14 performs video decoding according to the rules of MPEG2 independently for each of the four stream IDs contained therein, and obtains a decoding result output 105. The obtained decoding result output 105 is output to the display processor 16.

  When receiving the input of the decoding result output 105, the display processor 16 performs a process so that it can be displayed on the screen. Of the decoding result output 105, the video originally having the stream ID = 0xE0 is reduced from the original size to a quarter size and processed so as to be arranged at the upper left of the screen.

  Similarly, the video having the stream ID of 0xE1 is reduced to one fourth at the upper right of the screen, the video of the stream ID = 0xE2 is reduced to the lower left, and the video of the stream ID = 0xE3 is reduced to the lower right of the screen. , To be arranged.

  The processed decoded result output 105 is finally output to the outside of the digital receiving apparatus as a video baseband signal 106.

  By the above operation, on the screen of the image receiving device (not shown) which receives the input of the video baseband signal 106, the program originally having PID1 is at the upper left, the program having PID2 is at the upper right, and the program having PID3 is at the lower left. , PID4 are displayed in the lower right at the same time in a reduced arrangement. If there is a program to be output on the full screen among the four screens, the display processor 16 outputs the decoding result of the specific stream ID without reducing the size, so that the full screen can be displayed immediately.

  As described above, according to the digital receiving apparatus in the first embodiment of the present invention, a plurality of predetermined programs are arranged on a multi-screen from a received transport stream in accordance with a PID that can be set on the receiver side. be able to.

In the first embodiment, for the sake of explanation, it is assumed that the number of PIDs to be simultaneously processed is four. However, it is obvious that the same effect can be obtained with the present invention even if the number of PIDs is larger or smaller. As another embodiment, 9 or 16 division is used.
(Embodiment 2)
Hereinafter, a digital signal receiving apparatus according to Embodiment 2 of the present invention will be described. The digital signal receiving apparatus according to the second embodiment has the same configuration as that of the first embodiment, and has the same operation as that of the first embodiment except that the operation of the video decoding unit 14 is different. Is what you do. Therefore, FIG. 1 is used for the description as in the case of the first embodiment. Hereinafter, the operation of the digital signal receiving apparatus according to the second embodiment will be described focusing on the operation of the video decoding means 14.

  First, as in the first embodiment, the input transport stream 100 is a transport stream in which four video signals having PIDs of PID1, PID2, PID3, and PID4 are multiplexed, respectively. The replacement means 12 and the buffer memory 13 perform exactly the same operation as in the first embodiment.

  Next, the operation of the video decoding means 14 will be described.

  Upon receiving the input of the PES data 103, the video decoding means 14 performs video decoding according to the rules of MPEG2 independently for each stream ID included in the PES data 103, in this case. , Decodes only the I picture specified by MPEG2, which constitutes the PES data, and skips the P picture and the B picture which are the other constituent elements so that decoding and screen display are not performed.

  Lastly, the display processor 16 performs a process for reducing and arranging the screen on the decoded result output 105 obtained as described above, in which only the I picture is decoded, as in the first embodiment.

  This eliminates the need to place reference images corresponding to a plurality of stream IDs in the decoding memory 15, thereby enabling decoding of a plurality of programs with a reduced decoding memory capacity.

As described above, according to the digital signal receiving apparatus of the second embodiment, it is possible to perform multi-segment display of a screen in a configuration in which the number of decoding memories is reduced.
(Embodiment 3)
Hereinafter, a third embodiment of the present invention will be described with reference to FIG. FIG. 5 is a block diagram showing a configuration of a digital signal receiving device according to Embodiment 3 of the present invention. 5, the same reference numerals as those in FIG. 1 denote the same or corresponding parts. Reference numeral 34 denotes a video decoding unit that receives an output of the buffer memory and decodes a video signal according to MPEG2, and 35 denotes an image size conversion unit that up-samples or down-samples the output of the video decoding unit. Reference numeral 37 denotes control means for controlling these functional blocks as a whole, and is generally realized by a control microcomputer incorporated in a device.

  In the figure, a signal 300 is an input transport stream, 301 is a plurality of PES signals after PID filtering, 302 and 303 are PES data, 304 is a data request signal from the video decoding means to the buffer memory, and 305 is a video decoding result. The video baseband signals respectively correspond to the input transport stream 100, the PES signal 101, the PES data 102 and 103, the data request signal 104, and the video baseband signal 106 in the first embodiment.

  The digital signal receiving apparatus according to Embodiment 3 configured as described above will be described with reference to FIG.

  First, the input transport stream 300 is a transport stream in which four video signals having PIDs of PID1, PID2, PID3, and PID4 are multiplexed, respectively, and includes a PID filter unit 1, a stream ID changing unit 12, a buffer memory 13 Performs exactly the same operation as in the first embodiment.

  Next, the operation of the video decoding means 34 and subsequent operations will be described.

  When receiving the input of the PES data 303, the video decoding means 34 performs video decoding in accordance with the rules of MPEG2 independently for each stream ID included in the PES data 303 as in the first embodiment. The stored reference image is transferred to the image size converter 35 before being stored in the decoding memory 36.

  Upon receiving the input of the reference image obtained by the decoding, the image size converting means 35 down-samples the reference image to the original half size in the horizontal and vertical directions. On the other hand, when reading out the reference image from the decoding memory 36, upsampling is performed twice as large as the original size in each of the horizontal and vertical directions.

  Further, when outputting the decoding result as the video baseband signal 305, the image size conversion means 35 does not perform the upsampling operation at the time of reading, and outputs the reduced image stored in the decoding memory 15 as it is.

  This allows simultaneous decoding of four programs while keeping the frame memory size in the decoding memory 36 small.

  As described above, according to the digital signal receiving apparatus of the third embodiment, it is possible to perform multi-segment display of a screen in a configuration in which the size of the decoding memory is reduced.

  Although it is assumed in the third embodiment that the number of PIDs to be simultaneously processed is four for the sake of explanation, the present invention can obtain the same effect when the number of PIDs is larger or smaller.

Further, when the video decoding means 34 performs the inverse discrete cosine transform, only the lower order coefficient of the IDCT coefficient may be calculated, and the higher order coefficient may be regarded as “0”, and the calculation therefor may be omitted. In this case, since the wide-area portion of the decoding result can be removed, it is possible to prevent aliasing noise when storing the reference image data in the decoding memory and to reduce the total amount of calculation for the decoding operation. .
(Embodiment 4)
Hereinafter, a digital signal receiving apparatus according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 6 is a block diagram showing a configuration of a digital signal receiving apparatus according to Embodiment 4 of the present invention. 6, the same reference numerals as those in FIG. 1 denote the same or corresponding parts. Reference numeral 43 denotes TS conversion means for converting the output of the stream ID replacement means 12 into a transport stream, and 44, PS conversion means for converting the output of the stream ID replacement means 12 into a program stream. Reference numeral 45 denotes control means for controlling the entirety of these functional blocks, and is generally realized by a control microcomputer incorporated in a device.

  In the figure, a signal 400 is an input transport stream, and 401 is a plurality of PES signals after PID filtering, and correspond to the input transport stream 100 and the PES signal 101 in the first embodiment, respectively. Reference numeral 402 denotes PES data output from the stream ID changing means, 403 denotes a transport stream to be output, and 404 denotes a program stream to be output.

  The digital signal receiving apparatus according to Embodiment 4 configured as described above will be described with reference to FIG.

  First, as in the first embodiment, the input transport stream 400 is a transport stream in which four video signals having PIDs of PID1, PID2, PID3, and PID4 are multiplexed, respectively. The replacement means 12 performs exactly the same operation as in the first embodiment.

  Next, the operation of the TS converter 43 and the PS converter 44 will be described.

  Upon receiving the input of the PES data 402 output from the stream ID reassigning means 12, the TS converting means 43 adds a 4-byte transport packet header defined by MPEG2 to each of 184 bytes, and adds 188 bytes. Is converted into a transport stream composed of the transport packets.

  In the same manner as described above, upon receiving the input of the PES data 402 output from the stream ID reassigning means 12, the PS conversion means 44 converts this into a program stream defined by MPEG2 and outputs it.

  As a result, from the transport stream multiplexed with a plurality of PIDs, a transport stream or a program stream of one PID multiplexed with one PID and a stream ID is output.

  Generally, when a digital stream is recorded on a recording medium such as a magnetic tape or a magnetic or optical disk medium, a transport stream or a program stream is used. However, according to the digital signal receiving apparatus of the fourth embodiment, a plurality of PIDs are used. Is converted into a 1PID transport stream or a program stream and output, so that a plurality of programs can be simultaneously recorded even in a device having a recording format in which only one program, that is, only one PID, can be simultaneously recorded. Can be made possible.

  In addition, a digital signal processing device that receives a transport stream or a program stream obtained by the digital signal receiving device according to the present embodiment and displays a plurality of programs may be used as a pair. This is provided with the video decoding means, the decoding memory, and the display processor according to any one of the first to third embodiments of the present invention. Multi-segment display is possible.

  In each of the embodiments of the present invention, the description has been given assuming that the high-efficiency coding method conforms to MPEG2. However, the present invention is not limited to this. May be used.

  The stream ID changing means in the embodiment of the present invention corresponds to the stream identification number adding means in the present invention, and the video decoding means, the decoding memory and the image size converting means in the embodiment of the present invention Corresponds to the decoding means of the present invention.

  Also, in any of the embodiments of the present invention, the operation of the digital signal receiving device and the digital signal processing device has been described as being realized as hardware, but this is achieved by the operation of a program using a computer. Alternatively, it may be realized by software.

  Further, in any of the embodiments of the present invention, the digital signal receiving apparatus and the digital signal processing apparatus of the present invention have been mainly described. However, as a recording medium of the present invention, all or one of the functions of each of the above-described units are described. A recording medium that stores a program that causes a computer to execute all or a part of each step or each step may be used.

  The present invention has an effect that it is possible to simultaneously display a plurality of programs set on the receiving side by arranging the decoded output at an arbitrary position on the screen, and to receive an encoded bit stream. It is useful as a digital signal receiving device for decoding, displaying, and the like.

Block diagram of digital signal receiving apparatus according to first and second embodiments of the present invention Explanatory drawing (1) showing the definition of a bit stream sequence of a PES signal defined by MPEG2 Explanatory drawing (2) showing the definition of a bit stream sequence of a PES signal defined by MPEG2 Explanatory drawing (3) showing the definition of a bit stream sequence of a PES signal defined by MPEG2 Block diagram of digital signal receiving apparatus in Embodiment 3 of the present invention Block diagram of digital signal receiving apparatus according to Embodiment 4 of the present invention. FIG. 1 is a block diagram for explaining the operation of a conventional digital signal receiving apparatus.

Explanation of reference numerals

11, 91 PID filter means 12 Stream ID changing means 13, 92 Buffer memory 14, 34, 93 Video decoding means 15, 94 Decoding memory 16 Display processor 17, 37, 45, 95 Control means 43 TS conversion means 44 PS conversion means

Claims (7)

According to the high efficiency coding method, a transport stream formed by multiplexing a plurality of programs identified by a packet identification number (PID) is input, and all or a part of the plurality of programs are respectively transmitted from the transport stream. PID filter means for separating each PID and outputting as payload data;
Stream identification number assigning means for creating one packetized elementary stream (PES) by assigning different stream identification numbers to the respective payload data in accordance with the PIDs;
Decoding means for independently decoding the PES data for each stream identification number included therein;
A display processor for arranging the decoding result for each of the stream identification numbers on the same screen. The digital signal receiving device according to claim 1, wherein the display processor reduces the decoding result for each stream identification number at a predetermined reduction rate. The digital signal receiving device according to claim 1, wherein the high-efficiency encoding is based on MPEG2. The digital signal receiving device according to claim 1, wherein the decoding unit decodes only the I picture specified by MPEG2 from the PES. 5. The digital signal receiving apparatus according to claim 1, wherein said decoding means decodes said PES data such that said decoding result is reduced at a predetermined reduction rate. 6. The digital signal receiving apparatus according to claim 5, wherein the decoding means calculates only low frequency components when performing the inverse DCT calculation. A program recording medium on which a program for causing a computer to execute all or a part of the functions of each means or each part of the digital signal receiving apparatus according to claim 1 is recorded.

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