JPH11340936A - Method and device for multiplexing data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate synchronism management by reducing buffer capacity and multiplex delay by selecting a storage part having the maximum occupancy amount, outputting multiplexed data by switching encoded stream data, and generating a multiplexed stream. SOLUTION: A channel selection control part 30 retrieves respective buffer occupancy amounts in order and selects the buffer having the maximum occupancy amount and storing data required for multiplexing. A TP header is generated from a TP header generating part 23. A NULL packet is generated from a NULL packet generating part 24. Corresponding to the state of the multiplex buffer and the multiplex request of a control data output control part 25, the channel selection control part 30 controls a switch 28 and selects data to be multiplexed. The multiplexed data are inputted to a multiplex register 31. Based on the analyzed result from the channel selection control part 30 and header analytic part 22, a reproduction output time managing information (PTS)/ decoding time managing information (DTS) exchange part 32 rewrites the PTS/ DTS in the multiplex register 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a multiplexing apparatus and method for packetizing video and audio coded data of a plurality of programs and further multiplexing them into a single bit stream.

[0002]

2. Description of the Related Art In recent years, MPEG (Moving Pictu
re Expert Group), etc., is coded and multiplexed using information compression technology and multiplexing technology by 2 etc., and one piece of high-quality video and audio data of a plurality of programs under a limited transmission band. 2. Description of the Related Art Digital satellite broadcasting systems have been widely used in which a bit stream is transmitted through a communication satellite, and the receiving side receives, separates, and decodes the bit stream.

On the transmitting side, the video and audio information is encoded by encoding such as MPEG2, the digitally encoded data is multiplexed by multiplexing to form a bit stream, and then error correction processing and modulation processing are performed. To the communication satellite by the transmitting antenna.

FIG. 13 shows a configuration of a multiplexing device 104 used on the transmitting side (transmitting device 100). The multiplexing device 104 includes a packetized elementary device in the preceding stage.
Stream (Packetized Elementary Stream, hereafter PE
S stream) generation units 101 ₁ , 101 ₂ and 101
₃ is decomposed into transport packets (hereinafter referred to as TP) in a relatively short transmission unit of 188 bytes,
A plurality of TPs are connected by time division multiplexing and output as a transport stream (Transport Stream; hereinafter, referred to as TS).

[0005] The multiplexing device 104 is connected to the transmission line 11.
0 _1, 110 temporarily buffers the PES inputted from ₂ and 110 ₃ in multiplexing buffer 111 _1, 111 ₂ and 111 _3.

[0006] The header of PES data passing through the transmission lines 110 ₁ , 110 ₂ and 110 ₃ is always analyzed by the header analyzer 112, and the analysis result is sent to the TP header generator 113. Then, the TP header generation unit 113 generates a TP header.

Further, a null (NULL) packet generation unit 114
As a result, a NULL packet is generated. The control data output control unit 115 that performs multiplex control of control data (Service Information; hereinafter, referred to as SI) reads out the SI packet from the control data generation unit 116. And
The control data output control unit 115 determines a predetermined S
An SI multiplexing request is made to the channel selection control unit 120 using the control line 117 based on the I multiplexing interval. The state of the multiplexing buffers 111 ₁ , 111 ₂ and 111 ₃ is constantly monitored by the channel selection control unit 120 through the control line 119, and a request from the control data output control unit 115 is waited by the channel selection control unit 120. The channel selection control unit 120 controls the switch 118 according to the state of the multiplexing buffers 111 ₁ , 111 ₂ and 111 ₃ and the multiplexing request of the control data output control unit 115 to select the data to be multiplexed. The multiplexed data enters the multiplexing register 121. Then, based on the analysis results from the channel selection control unit 120 and the header analysis unit 112, the PTS / DTS
The replacement unit 122 rewrites the PTS / DTS written in the data in the multiplex register 121. Further, based on a signal from the channel selection control unit 120, a continuous counter (hereinafter referred to as CC) adding unit 12
At 3, the CC is added to the data in the multiplexing register 121. The data to which the PTS / DTS is switched and the CC is added is output at a constant bit rate through the transmission path. Then, the output data is subjected to error correction processing by an error correction unit 105 connected to the multiplexing device 104, modulated by a modulation unit 106, and transmitted from a transmission antenna 107 to a communication satellite.

However, the channel selection control unit 1
The channel selection method performed in step 20 increases the required capacity of the multiplexing buffer. Therefore, there is a problem that a buffer having a large capacity must be prepared, and there is a problem that the cost increases when a multiplexing device is configured. In addition, the multiplexing delay of the bit stream increases, and it becomes difficult to maintain synchronization management.

[0009]

As described above, in the conventional channel selection method, it is necessary to prepare a buffer having a large capacity in the multiplexing device, and therefore, there is a problem that the cost of the multiplexing device is increased. . In addition, the multiplexing delay of the bit stream increases, and it becomes difficult to maintain synchronization management.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a multiplexing apparatus that reduces the required capacity of a buffer to be mounted, reduces cost, and reduces multiplexing delay to facilitate synchronization management. It is intended to provide a method.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention searches the data occupancy of a plurality of n storage units for temporarily storing a plurality of n coded stream data, The storage unit having the maximum occupancy is selected, the coded stream data from this storage unit is switched, multiplexed data is output, and a multiplexed stream is generated using the multiplexed data.

In order to solve the above problem, the present invention searches for the data occupancy of a plurality of n storage units that temporarily store a plurality of n coded stream data, and determines at least the maximum occupancy. If a plurality of storage units have the same maximum occupancy when selecting a storage unit to be owned, the storage unit is selected by the round robin method.

Further, in order to solve the above problem, the present invention searches for the data occupancy of a plurality of n storage units for temporarily storing a plurality of n coded stream data, and determines at least the maximum occupancy. If a plurality of storage units have the same maximum occupancy when selecting a storage unit to be owned, the storage unit is selected by the round robin method.

As described above, according to the present invention, the required capacity of the multiplexing buffer in the multiplexing device can be reduced, and the cost can be reduced when configuring the multiplexing device.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a data multiplexing method and apparatus according to the present invention will be described. This embodiment is a multiplexing device 11 provided on the transmitting device 2 side of the digital satellite broadcasting system 1 shown in FIG.

First, a schematic configuration of the digital satellite broadcasting system 1 will be described. This digital satellite broadcasting system 1
Is composed of a transmitting device 2 and a receiving device 4, and the receiving device 4 receives a transmission signal transmitted from the transmitting device 2 to the artificial satellite 3 and converts the signal into a reproducible video / audio signal.

The transmitting device 2 is an MPEG (Moving Picture).
Expert Group) 2 and the like to perform coding processing on the image and sound information using the information compression technology,
Elementary Stream (Packetized Elementary
Stream, hereinafter referred PES stream) and n pieces of PES stream generation unit 10 _1, 10 ₂ ··· 10 _n for generating,
The n PES streams are decomposed as transport packets in a relatively short transmission unit of 188 bytes, and these transport packets are time-division multiplexed and connected to form a transport stream (Transport Stream).
m; hereinafter referred to as TS).
And an error correction unit 12 that performs encoding for error correction in advance so that the reception side can correct a correct code even when noise generated during transmission is superimposed on the TS from the multiplexing device 11. The modulation unit 13 includes a modulation unit 13 that performs digital modulation processing on the output code from the correction unit 12 using, for example, QPSK or the like, and a transmission antenna 14.

The PES stream generators 10 ₁ , 10 ₂ ...
A plurality of output codes (PES streams) from 10 _n
Is input to the multiplexing device 11, is packetized into a TP, is multiplexed, and is output as a TS. The error correction unit 12 corrects this TS so that even if noise generated during transmission is superimposed, the reception side can correct the TS to a correct code.
Encoding for error correction is performed in advance. The output code of the error correction unit 12 is digitally modulated by QPSK or the like by the modulation unit 13 and output, and transmitted from the transmission antenna 14 to the artificial satellite 3.

Next, an outline of the receiving device 4 will be described. The RF signal emitted from the artificial satellite 3 is received by the receiving antenna 16, and the LNB (Low Noise Block Converte)
r) 15, the IF signal is subjected to frequency conversion to an intermediate frequency, and is called an integrated receiver / decoder (so-called set-top box).
r; hereinafter referred to as IRD). IRD17
Then, an IF signal is input, demodulation, separation of video / audio code into a desired program, and decoding signal processing are performed.
A video / audio signal that can be reproduced by the V receiver 18 is output.

In the digital satellite broadcasting system 1 outlined above, the multiplexer 11 according to the embodiment of the present invention decomposes n PES streams into transport packets in a relatively short transmission unit of 188 bytes. The plurality of transport packets are time-division multiplexed and connected to form a transport stream (Transport Stream).
port Stream; hereinafter referred to as TS).

First, a first embodiment of the multiplexer 11 will be described. In the first embodiment, as shown in FIG. 2, three output codes (PES streams) from PES stream generators 10 ₁ , 10 ₂ and 10 ₃ are transmitted through a transmission line 20.
₁ , 20 ₂ , 20 ₃ , which are multiplexed buffers 21 ₁ , 21
21 ₂ and 21 ₃ , a control data generating unit 26 for converting information necessary for selecting or decoding a program on the receiving side into TP, and control data for reading out control data from the control data generating unit 26 An output control unit 25;
TP as a code to fill the gap of the bit stream
, A header analysis unit 22 that analyzes the headers of the three PES streams, and a TP necessary to packetize a predetermined amount of data including data extracted from the three PES streams. A TP header generator 23 for generating a header, and a control data generator 2
6. Channel selection control unit 30 for determining which channel code to select among multiplexing buffers 21 ₁ , 21 ₂ and 21 ₃ , null packet generation unit 24 and TP header generation unit 23, and channel selection control The control data generator 26, each multiplexing buffer 21 ₁ ,
21 ₂ and 21 ₃ , a switch 28 for switching the code of one of the null packet generator 24 and the TP header generator 23, a multiplex register 31 for storing the code selected by the switch 28, Of the program multiplexed in the multiplexing register 31
The playback output time management information (Presentation Time Stamp; hereinafter referred to as PTS) is converted to decoding time management information (Decoding Time
Stamp; hereafter referred to as DTS) PTS /
A DTS replacement unit 32 and a CC adding unit 3 for adding a continuous count value (CC) to data in the multiplexing register 31
3 is provided.

First, a PES stream generator 1 for generating and inputting the PES stream to the multiplexer 11.
A specific example of 0 ₁ , 10 ₂ ... 10 _n will be described. P
The ES stream generators 10 ₁ , 10 ₂ ... 10 _n include:
As shown in FIG. 3A or FIG. 3B, an encoding device (encoder) is built-in.
Is performed. Of (a) is 3, for example, an optical disk reproducing apparatus or the image signal and the audio signal from the data generator 40 ₁ and 40 _2, such as a hard disk device in each of the encoders 41 ₁ and 41 ₂ MPEG2
, A multiplexing unit 42 multiplexes them to generate one program (program), and generates a PES stream from an output terminal 43 as a PES stream. FIG. 3B shows that the image signal from the data generator 44 is converted into an MPEG2 signal by the encoder 45.
2 shows a PES stream generation unit that generates a PES stream by compression encoding.

Each of the multiplexing buffers 21 ₁ , 21 ₂ and 21 ₃ is a FIFO type buffer for temporarily storing a PES stream. In the multiplexing buffers 21 ₁ , 21 ₂ and 21 ₃ , the three PES streams are packetized as transport packets (Transport Packets; hereinafter, referred to as TPs) and then waited until multiplexed.

In the control data generator 26, program specific information (Program Specific Infom) which is information necessary for selecting and decoding a program on the receiving side.
service information (hereinafter referred to as PSI) and various kinds of information on the whole or a part of the program.
formation; hereinafter referred to as SI) and TP-converted. In some cases, a program time reference (Program Clock Reference; hereinafter, referred to as PCR) unique to each program is generated as a reference value using a system time generated from a basic clock in the multiplexer. .

The control data output control unit 25 manages the transmission cycle for each control data, and
6, when it is time to transmit certain control data, a multiplexing request for each control data is sent to the channel selection control unit 30, and at the same time, the TP of the control data is transmitted.
In the output register in the control data generator 26.

The null packet generation unit 24 generates a TP as a code which has no meaning as data at the timing when neither PES data nor control data need to be multiplexed, but fills a gap of a bit stream. I do.

When three PES streams are read from the multiplexing buffers 21 ₁ , 21 ₂ and 22 ₃ for multiplexing, the TP header generating unit 23 needs to multiplex the TP headers prior to the reading. Generate

In the PTS / DTS switching unit 32, the PTs of programs multiplexed in the multiplexing register 31 are
If the value of S or DTS is not appropriate for the PCR of the program, the value of PTS or DTS is replaced.

The header analysis unit 22 includes transmission lines 20 ₁ and 20 ₂
And 20 ₃ have constantly analyzing the header of the PES stream through and sends the analysis result to the TP header generating unit 23.

The channel selection controller 30 includes a control data generator 26, multiplexing buffers 21 ₁ , 21 ₂ and 2
1 _3, of the null packet generator 24 determines whether to select the code of any channel, by sending a selection signal to the switch 28, a control unit for controlling the multi-channel.

If the multiplexing buffers 21 ₁ , 21 ₂ and 2
When you select one of the 1 _3, prior to reading from multiplex buffer, controls the switch 28 to read out from the TP header generator 23. Also, TP
At the time of reading from the header generation unit 23, parameters that change depending on the channel and timing to be read out of the contents described in the TP header are sent. As contents to send,
A packet identification number (Packet ID; hereinafter, referred to as PID) or an adaptation field control signal (ad
aptation_field_control). The code multiplexed by the switch 28 is sent to the multiplexing register 31 as a TP code.

When selecting the channels of the multiplexing buffers 21 ₁ , 21 _2, and 21 ₃ , the channel selection control unit 30 sequentially searches each buffer occupancy obtained by the control line 29, and Is selected, and a buffer in which data necessary for multiplexing is stored is selected. That is, as shown in FIG. 4, the multiplexing buffers 21 ₁ , 2
1 when selecting the ₂ and CH1 was corresponding to 21 _3, CH2 and CH3 has a maximum occupancy of, and selects the CH3 of data is accumulated in the multiplexing required amount.

[0033] In the multiplexer 11 in this manner, it has constantly analyzes the header of the data header analyzing unit 22 passes through the transmission line 20 _1, 20 ₂ and 20 _3, and sends the analysis result to the TP header generator 23 . Then, the TP header generation unit 23 generates a TP header. The NULL packet generator 24 generates a NULL packet. Also, the control data output control unit 25 that performs multiplex control of the control data reads the SI packet from the control data generation unit.
Then, the control data output control unit 25 controls the channel selection control unit 3 based on the predetermined SI multiplexing interval.
A multiplexing request for SI is made to 0 using the control line 27. The state of the multiplexing buffer is constantly monitored by the channel selection control unit 30 through the control line 29, and the control data output control unit 2
5 is waiting in the channel selection control unit 30. Multiplexing buffer status and control data output control unit 25
In response to the multiplexing request, the channel selection control unit 30 controls the switch 28 to select data to be multiplexed. The multiplexed data enters the multiplexing register 31. Then, based on the analysis results from the channel selection control unit 30 and the header analysis unit 22, the PTS / DTS switching unit 32 causes the PTS / DT written in the data in the multiplexing register 31 to change.
Rewrite S. Further, the multiplexing register 31 is provided in the CC adding unit 33 based on the signal from the channel selection control unit 30.
CC is added to the data in. The data to which the PTS / DTS is switched and the CC is added is output through the transmission path. In this configuration, the channel selection control unit 30
The method of selecting a channel is to sequentially search the buffer occupancy obtained by the control line 29 and select a buffer having the maximum occupancy and storing data necessary for multiplexing.

Therefore, according to the first embodiment, since the maximum occupancy of the multiplexing buffer is reduced as compared with the conventional example, the required buffer amount of the multiplexing buffer is reduced, leading to a reduction in the cost of the multiplexer. .

Next, a second embodiment of the multiplexer 11 will be described. The configuration of the second embodiment is the same as the configuration shown in FIG. The difference lies in the channel selection method of the channel selection control unit 30.

In the channel selection method, each buffer occupancy obtained by the control line 29 is searched in order, and the buffer having the largest occupancy is selected. However, the same occupancy as in CH1 and CH2 in FIG. When there are a plurality of buffers having the following, the selection is performed by the round robin method. The round robin method is, for example, first, “1, 2, 3”
, The next time the search is performed, the search is performed as “2, 3, 1”, and then “3, 1,.
This is a method in which the search order is shifted in order each time a search is made for "2,""1, 2, 3".

Therefore, according to the second embodiment, there is no bias that only channels in the channel selection method are easily selected, and each channel is selected equally. Since the maximum occupied amount of the multiplexing buffer is suppressed as compared with the conventional example, the required amount of the multiplexing buffer is suppressed, which leads to a reduction in the cost of the multiplexer.

Next, a third embodiment of the multiplexing device 11 will be described. The configuration of the third embodiment is the same as the configuration shown in FIG. The difference is also the channel selection method of the channel selection control unit 30.

According to the channel selection method, each buffer occupancy obtained by the control line 29 is searched in order, a buffer having the maximum occupancy is selected, and an amount necessary for multiplexing in the selected buffer is determined. Even if the data is not accumulated, the dummy data is forcibly inserted and multiplexed. That is, as shown in FIG. 6, even if all the buffers from CH1 to CH3 do not have the data amount necessary for multiplexing, CH2 having the largest occupancy is selected from among them, and the dummy hatched area is forcibly selected. Multiplex the data in between.

Therefore, according to the third embodiment, the maximum occupied amount of the multiplexing buffer is reduced as compared with the conventional example, so that the required buffer amount of the multiplexing buffer is reduced, leading to a reduction in the cost of the multiplexing device. .

FIG. 7 shows the difference in the maximum value of the buffer occupancy between the first to third embodiments and the conventional channel selection method. The eight bands described for each example are M
This is a PEG2 video stream, from the left (1) 3.81
Stream obtained by multiplexing three Mbps, (2) 4.2Mbp
stream obtained by multiplexing three s, (3) 4.2
It is a stream obtained by multiplexing three Mbps, and (4)
It is a stream obtained by multiplexing 2.1 Mbps, 4.2 Mbps and 6.3 Mbps. (5) Similarly, 2.1 Mbps, 4.2 Mbps and 6.3 Mbps
And (6) 6.3 Mbps
And (7) a stream obtained by multiplexing 6.3 Mbps, 4.2 Mbps and 2.1 Mbps, and (8) a stream obtained by multiplexing three 6.3 Mbps. It is a stream obtained by In each example, the PES input to the multiplexing buffers 21 ₁ , 21 ₂ , 21 ₃
This shows the data input rate. In each of the first to third embodiments, the required buffer amount of the multiplexing buffer is reduced as compared with the conventional example, so that the cost of the multiplexing device is reduced.

In the above three embodiments, the channel selection control unit 30 sequentially searches the buffer occupancy obtained by the control line 29 and selects the buffer having the maximum occupancy. However, when calculating the maximum occupancy of the multiplexing buffer, if it is known by the alignment process that the amount of data to be output next is smaller than the normal amount, it is necessary to correct the calculation method. In other words, it is necessary to convert the amount of data to be output next to the amount of data to be output normally to determine the maximum occupancy.

A specific example will be described with reference to FIGS. FIG. 8 shows the state of the multiplexing buffer at a certain point in time. According to the MPEG2 standard, the end of the TP header and the start of the PES header must be connected in the TP. For this reason, when converting to TP, an amount smaller than the amount of data that is normally read is read, and in the next TP, TP is read.
An alignment process is performed to adjust the PES header after the header. In this case, data is extracted in the state of the multiplexing buffer as shown in FIG. 8A, and is converted to TP as shown in FIG. 8B. Specifically, the 30-byte PES payload area data of FIG. 9A is inserted after the TP header as shown in FIG. 9B, and the invalid data is packed by 154 bytes to form a 188-byte TP packet. Further, the remaining PES header and PES payload are inserted so that the PES header comes after the TP header as shown in FIG. 9C.

Therefore, when estimating the maximum occupancy of the multiplexing buffer in the channel selection control unit 30, the maximum occupancy is calculated by converting the data length extracted in the alignment process back to the data length normally extracted. To
As a result, the required buffer amount of the multiplexing buffer is reduced, and the delay due to the multiplexing process is reduced.

This alignment process can be performed in the channel selection control unit 30 by using the data length of the PES header and the value of the payload data obtained by analyzing the PES header by the header analysis unit 22. The above maximum occupancy can be converted again. FIG.
4 shows a configuration of an ES header.

Here, the input bit rate information of the PES stream is described in the PES private data area inside the option field in the PES header shown in FIG. The input bit rate information is analyzed by the header analysis unit 22, the output bit rate is calculated by the bit rate calculation unit (not shown) based on the input bit rate information, and the rate at the stage of output from the multiplexer is changed. can do.

In each of the above embodiments, the header analysis unit 22 always analyzes the PES header of the PES data passing through the transmission path, and the analysis result is used as the TP header generation unit 2
3 Then, the TP header generator 23 generates a TP header as shown in FIG. The TP header is composed of 4 bytes. The input bit rate information and the like can be described in the transport private data in the option field.

The multiplexed stream (TS) output to the transmission line by each of the multiplexing devices is subjected to error correction processing by an error correction unit 12 to be converted into a stream with a constant rate, and is modulated by a modulation unit 13. Are transmitted from the transmission antenna 14 to the communication satellite 3.

In the receiving apparatus 4 shown in FIG. 1, the transmission stream is decoded by the IRD.
Seventeen. The configuration of the IRD 17 is shown in FIG.

The IF signal from the LNB 15 is input from the input terminal 82, and is tuned and QPSK-demodulated in the front-end unit 83, and is output to a demultiplexer 84 which is subjected to error correction as necessary.

The demultiplexer 84 performs framing to a TP code sequence and performs a process of determining whether or not the data is the desired data for each TP. Subsequently, if the desired code is an encrypted code, the code is supplied to the descrambler 85. The descrambler 85 is an IC card 9
Based on the descrambling key supplied from 4, the data is decrypted. The output code of the descrambler 85 is temporarily stored in the DRAM 86 via the demultiplexer 84.

A video decoder 87 based on MPEG2 is
The code read from the DRAM 86 is temporarily stored in a DRAM 88, which is a code buffer as appropriate, and is subjected to MPEG2 decoding processing while measuring the timing, and is further encoded into an NTSC signal, thereby obtaining an analog luminance signal, color difference signal, or composite signal. And output.

Audio decoder 89 based on MPEG
Temporarily stores the code read from the DRAM 86 in the DRAM 90, which is a code buffer, and performs the decoding process of the MPEG2 while measuring the timing.
/ A conversion and output.

The CPU 92 processes the user command from the front panel 93 according to the program code embedded in the ROM 91,
3, the demultiplexer 84 and the IC card interface 95 are controlled. Further, the video decoder 87 and the audio decoder 89 are controlled via the demultiplexer 84.

[0055]

According to the present invention, the required capacity of the multiplexing buffer can be reduced, and the cost as an apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a digital satellite broadcasting system in which a multiplexing device according to an embodiment of the present invention is provided on a transmitting device side.

FIG. 2 is a block diagram showing a configuration of first to third embodiments of the multiplexer.

FIG. 3 is a block diagram illustrating a specific example of a PES stream generation unit that sends a PES stream to the first to third embodiments.

FIG. 4 is a diagram for explaining the operation of the first embodiment.

FIG. 5 is a diagram for explaining the operation of the second embodiment.

FIG. 6 is a diagram for explaining the operation of the third embodiment.

FIG. 7 is a diagram comparing the buffer occupancy of the first to third embodiments with the buffer occupancy of the conventional example.

FIG. 8 is used to explain the alignment process.
FIG. 4 is a diagram illustrating a state of a multiplexing buffer at a certain time.

FIG. 9 is a diagram for explaining the alignment processing in detail.

FIG. 10 is a format diagram of a PES header.

FIG. 11 is a format diagram of a TP.

FIG. 12 is a block diagram showing a configuration of an integrated receiving and decoding device which is a main part of the digital satellite broadcasting system.

FIG. 13 is a block diagram illustrating a configuration of a conventional multiplexer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Multiplexer, 21 Multiplexing buffer, 22 Header analyzer, 23 TP header generator, 24 Null packet generator, 25 Control data output controller, 26 Control data generator, 28 switch, 30 Channel selection controller 31 Multiplexer Register, 32 PTS / DTS replacement part

Claims (22)

[Claims] 1. A data multiplexing method for multiplexing a plurality of n coded stream data, wherein a data occupancy of a plurality of n storage units for temporarily storing the plurality of n coded stream data is searched. And selecting a storage unit having at least the maximum occupancy, switching coded stream data from the storage unit to output multiplexed data, and generating a multiplexed stream using the multiplexed data. Data multiplexing method. 2. When selecting the storage unit having the maximum occupation amount, if it is known that the data amount to be output next by the alignment process is smaller than the normal amount, the data amount to be output next is set to the normal amount. 2. The data multiplexing method according to claim 1, wherein the maximum occupancy is obtained by re-converting the maximum occupancy. 3. In addition to the encoded stream data from the plurality of n storage units, control data relating to a program included in the encoded stream data, data for filling gaps in the bit stream, and packetized data 2. The data multiplexing method according to claim 1, wherein the data header data is selectively switched and output. 4. The data multiplexing method according to claim 1, wherein the storage unit is selected according to the maximum value of the data occupancy normalized on a byte basis. 5. The data multiplexing method according to claim 4, wherein a storage unit in which data of a required multiplexing amount is accumulated and which has a maximum occupancy is selected. 6. The data multiplexing method according to claim 4, wherein when data of a required multiplexing amount is not stored in the storage unit having the maximum occupation amount, dummy data is inserted to make a data amount of a multiplexing unit. Method. 7. The data multiplexing method according to claim 4, wherein when a plurality of storage units have the same maximum occupancy, the storage unit is selected by a round robin method. 8. The data multiplexing method according to claim 1, wherein the storage unit is selected according to the maximum value of the data occupancy normalized on a multiplexed data length basis. 9. The data multiplexing method according to claim 8, wherein a storage unit in which a necessary amount of multiplexing data is stored and which has a maximum occupancy is selected. 10. The data multiplexing method according to claim 8, wherein when data of a required multiplexing amount is not stored in the storage unit having the maximum occupation amount, dummy data is inserted to make the data amount of a multiplexing unit. Method. 11. The data multiplexing method according to claim 8, wherein when a plurality of storage units have the same maximum occupancy, the storage unit is selected by a round robin method. 12. A data multiplexing method for multiplexing a plurality of n coded stream data, wherein a data occupancy of a plurality of n storage units for temporarily storing the plurality of n coded stream data is searched for. A data multiplexing method characterized by selecting a storage unit by a round robin method when a plurality of storage units have the same maximum occupancy when selecting a storage unit having at least the maximum occupancy. 13. When selecting the storage unit having the maximum occupancy, if it is known that the data amount to be output next by the alignment process is smaller than the normal amount,
13. The data multiplexing method according to claim 12, wherein the amount of data to be output next is converted back to the amount of data to be output normally to determine the maximum occupancy. 14. A data multiplexing method for multiplexing a plurality of n coded stream data, wherein a data occupancy of a plurality of n storage units for temporarily storing the plurality of n coded stream data is searched. When selecting a storage unit having at least the maximum occupancy, when a plurality of storage units have the same maximum occupancy, the storage unit next to the storage unit that has output the data is selected. Data multiplexing method. 15. When selecting the storage unit having the maximum occupation amount, if it is known that the data amount to be output next by the alignment process is smaller than the normal amount,
15. The data multiplexing method according to claim 14, wherein the amount of data to be output next is converted back to the amount of data to be output normally to determine the maximum occupancy. 16. A data multiplexing device for multiplexing a plurality of coded stream data, comprising: a plurality of n storage means for temporarily storing the plurality of n coded stream data; Selection control means for retrieving the data occupancy of the storage means and selecting the storage means having at least the maximum occupancy, and switching for switching and outputting coded stream data from the selected storage means controlled by the selection control means Means for multiplexing the switching output from the switching means. 17. When selecting the storage unit having the maximum occupation amount, the selection control means determines that the next data amount to be output by the alignment processing is smaller than the normal amount, and then selects the next storage unit. 17. The data multiplexing device according to claim 16, wherein the maximum occupancy is obtained by re-converting the data amount to be output to the data amount to be output normally. 18. The switching means, in addition to the coded stream data from the plurality of n pieces of storage means, control data relating to a program included in the coded stream data, data for filling gaps in the bit stream, Furthermore, the header data of the packetized data is
17. The data multiplexing device according to claim 16, wherein the data is switched and output under the control of the selection control means. 19. A data multiplexing apparatus for multiplexing a plurality of coded stream data, comprising: a plurality of n storage means for temporarily storing the plurality of n coded stream data; Selection control means for retrieving the data occupancy of the storage means and selecting the storage means having at least the maximum occupancy, and switching for switching and outputting coded stream data from the selected storage means controlled by the selection control means Means, and output means for multiplexing the switching output from the switching means, wherein the selection control means uses a round robin method when the plurality of n storage means have the same maximum occupancy. A data multiplexing device for selecting a storage means. 20. When selecting the storage unit having the maximum occupation amount, the selection control means determines that the amount of data to be output next by the alignment process is smaller than the normal amount, and then selects the next storage unit. 20. The data multiplexing apparatus according to claim 19, wherein the maximum occupancy is obtained by converting the amount of data to be output to a normally output data amount. 21. A data multiplexing device for multiplexing a plurality of coded stream data, comprising: a plurality of n storage means for temporarily storing the plurality of n coded stream data; Selection control means for retrieving the data occupancy of the storage means and selecting the storage means having at least the maximum occupancy amount; Means, and output means for multiplexing switching output from the switching means, wherein the selection control means outputs data when the plurality of n storage means have the same maximum occupancy. A data multiplexing device for selecting a storage unit next to a storage unit. 22. When selecting the storage unit having the maximum occupation amount, if the selection control unit determines that the data amount to be output next by the alignment process is smaller than the normal amount, the selection control unit outputs the next output value. 22. The data multiplexing apparatus according to claim 21, wherein the maximum occupation amount is obtained by converting the data amount to be output to a data amount to be output normally.