KR100785788B1 - Multi Channel MPEG-2 Transport Stream Multiplexing Device and Method thereof - Google Patents

Abstract

The multi-channel MPEG-2 transport stream multiplexing apparatus according to the present invention checks the presence or absence of PCR of a transport stream packet input from one or more program sources, and estimates the PCR of a transport stream packet not including PCR based on the identified PCR. On the basis of the PCR inserting unit for inserting the PCR in the transport stream packet for each program, the packet waiting unit for waiting for the predetermined time unit of the transport stream packet for each program in which the PCR is inserted and the number of unit of the transport stream packet waiting The multiplexing unit obtains the number of packets to be scheduled and sent for each program, and outputs a transport stream packet for each program as one transport stream packet sequence. The present invention provides a multiplexing apparatus and method for equally dividing and inputting multi-channel transport streams when multi-channel MPEG-2 streaming is performed through an IP network.

Description

Multi-channel MPEG-2 Transport Stream Multiplexing Device and Method

1 is a conventional multichannel MPEG-2 transport stream transmission system.

2 is a multi-channel MPEG-2 transport stream multiplexing apparatus according to an embodiment of the present invention.

3 is a multi-channel MPEG-2 transport stream multiplexing apparatus according to another embodiment of the present invention.

4 is a PCR slope used to estimate the PCR according to an embodiment of the present invention.

5 is an output stream in which each program transport stream is synchronized according to an embodiment of the present invention.

6 shows a relationship between a transport stream outputted in synchronization with a transport stream packet input for each program.

7 is a multi-channel MPEG-2 transport stream multiplexing method according to an embodiment of the present invention.

8 is a multi-channel MPEG-2 transport stream multiplexing method according to another embodiment of the present invention.

The present invention relates to an apparatus and method for multi-channel MPEG-2 transport stream multiplexing, and more particularly, to an apparatus and method for multi-channel MPEG-2 transport stream multiplexing applying flexible synchronization of time units.

In the present invention, a multi-channel HDTV streaming system for streaming a plurality of MPEG-2 through an IPv6 or IPv4 network is considered.

1 is a conventional multichannel MPEG-2 transport stream transmission system. Referring to FIG. 1, a system for transmitting a multi-channel MPEG-2 transport stream sends a transport stream input from each program source to the client 140 using the transport stream server 110 and the transport stream relay server 120. .

In the multi-channel system, the transport stream server 110 and the transport stream relay server 120 are used to multi-cast or unicast each client 140 in preparation for different environmental components in the network 130. Send the transport stream.

However, the client 140 has a different playing time at the time of playing the program, or the rate of packet transmission is different for each client (141, 142), causing frequent buffering. In particular, this problem is likely to increase as the number of channels increases, so an appropriate multiplexing technique is required.

An object of the present invention is to provide a multiplexing apparatus and method in which streams of multiple channels are equally divided and input and output to a multiplexer.

As such, the present invention solves a problem caused by different environmental components of a user's network when providing hierarchical services.

One embodiment of the multi-channel MPEG-2 transport stream multiplexing apparatus according to the present invention for achieving the above technical problem is to determine whether the PCR of the transport stream packet input from at least one program source, PCR based on the identified PCR A PCR insertion unit for estimating PCR of a transport stream packet not included and inserting PCR into the transport stream packet for each program, a packet waiting unit for waiting for a predetermined time unit for the transport stream packet for each program into which the PCR is inserted; A multiplexing unit obtains the number of packets to be scheduled and sent for each program based on the number of transport stream packets waiting in the packet waiting unit, and outputs the transport stream packets for each program as one transport stream packet sequence.

One embodiment of the multi-channel MPEG-2 transport stream multiplexing method according to the present invention for achieving the above technical problem is to determine whether the PCR of the transport stream packet input from at least one program source, PCR based on the identified PCR Estimating a PCR of a transport stream packet not included and inserting PCR into the transport stream packet for each program, waiting for the transport stream packet for each program into which the PCR is inserted, by a predetermined time unit, and waiting Obtaining the number of packets to be scheduled and sent for each program based on the number of transport stream packets per unit time, and outputting the transport stream packets for each program as one transport stream packet sequence.

As described above, in order to solve the problem caused by different environmental components of the user's network when multichannel MPEG-2 streaming is performed through the IP network, the multichannel streams are equally divided and input and output to the multiplexer. An apparatus and method for multi-channel MPEG-2 transport stream multiplexing are provided.

Hereinafter, an apparatus and method for multichannel MPEG-2 transport stream multiplexing according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a conventional multichannel MPEG-2 transport stream transmission system. Referring to FIG. 1, a multi-channel MPEG-2 transport stream transmission system includes a transport stream server 110, a transport stream relay server 120, a network 130, and a client 140.

The transport stream server 110 includes a source 111, a multiplexer 112, and a sender 113.

The transport stream from the source section 111 enters the multiplexer 112. The source unit 111 is a multi-channel hierarchical source.

The content of the content of the transport stream input from the source section 111 is different. In addition, even in the case of contents having the same contents, they come in the form of hierarchical streams having different levels of image quality.

These various types of transport streams contain the information of PIDs in PMT and PAT as a program so that they are managed according to the standard as a whole according to the protocol of MPEG system. If there is PID colliding with each other, adjustment is made.

The multiplexed stream thus adjusted enters the multiplexer 112 for each program source. In the multiplexer 112, there is a need for an algorithm in which streams of multiple channels are equally divided and input and output. The present invention provides a multi-channel MPEG-2 transport stream multiplexing apparatus and method applying flexible synchronization of time units.

The transport stream relay server 120 includes a stream source 121 and a sender 122. The stream source 121 receives the multiplexed stream from the network. The sender 122 delivers this to the client.

A system for transmitting a multi-channel MPEG-2 transport stream sends a transport stream input from each program source to the client 140 using the transport stream server 110 and the transport stream relay server 120.

In the multi-channel system, the transport stream server 110 and the transport stream relay server 120 are used to multi-cast or unicast each client 140 in preparation for different environmental components in the network 130. Send the transport stream.

2 is a multi-channel MPEG-2 transport stream multiplexing apparatus according to an embodiment of the present invention. Referring to FIG. 2, the multi-channel MPEG-2 transport stream multiplexing apparatus includes a PCR inserting unit 210, a packet waiting unit 220, and a multiplexing unit 230.

 The PCR inserting unit 210 checks the presence or absence of a PCR (Program Clock Reference) of the transport stream packet input from at least one program source, and estimates the PCR of the transport stream packet not including the PCR based on the identified PCR. PCR is inserted into a transport stream packet for each program.

The packet waiting unit 220 waits for each program transport stream packet into which the PCR is inserted in a predetermined time unit.

The multiplexer 230 obtains the number of packets to be scheduled and sent for each program based on the number of transport stream packets waiting in the packet waiting unit, and outputs the transport stream packets for each program as one transport stream packet sequence. do.

In scheduling, first, a scheduling unit is obtained and based on this, the number of packets to be scheduled and sent for each program is obtained.

The scheduling unit is an integer value obtained by dividing the number of transport stream packets of each program waiting in the packet waiting unit by the smallest number of transport stream packets among all programs.

The following formula calculates a scheduling unit. Rf (k) means scheduling factor of the k-th program.

nProgPck (k) means the number of transport stream packets for a certain time of the k-th program measured at a specific time. The number of packets to be sent for each program is calculated based on the scheduling unit.

The number of packets to be scheduled and sent for each program is an integer value obtained by dividing the number of transport stream packets of each program waiting per unit time by the sum of the number of packets waiting in all programs and multiplying the scheduling unit.

Sf(k)는 k번째 프로그램의 스케줄링되는 패킷의 개수를 의미한다.The third equation is to calculate the number of packets to be scheduled and sent for each program.

Sf (k) means the number of packets scheduled in the k-th program.

3 is a multi-channel MPEG-2 transport stream multiplexing apparatus according to another embodiment of the present invention. 3 shows synchronization through packet flow and control of each queue. Referring to FIG. 3, the multi-channel MPEG-2 transport stream multiplexing device includes a PCR calculator 310, a connection queue 320, a synchronization manager 330, and a multiplexer 340.

The PCR calculator 210 checks whether the incoming transport stream packet has PCR information. If the packet contains PCR information, the PCR of each incoming packet is estimated based on the PCR information of the incoming packet.

The predicted PCR calculation information inserts the calculated time information into the object of the packet which is input for the queues 311 and 312 for each input program. It is possible to estimate the time that each incoming packet should be sent. The PCR calculated packets are transmitted to the connection queue 320 in the center and wait until enough PCR information is calculated for every program.

Transport stream packets waiting in the central connection queue 320 are divided into respective programs and input to the output program queues 321 and 322. At least one output program queue 321 or 322 is required for each program.

The central queue 320 waits all of the one or more program-specific transport stream packets inserted with the PCR in the same time unit. If enough PCR information is provided for each program, the synchronization manager 330 calculates the amount of data for each program to be sent for a specific limited time for each program, and outputs the respective program queues 321 and 322 according to the ratio. Is output from the input to the multiplexer 340.

As such, the present invention allows a balanced stream for each program to be output as one. In addition, the scheduling factors are constantly updated as you specify specific times for the programs.

4 is a PCR slope used to estimate the PCR according to an embodiment of the present invention. Referring to FIG. 4, when a transport stream packet is input to a multi-channel MPEG-2 transport stream multiplexing device, a PCR of a TS packet is found through a parsing process.

When the first PCR packet comes in, the reference clock is determined based on the PCR information, and the time when the next packet should be transmitted can be estimated.

Each incoming byte will come in at a constant rate of growth after initially setting the reference clock. The increase rate can be expressed by PCR slope, which is the slope between the PCR and the byte read from the packet.

Equation 1 shows a method of obtaining a PCR slope, which is a slope between the PCRs, and multiplying the input bytes up to this point by the positive PCR increment.

The first equation is as follows. Equation 1 is a formula for calculating PCR value of each packet using PCR slope. The first equation is for obtaining the PCR value of the k th byte.

Here, i and j mean the i, j th byte in the bitstream. Accordingly, PCR (i) and PCR (j) mean PCR values of the i and j th bytes, respectively.

The reason why a formula for obtaining PCR for each packet is necessary is that not all packets contain PCR information. In MPEG-TS, PCR information needs to be provided in 0.7 seconds, but we have no choice but to predict the PCR value of incoming packets with the given PCR information.

In this case, since it is difficult to measure the packet exactly as we need time, we predict the PCR value for every packet and get the packet in exactly the amount of time we need.

Since the time to be transmitted for each byte is proportional to the increase rate of the PCR, the slope of each byte and the PCR was obtained, and the PCR time for each packet was calculated and calculated according to the above formula.

5 is an output stream in which each program transport stream is synchronized according to an embodiment of the present invention. Referring to FIG. 5, the multiplexing apparatus 500 outputs one stream by synchronizing a layered stream input from various sources.

Layered streams coming from multiple sources should be sent in a balanced way. Naturally, HD video will have to send more data than SD video during the same time, and even the same HD video will have different amount of data to be transmitted in the same time zone depending on the size of each frame.

Therefore, the amount of data to be transmitted is obtained for each stream for a specific time, and then the amount of incoming data is measured. Based on the information, it is calculated and scheduled using the following equation.

Equation 2 is a formula for calculating the scheduling factor (Rf (i)), which is the size of stream periods combined for each program, by calculating the number of incoming packets for each program. Here nProgPck (i) means the number of packets received for each same time for each stream.

By calculating the ratio of packets to be sent for each program within this calculated scheduling factor size, we can get the balanced scheduling factor values that the whole program should send.

Equation 3 calculates the value. These values are sent to the Schduler of the CprogSyncOut module to control the output of the packets in each program queue so that the synchronized stream is output.

6 shows a relationship between a transport stream outputted in synchronization with a transport stream packet input for each program. Referring to FIG. 6, in the scheduling according to scheduling factors, PCR slope may be calculated when two or more packets containing PCR values are received.

This delays scheduling and transmission to the MUX until at least two PCR packets come in and stores the packets in a temporary queue. The scheduling algorithm is then updated continuously after every PCR entry for dynamic scheduling.

7 is a multi-channel MPEG-2 transport stream multiplexing method according to an embodiment of the present invention. Referring to FIG. 7, the presence or absence of a PCR of a transport stream packet input from at least one program source is estimated, and the transport stream packet of each program is estimated by estimating the PCR of a transport stream packet not including PCR based on the identified PCR. Insert the PCR (S701).

The transport stream packet for each program into which the PCR is inserted waits for a predetermined time unit. More specifically, first, all of the one or more program-specific transport stream packets in which the PCR is inserted into the central queue wait in the same time unit (S702).

The number of packets to be scheduled and sent for each program is calculated based on the number of waiting transport stream packets per unit time (S703).

The transport stream packet for each program is output as one transport stream packet sequence (S704). That is, each program queue divides the transport stream packets waiting in the central queue into respective programs and inputs them into the respective program queues.

Scheduling is a scheduling unit which is an integer value of the number of transport stream packets of each program waiting per unit time in the packet waiting unit by the smallest number of transport stream packets among all programs, and a transport stream of each program waiting scheduling units per unit time. It is based on the integer value of the number of packets divided by the sum of the number of packets waiting in all programs.

More specifically, the following equation is used. The second equation is an equation for obtaining the scheduling unit size.

Rf (k) means scheduling factor of the k-th program. nProgPck (k) means the number of TS packets for a certain time of the k-th program measured at a specific time.

The third equation is to calculate the number of packets to be sent for each program. Sf (k) means the number of packets scheduled in the k-th program.

도 8은 본 발명의 다른 일 실시예에 의한 다채널 MPEG-2 전송 스트림 다중화 방법이다. 도 8을 참조하면, 모듈로 Packet이 들어오면, 먼저 PCR이 들어 있는 Packet인지 검사한다(S801).

8 is a multi-channel MPEG-2 transport stream multiplexing method according to another embodiment of the present invention. Referring to FIG. 8, when a packet comes into the module, it is first checked whether the packet contains PCR (S801).

If the packet does not contain the PCR, it is stored in the temporary queue until the PCR information is temporarily input (S802).

The examined PCR information is used to calculate the PCR slope (S803). This is because PCR information of other packets between different PCR packets can be obtained only when the PCR slope is calculated.

When the PCR slope information can be obtained later, the packets stored temporarily are checked whether the slope values of all the input programs are obtained (S804).

If the slope values of all input programs are obtained, PCR values are input to all packets (S805) and sent to the central queue (S806).

In the central queue, it is checked whether packets for each program have been collected for each program (S807).

When all the packets are collected, they are sent to the queue of the respective program (S808). Obtaining scheduling factors (S809). At this time, Equations 2 and 3 are used.

The second equation is an equation for obtaining the scheduling unit size.

Rf (k) means scheduling factor of the k-th program. nProgPck (k) means the number of TS packets for a certain time of the k-th program measured at a specific time.

The third equation is to calculate the number of packets to be sent for each program. Sf (k) means the number of packets scheduled in the k-th program.

Using the calculated information, the output side adjusts each program queue to finally output the synchronized transport stream (S810).

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and may also be implemented in the form of a carrier wave (for example, transmission over the Internet). Include. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

As described above, the apparatus and method for multi-channel MPEG-2 transport stream multiplexing according to the present invention provide a multiplexing apparatus and method in which streams of multiple channels are equally divided and input and output to the multiplexer. The present invention solves a problem caused by different environmental components of a user's network when providing hierarchical services.

Claims (6)

In the multi-channel MPEG-2 transport stream multiplexing device, By checking the presence or absence of a PCR (Program Clock Reference) of the transport stream packet input from at least one program source, and estimating the PCR of the transport stream packet that does not include PCR based on the identified PCR to the transport stream packet for each program A PCR insertion unit for inserting a PCR; A packet waiting unit waiting for a transport stream packet for each program into which the PCR is inserted in a predetermined time unit; A multiplexer configured to obtain the number of packets to be scheduled and sent for each program based on the number of transport stream packets waiting in the packet waiting unit, and output the transport stream packets for each program as one transport stream packet sequence; And a multi-channel MPEG-2 transport stream multiplexing device. The method of claim 1, wherein the scheduling A scheduling unit which is an integer value obtained by dividing the number of transport stream packets of each program waiting in the packet waiting section by the smallest number of transport stream packets among all programs; And The multi-channel MPEG-2 transport stream is based on an integer value of a value obtained by dividing the number of transport stream packets of each program waiting for the scheduling unit by a unit by the sum of the number of packets waiting in all programs. Multiplexing device. The method of claim 1, wherein the packet waiting unit A central queue in which all of the at least one program-specific transport stream packet into which the PCR is inserted waits in the same time unit; And And one or more program queues in which transport stream packets queued to the central queue are inputted for each program. In the multi-channel MPEG-2 transport stream multiplexing method, (a) Checking the presence or absence of a PCR (Program Clock Reference) on the transport stream packet input from at least one program source, estimating the PCR of the transport stream packet not including PCR based on the identified PCR and transmitting the program for each program Inserting a PCR into the stream packet; (b) waiting for a transport stream packet for each program into which the PCR is inserted in a predetermined time unit; And (c) obtaining the number of packets to be scheduled and sent for each program based on the number of waiting transport stream packets per unit time, and outputting the transport stream packets for each program as one transport stream packet sequence; A multi-channel MPEG-2 transport stream multiplexing method, characterized in that. 5. The method of claim 4, wherein the scheduling is A scheduling unit which is an integer value obtained by dividing the number of transport stream packets of each program waiting in the packet waiting section by the smallest number of transport stream packets among all programs; And The multi-channel MPEG-2 transport stream is based on an integer value of a value obtained by dividing the number of transport stream packets of each program waiting for the scheduling unit by a unit by the sum of the number of packets waiting in all programs. Multiplexing method. The method of claim 4, wherein step (b) (b1) waiting for all of the at least one program-specific transport stream packet into which the PCR is inserted in the same time unit; And and (b2) dividing the queued transport stream packets for each program and inputting them in a queue for each program.

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