JP2006157473A - Stream multiplex transmitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a stream multiplex transmitter that prevents the occurrence of a burst output. <P>SOLUTION: An input stream packet is temporarily stored in channel buffers (5a to 5n) provided in input lines (2a to 2n), and a packet of a selected channel is transferred to a packet multiplexing part (4). A multiplexing control part (6) for performing multiplexing control has information about the transmission rate of each channel and packet length, selects a channel on the basis of the information and defines a time interval for channel selection. The time interval for channel selection is defined as a value obtained by dividing the packet length of the selected channel by a multiplexed transmission rate. If no information about the channel transmission rate and the packet length is obtained, an input transmission rate estimating part (20) for estimating an input transmission rate and packet length from input stream information can be used. Further, to cope with the case in which jitter is included in an input stream, a virtual transmission rate setting part (10) for increasing a channel transmission rate by as much as α times can be provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stream multiplexing transmission device that multiplexes and transmits a plurality of streaming data to a single communication path while maintaining a constant bit rate, and in particular, packets are instantaneously output to a transmission path at a high bit rate. The present invention relates to a stream multiplexing transmission apparatus that prevents the above-described problem.

  In the IP network, a streaming-type information providing service, which is a technology for reproducing video and audio data transmitted by a server while sequentially receiving the client, has come to be performed. Streaming technology not only enables visual communication such as live broadcasts and videophones, but also enables large-capacity content such as movies to be viewed without waiting for the download to complete. There is an advantage that convenience is improved.

  In a broadcast service using IP technology based on the Telecommunications Service Utilization Broadcasting Act, IP multicast technology is used to realize simultaneous broadcasting for a plurality of clients. In addition, a video-on-demand service is also implemented in which a viewer requests a program that he / she wants to watch at a desired time to view a moving image such as a movie by streaming. As a result, there is an increasing need to simultaneously output a large number of contents of various qualities in the streaming format, and the cost for the server can be reduced by efficiently performing a plurality of streamings in one server.

  In a streaming transmission device, when a plurality of streaming data (streams) are simultaneously input from an external input device such as a real-time encoder or a data storage device represented by a disk array and output to a network, they are multiplexed to an output interface. Output. At this time, when packet transmission control is performed at each timing independently for each input streaming data, a large number of packets of one streaming data are continuously output during a certain period of time, or between each streaming data When the output timing overlaps, the output bit rate may increase instantaneously. As a result, the streaming data receiving client may not be able to receive all packets, resulting in degradation of viewing quality. In a network device that relays IP packets between two networks when streaming data is sent from a streaming transmission device connected to a network with a high transmission speed to a client connected to a network with a low transmission speed. A buffer overflow occurred temporarily, a part of the packet forming the streaming content was lost, and the quality of the content was deteriorated.

  As a conventional technique for limiting the output transmission rate of streaming data, in a streaming packet transfer apparatus, when the average packet interval is equal to or greater than the minimum timer period of the waiting timer, the average packet interval is set as the stream packet reading period in the waiting timer. Set the number of packets to be read at one to 1 and, if the average packet interval is less than the minimum timer period, set the minimum timer period as the read period and set the waiting timer and set the minimum timer period to the average packet interval A technique for suppressing an instantaneous increase in the stream speed of a packet by using a timer mechanism longer than the average packet interval to be read by obtaining from the result obtained by dividing by is known (for example, see Patent Document 1). ).

    Separately, as a video multiplexing method, a video signal packetizing circuit for packetizing video, an effective data counter circuit for measuring the data rate by counting the number of packets passing within a certain time, and measured data By providing a priority order determination circuit for assigning priorities in order from speed to speed, and a multiplexing circuit for switching the packet data of the video signal based on the determined priority order to generate multiplexed data. There is a known video multiplexing device for reducing the required capacity of the mounted buffer and reducing the cost even for data with different speeds and packet sizes (see, for example, Patent Document 2).

JP 2004-23131 A JP 2004-200767 A

Since the technique for suppressing the increase in the packet stream speed described in Patent Document 1 described above targets a single piece of streaming data, the packet interval between the pieces of streaming data is not controlled when a plurality of pieces of streaming data are input. When this method is applied to synthesize a plurality of streams, there is a drawback that an instantaneous output bit rate is increased.
In addition, in the video multiplexing apparatus that multiplexes by giving the priority order described in Patent Document 2, the multiplexing of packets is controlled based on the data rate, but it is not possible to suppress an instantaneous increase in bit rate.

An object of the present invention is a stream multiplexing apparatus that multiplexes and transmits a plurality of streams, and packets are output to an output interface in a short time, and packets are instantaneously output to a transmission line at a high bit rate. It is to prevent.
Furthermore, another object of the present invention is to realize a packet multiplexing transmission apparatus that multiplexes and outputs various streams or contents distributed from a video distribution server so as not to generate a burst output.
Furthermore, another object of the present invention is to realize a stream multiplexing transmission apparatus that can multiplex various streams output from a stream server without packet retention.

A stream multiplexing transmission apparatus according to the present invention is a stream multiplexing transmission apparatus that multiplexes sequentially input stream packets and transmits them to an output line.
Each having a channel buffer for temporarily storing the input stream packet, and a plurality of input lines constituting a channel for which a transmission rate is set;
Packet multiplexing means for multiplexing stream packets transferred from the channel buffer of the selected channel and outputting them to the output line;
Information relating to the transmission rate and packet length of each channel and information relating to the multiplexing transmission rate of the multiplexing transmission device, and comprising multiplexing control means for controlling channel selection and channel selection time intervals,
The packet multiplexing means sequentially multiplexes the stream packets transferred through the channel selected by the multiplexing control means at the controlled time interval.

  In the present invention, since the channel selection and the channel selection time interval are controlled based on the multiplexing transmission rate and the transmission rate and packet length of each channel, even if a large number of various contents or streams are input simultaneously, Multiplexing can be performed without generating a burst output.

Another stream multiplex transmission device according to the present invention is a stream multiplex transmission device that multiplexes sequentially input stream packets and transmits them to an output line.
Each having a channel buffer for temporarily storing input stream packets, and a plurality of input lines constituting a channel for transferring stream packets to be multiplexed;
Packet multiplexing means for multiplexing stream packets transferred from the channel buffer of the selected channel and outputting them to the output line;
Information on the transmission rate and packet length of each channel is received, the packet length, the virtual transmission rate obtained by increasing the transmission rate of each channel by α times (α ≧ 1), and the virtual multiplexing transmission rate obtained from the virtual transmission rate A virtual transmission rate setting means for outputting;
Multiplexing control means for receiving information on the virtual multiplexing transmission rate output from the virtual transmission rate setting means, the virtual transmission rate of each channel and the packet length, and controlling the channel selection and the channel selection time interval;
It further comprises transmission determination means for determining whether or not a stream packet should be transferred from the channel selected by the multiplexing control means to the packet multiplexing means.

    In the present invention, since the multiplexing process can be executed at a virtual transmission rate in which the transmission rate of each channel is increased by α times (α ≧ 1), the chance of channel selection increases. As a result, it is possible to solve the problem that the buffer overflow occurs in the channel buffer even if jitter occurs in the input stream. Further, since it has a transmission judgment means for judging whether or not the stream packet of the selected channel should be transferred to the packet multiplexing means, the buffer overflow in the client that receives the stream output from the stream multiplexing transmission apparatus according to the present invention. It is possible to eliminate the problem that occurs.

Another stream multiplex transmission device according to the present invention is a stream multiplex transmission device that multiplexes sequentially input stream packets and transmits them to an output line.
Each having a channel buffer for temporarily storing input stream packets, and a plurality of input lines constituting a channel for transferring stream packets to be multiplexed;
Packet multiplexing means for multiplexing stream packets transferred from the channel buffer of the selected channel and outputting them to the output line;
Input transmission rate estimation means for estimating or detecting the transmission rate and packet length of each channel from information about the input stream, and setting a multiplexed transmission rate;
Receiving information on the transmission rate and packet length of each channel output from the input transmission rate estimation means and the multiplexing transmission rate, and multiplexing control means for controlling channel selection and channel selection time intervals,
The packet multiplexing means sequentially multiplexes the stream packets transferred via the channel selected by the multiplexing control means at the controlled time interval.

  The stream multiplexing transmission apparatus according to the present invention includes input transmission rate estimation means for estimating or detecting the transmission rate and packet length of each channel from the information regarding the input stream, so that the transmission rate and packet length of each channel are not known. Even so, the channel selection and the channel selection time interval can be controlled appropriately, and as a result, the problem of instantaneous burst output can be solved.

Another stream multiplex transmission device according to the present invention is a stream multiplex transmission device that multiplexes sequentially input stream packets and transmits them to an output line.
Each having a channel buffer for temporarily storing input stream packets, and a plurality of input lines constituting a channel for transferring stream packets to be multiplexed;
Packet multiplexing means for multiplexing stream packets transferred from the channel buffer of the selected channel and outputting them to the output line;
Input transmission rate estimation means for estimating or detecting the transmission rate and packet length of each channel from information about the input stream;
Receives information on the transmission rate and packet length of each channel output from the input transmission rate estimation means, and increases the packet length, the transmission rate of each channel by α times (α ≧ 1), and the virtual transmission rate Virtual transmission rate setting means for outputting the virtual multiplexed transmission rate obtained from
Multiplexing control means for receiving information on the virtual multiplexing transmission rate output from the virtual transmission rate setting means, the virtual transmission rate of each channel, and the packet length, and controlling channel selection and channel selection time intervals;
And a transmission determining means for determining whether or not a stream packet should be transferred from the channel selected by the multiplexing control means to the packet multiplexing means.

Even if a large number of various contents or streams are input at the same time, they can be multiplexed while suppressing the instantaneous bit rate.
Also, by providing means for estimating or detecting the transmission rate and packet length of each channel from information about the input stream, even if the transmission rate and packet length of each channel are not known, instantaneous burst output occurs Can be prevented.
Furthermore, by providing virtual transmission rate setting means for increasing the transmission rate of each channel by α times (α ≧ 1), even if jitter occurs in the input stream, problems such as buffer overflow in the channel buffer are eliminated. be able to.

  FIG. 1 is a diagram showing a first embodiment of a stream multiplexing transmission apparatus according to the present invention. A stream multiplexing transmission apparatus 1 according to the present invention has a plurality of input lines 2a to 2n and one output line 3, and multiplexes for multiplexing streaming data (stream packets) between the input line and the output line. The control unit 4 is provided. The input lines 2a to 2n constitute a channel for transferring stream packets, and each input line has channel buffers 5a to 5n for temporarily storing the input stream packets. The input lines 2a to 2n are directly connected to, for example, a stream server (or including a video distribution server, a content distribution server, a video storage device, a live encoder, etc.) via an input interface (not shown) or via a network interface. Connected to the network to which the video distribution server is connected. The output line 3 is connected to another network via an output interface (not shown), and sends a stream packet to the client terminal via the network. Therefore, the stream sent from the stream server is input to the multiplexing sending device 1 according to the present invention via the input interface, transferred to the multiplexing unit 4 via the input lines 2a to 2n and the channel buffers 5a to 5n, The signals are multiplexed under the control of the multiplexing control unit 6 and output to the output line 3, and transmitted to the client terminal via the output interface and the network.

  Each of the input lines 2a to 2n constituting the channel is set with a channel transmission rate Ri (where i represents the i-th channel) and a packet length Li of the stream packet transferred through the channel, respectively. Information relating to the channel transmission rate and the packet length is previously input and stored in the multiplexing control unit 6. A multiplexed transmission rate R0 is set in the stream multiplexing transmission device 1, and this multiplexed transmission rate R0 is equal to or greater than the total value of the channel transmission rates Ri of all channels.

  Each input stream packet is temporarily stored in the channel buffer of the input line. The multiplexing control unit 6 selects a channel to be multiplexed based on information on the channel transmission rate and packet length of each channel and the set multiplexing transmission rate, and is stored in the channel buffer of the selected channel. The stream packet is transferred to the multiplexing unit and the channel selection time interval is controlled. The control of the time interval for channel selection is performed by selecting a channel to be multiplexed next after the lapse of the time period, with a time period obtained by dividing the packet length Li of the selected channel by the multiplexing transmission rate R0. During this time period, channel selection is stopped.

Next, channel selection by the multiplexing control unit will be described. The set multiplexing transmission rate is R0, the transmission rate of the i-th channel is Ri, the packet length of the stream packet transferred via the i-th channel is Li, and the multiplexing transmission apparatus starts multiplexing. A packet for each channel from the multiplexing start time in the i-th channel, where B is the target multiplexed byte number that is the expected value or target value of the number of output bytes to the multiplexing unit 4 from the time to the channel selection time If the channel selection byte number obtained by the length and the number of selections, that is, the accumulated byte number of the multiplexed stream from the multiplexing start time of the i-th channel is Bi, channel selection at a certain channel selection time is expressed by the following equation: Select a channel i to satisfy.
(Ri / R0) × B−Bi ≧ 0
In this case, when a plurality of channels satisfy the above equation, the channel having the largest value on the left side of the above equation can be selected, or one channel among the channels satisfying the above equation can be selected.
In the above equation, Ri / R0 indicates the ratio of the i-th channel in the multiplexed transmission rate, and the value output from the channel i at the channel selection time occupies by multiplying the value by the target number of multiplexed bytes. The number of powers is calculated. By comparing this value with the cumulative number of bytes Bi of the channel i, it is possible to easily determine whether or not the channel i should be selected. That is, in the above formula, if the value on the left side is positive, it means that the ratio of the number of bytes for which channel i is selected is small, and it can be determined that it should be selected, while the value on the left side is negative Since it indicates that the number of selected bytes of the channel i is large with respect to the entire channel, it is determined that it should not be selected.

  The packet multiplexing unit 4 receives stream packets stored in the channel buffer of the selected channel. In addition, the multiplexing control unit 6 adds the channel selection byte number Bi of the selected channel i by Li and sets the timing of the next channel selection as the time when Li / R0 has elapsed, and selects other channels until that time. Stop. If there is no channel to be selected at the time at which the channel is to be selected, the time accumulated at the time at the time can be set as the next channel selection time.

  In this way, by collectively controlling the packet transfer time from each channel buffer, it is possible to maintain the packet transmission interval compared to the case where each channel buffer independently transfers the channel to the multiplexing unit, and to multiplex The transmission rate is limited. With regard to this effect, an example in which a channel with a channel transmission rate of 8 Mbps and a packet length of 1500 bytes (packet transmission interval is 1500 μsec) is used for 10 channels, and is sent to an output transmission line with an interface speed of 1 Gbps at a multiplexing transmission rate of 80 Mbps I will explain. In this example, when each channel independently sends a packet, the output time of the packet to the multiplexing unit of each stream may overlap in time, and the packet output time overlaps in all streams As shown in FIG. 2, the packet output in a short time is concentrated, the buffer overflows in the multiplexing unit, or the packets are output continuously continuously at the multiplexing transmission rate with the interface speed as the upper limit. Will occur. On the other hand, by controlling the channel selection time based on the control method according to the present invention, the packet interval / multiplexed transmission rate (in this example, 1500 bytes / 80 Mbps = 150 μsec) transmission interval (multiplexed from the channel buffer) Packet transfer is performed at the time interval between the start of packet transfer to the packetizer and the start of transfer of the next packet, and it is understood that output at the multiplexed transmission rate can be controlled. Is done.

Next, a second embodiment of the present invention will be described. The configuration of the second embodiment is shown in FIG. In FIG. 3, the same components as those used in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. In this example, the virtual transmission rate setting unit 10 and the transmission determination unit 11 are added to the stream multiplexing transmission apparatus of the first embodiment shown in FIG. 1, and the virtual transmission rate is set based on the channel transmission rate of each channel. And a function for determining whether or not to transmit a packet from the selected channel. When jitter occurs in the input stream, the stream may be input to the channel buffer at a speed higher than the temporarily set transmission rate, and there is a possibility that the buffer overflows in the channel buffer. Therefore, in this example, in order to enable packet output from the channel buffer at a transmission rate faster than the set transmission rate, the virtual transmission rate setting unit multiplies the channel transmission rate by α (α ≧ 1.0).
And that value is set as the virtual transmission rate. Further, a value equal to or greater than the total value of the virtual transmission rates of all channels is set as the virtual multiplexing transmission rate. By setting the virtual transmission rate and the virtual multiplexing transmission rate in this manner, channel selection opportunities increase, and packet retention in the channel buffer can be avoided.

On the other hand, if packets continue to be output at a transmission rate higher than the actual reference transmission rate over a long period of time, there is a risk of buffer failure at the client that receives the stream output from the stream packet transmission device. A transmission determination unit 11 is provided as a function of determining whether or not to transmit the selected packet. Note that the connection positions of the multiplexing control unit 6 and the transmission determination unit 11 can be set in reverse.

  Next, the multiplexing process will be described. The multiplexing control unit 6 performs channel selection at a channel selection time that is a transmission time for each packet in order to multiplex the stream of each channel at the set virtual multiplexing transmission rate. The transmission judgment unit 11 stores packets in the channel buffer selected by the multiplexing control unit, and the number of output bytes of the selected channel is less than the expected value or the target value of the output bytes of the channel. It decides to send the packet, and receives and multiplexes the packet from the buffer of the channel selected by the multiplexing control unit.

The multiplexing control unit starts multiplexing processing, or starts or ends a new channel, and updates the virtual multiplexing transmission rate as the multiplexing start time, and performs the following processing.
The channel selection time is updated by adding the value obtained by dividing the packet length of the channel selected at the previous channel selection time by the virtual multiplexing transmission rate to the previous channel selection time, and the multiplexing process is performed until the next channel selection time. Stop.

The virtual multiplexing transmission rate is R ′, the virtual target multiplexing byte number that is the expected value of the number of output bytes to the multiplexing unit from the multiplexing start time to the channel selection time is B ′, and the virtual transmission of the stream i When the rate is Ri ′ and the virtual channel selection byte number obtained from the packet length for each channel from the multiplexing start time and the number of channel selections, that is, the accumulated byte number is Bi ′, channel selection at a certain channel selection time is, for example, It is calculated as follows.
(Ri ′ / R ′) × B′−Bi ′ ≧ 0
One of the channels i satisfying the above equation is the selected channel. At this time, when a plurality of channels satisfy the above equation, a method of selecting a channel having the largest value on the left side of the above equation can be used, or even if one channel among the channels satisfying the above equation is selected. good. The multiplexing control unit accumulates Bi ′ by the packet length Li regardless of whether the packet is output from the selected channel.

  Next, processing of the transmission determining unit 11 will be described. The transmission judgment unit stores the packet in the channel buffer of the selected channel, and the condition of Bi ≦ TBi (where Bi is the number of output bytes of the channel from the multiplexing start time, TBi is the output of channel i) If the expected number of bytes) is satisfied, it is determined that the packet is transmitted from the selected channel. Here, the expected value TBi of the output byte of channel i is represented by, for example, TBi = Ri × t + β (β is a positive value or a negative value), where t is the elapsed time from the multiplexing start time to the channel selection time. be able to. For example, by setting β to a value equal to or less than the buffer size of the client that receives the stream sent from the stream multiplexing sending device, a stream that is excessively input to the channel buffer for a long time (eg, file input) In this case, it is possible to prevent buffer overflow in the client.

  When the transmission determining unit determines to transmit the packet selected by the multiplexing control unit, the packet multiplexing unit accepts a packet from the selected channel. The next channel selection time is the time when Li / R 'has elapsed from the previous channel selection time. At this time, if there is no channel selected at the channel selection time, the time obtained by adding a certain value at the channel selection time is set as the next channel selection time. In this way, by performing multiplexing control using the virtual multiplexing transmission rate, even when the input stream has jitter and the packet input time interval is not constant, an output limited to the virtual multiplexing transmission rate is obtained. It becomes possible.

  Next, a third embodiment of the stream multiplexing transmission apparatus according to the present invention will be described. The configuration of the third embodiment is shown in FIG. In FIG. 4, the same components as those used in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. In this example, when the transmission rate and packet length of the input stream are not known, the input stream information is used to estimate or detect the transmission rate and packet length of the input stream. As shown in FIG. 4, the channel buffers 5a to 5n are provided with an input transmission rate estimation unit 20 to estimate or detect the transmission rate of each channel and the packet length of the stream packet to be transmitted, and to obtain the transmission rate of each channel obtained. The multiplexed transmission rate set based on the packet length and the channel transmission rate is transmitted to the multiplexing control unit 6. The multiplexing control unit 6 determines channel selection and timing using the received multiplexing transmission rate and packet length.

  The input transmission rate estimation unit 20 can estimate the transmission rate from, for example, the number of packets input to the channel buffer in a certain unit time and the packet length. As another method, the transmission rate can be estimated from the bit rate information described in the input stream and the time stamp information (time information) indicating the time on the stream. For example, when the input stream is an MPEG-2 transport stream, the elapsed time on the stream calculated by the difference between two consecutive PCR values is used to divide the number of bits of the stream input to the channel buffer between them. Thus, the transmission rate can be estimated.

  FIG. 5 shows a fourth embodiment of the stream multiplexing transmission apparatus according to the present invention. In FIG. 5, the same components as those used in FIGS. 3 and 4 are denoted by the same reference numerals, and the description thereof is omitted. In this example, an input transmission rate estimation unit 20, a virtual transmission rate setting unit 10, and a transmission determination unit 11 are provided in the embodiment shown in FIG. As described above, by providing the input transmission rate estimation unit, virtual transmission rate setting unit, and transmission determination unit, it is possible to flexibly cope with the case where the channel transmission rate and packet length are unknown, and the input stream has jitter. Even in such a case, it is possible to effectively prevent the occurrence of problems such as packet overflow.

  FIG. 6 is a diagram showing another embodiment of the stream multiplexing shaper according to the present invention. As the stream input signal source 30, for example, a network interface, a live encoder, or a disk can be used. Streams transmitted from the input signal source via the input interface are temporarily stored in the input channel buffers 31a to 31n. Information for estimating the bit rate and packet length of each channel is input to the channel selector 32 corresponding to the multiplexing control unit. The channel selector selects a channel to be multiplexed based on these pieces of information, and supplies the selected channel number to the switching element. The channel is selected by switching the switching element. Information for estimating the bit rate and packet length is also supplied to the transmission determination unit 33 corresponding to the transmission determination unit, and the channel number selected from the channel selector is supplied. The number of output bytes is supplied. Based on the received information, the transmission determination unit 33 determines whether or not to output the packet of the channel with the number selected by the channel selector, and transmits the determination result to the switching element. Therefore, only the packets selected by the channel selector and determined to be output by the transmission determiner are output to the packet multiplexer 34, multiplexed, and sequentially transmitted to the output line. Since the channel selector can have the function of the virtual transmission rate setting unit for increasing the transmission rate of the channel, the channel selector can execute the functions of both the multiplexing control unit and the virtual transmission rate setting unit.

  Next, the results of a simulation experiment for confirming the effectiveness of the stream transmission device according to the present invention will be described. In this experiment, the output bit rate from the stream server was measured. In this experiment, all streams were MPEG-2TS, and a total of about 300 Mbps of 16 streams of 6 Mbps × 5, 18 Mbps × 5, and 30 Mbps × 6 was used. Further, the increase rate α of the virtual bit rate is set to α = 1.01 to avoid about 1% packet retention. The output IP packet is RTP, and the RTP payload is 7TS. The output interface is 1 Gbps. As the measurement results, FIG. 7 shows the measurement results of the conventional method and the measurement method of the present invention in which the total output bit rate (300 Mbps) of the multiplexed streams and one stream of 30 Mbps are controlled independently. In FIG. 7, the solid line indicates the measurement result of the method according to the present invention, and the broken line indicates the measurement result of the conventional method. The horizontal axis indicates the time in units of 1 msec, the vertical axis indicates the bit rate, and the value for 0.1 second after a lapse of a certain time from the start of the stream output.

  As shown in FIG. 7, in the independently controlled method, bursts exceeding a maximum of 400 Mbps occur when one stream is viewed, and the bursts overlap between the streams, so that the total bit rate is instantaneously 1 Gbps. You can see that it is close. On the other hand, in the method according to the present invention, it was confirmed that a single stream was multiplexed to the virtual bit rate and the entire stream was shaped to the virtual output multiplexing rate.

1 is a diagram showing a first embodiment of a stream multiplexing transmission device according to the present invention. FIG. It is the figure which compared and showed the relationship between a packet transmission interval and the number of output bytes in this invention and a conventional system. It is a diagram which shows 2nd Example of the stream multiplexing transmission apparatus by this invention. FIG. 6 is a diagram showing a third embodiment of the stream multiplexing transmission device according to the present invention. FIG. 10 is a diagram showing a fourth embodiment of the stream multiplexing transmission device according to the present invention. It is a diagram which shows another Example of the stream multiplexing transmission apparatus by this invention. It is a diagram which shows the result of the simulation experiment of the conventional system controlled independently, and the system by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stream multiplexing transmission apparatus 2a-2n Input line 3 Output line 4 Packet multiplexing part 5a-5n Channel buffer 6 Multiplexing control part 10 Virtual transmission rate setting part 11 Transmission determination part 20 Input transmission rate estimation part 30 Input signal source 31a ~ 31n Channel buffer 32 Channel selector 33 Transmission decision unit 34 Packet multiplexing device

Claims (15)

In a stream multiplexing transmission device that multiplexes sequentially input stream packets and transmits them to an output line,
Each having a channel buffer for temporarily storing the input stream packet, and a plurality of input lines constituting a channel for which a transmission rate is set;
Packet multiplexing means for multiplexing stream packets transferred from the channel buffer of the selected channel and outputting them to the output line;
Information relating to the transmission rate and packet length of each channel and information relating to the multiplexing transmission rate of the multiplexing transmission device, and comprising multiplexing control means for controlling channel selection and channel selection time intervals,
The stream multiplexing transmission apparatus, wherein the packet multiplexing means sequentially multiplexes the stream packets transferred via the channel selected by the multiplexing control means at the controlled time interval.   2. The stream multiplexing transmission apparatus according to claim 1, wherein the multiplexing control means sets a time period obtained by dividing the packet length of the selected channel by the multiplexing transmission rate as a channel selection time interval, and A stream multiplexing transmission apparatus characterized in that channel selection is suspended during the period.   3. The stream multiplexing transmission device according to claim 1, wherein the multiplexing control means obtains a ratio between a channel transmission rate and a multiplexing transmission rate based on a channel packet length and the number of selections when the channel is selected. A stream multiplexing transmission apparatus, wherein a channel larger than a ratio of a selected channel selection byte number and a target multiplexing byte number of the multiplexing transmission apparatus is selected.   The stream multiplexing transmission apparatus according to any one of claims 1 to 3, wherein the multiplexing transmission rate is set to a value equal to or greater than a total value of transmission rates of all channels. A stream multiplex transmission device characterized.   4. The stream multiplex transmission apparatus according to claim 3, wherein when the channel is selected, the multiplexing control means calculates a time obtained by integrating a predetermined time period when there is no corresponding channel. A stream multiplex transmission apparatus characterized in that a selection time is set. The stream multiplexing transmission device according to any one of claims 1 to 5, further comprising virtual transmission rate setting means for increasing the transmission rate of each channel by α times (α ≧ 1),
The multiplexing control means receives the virtual transmission rate and the virtual multiplexed transmission rate of each channel set by the virtual transmission rate setting means, and uses the virtual multiplexed transmission rate and the virtual transmission rate for which the channel is set A stream multiplexing transmission apparatus that controls time intervals for selection and channel selection. In a stream multiplexing transmission device that multiplexes sequentially input stream packets and transmits them to an output line,
Each having a channel buffer for temporarily storing input stream packets, and a plurality of input lines constituting a channel for transferring stream packets to be multiplexed;
Packet multiplexing means for multiplexing stream packets transferred from the channel buffer of the selected channel and outputting them to the output line;
Information on the transmission rate and packet length of each channel is received, the packet length, the virtual transmission rate obtained by increasing the transmission rate of each channel by α times (α ≧ 1), and the virtual multiplexing transmission rate obtained from the virtual transmission rate A virtual transmission rate setting means for outputting;
Multiplexing control means for receiving information on the virtual multiplexing transmission rate output from the virtual transmission rate setting means, the virtual transmission rate of each channel and the packet length, and controlling the channel selection and the channel selection time interval;
A stream multiplex transmission apparatus comprising: a transmission determination unit that determines whether or not to transfer the stream packet of the channel selected by the multiplexing control unit to the packet multiplexing unit.   8. The stream multiplexing transmission device according to claim 7, wherein the multiplexing control means sets a time period obtained by dividing the packet length of the selected channel by the virtual multiplexing transmission rate as a channel selection time interval, A stream multiplexing transmission apparatus characterized in that channel selection is suspended during a time period.   9. The stream multiplexing transmission apparatus according to claim 7 or 8, wherein the multiplexing control means sets the ratio of the channel virtual transmission rate and the virtual multiplexing transmission rate to the channel packet length and the number of selections when the channel is selected. A stream multiplexed transmission device, wherein a channel larger than the ratio of the channel selection byte number obtained by the above and the target multiplexed byte number of the multiplexed transmission device is selected.   10. The stream multiplexing transmission device according to claim 7, wherein the transmission determination unit stores the stream packet in a channel buffer of the selected channel and outputs the output byte of the selected channel. A stream multiplexing transmission apparatus, wherein when the number is equal to or less than an expected value of a predetermined channel output byte, it is determined to transfer the stream packet of the selected channel to the packet multiplexing means.   8. The stream multiplexing transmission apparatus according to claim 7, wherein the virtual transmission rate setting means sets the virtual multiplexing transmission rate to a value equal to or greater than a total value of virtual transmission rates of all channels. Sending device. In a stream multiplexing transmission device that multiplexes sequentially input stream packets and transmits them to an output line,
Each having a channel buffer for temporarily storing input stream packets, and a plurality of input lines constituting a channel for transferring stream packets to be multiplexed;
Packet multiplexing means for multiplexing stream packets transferred from the channel buffer of the selected channel and outputting them to the output line;
Input transmission rate estimation means for estimating or detecting the transmission rate and packet length of each channel from information about the input stream, and setting a multiplexed transmission rate;
Receiving information on the transmission rate and packet length of each channel output from the input transmission rate estimation means and the multiplexing transmission rate, and multiplexing control means for controlling channel selection and channel selection time intervals,
The stream multiplexing transmission apparatus, wherein the packet multiplexing means sequentially multiplexes the stream packets transferred via the channel selected by the multiplexing control means at the controlled time interval.   13. The stream multiplexing transmission apparatus according to claim 12, wherein the input transmission rate estimation means estimates or detects a channel transmission rate and a packet length based on the number of bytes of the stream input to the channel buffer during a unit time period. A stream multiplexing transmission device characterized by the above.   13. The stream multiplexing transmission apparatus according to claim 12, wherein the input transmission rate estimation means estimates the transmission rate and packet length of the input stream from transmission rate information described in the stream or time information on the stream. A stream multiplex transmission device characterized. In a stream multiplexing transmission device that multiplexes sequentially input stream packets and transmits them to an output line,
Each having a channel buffer for temporarily storing input stream packets, and a plurality of input lines constituting a channel for transferring stream packets to be multiplexed;
Packet multiplexing means for multiplexing stream packets transferred from the channel buffer of the selected channel and outputting them to the output line;
Input transmission rate estimation means for estimating or detecting the transmission rate and packet length of each channel from information about the input stream;
Receives information on the transmission rate and packet length of each channel output from the input transmission rate estimation means, and increases the packet length, the transmission rate of each channel by α times (α ≧ 1), and the virtual transmission rate Virtual transmission rate setting means for outputting the virtual multiplexed transmission rate obtained from
Multiplexing control means for receiving information on the virtual multiplexing transmission rate output from the virtual transmission rate setting means, the virtual transmission rate of each channel, and the packet length, and controlling channel selection and channel selection time intervals;
A stream multiplexing transmission apparatus comprising: a transmission determination unit that determines whether or not a stream packet should be transferred from the channel selected by the multiplexing control unit to the packet multiplexing unit.