JP2001111969A - Ts packet data multiplexing method and ts packet data multiplexer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a TS packet data multiplexing method and a multiplexer that can utilize a VBR system video encoder having a standard interface as it is and enhance the transmission efficiency. SOLUTION: In the case that a output of a VBR system video encoder includes an Null packet data by replacing the Null packet data with TS packet data from other packet data transmitter TS packet data from the other packet data transmitter can be efficiently multiplexed onto a TS packet data stream from the video encoder. Thus, a buffer memory 1 always stores inserting purpose TS packet data. The data storage quantity of the buffer memory 1 is controlled by supplementing TS packet data from the packet data transmitter 30 with cooperation of a memory quantity monitor section 2, a packet data request section 3, and a packet data write section 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a technique for multiplexing TS packet data, and more particularly to a technique for multiplexing TS packet data other than video data with TS packet data such as MPEG2.

[0002]

2. Description of the Related Art MPEG2 (Moving Picture Expert) has recently attracted attention as a video data distribution technique.
s Group Phase-2) technology. In the MPEG2 system, an MPEG2 code sequence firstly includes a PES (Packetize
d Elementaly Stream) packets, and then packetized into TS (Transport Stream) packets for multiplexing and transmission. These TS packets are
For example, the packet is further packetized into an ATM (Asynchronous Transfer Mode) cell and transferred on an ATM network.

A signal to be code-compressed represented by MPEG2 has a characteristic that the amount of information varies depending on the video to be compressed. For example, a high compression rate can be obtained for a landscape with little motion, and the amount of information is small. On the other hand, in the case of a video whose subject fluctuates drastically, such as a sports broadcast, the compression ratio is low and the amount of information is large. That is, in the case of the above-described MPEG2, the data amount of a TS packet obtained as a result of code compression changes with time.

On the other hand, many existing systems often assign a fixed transmission rate to each channel. Therefore, even if the amount of information obtained as a result of code compression is small in order to adapt to such an environment, the amount of information output from the transmitting side can be kept constant by adding a Null packet having Null data on the transmitting side. Keeping is done.

[0005] However, transmitting a Null packet means transmitting so-called useless data.
Poor transmission efficiency.

[0006] Statistical multiplexing techniques have been proposed as techniques for improving transmission efficiency by focusing on such problems. The statistical multiplexing technique is a technique for monitoring the video coding difficulty output from a plurality of video encoders on the multiplexing device side and performing control for allocating a coding bit rate to each video encoder so as to obtain an appropriate image quality. If this technique is employed, the transmission rate allocated to each stream can be dynamically adjusted according to the amount of information generated as a result of code compression, and high transmission efficiency can be obtained.

[0007]

However, such a statistical multiplexing technique has the following disadvantages.

First, this statistical multiplexing technique is a technique relating to coding bit rate allocation control of a plurality of videos, and does not consider efficient multiplexing of data other than videos. That is, packet data having information other than video cannot be efficiently multiplexed by the above-described statistical multiplexing technique.

Further, in order to apply this statistical multiplexing technique, information on the video coding difficulty output from the encoder is required. Therefore, in a video encoder system that performs multiplexing, apart from the normal interface,
An interface for multiplexing is required. That is, if the above-described statistical multiplexing technique is adopted, a video encoder having a standard interface cannot be used as it is, and its configuration must be complicated.

Accordingly, the present invention provides a multiplexing method and a multiplexing apparatus for TS packet data which can use a VBR video encoder having a standard interface as it is and can improve transmission efficiency. With the goal.

Further, the present invention relates to the multiplexing method and the multiplexing apparatus, wherein TS packet data having information other than video is multiplexed into TS packet data output from a VBR video encoder with a simple configuration. It is an object of the present invention to provide a multiplexing method and a multiplexing device that can perform the multiplexing.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an output of a video encoder of the VBR system with N output.
If the packet data includes the Null packet, the Nu
By replacing the ll packet data with the TS packet data from another packet data transmitting device, the TS packet data from the other packet data transmitting device is efficiently multiplexed with the TS packet data sequence from the video encoder.

Specifically, the present invention provides the following TS
A packet data multiplexing method and a TS packet data multiplexing device are provided.

That is, according to the present invention, a first step of preserving TS packet data output from a specific packet data transmitting apparatus as packet data for insertion in a buffer memory in advance; T consisting of TS packet data output from the encoder device
A second step of receiving, for each TS packet data, whether or not the TS packet data is a null data packet,
A third step of replacing the packet data for insertion with the null packet data when the S packet data is the null packet data, whereby the TS packet data from the specific packet data transmitting device; TS efficiently multiplexing with TS packet data from a video encoder device
A packet data multiplexing method is obtained.

In particular, in the TS packet data multiplexing method, the first step is a step of monitoring a data amount of the insertion packet data held in the buffer memory, and as a result of the monitoring, Requesting the specific packet data transmitting device to add TS packet data when the data amount is less than a predetermined amount;
TS transmitted from the specific packet data transmission device
Writing packet data into the buffer memory as the insertion packet data.

Here, in the above-described TS packet data multiplexing method, the TS packet data output from the specific packet data transmitting device may include, for example, data other than video data. The video encoder device may be, for example, an MPEG2 encoder.

Further, according to the present invention, a TS packet data sequence composed of TS packet data output from the video encoder device and connected to the VBR video encoder device and a specific packet data transmitting device, and the specific packet In a TS packet data multiplexing device for efficiently multiplexing specific TS packet data transmitted from a data transmitting device and outputting TS packet multiplexed data, a buffer memory for holding the specific TS packet data; A memory amount monitoring unit that monitors whether or not the specific TS packet data held in the storage unit is equal to or more than a predetermined amount; and, if necessary, the specific packet data transmission device according to the monitoring result of the memory monitoring unit. A packet data request for adding the specific TS packet data is required. Receiving the specific TS packet data transmitted by the specific packet data transmitting device in response to a request from the packet data requesting unit, receiving a packet data writing unit that writes the packet data into the buffer memory, and receiving the TS packet data sequence. For each of the TS packet data, a Null packet detection unit that detects whether the TS packet data is Null packet data having Null data, and the TS packet data to be detected by the Null packet detection unit is Null. If it is packet data, the specific TS packet data held in the buffer memory is read out,
A packet data reading unit that outputs the specific TS packet data in place of the null packet data; and a delay unit that receives the same TS packet data sequence as the null packet detection unit and delays the packet data by a predetermined time for each packet data. Connected to the delay unit and the packet data reading unit, and when the specific TS packet data is input from the packet data reading unit, the specific TS packet data is input through the delay unit. A packet data selection unit that outputs the TS packet multiplexed data obtained by multiplexing the specific TS packet data with the TS packet data input via the delay unit, in order to select the TS packet data prior to the TS packet data. Thus, a TS packet data multiplexing device characterized by comprising:

Here, the memory amount monitoring unit monitors the amount of the specific TS packet data held in the buffer memory, for example, by checking the input / output of the buffer memory. Also,
TS transmitted from the specific packet data transmission device
The packet data has, for example, contents other than video.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for multiplexing TS packet data according to an embodiment of the present invention and a multiplexing apparatus to which the method is applied will be described in detail with reference to the drawings.

Referring to FIG. 1, T according to the present embodiment is shown.
The S-packet data multiplexing device 10 is connected to the VBR video encoder device 20 and the packet data transmitting device 30, and can efficiently multiplex data received from these devices and output TS packet multiplexed data.

More specifically, the TS packet data multiplexer 1
0 is a buffer memory 1, a memory amount monitoring unit 2, a packet data requesting unit 3, a packet data writing unit 4, a Null
1 comprises a packet detecting unit 5, a packet data reading unit 6, a delay unit 7, and a packet data selecting unit 8.

The buffer memory 1 is for holding TS packet data transmitted from the packet data transmitting device 30. Hereinafter, the TS packet data transmitted from the packet data transmission device 30 is referred to as V
TS transmitted from the BR type video encoder device 20
It is referred to as separate TS packet data to distinguish it from packet data. In the buffer memory 1, another TS packet data is written by the packet data writing unit 4 and another TS packet data is read by the packet data reading circuit unit 6 as described later.

The memory amount monitoring unit 2 monitors the amount of another TS packet data held in the buffer memory 1. More specifically, the memory amount monitoring unit 2 monitors input / output of the buffer memory 1, for example, instructions to the buffer memory 1 from the packet data writing unit 3 and the packet data reading unit 6, which will be described later. , Another T in the buffer memory 1
The storage amount of S packet data can be known. The memory amount monitoring unit 2 sends the monitoring result to the packet data requesting unit 3 as a monitoring result signal. The monitoring result signal is, for example, the TS held in the buffer memory 1.
If the amount of packet data is equal to or more than a predetermined amount, it indicates “1”, and the T stored in the buffer memory 1
This indicates "0" when the amount of S packet data falls below a predetermined amount.

The packet data request unit 3 receives a monitoring result signal from the memory monitoring unit 2 and performs an operation according to the monitoring result signal. That is, according to the above example, when the monitoring result signal indicates “0”, the packet data requesting unit 3 requests the packet data transmitting device 30 to add another TS packet data to the TS packet request signal. When the monitoring result signal indicates “1”, the output of the TS packet request signal to the packet data transmitting device 30 is stopped.

When receiving the TS packet request signal from the packet data request unit 3, the packet data transmitting device 30 transmits another TS packet data in response to the request. The transmitted other TS packet data is input to the packet data writing unit 4.

The packet data writing section 4 receives the different TS packet data transmitted by the packet data transmitting device 30 and writes the different TS packet data into the buffer memory 1.

In the present embodiment, a control line for controlling writing from the packet data writing unit 4 to the buffer memory 1 is connected to the memory amount monitoring unit 2 as described above.
Being monitored by

On the other hand, the Null packet detector 5
The input is a TS packet data string composed of a plurality of TS packets transmitted from the video encoder device 20 of the R system. Upon receiving this TS packet data sequence, Nul
The 1-packet detection unit 5 determines, for each TS packet data, that the TS packet data has Null data.
Detects whether the data is packet data. In other words,
The Null packet detection unit 5 detects the position of a Null packet in the TS packet data sequence. In the present embodiment, upon detecting the position of a Null packet, the Null packet detection unit 5 outputs a Null packet detection signal to the packet data reading unit 6.

When receiving the Null packet detection signal from the Null packet detection unit 5, the packet data reading unit 6 reads another TS packet data from the buffer memory 1, and stores the read another TS packet data in the insertion T packet.
The data is sent to the packet data selection unit 8 as S packet data.

In the present embodiment, the control line for reading control from the packet data reading unit 6 to the buffer memory 1 is also monitored by the memory amount monitoring unit 2. By such an operation of the memory amount monitoring unit 2, when the packet data reading unit 6 issues an instruction to read another TS packet data to the buffer memory 1,
In the buffer memory 1, there is another TS packet data to be read without fail.

Apart from such a series of flows, the TS packet data sequence transmitted from the VBR video encoder 20 is also input to the delay unit 7.

The delay unit 7 receives the TS packet data sequence, delays the TS packet data by a predetermined time for each TS packet data, and thereafter sends the delayed TS packet data to the packet data selection unit 8. The amount of delay in the delay unit 7, that is, the “predetermined time”, is such that when the corresponding TS packet is input to the null packet detecting unit 5 and the TS packet is a null packet, the packet data reading unit 6 This time corresponds to the time from when another TS packet data is read out to the packet data selection unit 8 as TS packet data for insertion. Therefore, in this embodiment, when there is Null packet data delayed by the delay unit 7, the corresponding TS packet data for insertion and the delayed Null packet data are transmitted at substantially the same time. This is input to the selection unit 8.

The packet data selecting section 8 is connected to the delay section 7 and the packet data reading section 6 as apparent from the above description and from FIG. The packet data selection unit 8 usually has the T
The S packet data is selected and output. When the insertion TS packet data is input from the packet data reading unit 6, the insertion TS packet data is preferentially selected. As a result, from the packet data selection unit 8,
A data string in which the Null packet in the TS packet data string is replaced by the TS packet data for insertion is transmitted. That is, the TS packet multiplexed data output from the packet data selection unit 8 is based on the TS packet data sequence output from the VBR video encoder 20.
Another TS packet data is multiplexed at the position of the full packet data.

As described above, in the present embodiment, V
Without changing the configuration of the BR video encoder device, Nu which has conventionally been a factor in lowering its transmission efficiency
By replacing the 11 packet data with another TS packet data, it is possible to generate TS packet multiplexed data with improved transmission efficiency.

Further, according to such a configuration, the TS packet data transmitted from the packet data transmitting device 30 does not necessarily have to be related to a video, and even if it has contents other than a video, the same configuration is used. Can be addressed.

Further, according to the TS packet data multiplexing apparatus of the present embodiment, the multiplexing process is performed in real time.

The concept of the present invention shown in the present embodiment can be applied as follows. For example, if the output TS rate of the multiplexing device is equal to or higher than the TS rate from the VBR video encoder device, depending on the conventional multiplexing control, null packets are transmitted inside the multiplexing device in order to maintain the multiplexed output TS rate at a constant rate. Means of generating and inserting were adopted. On the other hand, if the concept of the present invention is applied, in the operation of the conventional multiplexing control, it is possible to multiplex another TS packet data at the position where the null packet is inserted inside the multiplexing device.

[0038]

As described above, according to the present invention,
A VBR video encoder having a standard interface can be used as it is, and the transmission efficiency of TS packet data can be improved.

Further, according to the present invention, TS packet data having information other than video can be multiplexed into TS packet data output from the VBR video encoder with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a TS packet data multiplexing apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Buffer memory 2 Memory amount monitoring unit 3 Packet data requesting unit 4 Packet data writing unit 5 Null packet detecting unit 6 Packet data reading unit 7 Delay unit 8 Packet data selecting unit 10 TS packet data multiplexing device 20 VBR video encoder device 30 Packet data transmission device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Rei Sato 5-7-1 Shiba, Minato-ku, Tokyo Inside NEC Corporation (72) Inventor Yasushi Nakata 2-4-2 Daiba, Minato-ku, Tokyo Inside Fuji Television Co., Ltd. (72) Inventor Masataka Ikeda 2-4-8, Daiba, Minato-ku, Tokyo F-Terminal Co., Ltd. F Term (reference) 5C059 MA00 RB02 UA31 5C063 AB05 AC01 DA01 DA13 DB10 5K028 AA11 DD06 EE03 EE07 LL02 LL15 RR02 SS05 5K030 GA03 HA08 HB02 HB09 HB16 JA01 KA03 KA13 LA06 LC01 LE06 MA04 MA13

Claims (7)

[Claims] 1. A first step in which TS packet data output from a specific packet data transmitting device is previously stored in a buffer memory as packet data for insertion, and output from a video encoder device of a VBR system. Receiving a TS packet data string composed of TS packet data,
For each TS packet data, the TS packet data is N
The second to check if it is a null data packet
And when the TS packet data is Null packet data, the third step of replacing the insertion packet data with the Null packet data, whereby the TS packet from the specific packet data transmitting device is replaced. A TS packet data multiplexing method, comprising: efficiently multiplexing packet data and TS packet data from the video encoder device. 2. The TS packet data multiplexing method according to claim 1, wherein the TS packet data output from the specific packet data transmitting device has data other than video data. Multiplexing method. 3. The TS packet data multiplexing method according to claim 1, wherein the VBR video encoder device is an MPEG2 encoder. 4. The TS packet data multiplexing method according to claim 1, wherein said first step monitors a data amount of insertion packet data held in said buffer memory. Requesting, when the amount of data held in the buffer memory falls below a predetermined amount as a result of the monitoring, requesting the specific packet data transmitting apparatus to add TS packet data; Writing the TS packet data transmitted from the specific packet data transmitting device into the buffer memory as the insertion packet data. 5. A TS packet data sequence which is connected to a VBR video encoder device and a specific packet data transmitting device and is composed of TS packet data output from the video encoder device and transmitted from the specific packet data transmitting device. TS that efficiently multiplexes with specific TS packet data and outputs TS packet multiplexed data
In the packet data multiplexing device, a buffer memory holding the specific TS packet data, and a memory amount monitoring unit monitoring whether the specific TS packet data held in the buffer memory is equal to or more than a predetermined amount. A packet data request unit for requesting the specific packet data transmission device to add the specific TS packet data as necessary according to the monitoring result of the memory monitoring unit; and Upon receiving the specific TS packet data transmitted by the packet data transmitting device and receiving the TS packet data string and the TS packet data string to be written in the buffer memory, the TS packet data is transmitted for each TS packet data. Whether it is Null packet data having Null data A Null packet detector for detecting whether or not the TS packet data to be detected by the Null packet detector is Null packet data;
A packet data reading unit that reads the specific TS packet data held in the buffer memory and outputs the specific TS packet data instead of the null packet data; and the same TS packet data as the null packet detection unit A delay unit that receives the column and delays the packet data by a predetermined time, and is connected to the delay unit and the packet data reading unit;
When the specific TS packet data is input from the packet data reading unit, the specific TS packet data is selected with priority over the TS packet data input via the delay unit, A TS packet data multiplexing apparatus, comprising: a packet data selecting unit that outputs the TS packet multiplexed data obtained by multiplexing the specific TS packet data with TS packet data input via a delay unit. 6. The TS packet data multiplexing apparatus according to claim 5, wherein the memory amount monitoring unit checks the input / output of the buffer memory so as to check the specific TS packet data held in the buffer memory. A TS packet data multiplexing device for monitoring the amount of the packet data. 7. The TS packet data multiplexing device according to claim 5, wherein the TS transmitted from the specific packet data transmitting device is
A TS packet data multiplexing device, wherein the packet data has contents other than video.