WO2010009657A1

WO2010009657A1 - A method for transmitting service data stream

Info

Publication number: WO2010009657A1
Application number: PCT/CN2009/072752
Authority: WO
Inventors: 晏祥彪; 王标
Original assignee: 中兴通讯股份有限公司
Priority date: 2008-07-25
Filing date: 2009-07-14
Publication date: 2010-01-28
Also published as: CN101330398B; CN101330398A

Abstract

A method for transmitting service data stream is provided in the present invention, which comprises the following steps of: taking video, audio or data of mobile multimedia broadcast service as a payload of a multiplexing block, encapsulating the basic description information of the multiplexing block in the head of the multiplexing block, wherein said basic description information comprises the type of the multiplexing block, and the type is used for identifying whether the payload of the multiplexing block is video, audio or data; encapsulating the multiplexing block consisting of the payload and the head as a payload in a corresponding video unit, a corresponding audio unit or a corresponding data unit; and encapsulating the video unit, the audio unit or the data unit in a multiplexing sub-frame according to the mobile multimedia broadcast multiplexing standards, then combining the multiplexing sub-frames into a multiplexing frame, and transmitting the multiplexing frame through a mobile multimedia broadcast network. The method can improve transmission efficiency and fault-tolerance of a mobile multimedia broadcast system.

Description

Method for transmitting service data stream

Technical field

The present invention relates to the field of mobile multimedia broadcast technologies, and in particular, to a method for transmitting a mobile multimedia broadcast service data stream.

Background technique

Mobile multimedia broadcasting is a multimedia playback technology that has emerged in recent years. With a handheld terminal, you can watch multimedia services such as TV at high speed. The terminal receives the multimedia service program list through the wireless broadcast channel, and can select the channel that the user has the right to watch, and receive the multimedia data of the selected channel, so as to realize watching TV on the mobile terminal.

At present, mobile multimedia broadcasting systems can use a variety of data transmission methods, such as transport streams, multi-protocol encapsulation, IP data encapsulation, and the like. In China's mobile multimedia broadcasting system, the multiplexed frame structure is the second part of the mobile multimedia broadcast series standard, which includes multiplexed frame headers composed of payload, length information, and media parameters. The multiplex frame defines the encapsulation format of the data stream, one multiplex frame is composed of a plurality of multiplex subframes, and the number of multiplex subframes is included in the multiplex frame header.

The content of a multimedia broadcast service is encapsulated in each multiplex subframe, and its structure is as shown in FIG. 1. The multiplex subframe includes a multiplex subframe header, a video segment, an audio segment, and a data segment. As shown in FIG. 2a, the video segment is encapsulated by multiple video units; as shown in FIG. 2b, the audio segment is encapsulated by multiple audio units; as shown in FIG. 2c, the data segment is encapsulated by multiple data units. to make.

From the above, the video unit, audio unit and data unit are the smallest units in the existing data stream encapsulation method. When an error occurs in data transmission, since there is no obvious boundary distinction between the video unit, the audio unit, and the adjacent unit, the data of all the units of the video segment/audio segment/data segment needs to be discarded, that is, only The unit of the erroneous part is discarded, resulting in error diffusion, which greatly affects the transmission efficiency and fault tolerance of the multimedia broadcast system.

Summary of the invention

The technical problem to be solved by the present invention is to provide a data stream of a mobile multimedia broadcast service. A delivery method capable of improving transmission efficiency and fault tolerance of a mobile multimedia broadcast system.

In order to solve the above technical problem, the present invention provides a method for transmitting a service data stream, including: using video, audio or data of a mobile multimedia broadcast service as a payload of a multiplexing block, and basicizing the multiplexing block The description information is encapsulated in a header of the multiplexing block, the basic description information includes a type of the multiplexing block, and the type is used to identify that the payload of the multiplexing block is video, audio or data; The multiplexing block formed by the part is encapsulated as a payload in a corresponding video unit, an audio unit or a data unit; the video unit, the audio unit or the data unit is encapsulated in a multiplex subframe according to a mobile multimedia broadcast multiplexing standard, and then The multiplexed subframes are grouped into multiplexed frames, and the multiplexed frames are transmitted through a mobile multimedia broadcast network. Further, when the type of the multiplex block indicates that the service data carried in the payload of the multiplex block is data, a data unit type indicating a type of the data is added at a header of the multiplex block.

Further, the content of the data unit type is the same as the data unit type in the data segment header of the multiplex subframe.

Further, when the length of the video unit, the audio unit, or the data unit of the mobile multimedia broadcast service is greater than the payload length of the multiplex block, two or more multiplex blocks are used to carry the mobile multimedia broadcast service. a video unit, an audio unit, or a data unit, setting a start flag in a first multiplex block carrying the video unit, audio unit, or data unit, and setting a last multiplex block in the video unit, audio unit, or data unit End tag.

Further, the header of the multiplexing block further includes one or more of the following information: a start code, which is used to identify a starting position of the multiplexing block; a payload length of the multiplexing block; and fault tolerant information , which includes verification information of the header of the multiplexing block. The present invention provides a method for transmitting a service data stream in a mobile multimedia broadcast network, in which a video unit, an audio unit or a data unit of a mobile multimedia broadcast multiplex frame is encapsulated by one or more multiplex blocks, and A multiplexing block type is used to distinguish a multiplexing block of a video unit, a multiplexing block of a audio unit, and a multiplexing block of a data unit, wherein a multiplexing unit for a data unit can utilize a data unit type to distinguish data sources and categories; The multiplex block also uses the start code as the isolation to implement error isolation; by multiplexing the block mark, multiple multiplex blocks are used to transmit one multimedia service data; and the method of the present invention ensures that the mobile multimedia broadcast system has transmission High efficiency and good fault tolerance. In addition, the head overhead of the multiplex block structure in the method is relatively small, and the performance of the multimedia broadcast transmission is guaranteed. BRIEF abstract

1 is a schematic structural diagram of a multiplex subframe;

2a is a schematic structural diagram of a video segment;

Figure 2b is a schematic structural view of an audio segment;

Figure 2c is a schematic structural diagram of a data segment;

FIG. 3 is a flowchart of data stream transmission in the embodiment;

FIG. 4 is a schematic structural diagram of a multiplexing block in the embodiment. Preferred embodiment of the invention

The invention will be further described in detail below with reference to the accompanying drawings.

The main idea of the present invention is: using one or more multiplex blocks to carry service data of a mobile multimedia broadcast system, adding some basic information of the multiplex block in the multiplex block header, including a multiplex block type, which is used Differentiating between a video multiplexing block, an audio multiplexing block, and a data multiplexing block; packaging the multiplexing block as a payload in a video unit and an audio unit of a mobile multimedia broadcast standard multiplexing frame according to a multiplexing block type, and then using the video unit The audio unit and the data unit are respectively encapsulated in the multiplex subframe, and finally the multiple multiplex subframes are formed into a mobile multimedia broadcast standard multiplex frame, and transmitted through the mobile multimedia broadcast network.

Each multiplex block header also contains a start code, a start tag, an end tag, a payload length, and error correction fault tolerance information (e.g., a redundancy check word CRC). When the multiplex block type indicates that a multiplex block of data is carried in the payload of the multiplex block, a data unit type may also be included in the multiplex block for distinguishing the data source and the class.

In the embodiment, the method for transmitting the mobile multimedia service data stream is as shown in FIG. 3, which includes the following steps.

Step 310: The service data of the mobile multimedia broadcast is carried by using one or more multiplexing blocks, where the service data of the mobile multimedia broadcast is divided into a video service, an audio service, and a data service according to a media attribute, and the video service includes a television image, Movie images, animations, etc.; audio services include television audio, sound broadcasting, music, voice, etc.; data services include file downloading, data transmission, traffic information, stock data, etc. The multiplex block consists of a header and a payload, carrying mobile multimedia Broadcast service data (video, audio or data) as the payload of the multiplex block, which will serve as the multiplex block payload The basic description information of the service data is encapsulated in a multiplex block header, and the basic description information includes a type of the multiplex block, where the type is used to identify that the payload of the multiplex block belongs to a video service and an audio service of the mobile multimedia broadcast. Or data services.

Specifically, the multiplex block type is used to indicate that the multiplex block is a multiplex block that carries a multimedia broadcast video service, a multiplex block that carries an audio service, or a multiplex block that carries a data service; the header further includes a data unit type, The multiplex block for carrying data is used, that is, when the multiplex block is a multiplex block carrying data, the data unit type is used to indicate the type of data. The definition of the data unit type is the same as the data unit type in the data section header of the multiplexed subframe.

As shown in Figure 4, the multiplex block header structure includes start code, start tag, end tag, payload length, and CRC fault tolerance in addition to the type and data unit type.

The multiplex block header may further include a start code, a start tag, an end tag, a payload length, and a CRC error correction, where the start code is used to identify the start of the multiplex block, and the start tag is used to describe the first complex With the block, the end tag is used to describe the last multiplex block, the payload length refers to the length of the multiplex block payload, and the CRC error correction is the parity information of the multiplex block header.

When the length of the service data unit (video unit, audio unit, and data unit) of the mobile multimedia broadcast is less than or equal to the payload length of the multiplex block, a multiplex block is used to carry the service data unit of the mobile multimedia broadcast, and in the complex Setting a start tag and an end tag simultaneously with a block; when the length of the service data unit of the mobile multimedia broadcast is greater than the payload length of the multiplex block, the service data unit of the mobile multimedia broadcast is carried by using two or more multiplex blocks , the start tag is set in the first multiplex block, and the end tag is set in the last multiplex block.

Step 320: Encapsulate the one or more multiplexing blocks in the corresponding video unit, audio unit or data unit according to the definition of the video unit, the audio unit and the data unit according to the mobile multimedia broadcast multiplexing standard.

Step 330: The video unit, the audio unit, or the data unit is encapsulated in a video segment, an audio segment, and a data segment according to a mobile multimedia broadcast standard multiplexing frame structure, where the video segment, the audio segment, and the data segment form a multiplexing subframe. Finally, a plurality of multiplexed sub-frames are combined into a multiplexed frame, and data is transmitted through a mobile multimedia broadcast network.

4 is a schematic structural diagram of a multiplexing block used in a method for transmitting a service data stream in the embodiment, which includes a header and a payload, wherein the header includes a start code, a start tag, an end tag, and Type, payload length, data unit type, and redundancy check word, and where:

The start code is used to identify the starting position of the multiplex block, and is the first part of the multiplex block header, which The first byte of the multiplex block can be occupied. In this embodiment, the start code occupies 8 bits (1 byte) and takes a fixed value of 0X55. The start code is also the boundary of the multiplex block in the video unit, the audio unit, and the data unit, in addition to being the start of the multiplex block, for locating and dividing the multiplex block. In addition, when extracting the multiplex block in the video unit, the audio unit and the data unit, the terminal can implement the integrity of the multiplex block by checking the start code and the length;

The start tag and the end tag are respectively used to identify whether the current multiplex block is the beginning or the end of a video unit, an audio unit or a data unit, and the start tag is transmitted when the video unit, audio unit or data unit is divided into multiple multiplex blocks. Used to describe the first multiplex block, and the end tag is used to describe the last multiplex block;

The payload length is used to identify the payload length of the multiplex block, and its unit is byte;

A type refers to a multiplex block type, which is used to indicate the type of service data carried by the multiplex block, that is, whether the multiplex block carries video, audio, or data, as shown in Table 1. The multiplex block carrying the video constitutes a video unit, the multiplex block carrying the audio constitutes an audio unit, and the multiplex block carrying the data constitutes a data unit;

Numerical example of multiplex block type

The data unit type is used when the multiplex block carries data, and is used to indicate the type of data, see table

2;

Table 2 Numerical examples of data unit types

Value data unit type

0 ESG (Electronic Business Guide) data

1 ESG program prompt information

2 - 127 Reserved

128 - 159 160 - 169 Data Broadcasting

170 - 255 reserved

Redundancy check word CRC is the redundancy check word of the multiplex block header;

The payload refers to the payload of the multiplex block, that is, the service data carried in the multiplex block. The payload of the multiplexing block in this embodiment may be audio, video or data.

In this embodiment, the overhead of designing the multiplex block header structure includes a start code of 8 bits (bit), a start mark and an end mark of 2 bits, a type 2 bit, a length information of 12 bits, and a data unit type of 8 bits. And CRC8 bits. In other embodiments, each field has a variable bit size, but a maximum of 40 bits, which has higher encapsulation and transmission efficiency than the 96-bit overhead of the multi-protocol encapsulation in the European Digital Television DVB standard.

In this embodiment, when the terminal parses the video unit, the audio unit, or the data unit, errors generated by any of the multiplexing blocks do not affect other multiplexing blocks, that is, error isolation is implemented; multiplexing frames for mobile multimedia broadcasting Structure design, the multiplex block type specifically proposed in this embodiment ensures that the mobile multimedia broadcast system has the characteristics of high transmission efficiency and good fault tolerance.

The method of the present invention is not limited by the type of the transmission protocol, and is applicable to various protocols such as a real-time streaming protocol, a file transfer protocol, and a multiplexed transport protocol, so that the influence of the protocol is not considered in the multiplex block header.

There are a variety of other embodiments of the present invention, and those skilled in the art can make various changes and modifications in accordance with the present invention without departing from the spirit and scope of the invention. It is intended to fall within the scope of the appended claims.

Industrial applicability

The method for transmitting a mobile multimedia broadcast service data stream provided by the present invention can ensure that the mobile multimedia broadcast system has the characteristics of high transmission efficiency and good fault tolerance. In addition, the head overhead of the multiplex block structure in the method is relatively small, and the performance of the multimedia broadcast transmission is guaranteed.

Claims

Claim

1. A method for transmitting a service data stream, comprising:

Using the video, audio or data of the mobile multimedia broadcast service as the payload of the multiplexing block, and encapsulating the basic description information of the multiplexing block at the head of the multiplexing block, the basic description information including the complex Using a type of a block, the type being used to identify that the payload of the multiplex block is video, audio, or data;

Encapsulating the multiplex block composed of the payload and the header as a payload in a corresponding video unit, audio unit or data unit;

Encapsulating the video unit, the audio unit, or the data unit in a multiplex subframe according to a mobile multimedia broadcast multiplexing standard, and then constituting the multiplex subframe into a multiplex frame, and transmitting the multiplex frame by using a mobile multimedia broadcast network .

2. The method according to claim 1, further comprising: when the type of the multiplexing block indicates that the service data carried in the payload of the multiplexing block is data, at the head of the multiplexing block A data unit type is added to indicate the type of the data.

3. The method of claim 2, wherein the content of the data unit type is the same as the data unit type in the data segment header of the reuse subframe.

4. The method of claim 1, further comprising: when the length of the video unit, audio unit, or data unit of the mobile multimedia broadcast service is greater than a payload length of the multiplex block, using two or Two or more multiplex blocks carrying the video unit, audio unit or data unit of the mobile multimedia broadcast service, and setting a start tag on a first multiplex block carrying the video unit, audio unit or data unit, An end tag is set at the last multiplex block that carries the video unit, audio unit, or data unit.

5. The method of claim 1 wherein the header of the multiplexing block further comprises one or more of the following information:

a start code, which is used to identify a starting position of the multiplexing block; a payload length of the multiplexing block;

Fault tolerant information including check information of a header of the multiplex block.

6. The method of claim 1, wherein the type of the multiplexing block occupies 2 bits.

7. The method of claim 2, wherein the data unit type occupies 8 bits.

8. The method of claim 4, wherein the start tag and the end tag each occupy lbit.

9. The method of claim 5, wherein the start code occupies 8 bits; the payload length occupies 12 bits; and the fault tolerance information occupies 8 bits.

10. The method of claim 1 wherein the head of the multiplex block occupies no more than 40 bits.