CN1972166B - An audio stream transport method of mobile multimedia broadcast system - Google Patents

Abstract

An audio stream transmission method for a mobile multimedia broadcasting system, comprising the steps of: (1) uniformly numbering the audio streams to be transmitted, each audio stream having a unique number; (2) dividing each audio stream into multiple audio units , and encapsulate the audio unit in the audio segment, and record the length, audio stream number, and relative playing time of each audio unit in the audio segment header; (3) encapsulate the audio segment and other data that needs to be transmitted in a business channel (4) After receiving the audio segment, the terminal takes out each audio stream according to the length of each audio unit in the audio segment header and the audio stream number, and plays the audio stream. The invention is suitable for use in a mobile multimedia broadcasting system, can transmit one channel or multiple channels of audio data, and has higher transmission efficiency.

Description

An audio stream transmission method for a mobile multimedia broadcasting system

technical field

The present invention relates to a mobile multimedia broadcasting system, and more specifically, to a method for transmitting one-channel audio or multiple-channel audio in the mobile multimedia broadcasting system. the

Background technique

Mobile multimedia broadcasting is a multimedia playback technology that has emerged in recent years. Through the mobile terminal, in the case of high-speed movement, you can watch TV. The mobile terminal can receive the program list through the wireless protocol, and can select the program it is interested in, so as to receive the multimedia data stream and realize watching TV on the mobile terminal. the

The air data transmitted by the mobile multimedia broadcasting system is divided into different channels and transmitted through the multiplexing technology. The mobile terminal can receive the relevant data, and realize the normal broadcasting of the TV through the player on the terminal. the

For the same channel, the mobile multimedia broadcasting system can send one audio stream or multiple audio streams. the

There are two methods for realizing multiple audio streams in the prior art:

First, TS (Transport Stream, Transport Stream) mode, TS protocol is one of the MPEG (Moving Picture Expert Group, Motion Picture Experts Group) standards, it puts video, audio and control information in a fixed 188-byte size It is transmitted in the data packet, and different audio streams are distinguished through the PID (Program Identifier, program number) field, so that the playback of multiple audio streams can be supported. the

Second, the ISMA (Internet Streaming Media Alliance, Internet Streaming Media Alliance) method, the ISMA specification uses RTP (Real Time Transport Protocol, Real Time Transport Protocol) to transmit multimedia information, and multiple RTP channels can be opened to transmit different audio streams. This method is suitable for use on IP networks. the

However, the method for implementing multiple audio streams in the prior art has the following problems: each packet of the TS method is small, and the efficiency is relatively low, while the ISMA method has a small application range and can only be used on an IP network. the

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for implementing multiple audio streams suitable for use in a mobile multimedia broadcasting system, which can transmit audio data containing one or more audio streams in one channel. the

In order to solve the above problems, the invention provides a method for transmitting audio streams of a mobile multimedia broadcasting system, comprising the following steps:

(1) Number the audio streams to be transmitted uniformly, and each audio stream has a unique number;

(2) Each audio stream is divided into multiple audio units, and the audio units are encapsulated in the audio segment, and the length, audio stream number, and relative playback time of each audio unit are recorded in the audio segment header;

(3) Encapsulate the audio segment and other data that needs to be transmitted in a service channel for transmission;

(4) After receiving the audio segment, the terminal extracts each audio stream according to the length of each audio unit in the audio segment header and the audio stream number, and plays the audio stream. the

Wherein, the audio segment header also includes a check code. the

Wherein, a synchronization header is added between each audio unit for isolation. the

Wherein, the data in the service channel further includes a subframe header, and the subframe header includes the length of the audio segment and parameters of the audio segment. the

The present invention encapsulates multiple audio streams in one channel, divides the audio data in one channel into multiple audio units, and transmits them through one or more channels, so that one audio stream, two audio streams or More than two audio streams are transmitted in one channel at the same time, and have high transmission efficiency. the

Description of drawings

Fig. 1 is a schematic diagram of the channel data package encapsulation structure of one or more audio stream implementation methods of the mobile multimedia broadcasting system of the present invention;

Fig. 2 is a schematic diagram of implementing two audio streams using the present invention. the

Detailed ways

The method for implementing one or more audio streams of the mobile multimedia broadcasting system of the present invention will be further described below in conjunction with the accompanying drawings. the

As shown in Figure 1, the channel data includes: a subframe header, a video segment, an audio segment and a data segment, and the audio data is encapsulated in the audio segment. the

Wherein, the subframe header is mainly control information, specifically including: length information, video parameters, audio parameters, start playing time, check code, etc. The check code of the subframe header is used to verify the reliability of the subframe header information. the

The audio streams to be transmitted are uniformly numbered, and each audio stream has a unique number. The audio segment is divided into an audio segment header and multiple audio units, and each audio unit can be isolated with a synchronization header to achieve the function of error isolation. the

The audio segment header contains description information for multiple audio units, including: the total number of audio units, the length of each audio unit, the audio stream number of the audio unit, the relative playback time, and the check code. The length of the audio unit can be It is used to locate and divide each audio unit data, which can be set flexibly. The relative playback time refers to the playback time, and the audio stream number is used to identify which audio stream this audio unit belongs to. In addition, audio units can also be sequentially numbered as unit numbers. The check code of the audio segment header is used to verify the correctness of the audio segment header. the

Each audio stream is divided into multiple audio units, and the audio units are encapsulated in the audio segment, and then the audio segment and other data to be transmitted are encapsulated in a service channel for transmission. After receiving the audio segment, the terminal extracts each audio stream according to the length of each audio unit in the audio segment header and the audio stream number, and plays the audio stream. the

Through the above method, multiple audio streams are included in one channel, so that they can be transmitted over the air in the form of wireless multimedia broadcasting signals. the

Fig. 2 is a schematic diagram of realizing two audio streams using the multi-audio stream implementing method of the mobile multimedia broadcasting system of the present invention. The audio segment header and sync header are omitted in the figure. Suppose the first audio stream has 15 audio units, and the second audio stream has 10 audio units, as shown in Figure 2, the first audio stream includes: audio units 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 22, 23, 24, 25, the second audio stream includes: audio unit 2, 4, 6, 8, 10, 12, 14, 16, 18, 20. In the figure, there is a sync header between each audio unit to divide each audio unit. the

The audio units of the two audio streams may not be arranged in the above sequence, but the sequence can be flexibly adjusted. the

According to the above principles, one audio stream, two audio streams or more than two audio streams can be simultaneously transmitted in one or more data channels assigned to one channel. the

For example, when one channel contains two audio streams, each service data has a rate of 256Kbit/s. the

Among them: the section header is 122 bytes long, the video data is 22.5K bytes in total, the audio section is 8K bytes long, and the data section is 1K bytes long. For parts less than 32K bytes, all 0s can be filled. The audio segment includes 2 audio streams, each with 32Kbit/s. Compared with the TS method, the transmission efficiency is greatly improved. the

Such a channel can satisfy the transmission of 1 QVGA resolution, 25 frames of H264 or AVS-M video data, and the transmission of 2 32Kbit/s AAC audio stream data, and can provide users with quite satisfactory high quality Audio streaming of mobile broadcast TV programs. the

Claims (4)

1. the audio stream transport method of a mobile multimedia broadcast system comprises the steps:

(1) will need the unified numbering of the audio stream that transmits, each audio stream has unique number;

(2) each audio stream is divided into a plurality of audio units, and audio unit is encapsulated in the audio section, with the length of each audio unit, audio stream numbering, reproduction time is recorded in the audio frequency paragraph header relatively;

(3) audio section and other data encapsulation that need transmit are transmitted in a service channel;

(4) after terminal receives audio section, take out each audio stream, carry out the broadcast of audio stream according to length, the audio stream numbering of each audio unit in the audio frequency paragraph header.

2. the audio stream transport method of mobile multimedia broadcast system as claimed in claim 1 is characterized in that, described audio frequency paragraph header also comprises check code.

3. the audio stream transport method of mobile multimedia broadcast system as claimed in claim 1 is characterized in that, adds synchronous head between described each audio unit and does isolation.

4. the audio stream transport method of mobile multimedia broadcast system as claimed in claim 1 is characterized in that, the data in the described service channel also comprise the subframe head, and described subframe head comprises the length of audio section and the parameter of audio section.

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