CN1960509B - Method for implementing error isolation when transmitting mobile multimedia broadcasting media data - Google Patents

Abstract

The invention discloses a method for realizing error isolation when transmitting mobile multimedia broadcast media data, which is suitable for a mobile broadcast network and includes the following steps: (1) dividing media data into a plurality of independent media data units at a sending end; (2) record the length information of each media data unit in the header information of the media data; (3) add a synchronization code between each media data unit to separate; (4) include the header information, each media The data unit, and the media data of the synchronization code between the media data units are sent to the receiving terminal. Applying the method described in the present invention enables the terminal to correctly divide different data blocks in case of code errors after receiving media data so that errors will not spread, thereby realizing error isolation of media data.

Description

Method for implementing error isolation when transmitting mobile multimedia broadcasting media data

technical field

The invention relates to the technical field of mobile multimedia broadcasting or mobile phone television, in particular to a method for realizing error isolation when transmitting mobile multimedia broadcasting media data, which is applicable to mobile broadcasting networks.

Background technique

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

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

For the same channel, video data and audio data need to be sent. The video data is divided into several video units. Similarly, the audio data is also divided into several audio units. Each unit needs to be distinguishable, and to make An error in one unit cannot affect another unit. This requires a way to achieve error isolation.

At present, there are two commonly used methods to implement error isolation as follows:

1. TS (Transport Stream) mode, the TS protocol is one of the MPEG (Moving Picture Expert Group) standards, it puts a basic video and audio unit in multiple fixed 188-byte packets Since the size of the video unit and the audio unit can just fill up these fixed-size TS packets, a large amount of padding data is required.

2. ISMA (Internet Streaming Media Alliance) method. The ISMA specification uses RTP (Real-time Transport Protocol) to transmit media information. The size of the RTP packet is variable, and each video and audio unit can be transmitted in a different RTP packet. This method is suitable for use on IP networks.

The TS method needs to waste some bandwidth resources because the size of the packet is fixed, and the efficiency is relatively low, while the ISMA method can only be used on the IP network. Both of these methods use independent packets to segment video and audio data.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for implementing error isolation when transmitting mobile multimedia broadcast media data, so that after receiving the media data, the terminal can correctly divide different data blocks in the event of a bit error. so that errors do not propagate.

In order to solve the above-mentioned technical problem, the present invention provides a kind of method that realizes error isolation when transmitting mobile multimedia broadcasting media data, is applicable to in mobile broadcasting network, comprises the following steps:

(1) Divide the media data into multiple independent media data units at the sending end;

(2) recording the length information of each media data unit in the header information of the media data;

(3) Add synchronization code between each media data unit to separate;

(4) Send the media data including header information, media data units, and synchronization codes between the media data units to the receiving terminal.

Among them, it further includes: (5) The receiving terminal restores each media data unit according to the length information of each media data unit recorded in the header information and/or the synchronization code.

Wherein, the step (5) includes: (51A) The receiving terminal cuts out each media data unit from the received data according to the length information of each media data unit recorded in the received header information.

Wherein, the step (5) includes: (51B) The receiving terminal searches for the synchronization code in the received media data, and uses the data between two synchronization codes as the media data unit.

Wherein, the step (5) includes: (51) the receiving terminal cuts out each media data unit from the received data according to the length information of each media data unit recorded in the received header information;

(52) Check whether the first several bytes of the current media data unit cut out are synchronization codes, and check whether the first several bytes of the next media data unit are synchronization codes, if the check result is incorrect, then do not use all Instead of the media data unit cut out according to the length information described above, the synchronization code is searched in the received media data, and the data between two synchronization codes is used as the media data unit.

Wherein, the media data includes video data and/or audio data.

Wherein, in the step (1), each frame of media data can be cut into one or more media data units.

Wherein, in the step (1), the media data is divided into multiple independent media data units at any time interval.

A method for implementing error isolation when transmitting mobile multimedia broadcast media data according to the present invention is applicable to mobile broadcast networks. When sending media data, each media data is jointly divided by a length field and a synchronization code, which can Bit errors are prevented to ensure that media data units can be correctly segmented, thereby implementing error isolation of media data.

Description of drawings

Fig. 1 is a schematic flow block diagram of a method for implementing error isolation when transmitting mobile multimedia broadcast media data according to an embodiment of the present invention;

2 is a schematic diagram of video data error isolation in a method for implementing error isolation when transmitting mobile multimedia broadcast media data according to an embodiment of the present invention;

Fig. 3 is a schematic diagram of audio data error isolation in a method for implementing error isolation when transmitting mobile multimedia broadcast media data according to an embodiment of the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to FIG. 1 , it is a schematic flow block diagram of a method for implementing error isolation when transmitting mobile multimedia broadcast media data according to an embodiment of the present invention. The specific process is as follows:

Step 110: Divide the media data into multiple independent media data units at the sending end;

Step 120: Record the length information of each media data unit in the header information of the media data;

Step 130: adding a synchronization code between each media data unit to separate;

Step 140: Send the media data including the packet header information, each media data unit, and the synchronization code between the media data units to the receiving terminal.

Referring to Fig. 2, it is a schematic diagram of video data error isolation in a method for implementing error isolation when transmitting mobile multimedia broadcast media data according to an embodiment of the present invention. Video data consists of a video packet header, a plurality of synchronization codes, and a plurality of video units The video data can be divided into multiple independent video units, and one frame can be divided into one video unit or multiple video units. The specific process of video data error isolation is as follows:

At the sending end, the video data is divided into multiple independent video units, and then the length information of each video unit is recorded in the header information of the video data, and the video units are separated by adding synchronization codes between each video unit , and then send the video data including the header information, each video unit, and the synchronization code between the video units to the receiving terminal.

The receiving terminal restores each video unit according to the length information of each video unit recorded in the header information and/or the synchronization code. The restoration process is: the receiving terminal cuts out each video unit from the received data according to the length information of each video unit recorded in the received packet header information, and then checks the first few bytes of the cut out current video unit Whether it is a sync code, and check whether the first few bytes of the next video unit are sync codes, if the check result is correct, then use the current video unit, if the check result is not correct, then do not use the cut out according to the length information Instead, search for the sync code in the received video data, and use the data between the two sync codes as the video unit.

Referring to FIG. 3 , it is a schematic diagram of audio data error isolation in a method for implementing error isolation when transmitting mobile multimedia broadcast media data according to an embodiment of the present invention. Audio data consists of audio packet headers, multiple synchronization codes, and multiple audio units. Audio data can be divided into multiple independent audio units. The time interval is any value and can be adjusted. It can be 50ms as an audio unit or 100ms. as an audio unit. The specific process of audio data error isolation is as follows:

At the sending end, the audio data is divided into multiple independent audio units, and the length information of each audio unit is recorded in the header information of the audio data, and the audio units are separated by adding synchronization codes between each audio unit , and then send the audio data including the header information, each audio unit, and the synchronization code between the audio units to the receiving terminal.

The receiving terminal restores each audio unit according to the length information of each audio unit recorded in the header information and/or the synchronization code. The restoration process is: the receiving terminal cuts out each audio unit from the received data according to the length information of each audio unit recorded in the received packet header information, and then checks the first few bytes of the cut out current audio unit Whether it is a synchronous code, and check whether the first few bytes of the next audio unit are synchronous codes, if the verification result is correct, then use the current audio unit, if the verification result is incorrect, then do not use the audio unit, but search for the sync code in the received audio data, and use the data between the two sync codes as the video unit.

In addition, the synchronization code requirement between known video units will not appear in the video code stream, and the synchronization code requirement between audio units will not appear in the audio code stream, or in other words, the synchronization code will not appear in the video data, audio data will not appear in . The embodiment of the present invention selects a synchronization code with a length of 3 bytes, which is "0x00 00 01".

The present invention will be further described below through an example.

In this example, each data channel has a rate of 128Kbit/s, and one channel includes 2 data channels, which can have a rate of 256Kbit/s.

The total length of this channel is 32K bytes, of which: the video data has a total of 22.5K bytes, and the audio data has a length of 8K bytes. The audio data includes 2 audio tracks, each with 32Kbit/s. The frame rate is 25 Hz, cut into 25 video units, and the audio frequency of 100ms is 1 audio unit, cut into 20 audio units. By using the error isolation method described in the present invention between each video unit and audio unit, the security performance of media transmission is improved.

As mentioned above, such a TV channel can satisfy the transmission of one H264 or AVS-M video data with QVGA resolution and 25 frames, and the transmission of two AAC audio track data at 32Kbit/s, which can provide users with high Quality audio streaming mobile broadcast TV programs.

Claims (7)

1. A method for realizing error isolation when transmitting mobile multimedia broadcasting media data, is applicable in the mobile broadcasting network, is characterized in that, comprises the steps: (1) Divide the media data into multiple independent media data units at the sending end; (2) recording the length information of each media data unit in the header information of the media data; (3) Add synchronization code between each media data unit to separate; (4) Send the media data comprising the header information, each media data unit, and the synchronization code between the media data units to the receiving terminal; (5) The receiving terminal restores each media data unit according to the length information of each media data unit recorded in the header information and/or the synchronization code. 2. method as claimed in claim 1, is characterized in that, described step (5) comprises: (51A) The receiving terminal cuts out each media data unit from the received data according to the length information of each media data unit recorded in the received header information. 3. method as claimed in claim 1, is characterized in that, described step (5) comprises: (51B) The receiving terminal searches the received media data for a synchronization code, and uses data between two synchronization codes as a media data unit. 4. method as claimed in claim 1, is characterized in that, described step (5) comprises: (51) The receiving terminal cuts out each media data unit from the received data according to the length information of each media data unit recorded in the received header information; (52) Check whether the first several bytes of the current media data unit cut out are synchronization codes, and check whether the first several bytes of the next media data unit are synchronization codes, if the check result is incorrect, then do not use all Instead of the media data unit cut out according to the length information described above, the synchronization code is searched in the received media data, and the data between two synchronization codes is used as the media data unit. 5. The method of claim 1, wherein the media data comprises video data and/or audio data. 6. The method according to claim 1, characterized in that, in the step (1), each frame of media data can be cut into one or more media data units. 7. The method according to claim 1, characterized in that, in the step (1), the media data is divided into multiple independent media data units at any time interval.

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