JT/T 1078-2016GNSS system for operating vehicles - Video communication protocol (English PDF)

3.1 Terms and definitions

The following terms and definitions apply to this document.

3.1.1 Code rate

The number of data bits transmitted per unit time during data transmission.

The common unit is kilobits per second (kbps).

3.1.2

Frame rate

The number of times that the graphic processor can be updated per second when processing the field. It is used to measure the number of displayed frames. The unit of measurement is frame per second (FPS).

3.2 Abbreviations

The following abbreviations apply to this document.

4.1 Basic agreement of protocol

The communication method, data type, transmission rules and message composition of the protocol are in accordance with the requirements of clause

4 of JT/T 808-2011.

4.2 Convention on real-time audio-video transmission channel

A real-time audio-video transmission channel may either transmit one channel of video information or one channel of audio information, or transmit one channel of video information and one channel of audio information. There are two types of conventions on the real-time audio-video transmission channel.

4.3 Classification of audio-video communication messages

Audio-video data messages are divided into the following two categories.

5.1 Protocol command set

The comparison of the command messages between the video terminal and the video platform is as shown in Appendix A.

5.2 Inheritance commands

Inherit and use other commands in JT/T 808-2011 except for the message ID of 0x8804 (recording start command). In addition, for the multimedia type field in a total of five commands 0x0800 (multimedia event message upload),

5.3 Parameter setting commands

5.3.1 Setting of terminal audio-video parameters

The setting message of terminal audio-video parameters adopts the 0x8103 message as defined in 8.8 of JT/T 808-2011, meanwhile it adds the following audio-video parameter settings, as shown in Table 1.

5.4.2 Terminal upload passenger-traffic

Message ID. 0x1005.

Message type. signaling data message.

The terminal equipment uses video analysis to count the passengers getting on and off, send the counting result to the platform. The format of the message- body data is as shown in Table 16.

5.5 Real-time audio-video transmission command

5.5.1 Real-time audio-video transmission request

Message ID. 0x9101.

5.5.2 Audio-video real-time transmission control

Message ID. 0x9102.

Message type. signaling data message.

The platform sends the audio-video real-time transmission control commands, which are used to switch the code-stream, pause the code-stream transmission, close the audio-video transmission channel. The data-format of message-body is as shown in Table 18.

5.5.4 Real-time audio-video transmission status notification

Message. ID. 0x9105.

5.6 Historical audio-video query, playback and download commands

8.1 Time-based password report and request services

The time-based password is automatically generated by the enterprise's video monitoring platform every day, actively uploaded to the government's video surveillance platform of the belonging district.

8.2 Real-time audio-video services

8.2.1 Enterprise's video surveillance platform uploads audio-video data to

the government's video surveillance platform in real-time

The government's video surveillance platform sends real-time audio-video upload requests to the enterprise's video monitoring platform. After receiving the request, the enterprise's video monitoring platform shall respond to the government's video surveillance platform.

8.2.2 Enterprise's video monitoring platform stops uploading audio-video

data to the government's video surveillance platform in real-time

The government's video surveillance platform sends a request to stop the real- time audio-video upload to the enterprise's video monitoring platform.

8.3 Remote video searching services

8.3.1 Government's video surveillance platform obtains audio-video

resource directory from enterprise's video monitoring platform

The government's video surveillance platform sends a request for accessing the audio-video resource directory to the enterprise's video monitoring platform.

After receiving the request, the enterprise's video monitoring platform shall immediately search the latest audio-video resource directory from the terminal and update the local directory, respond to the government's video surveillance platform. If the response is successful, the enterprise's video monitoring platform sends the audio-video resource directory data to the government's video surveillance platform.

8.4 Remote video download services

8.4.1 Government's video monitoring platform downloads video data from

enterprise's video surveillance platform

The government's video surveillance platform sends a request for obtaining video data to the enterprise's video monitoring platform. After receiving the request, the enterprise's video monitoring platform shall respond to the government's video surveillance platform. If the response is successful, the government's video surveillance platform may request video data from the FTP server IP and port as specified by the enterprise's video monitoring platform.

8.4.2 Enterprise's video monitoring platform sends a download

completion notice to government's video surveillance platform

The enterprise's video monitoring platform sends a download completion notice to the government's video surveillance platform. After receiving the notice, the government's video surveillance platform indicates that the video data has been downloaded from the terminal, the government's video surveillance platform may request the video data from the video FTP server IP and port as designated by the enterprise's video monitoring platform.

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