Standard No.:	JT/T 1078-2016
English Name:	GNSS system for operating vehicles - Video communication protocol
Chinese Name:	道路运输车辆卫星定位系统 视频通讯协议
Professional Classification:	JT    Professional Standard - Transport
Issued by:	Ministry of Transport
Issued on:	2016-10-21
Implemented on:	2017-1-1
Status:	valid
Language:	English
File Format:	PDF
Word Count:	15000 words
Price(USD):	450.0
Delivery:	via email in 1 business day

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. This standard is developed in accordance with the rules given in GB/T 1.1-2009. This standard is under the jurisdiction of National Technical Committee on Transportation Information Communication and Navigation of Standardization Administration of China. GNSS system for operating vehicles - Video communication protocol 1 Scope This standard specifies the protocol basis and communication protocol between vehicle video terminal and video platform, the bit stream communication between audio and video stream server and client media player, and the communication protocol basis, communication protocol flow, constant definition and protocol data body format between video platforms in the GNSS system for operating vehicles. This standard is applicable to the transmission of audio and video data between the vehicle video terminal of GNSS system for operating vehicles and the enterprise video monitoring platform, as well as the exchange and sharing of audio and video resources between different video platforms. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. JT/T 808-2011 GNSS system for operational vehicles - General specifications for vehicle terminal communication protocol and data format JT/T 809-2011 GNSS system for operating vehicles - General specifications for data exchange between platforms JT/T 1076-2016 GNSS system for operating vehicles - Technical specification for vehicle video terminal JT/T 415-2006 Electronic government platform for administration of road transportation - Cataloguing and coding rules IETF RFC 3550 Real-time transport protocol IETF RFC 2854 The text/html media type 3 Terms, definitions and abbreviations 3.1 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1.1 bit rate number of data bits transmitted per unit time during data transmission, which is commonly expressed by kilobits per second (kbps) 3.1.2 frame rate indicating the number of times that the graphics processing unit can update every second when processing the field, and is used to measure the display frame number, and the measurement unit is Frame per Second (FPS) 3.2 Abbreviations For the purposes of this document, the following abbreviations apply. AAC: Advanced Audio Coding MPEG: Moving Pictures Experts Group RTP: Real-time Transport Protocol TCP: Transmission Control Protocol UDP: User Datagram Protocol URL: Uniform Resource Locator UTF-8: 8-bit Unicode Transformation Format FTP: File Transfer Protocol 4 Basis of protocol between video terminal and video platform 4.1 Basic convention of protocol The communication mode, data type, transmission rules and message composition of the protocol shall be as specified in JT/T 808-2011, clause 4. The communication connection mode of signaling data messages in the protocol shall be as specified in JT/T 808-2011, clause 5. The message processing mechanism of signaling data messages in the protocol shall be as specified in JT/T 808-2011, clause 6. The encryption mechanism of signaling data messages in the protocol shall be as specified in JT/T 808-2011, clause 7. All parties with respect to the platform and terminal communication in the protocol shall meet the following requirements: ——Unless otherwise expressly agreed, all messages shall be replied; ——For those no special reply message is specified, general reply shall be adopted; ——For subpacketed messages, the reply party shall reply each subpacketed message packet by packet. 4.2 Real-time audio and video transmission channel protocol One real-time audio and video transmission channel may transmit one channel of video information or one channel of audio information, and may also transmit one channel of video information and one channel of audio information. There are two kinds of real-time audio and video transmission channel protocols: ——Where TCP is adopted, each TCP connection may carry multiple audio and video channels. If there is no data transmission within the set timeout period, both the terminal and the monitoring center may actively close the TCP connection for audio and video data transmission. ——Where UDP is adopted, each UDP port may carry multiple audio and video channels. 4.3 Classification of audio and video communication messages Audio and video data messages shall be classified into the following two categories: ——Signaling data message: the data format shall comply with JT/T 808-2011, and new protocol instructions and data formats shall be added on the basis of its protocol format. For the message communication, the link having already been established between the vehicle video terminal and the enterprise video monitoring platform shall be used, and no link shall be newly established. ——Bit stream data message: used for network real-time audio and video transmission, network video playback, voice conversation, voice monitoring, voice broadcast, etc. A link shall be newly established for message communication, instead of using the link for transmitting the locating information. 5 Communication protocol between video terminal and video platform 5.1 Protocol instruction set See Annex A for comparison table of instruction messages between video terminal and video platform. 5.2 Inheriting instructions Instructions other than message ID 0x8804 (recording start command) in JT/T 808-2011 shall be inherited. In addition, for the fields of multimedia type in five instructions, namely 0x0800 (multimedia event message upload), 0x0801 (multimedia data upload), 0x8802 (storage multimedia data retrieval), 0x0802 (storage multimedia data retrieval reply) and 0x8803 (storage multimedia data upload), in JT/T 808-2011, only those of picture type are included in this standard, and the data of audio and video types shall be transmitted according to those specified in 5.4 and 5.5. 5.3 Parameter setting instruction 5.3.1 Audio and video parameter setting of terminal For the audio and video parameter setting message of the terminal, the 0x8103 message defined in JT/T 808-2011, 8.8 shall be adopted, with the following audio and video parameter settings added, as shown in Table 1. Table 1 Audio and video setting parameters Parameter ID Data type Description and requirement 0x0075 Audio and video parameter settings, see Table 2 for description 0x0076 Audio and video channel list settings, see Table 3 for description 0x0077 Individual video channel parameter settings, see Table 5 for description 0x0079 Particular alarm recording parameter settings, see Table 7 for description 0x007A DWORD Video-related alarm mask word, corresponding to the definition of video alarm mark bit in Table 13. Where the corresponding bit is 1, the corresponding type of alarm is masked 0x007B Image analysis alarm parameter settings, see Table 8 for description 0x007C Terminal dormancy wake-up mode settings, see Table 9 for description Table 2 Definition and statement of audio and video parameters Start byte Field Data type Description and statement 0 Real-time stream coding mode BYTE 0: CBR (constant bit rate); 1: VBR (variable bit rate); 2: ABR (average bit rate); 100~127: Customized 1 Resolution of real-time streams BYTE 0: QCIF; 1: CIF; 2: WCIF; 3: D1; 4: WD1; 5: 720P; 6: 1080P; 100~127: Customized 2 Keyframe interval of real-time stream WORD Range (1~1,000) frames 4 Target frame rate of real-time stream BYTE Range (1~120) frames/s 5 Target bit rate of real-time stream DWORD Unit is kilobits per second (kbps) 9 Stored stream coding mode BYTE 0: CBR (constant bit rate); 1: VBR (variable bit rate); 2: ABR (average bit rate); 100~127: Customized 10 Resolution of stored streams BYTE 0: QCIF; 1: CIF; 2: WCIF; 3: D1; 4: WD1; 5: 720P; 6: 1080P; 100~127: Customized 11 Keyframe interval of stored stream WORD Range (1~1,000) frames 13 Target frame rate of stored stream BYTE Range (1~120) frames/s 14 Target bit rate of stored stream DWORD Unit is kilobits per second (kbps) 18 OSD subtitle overlay settings WORD Set by bit: 0 means no overlay and 1 means overlay; bit0: date and time; bit1: license plate number; bit2: logical channel number; bit3: longitude and latitude; bit4: driving record speed; bit5: satellite positioning speed; bit6: continuous driving time; bit7~bit10: reserved; bit11~bit15: customized 20 Enable audio output or not BYTE 0: not enable; 1: enable Table 3 List of audio and video channels Start byte Field Data type Description and statement 0 Total number of audio and video channels BYTE Indicated by 1 1 Total number of audio channels BYTE Indicated by m 2 Total number of video channels BYTE Indicated by n 3 Audio and video channel comparison BYTE [4×(1+m+n)] See Table 4.

Foreword i 1 Scope 2 Normative references 3 Terms, definitions and abbreviations 3.1 Terms and definitions 3.2 Abbreviations 4 Basis of protocol between video terminal and video platform 4.1 Basic convention of protocol 4.2 Real-time audio and video transmission channel protocol 4.3 Classification of audio and video communication messages 5 Communication protocol between video terminal and video platform 5.1 Protocol instruction set 5.2 Inheriting instructions 5.3 Parameter setting instruction 5.4 Video alarm instruction 5.5 Real-time audio and video transmission instructions 5.6 Historical audio and video query, playback and download instructions 5.7 Pan-tilt control instruction 5.8 Dormancy wake-up instruction to the terminal 6 Bit stream communication between audio and video stream server and client media player 6.1 Audio and video stream and transparent transmission data encapsulation format 6.2 Format of URL instruction for audio and video stream request 7 Communication protocol basis between video platforms 8 Communication protocol flow between video platforms 8.1 Time-limited password reporting and request services 8.2 Real-time audio and video services 8.3 Remote video retrieval services 8.4 Remote video download services 8.5 Remote video playback services 9 Definition of constants on communication protocol between video platforms 9.1 Identification of service data types 9.2 Identification of sub-service types 9.3 Video-alarm type codes 10 Format of data bodies of communication protocol between video platforms 10.1 Time-limited password reporting and request services 10.2 Real-time audio and video services 10.3 Remote video retrieval 10.4 Remote video playback 10.5 Remote video download Annex A (Nominative) Comparison table of messages between video terminal and video platform