What exactly is RTMP

RTMP is the acronym for Real Time Messaging Protocol. This protocol is based on TCP and is a protocol family, including RTMP basic protocol and RTMPT/RTMPS/RTMPE and many other variants. RTMP is a network protocol designed for real-time data communication. It is mainly used for audio, video and data communication between the Flash/AIR platform and the streaming media/interactive server that supports the RTMP protocol. Software that supports this agreement includes Adobe Media Server/Ultrant Media Server/red5, etc. RTMP, like HTTP, belongs to the application layer of the TCP/IP four-layer model.
RTMP is the abbreviation of Routing Table Maintenance Protocol. In the AppleTalk protocol suite, the Routing Table Maintenance Protocol (RTMP) is a transport layer protocol that establishes and maintains the routing table in the AppleTalk router. RTMP is based on the Routing Information Protocol (RIP). Just like RIP, RTMP uses hop count as the routing measurement standard. A data packet is sent from the source network to the destination network, and the calculation result of the number of routers or other intermediate media nodes that must pass is the hop count.

1. Transmission protocol
RTMP (Real Time Messaging Protocol) is an open protocol developed by Adobe Systems for audio, video and data transmission between Flash players and servers.
It has many variants:
1) RTMP works on TCP and uses port 1935 by default;
2) RTMPE adds encryption function on the basis of RTMP;
3) RTMPT is encapsulated on the HTTP request, which can penetrate the firewall;
4) RTMPS is similar to RTMPT, adding the security function of TLS/SSL;

2. Detailed introduction
The RTMP protocol (Real Time Messaging Protocol) is used by Flash for the transmission of objects, video, and audio. This protocol is based on the TCP protocol or the polling HTTP protocol.
The RTMP protocol is like a container for data packets.These data can be data in AMF format or video/audio data in FLV.
A single connection can transmit multiple network streams through different channels. The packets in these channels are all transmitted in fixed-size packets.
Connection
A simple code for Actionscript to connect and play a stream:
var videoInstance:Video = your_video_instance;
var nc:NetConnection = new NetConnection();
var connected:Boolean = nc.connect("rtmp:/localhost/myapp");
var ns:NetStream = new NetStream(nc);
videoInstance.attachVideo(ns);
ns.play("flvName");
The default port is 1935

3. Handshake request and response editing
Client → Server: Send a handshake request to the server. This is not part of the protocol package. The first byte of the handshake request is (0×03), followed by 1536 bytes. Although it seems that the content of this part is for the RTMP protocol It's not critical, but it can't be treated casually.
Server → Client: The server responds to the client's handshake request. This part of the data is still not part of the RTMP protocol. The starting byte of the response is still (0x03), but it is followed by two lengths of 1536 bytes (total It is 3072 bytes) of the packet block. The first 1536 block seems to be any content, or even Null does not matter. The second 1536 code block is the handshake sent by the client to the server in the previous step The content of the request.
Client→Server: The second 1536-byte data block that the server responded to the client in the previous step.
At this point, the handshake between the client and the server ends, and the contents of the RTMP protocol package will be sent below.
Client → Server: Send a connection package to the server.
Server → Client: The server responds.
... .... and many more... ...
RTMP data type
0×01 Chunk Size changes the chunk size for packets
0×02 Unknown anyone know this one?
0×03 Bytes Read send every x bytes read by both sides
0×04 Ping ping is a stream control message, has subtypes
0×05 Server BW the servers downstream bw
0×06 Client BW the clients upstream bw
0×07 Unknown anyone know this one?
0×08 Audio Data packet containing audio
0×09 Video Data packet containing video data
0x0A-0×11 Unknown anyone know?
0×12 Notify an invoke which does not expect a reply
0×13 Shared Object has subtypes
0×14 Invoke like remoting call, used for stream actions too.
Shared Object data type
0×01 Connect
0×02 Disconnect
0×03 Set Attribute
0×04 Update Data
0×05 Update Attribute
0×06 Send Message
0×07 Status
0×08 Clear Data
0×09 Delete Data
0x0A Delete Attribute
0x0B
Initial Data
RTMP packet structure
The RTMP packet contains a fixed-length packet header and a packet body with a maximum length of 128 bytes. The packet header can be any of the following 4 lengths: 12, 8, 4, or 1 byte(s).
The first two bits of the first byte are very important, it determines the length of the header. It can be calculated with the mask 0xC0. The following table lists the possible header length: Bits Header Length
00 12 bytes
01 8 bytes
10 4 bytes
11 1 byte
In fact, the RTMP packet structure uses the AMF format.
The following is a process of sending a stream from the client to the server:
Client→Server: Send a request to create a stream.
Server→Client: Returns an index number representing the stream.
Client→Server: Start sending.
Client→Server: Send video and audio data packets (these packets are on the same channel and are uniquely identified by the stream index number).

 

 

 

How far(long) the transmitter cover? The transmission range depends on many factors. The true distance is based on the antenna installing height , antenna gain, using environment like building and other obstructions , sensitivity of the receiver, antenna of the receiver . Installing antenna more high and using in the countryside , the distance will much more far. EXAMPLE 5W FM Transmitter use in the city and hometown: I have a USA customer use 5W fm transmitter with GP antenna in his hometown ,and he test it with a car, it cover 10km(6.21mile). I test the 5W fm transmitter with GP antenna in my hometown ,it cover about 2km(1.24mile). I test the 5W fm transmitter with GP antenna in Guangzhou city ,it cover about only 300meter(984ft). Below are the approximate range of different power FM Transmitters. ( The range is diameter ) 0.1W ~ 5W FM Transmitter ：100M ~1KM 5W ~15W FM Ttransmitter : 1KM ~ 3KM 15W ~ 80W FM Transmitter : 3KM ~10KM 80W ~500W FM Transmitter : 10KM ~30KM 500W ~1000W FM Transmitter : 30KM ~ 50KM 1KW ~ 2KW FM Transmitter : 50KM ~100KM 2KW ~5KW FM Transmitter : 100KM ~150KM 5KW ~10KW FM Transmitter : 150KM ~200KM How to contact us for the transmitter? Call me +8618078869184 OR Email me [email protected] 1.How far you want to cover in diameter ? 2.How tall of you tower ? 3.Where are you from ? And we will give you more professional advice. About Us FMUSER.ORG is a system integration company focusing on RF wireless transmission / studio video audio equipment / streaming and data processing .We are providing everything from advice and consultancy through rack integration to installation, commissioning and training.   We offer FM Transmitter, Analog TV Transmitter, Digital TV transmitter, VHF UHF Transmitter, Antennas, Coaxial Cable Connectors, STL, On Air Processing, Broadcast Products for the Studio, RF Signal Monitoring, RDS Encoders, Audio Processors and Remote Site Control Units, IPTV Products, Video / Audio Encoder / Decoder, designed to meet the needs of both large international broadcast networks and small private stations alike.   Our solution has FM Radio Station / Analog TV Station / Digital TV Station / Audio Video Studio Equipment / Studio Transmitter Link / Transmitter Telemetry System / Hotel TV System / IPTV Live Broadcasting / Streaming Live Broadcast / Video Conference / CATV Broadcasting system.   We are using advanced technology products for all the systems, because we know the high reliability and high performance are so important for the system and solution . At the same time we also have to make sure our products system with a very reasonable price.   We have customers of public and commercial broadcasters, telecom operators and regulation authorities , and we also offer solution and products to many hundreds of smaller, local and community broadcasters .   FMUSER.ORG has been exporting more than 15 years and have clients all over the world. With 13 years experience in this field ,we have a professional team to solve customer's all kinds of problems. We dedicated in supplying the extremely reasonable pricing of professional products & services. Contact email : [email protected] Our Factory We have modernization of the factory . You are welcome to visit our factory when you come to China. At present , there are already 1095 customers around the world visited our Guangzhou Tianhe office . If you come to China , you are welcome to visit us . At Fair This is our participation in 2012 Global Sources Hong Kong Electronics Fair . Customers from all over the world finally have a chance to get together. Where is Fmuser ? You can search this numbers " 23.127460034623816,113.33224654197693 " in google map , then you can find our fmuser office . FMUSER Guangzhou office is in Tianhe District which is the center of the Canton . Very near to the Canton Fair , guangzhou railway station, xiaobei road and dashatou , only need 10 minutes if take TAXI . Welcome friends around the world to visit and negotiate . Contact: Sky Blue Cellphone: +8618078869184 WhatsApp: +8618078869184 Wechat: +8618078869184 E-mail: [email protected] QQ: 727926717 Skype: sky198710021 Address: No.305 Room HuiLan Building No.273 Huanpu Road Guangzhou China Zip:510620 English: We accept all payments , such as PayPal, Credit Card, Western Union, Alipay, Money Bookers, T/T, LC, DP, DA, OA, Payoneer, If you have any question , please contact me [email protected] or WhatsApp +8618078869184 PayPal.  www.paypal.com We recommend you use Paypal to buy our items ,The Paypal is a secure way to buy on internet . Every of our item list page bottom on top have a paypal logo to pay. Credit Card.If you do not have paypal,but you have credit card,you also can click the Yellow PayPal button to pay with your credit card. --------------------------------------------------------------------- But if you have not a credit card and not have a paypal account or difficult to got a paypal accout ,You can use the following: Western Union.  www.westernunion.com   Pay by Western Union to me : First name/Given name: Yingfeng Last name/Surname/ Family name: Zhang Full name: Yingfeng Zhang Country: China City: Guangzhou  --------------------------------------------------------------------- T/T .  Pay by T/T (wire transfer/ Telegraphic Transfer/ Bank Transfer)  First BANK INFORMATION (COMPANY ACCOUNT): SWIFT BIC: BKCHHKHHXXX Bank name: BANK OF CHINA (HONG KONG) LIMITED, HONG KONG Bank Address: BANK OF CHINA TOWER, 1 GARDEN ROAD, CENTRAL, HONG KONG BANK CODE: 012 Account Name : FMUSER INTERNATIONAL GROUP LIMITED Account NO. : 012-676-2-007855-0 --------------------------------------------------------------------- Second BANK INFORMATION (COMPANY ACCOUNT): Beneficiary: Fmuser International Group Inc Account Number: 44050158090900000337 Beneficiary's Bank: China Construction Bank Guangdong Branch SWIFT Code: PCBCCNBJGDX Address: NO.553 Tianhe Road, Guangzhou, Guangdong,Tianhe District, China **Note: When you transfer money to our bank account, please DO NOT write anything in the remark area, otherwise we won't be able to receive the payment due to government policy on international trade business. * It will be sent in 1-2 working days when payment clear. * We will send it to your paypal address. If you want to change address, please send your correct address and phone number to my email [email protected] * If the packages is below 2kg,we will be shipped via post airmail, it will take about 15-25days to your hand. If the package is more than 2kg,we will ship via EMS , DHL , UPS, Fedex fast express delivery,it will take about 7~15days to your hand. If the package more than 100kg , we will send via DHL or air freight. It will take about 3~7days to your hand. All the packages are form China guangzhou. * Package will be sent as a "gift" and declear as less as possible,buyer don't need to pay for "TAX". * After ship, we will send you an E-mail and give you the tracking number. For Warranty . Contact US--->>Return the item to us--->>Receive and send another replace . Name: Liu xiaoxia Address: 305Fang HuiLanGe HuangPuDaDaoXi 273Hao TianHeQu Guangzhou China. ZIP:510620 Phone: +8618078869184 Please return to this address and write your paypal address,name,problem on note:

Our other product:

Professional lightning protection system for Tower	Professional FM Radio Station Equipment Package	FMUSER FU-1000C 1000W FM Transmitter With USB Audio Input Interface
FMUSER 200W FM Radio Broadcasting Package	Hotel IPTV Solution	FMUSER FSN-1000T V5.0 1KW FM Radio Broadcast Transmitter