Streaming overview:
The so-called streaming media refers to the media format played on the Internet by means of streaming transmission.
Streaming media is also called streaming media. It refers to businesses that use a video delivery server to send out programs as data packets and deliver them to the network.
After the user decompresses the data through the decompression device, the program will be displayed as before transmission.
Streaming media transmits audio, video and multimedia files in the form of streaming over the network.
Streaming media file format is a media format that supports streaming and playback.
The streaming method is to divide multimedia files such as video and audio into compressed packages through a special compression method.
Continuous and real-time transmission from the server to the user's computer. In systems that use streaming transmission, users don’t have to wait for the entire file like non-streaming playback.
The content can be seen after all downloads are completed, but only a few seconds or tens of seconds of startup delay can be used on the user’s computer
The corresponding player plays the compressed video or audio and other streaming media files, and the remaining part will continue to be downloaded until the playback is complete.
1. RTP: (Real-time Transport Protocol)
It is a transport layer protocol for multimedia data streaming on the Internet. The RTP protocol and the RTP control protocol RTCP are used together,
And it is built on the UDP protocol.
RTP is not like http and ftp which can download the entire movie file completely. It sends data on the network at a fixed data rate. The client also watches the movie file at this speed.
After the movie screen has been played, it cannot be played repeatedly, unless the data is requested from the server again.
2. RTCP: Real-time Transport Control Protocol or RTP Control Protocol or RTCP for short)
The real-time transmission control protocol is a sister protocol of the real-time transmission protocol (RTP).
Note: --: RTP protocol and RTP control protocol (RTCP) are used together, and it is based on UDP protocol (usually used for video conferencing)
3. RTSP: (Real Time Streaming Protocol)
Real-time streaming media session protocol, SDP (session description protocol), RTP (real-time transport protocol).
It is a multimedia streaming protocol used to control sound or video. RTSP provides an extensible framework that makes it possible to control and on-demand real-time data, such as audio and video.
The media data uses rtp and rtcp protocols. Generally use udp as the transport layer. Suitable for IPTV scenes. Data sources include live data and data stored in clips. The purpose of this protocol is to control multiple data transmission connections, to provide a way to select transmission channels, such as UDP, multicast UDP and TCP, and to provide methods for selecting a transmission mechanism based on RTP. The network communication protocol used during transmission is not within the scope of its definition. The server can choose to use TCP or UDP to transmit the streaming content, which is more tolerant of network delays.
--->: The biggest difference between RTSP and RTP is that: RTSP is a two-way real-time data transmission protocol, which allows the client to send requests to the server, such as playback, fast forward, and reverse operations. when
Of course, RTSP can transmit data based on RTP, and can also choose TCP, UDP, multicast UDP and other channels to send data, which has good scalability. It is similar to the http protocol
Network application layer protocol.
4. WebRTC:
The web side implements the streaming media protocol. When Google first launched WebRTC, the giants were either sitting on the sidelines or resisting it. Use RTP protocol transmission.
5. RTMP (Real Time Messaging Protocol)
A set of live video protocols developed by Macromedia is now owned by Adobe. Like HLS, it can be applied to live video, and it will not be lost based on TCP.
// The difference is that RTMP cannot be played in the iOS browser based on flash, but the real-time performance is better than HLS.
The real-time messaging protocol is an open protocol developed by Adobe Systems for audio, video, and data transmission between Flash players and servers.
// In the iOS code, RTMP is generally used to push the stream. You can use the third-party library librtmp-iOS to push the stream. librtmp encapsulates some core APIs for users to call
The RTMP protocol also requires the client and server to establish an RTMP Connection through a "handshake", and then transmit control information on the Connection. The RTMP protocol will format the data during transmission. In the actual transmission, in order to better achieve multiplexing, sub-packaging, and fairness of information, the sender will divide the Message into Chunks with Message ID, each Chunk May be a single message,
It may also be part of the Message. The receiving end will restore the chunk to a complete Message according to the length of the data contained in the Chunk, the length of the message id and the length of the message, so as to realize the sending and receiving of information.
6. HLS: HTTP Live Streaming (HLS)
It is an HTTP-based streaming media transmission protocol implemented by Apple Inc., which can realize live and on-demand streaming media. It is mainly used in the iOS system and provides audio and video live and on-demand solutions for iOS devices (such as iPhone and iPad). HLS on-demand is basically a common segmented HTTP on-demand. The difference is that its segments are very small. Compared with common streaming media live broadcast protocols, such as RTMP, RTSP, MMS, etc., the biggest difference in HLS live broadcast is that what the live broadcast client obtains is not a complete data stream.
The HLS protocol stores the live data stream as continuous, short-duration media files (MPEG-TS format) on the server side, and the client continuously downloads and plays these small files, because the server side will always update the latest live broadcast The data generates new small files, so as long as the client continuously plays the files obtained from the server in sequence, the live broadcast is realized. It can be seen that, basically, it can be considered that HLS is a technical way of >>on-demand to realize live broadcast <<. Since the data is transmitted through the HTTP protocol, there is no need to consider firewalls or proxies at all.
In addition, the duration of the segmented file is very short, and the client can quickly select and switch the bit rate to adapt to the playback under different bandwidth conditions. However, this technical characteristic of HLS determines its
The delay will always be higher than the ordinary live streaming protocol.
// Both iOS and Android naturally support this protocol, the configuration is simple, just use the video tag directly
***VLS: It is a kind of streaming server, which is specially used to solve various problems of streaming. It also has some characteristics of VLC. As a server, videolan can output http, rtp, rtsp streams.
In principle, RTSP, RTMP, and HTTP can all be used for live broadcast and on-demand broadcasting, but generally RTSP and RTMP are used for live broadcasting, and HTTP is used for on-demand broadcasting. What we chose is the RTMP protocol.
Various protocol delays and their reasons
rtmp and httpflv: The data of these two protocols are roughly the same, so the reasons for the delay are the same. It stands to reason that tcp streaming live broadcasts should have extremely low latency. Why do rtmp and httpflv still have latency? The reason is that on h264, rtmp and httpflv are flv tags that are transmitted. The data of video tag is usually h264 data. H264 decoding has an IBP. I is a key frame, which is a complete image. You must have an I before decoding. The latter BP, BP frames can be as few as you want, but I frames cannot be less, so I frames must be transmitted second in flv tag transmission (the first is h264spspps), but I frames are not often present in h264 streams , There is an I frame after a period of time. This period of time is commonly known as GOP. When encoding, the GOP is set very short. When the client connects, the server will find the nearest I frame in the stream at the fastest speed, and send it from the I frame. Live data, but when the GOP is very long, the I frame interval is very long, or wait for the next I frame to start sending data to the new connection, or find the nearest I frame in the buffer to start sending, here is the rtmp and hls protocol delay The key point is that on major CDN platforms, it is called "rtmp second opening technology". The principle is to decode the push data twice and set a small gop. In general, gop is set to 1s. Regardless of the delay of the network transmission link, the maximum data delay is 1s. Fortunately, the I frame is 0 delay!
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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
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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
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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.
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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
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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
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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.
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* 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.
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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: |
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