What kind of source data does streaming media need? Almost any data, avi, RM, etc. files you have, even tape, or analog signals just from the acquisition device.
Active data, how to deal with it? First, if it is an analog signal, it is necessary to convert it into digital signal (live broadcast usually converts the analog signal just collected into digital signal), and then code according to the required code rate. The codec is needed for coding. What encoder is needed depends on the format of the file you want. There are three popular streaming media formats: quick time, Windows Media Technology (WMT), real system. Three formats are different companies: quick time is apple, and I don't know what the suffix is, because it is not often contacted; WMT is Microsoft, and ASF is the suffix; Real system is a real company. This format is most contacted by all. RM and RMVB files are very common. The coding is in a certain format. It is also necessary to see if there is server software supporting this format on the server. The player of the client should support the playback of this format, so that the streaming media can flow.
After the stream media files are generated by encoding, the streaming media server is required to transmit the media, mainly encapsulating the data package with specific streaming media protocol.
Before listing streaming protocols, look at two common transport protocols: TCP and UDP. To ask the streaming media data transmission and file download data transmission is different, is the different transmission protocol. The file download uses TCP protocol, TCP is a connected protocol. Before data transmission, the connection will be established. The connection will not be disconnected until the data transmission is completed. TCP supports confirmation retransmission, which can ensure the integrity of data. Therefore, as long as the download is completed, the files downloaded to the client are the same as those on the server, and some of the data will not be lost. Streaming media can not use TCP protocol, because the retransmission mechanism of TCP can not meet the time requirements of streaming media. For streaming media, packet loss will not be more serious than video interruption. Streaming media uses the UDP protocol. UDP is a connectionless protocol and does not need to confirm retransmission. After the UDP package is sent, it does not need to wait for the confirmation of the receiver. Although some data may be lost, it can guarantee real-time performance. In one case, the streaming media transmitted by UDP has to be converted to TCP transmission. What is the case? If you are an intranet user or after a corporate firewall, you can only receive data through TCP because the UDP package will be rejected by the firewall. Only this TCP connection does not retransmission even if it loses packets.
Streaming data needs to be encapsulated in streaming protocol. According to the format, the protocol used is different. There are four famous streaming protocols: RTP, RTSP, RDP and MMS. RTP extends the domain of sequence number and time stamp based on UDP. RTSP is an extension of RTP protocol. When transmitting data, RTP protocol is used, and TCP connection is used when controlling data is transmitted. RDP is the extension of RTSP, which only strengthens the control protocol. Quick time is to transfer media files using rtp/rtsp, while real system uses rtsp/rdp to transfer media files. MMS is a special protocol for Microsoft. At first, mmsu is used to establish a connection (the combination of MMS and UDP). If the connection is not successful, mmst (MMS and TCP combination) is used to establish the connection. WMT uses MMS to transfer media files.
If there is no streaming server, can we achieve the effect of downloading and playing? The answer is yes, just use the HTTP connection on TCP. First, some data is downloaded to the buffer, and then the new data is downloaded to the buffer, and the existing data in the buffer is played. This stream is called HTTP stream, also called fake stream. This is back to the question we started to talk about, and the podcast clips we see and the shows on PPLive are actually HTTP streaming, not real streaming.
What is the difference between HTTP streaming and real media streaming? The difference is in many aspects:
(1) first, the HTTP stream only needs web server, and the real media stream needs a dedicated media server
(2) Then, the protocol needed by HTTP streaming is IP, TCP, HTTP from bottom to top, while real media stream needs IP, UDP and dedicated streaming protocol
(3) Also, because HTTP streaming uses TCP connections, if packet loss is lost, it will retransmit, and real media streams will not retransmit. It is also the reason that if we leave the influence of interrupt and so on, the video quality we see through HTTP stream is the same as that of the server, and through the real media stream, the quality will vary with the network condition
(4) From the start delay, the start delay of HTTP stream depends on the network connection status and the media code rate; The real media stream startup delay will not be more than a few seconds
(5) When you look at http streaming, you can only drag within the downloaded video range, while the real streaming media can be dragged in the full range
(6) Finally, HTTP streaming will store the downloaded media data into the hard disk, and the real media stream will not. The data it plays will be discarded immediately, which just protects the copyright of the media works.
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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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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.
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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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