Now? H264 has become the standard specification of video industry. The number of x264 used in enterprises is relatively large, open source, and resource consumption is relatively small.
First, introduce three common open source H264 encoders: JM, x264, t264
JM H264 has all the features of 264, but the program structure is long and the coding complexity is high, so commercial application is not recommended.
X264 has abandoned the new features of 264 which has little contribution to coding performance, but has high computational complexity, and recommended commercial applications.
T264 code is similar to x264, but the decoder can only solve t264 code, which is a bit pit.
Before using H264 encoder x264, we test its performance to determine if it needs to be optimized again.
The process of testing is as follows:
1. Download 264 source code to the x264 official website
Official site: http://www.videolan.org/developers/x264.html
Git address: git://git.videolan.org/x264.git (note. The original source code of x264 is compiled under Linux. If you want Windows version, please see the following)
Windows version x264 address: http://doom10.org/index.php?topic=3.0 (Note: Transplanted by a third party. Is it up to date by self inference)
2. According to the actual business needs, formulate corresponding test standards
Because x264 is made according to the standard of h264. Therefore, H264 standard and former standard are applicable.
In practice, there will be different requirements. For example, the frame rate requirements for monitoring are relatively low, and for example, network transmission requires higher bit rate, for example, CPU MEM is required for mobile platform.
The following are used in live video:
Resolution: 160 × 120 320 × 240 640 × four hundred and eighty
Frame rate: 101520530
Code rate: 128160256
Coding delay: < 200ms
Code rate accuracy: < 15%
Compatibility: Standard H264 decoder can be decoded
Operating system: WinXP win7-x86 win7-x64
CPU: AMD Athlon II x2240 (high configuration) AMD sp145 (low configuration)
MEM ：2GB
3. Create a new test project and call the x264 Library
New VC project. Read yuv sequence file (file source will be described below), code, output to H264 file
4. Find the structure of YUV sequence on the Internet. Learn what formats are there
YUV structure introduction English version: http://www.fourcc.org/yuv.php
YUV structure introduction Chinese translation version: http://blog.csdn.net/SearchSun/article/details/2443867
In these YUV formats. YUV420 is more common. The layout of a frame YUV420 in the file is as follows, for example, CIF image (352 * 288):
Y information 352 * 288 B
U information 352 * 288 / 4B
V Information 352 * 288 / 4B
The size of a frame data is calculated = 352 * 288 + 352 * 288/4 + 352 * 288 / 4. Common writing 352 * 288 * 3 / 2
5. Search YUV sequence files online or make it by yourself
YUV test sequence download address: http://dpinglee.blog.163.com/blog/static/144097753201242254639795/ (this is the most comprehensive one available online at present)
The most canonical ones found from the above link are: http://sp.cs.tut.fi/mobile3dtv/stereo-video/
YUV format has a variety of, plus different parameter configuration, there will be a very many. Before downloading, you must see if it is the format you need. Because these test sequence files are usually larger
5.1. YUV sequence file making method
1) Avi is the best way to download video files in random format from the Internet
2) Installation FFSetup.exe (Chinese name format factory), convert the downloaded video file to avi format, and select H264 as the video code in the conversion parameters
3) Use avitoyuv.exe Convert converted AVI file to YUV file
4) Use YUVViewer.exe Verify the correctness of the transformation
6. Search the YUV sequence file player online. Verify the validity of YUV files
After you find YUV sequence files, use YUVViewer.exe Verify the correctness of the file
Yuviewer download address: http://ishare.iask.sina.com.cn/f/21603725.html
7. Perform the test project. Read YUV file, output H264 file
8. During the coding process, observe the indicators of h264 encoder and record them
Under different parameter configurations. Observe whether the following indicators are normal:
Coding delay: can output log view in test program
Code rate accuracy: the same as above
Compatibility: it can play normally with h264visa
CPU: high configuration within 2% and low configuration within 4%
MEM ：？ Within MB
9. Search H264 file player online to verify the correctness of coding
Verify the correctness of h264 file after coding by using h264visa
H264visa download address: http://ishare.iask.sina.com.cn/f/25002676.html (this requires Sina points)
If you are interested in x264 coding and decoding, you intend to study it in depth and start from here: http://www.rosoo.net/a/200908/7424.html This is the article of Rosa laboratory. A professional research site for audio and video, streaming media solutions.
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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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