One, Mjpg-streamer open source library Due to the development of a real-time video push system, it may involve the implementation of a streaming media server, but it can be realized quickly and easily through the "MJPG-streamer" open source tool."MJPG-streamer" is a mature, lightweight video server software that can be used to capture camera images and publish them on real-time video servers.MJPG-streamer adopts the modularized design idea, including input module and output module. The input module defines the input source, such as camera, file, etc. MJPG-streamer then outputs the video through the output module, such as http output and other network output. Local output of the file . This article uses a binocular camera supporting UVC protocol as the input source of image data. The http protocol is used to push the video stream. Therefore, the components involved are the output_http output component and the input_uvc input component.With MJPG-streamer, it is easy to push the binocular camera video on the pcDuino to the http protocol. Second, to achieve and test The use of MJPG-streamer library to develop a real-time image transmission system is convenient and efficient. Its installation command is as follows: After the installation is complete, you can use the
When visiting the blog of Wang Boyuan yesterday, the polar guests discovered that the website jumped to the website www.cjb.net from time to time. It almost jumped to open wangbaiyuan.cn, and other websites did not encounter such strange events. .This situation first appeared only on 360 speed browsers, even if I subconsciously clear the cache, cookies, still did not work.In the end I changed other browsers and found that this was only happening on 360-speed browsers, and it happened occasionally; I had to give up trying to solve the unsuccessful method of uninstalling browser plug-ins.Perhaps 360 speed browser poisoning it, Oh, 360 also known as safe! This evening, I noticed that the annoying automatic jump to cjb.net reappeared, and this time no matter what the browser is, including Edge, IE.This led me to believe that the website was "invaded" and that the "intrusion" method was very obvious, with the js containing the jump code.Because when I examine the element "disable js" the jump will not occur.Then I took a look at Wang Baiyuan’s blog on an article page that references 30 js. As long as one of the js files is embedded with a malicious jump code, there will be
(1) Run as command: DOS>scanHost start_ip end_ip (2) Output: Active host IP address. Implementation principle: (1) An ICMP_ECHO request message is sent through an IP address, and an ICMP_response message is received, indicating that the IP host is active. (2) Using raw sockets (3) In order to improve the detection time, multi-thread technology is used.
C + + scan specified host open port, OS provides a connect () system call, used to establish a connection with a remote host port, if the port is in the frame listening state of the remote host, connect () connection is successful; otherwise, the port is closed.
In network communication, the application program of the source host knows the IP address and port number of the destination host, but does not know the hardware address of the destination host, and the data packet is first received by the network card and then processed by the upper layer protocol, if the received data If the hardware address of the packet does not match the local machine, it will be discarded.Therefore, the destination host hardware address must be obtained before communication.The ARP protocol plays this role.The source host sends an ARP request and asks “the hardware address of the host whose IP address is 192.168.0.1” and broadcasts this request to the local network segment (The hardware address of the Ethernet frame header is FF:FF:FF:FF:FF :FF indicates broadcast. When the destination host receives the broadcast ARP request and finds that the IP address matches the local machine, it sends an ARP reply packet to the source host and fills in its own hardware address in the reply packet. Each host maintains an ARP cache table, which can be viewed using the arp -a command.The entries in the cache table have an expiration time (generally 20 minutes). If no entry is
Disk and memory Extreme guests are deeply troubled by insufficient memory when using android Studio to develop Android. For this reason, a 4G memory module is purchased. The speed of the computer is therefore improved. The memory occupancy rate is generally 30%. The android studio and virtual machine are enabled. There is also a lot of memory.In order to make the remaining large amount of memory as much as needed, as much memory as possible makes the computer's performance improved.Extreme guests decide to adjust their virtual memory size while opening up a portion of memory when the hard disk is used.Of course, these methods are only suitable for the computer friends who are willing to use the memory. Those who have learned or know a little about computers know that memory and hard disks are the key parts of computers. Of course, now that smartphones are popular, even uncles and elder sisters in primary school culture know the memory, but they always have memory cards (memory cards) and memory (running memory )stupidly can not tell.The hard disk on your computer corresponds to the memory card of your phone.How much does the memory of a person who knows a computer computer
Windows 10 was finally officially released.Genuine Windows 7/8.1 users can wait for push and free upgrades, and contributors who participate in the Windows Insider beta program can easily “transform”. What about other people?Must you buy it? If I just want to taste fresh, how to activate Windows 10?Although Microsoft has been upgrading its countermeasures from generation to generation, it is never a problem to activate Dao Gao.Just now, foreign experts released the Windows 10 activation method. Command Line After Windows 10 is installed, first open the CMD command line window as an administrator. Professional Edition users please enter: slmgr /ipk W269N-WFGWX-YVC9B-4J6C9-T83GX slmgr /skms kms.xspace.in slmgr /ato Enterprise users please enter: slmgr /ipk NPPR9-FWDCX-D2C8J-H872K-2YT43 slmgr /skms kms.xspace.in slmgr /ato Windows10 key There is also a group of other keys that you can try on your own, as follows: Professional Edition: VK7JG-NPHTM-C97JM-9MPGT-3V66T Enterprise Edition: XGVPP-NMH47-7TTHJ-W3FW7-8HV2C Education Edition: YNMGQ-8RYV3-4PGQ3-C8XTP -7CFBY Professional Edition N:2B87N-8KFHP-DKV6R-Y2C8J-PKCKT Enterprise Edition N:WGGHN-J84D6-QYCPR-T7PJ7-X766F Education Edition N:84NGF-MHBT6-FXBX8-QWJK7-DRR8H Enterprise Edition S:FWN7H-PF93Q-4GGP8 -M8RF3-MDWWW Single language version: BT79Q-G7N6G-PGBYW-4YWX6-6F4BT Note: This article is for technical discussion purposes only, it does not encourage any piracy behavior, and is not responsible for any consequences of using the above keys. Please support genuine!
This article mainly introduces the overview of the network protocol: physical layer, link layer, network layer, transport layer, and application layer. This article uses the mailman and post office in life to help understand complex network protocols. It is easy to understand and humorous. Is a rare good article, need friends can refer to The transmission of signals always meets a certain protocol.For example, the Wolf is placed on the Great Wall because people have pre-set the physical signal of Wolf Smoke to represent the abstract signal of “enemies invasion”.Such a "wolf smoke = enemy invasion" is a simple agreement.The protocol can be more complex, such as Morse Code, using a combination of short and long signals to represent different English alphabets.For example, SOS (***---***, * for short signals, - for long signals).This "***= S, ---=O" is the agreement of the Morse code.However, one more level, people will know SOS is for help information, because we have "SOS = help" agreement exists in the mind.So "***---***=SOS=help" is a layered communication system consisting of two protocols. Telegraph using Morse Code Communication between computers also follows different levels of protocols to achieve computer communications. Physical layer The so-called physical layer refers to
In particular, since the popularity of the WeChat public platform, network APIs have become more and more popular.Internet enthusiasts who do not have any technology and resources can build their own public numbers through free and open APIs on the Internet, and their functions can also be quite powerful, such as checking the weather, checking stocks, checking train tickets, chatting and telling jokes, and checking IP addresses. Mobile phone ownership... Of course, the use of network APIs is not limited to WeChat development. It can also be applied to mobile software development such as Android. A lot of software has weather inquiries, but not all weather software developers have weather satellites and ground stations in their “home”; many softwares provide targeted services based on the location of users: for example, you want to use When you're hungry, you can order a fast food. It can find restaurants near you based on your location. You use a group to buy movie tickets for nearby movie theaters. Now the question is: Do you feel hungry? The map system?Nowadays, the well-known map applications in China include the Gaode map and Baidu map. Both provide APIs for positioning, navigation, and related developer SDKs and
About webservice Due to the JSON and JMI web services written in JAVA and PHP, this time it is natural to think about using webservice to manage the to-do list.What JAVA and PHP JSON, JMI, and webservice have in common is that they can provide server resource sharing. Web Service is cross-platform and can be invoked in different devices and different programming languages, so its application scope should be wider than RMI. Webservice implementation management to-do list based on MySQl database query Run the screenshot Add User: Add Items: Inquiry Items: Delete Items: Clear Items: How server-side code is implemented Here's how to implement the server-side code for the above functions:. My server has four main categories: database connection and method interface TodoListInterDbFace, database connection and method implementation class TodolistDb and method implementation class and webservice interface TodoListServerInterface, Webservice implementation class TodoListServer. The following is a schematic diagram: How the client code is implemented Wsimport -keep http://127.0.0.1:8002/webservice/TodoList?wsdl After parsing the WSDL: The main method for creating the TodoListClient class is: For the realization of the menu please refer to my blog article: http://wangbaiyuan.cn/java-rmi-6-making-the-command-line-navigation-menu.html