Which archiver to install. How to compress a video file without sacrificing quality What type of files are compressed better

Sysadmin(he's on English language sysadmin, system administrator) - an abbreviated name of a profession, the full name of which in Russian sounds like System Administrator. This profession has recently become very popular for most young and not so young people; they teach it, work in it, and get good money for it. This is due to the rapid development of various computer technology and their penetration into all spheres of human life. The word system administrator is often used in colloquial speech, in vacancies and resumes when searching for a job, in a word - everywhere. Below we will talk about what the profession is system administrator.

In modern realities, a system administrator can be called virtually any person who is involved in servicing and maintaining the operation of a specific computer network, including all its hardware and/or software components, which may include:

• Personal computers, both workstations and servers;
• Network equipment such as switches, routers, firewalls and more;
• Web servers, mail servers, database servers, and others.

Also, in certain cases, the system administrator may be responsible for ensuring proper information security.

Depending on his specialization, a system administrator can engage in the following activities:

• The administrator of workstations and servers most often repairs both hardware (failed motherboards, burnt-out power supplies), and software (Windows won’t load, commas won’t print in Word”e...).
• Administrator corporate network based on an Active Directory domain. A very popular activity, given the prevalence of Windows operating systems, as well as the need to somehow centrally control them. Such a specialist must be able to create, distribute into groups, edit users, give them the appropriate rights in the AD domain, and also be able to manage group policies for users, their computers and the groups they all belong to.
• Administration of networks and network equipment. His responsibilities include knowledge of network topology, the ability to work with both non-configurable and customizable network equipment, local planning computer network, as well as the ability to combine several remote workplaces into one network by setting up NATs and VPNs. You should also not forget to control access within this network and outside it - setting up a proxy.
• A web server administrator, who must at least be able to install, configure and maintain one of the following web servers - Apache, IIS, Nginx, and monitor hosting (which can be located both within the organization’s network and outside it). In addition, a good administrator should be able to configure normal resource distribution under high loads, clustering and many other specific things.
• Administration mail server is also a common task for a system administrator; his tasks include working with such popular solutions as Exim, Microsoft Exchange, Postfix, Sendmail, or corporate email solutions from Google or, for example, Yandex. In addition to the obvious control over accounts (creation, deletion, configuration), it is also necessary to be able to set up an antispam system, etc.
• Site administrator. These responsibilities may include simply filling the site with some content, but since we are talking about a system administrator, then in theory he should be able to set up hosting (including a web server, as mentioned above), install and configure the desired site, for example any content management system (CMS).
• Very rarely, the responsibilities of a system administrator may include the task of creating or maintaining a video surveillance system. The tasks include installing and configuring cameras, responding to various events, saving and playing back recordings. He has a weak attitude towards system administration, and often falls into his responsibilities in conjunction with some other responsibilities.

Left out of the system administrator's activities described above are such possible things as database administration ( Microsoft SQL, MySQL and its multiple branches, Oracle, etc.), 1C administration (not to be confused with “1C programmer”), PBX and much more.

In about times when volumes hard drives had ridiculous meanings, even the texts of the books when expanded seemed blasphemously huge. In fact, imagine a 40 MB hard drive, which also has Windows 3.1 (10 MB) and WinWord 6 (20 MB) installed. There was nothing surprising in the fact that this was the golden time of archivers, when dozens of their users knew not only by names and capabilities, but even by versions, not to mention dozens of keys, where “ maximum compression».

It’s becoming sad now, and not because disk volumes have exceeded terabytes, but because users are still trying to compress many of the current data using archivers, without thinking at all about the rationality and purpose of this process. And very often it turns out very awkwardly.

Archivers, like all programs based on mathematical algorithms, cannot go beyond certain laws, including entropy, and only remove repetitive information from files. This is why you won’t be able to compress an already compressed file – it may even become larger in size. The only time re-compression can work is when a newer archiver is used, compressing an archive packed with an older version of the program. But this is rather an exception. It would be interesting to know what not to waste time on, because many of the files are hundreds of megabytes in size, and archiving and unpacking is a seriously long process even for modern computers.

Let's start with the popular one: there is no point in packing videos and music . With regard to video, you need to know that it is not only initially packed with powerful archiver codecs, but some data that is not essential for viewing has even been removed from it. By the way, they are encoded according to a similar scheme JPEG files, and therefore they cannot be compressed either. Music files, although compressed, may still “make room” a little on the disk, but it makes no sense to fence the garden for the sake of 2-5%. In relation to pictures, you need to act according to the situation, but general principle This is - the more colors they have, the less chance there will be of compression. In general, pictures and photographs are a special case, since you can routinely sharply reduce their characteristics without losing quality when viewed on the target output device. Or do you really think you can distinguish between 4 billion colors? Rather, 256 adapted colors from the palette will be enough, and if you reduce the photo size and resolution, you can easily turn a 10-megabyte image into a 100-kilobyte one.

Programs and libraries are compressed rather weakly, given that in many cases they are initially compressed with dynamic codecs. Compression plays many roles here: protecting information, compression itself, obfuscating hackers from analysis, etc. And, besides, programs are usually distributed in compressed distributions, so there is no point in packaging them separately. As a result, disk images with programs and games. Save time – yours and others’...

There are dozens and hundreds of archivers freely available on the Internet. Each developer praises his own brainchild, and it is not easy for the average user to understand the question of which archiver compresses better.

Comparing archivers in this way may be considered biased, but the conditions of the procedure are made equal for the presented utilities. The equipment used was a home PC with average technical characteristics. The functions of the “guinea pig” were performed by a Microsoft Word document that any user encounters. Such files most often need compression, because they are in memory hard drive a lot accumulates, and there is no point in storing them this way. Compressed files are much easier to transfer; they are instantly copied to a memory card and quickly uploaded to data exchange sites.

Compression comparison

To conduct the software power analysis, an RTF extension document of approximately 4 megabytes in size was used. Then the file was duplicated and compressed using the presented programs. The duration of the procedure was not included in the data table; some distinctive features of the applications were also missed, which will be discussed later.

As the results of an experiment by computer scientists showed, the KGBArchiver 2 utility will help you compress a file in Winrar as much as possible; it was able to reduce the amount of data by 22 times. When on sections of hard The disk contains about 20 gigabytes of programs and other data that are rarely used, but it would be a shame to send them to the trash, then KGB will help compress it all to just 1 GB. But not everything is as rosy as it seems at first glance; let’s talk about all the features of this and other utilities in order.

KGB Archiver 2

You can’t argue with this, but the significant disadvantages of the utility include its speed. The file used in the experiment (4 MB in size) was compressed for 3 minutes. And if the information takes up 500-1000 MB, then the procedure will take half a day.

Unpacking the archive becomes even more problematic. The program performs this function as much as compression. This means that if a person spent half a day compressing files, then he will have to wait the same period to unpack them. This greatly limits the use of KGBArchiver.

The use of the utility is justified only when compressing small files and in situations where the degree of compression is more important than the time spent. When you need to transfer files to an almost full disk or USB drive, this program is suitable. But it is impossible to determine exactly what the size of the archive will be, and with erroneous assumptions this will be a waste of time.

WinRar

No one is considering alternatives. On the one hand, this is a matter of habit, but on the other hand, compressing a file using Winrar works very well. The application settings system, where there is a configuration of compression methods, is also clear; it is better to set it to “Maximum”.

As the results of the text show, the file size after working with WinRar decreased by 17 times. This is less than the previously mentioned utility, but here the procedure took a couple of seconds. Interestingly, data unpacking is even faster.

Benefits of the utility:

1. Clear interface.
2. Constant update.
3. Working with different formats.
4. Good compression rate.
5. Speed ​​of work.

Among the disadvantages, we can mention that the product is paid.

To summarize, it is better to compress a Winrar archive with this program; it shows impressive results. In configurations, if you set the maximum compression volume, you will be able to split the archive into parts. This allows you to reduce the size rar archive and transfer it to another medium in parts when the whole file does not fit.

WinUha

It’s difficult to call WinUha very popular, but the utility is of interest to some users. What fuels all this is that the developers claim that they have the most powerful archiver and competitors’ products cannot compare with it.

As the compression ratio test shows, the program works at the level of WinRar, but it takes longer to think. The file format plays an important role; WinUha actually works better with some types of data.

Advice! During installation, it is better to choose an English-language interface, because in the Russian version the program likes to produce errors.

From this we can conclude that WinUha is an average quality utility with an interesting method of data archiving. It is inferior to well-known analogues in terms of operating time, but with some formats it works faster than all others. This is not the most important characteristic, but she has the right to life.

Application 7Z

The 7z extension is opened by a program of the same name, which is considered the main competitor of WinRar. In particular, as an argument, supporters cite the file compression rate. It is worth noting that in Ultra mode, 7Z is still inferior to VinRar.

But it has these advantages:

• Unpacking 7z will not take much time;
• Application of AES-256 encryption method;
• Small volume of received archives;

If anyone is looking for an alternative to the usual WinRar, then it’s worth choosing this option. Free license, Russian-language control and adding to browser menus.

WinZip

On the Internet, most archives are presented in this format, although WinZip showed poor results in terms of compression. It's all about speed. After clicking on the archive, you can open it in just a second rtf file on your computer using MSWord. Opening an archive takes no longer than opening a folder.

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One of the most common types system programs are programs designed for archiving, packaging files by compressing the information stored in them.

Information compression is the process of transforming information stored in a file, as a result of which its redundancy is reduced and, accordingly, less memory is required for storage.

Compression of information in files is carried out by eliminating redundancy different ways, for example by simplifying the codes, eliminating constant bits, or representing repeating symbols or a repeating sequence of symbols in terms of a repetition factor and corresponding symbols. Various algorithms for such information compression are used.

Both one and several files can be compressed, which in compressed form are placed in the so-called archive file, or archive.

An archive file is a specially organized file containing one or more files in compressed or uncompressed form and official information about file names, date and time of their creation or modification, sizes, etc.

The purpose of file packaging is usually to ensure more compact placement of information on disk, reducing the time and, accordingly, the cost of transmitting information over communication channels to computer networks. In addition, packaging a group of files into one archive file significantly simplifies their transfer from one computer to another, reduces the time of copying files to disks, allows you to protect information from unauthorized access, and helps protect against infection by computer viruses.

Under compression ratio understand size relationships compressed file and the original, expressed as a percentage.

Compression ratio depends on the compression program used, the compression method, and the type of source file. Graphic image files are best compressed text files, data files whose compression ratio can reach 5 - 40%, files are compressed less executable programs and loading modules - 60 - 90%. Archive files are almost not compressed. Archiving programs differ in the compression methods they use, which consequently affects the compression ratio.

Archiving (packaging) - placing (downloading) source files into an archive file in compressed or uncompressed form.

Unzipping (unpacking) is the process of restoring files from an archive exactly as they were before being loaded into the archive. When unpacking, files are extracted from the archive and placed on disk or in RAM.

Programs that pack and unpack files are called archiver programs.

Large archive files can be placed on several disks (volumes). Such archives are called multi-volume. Tom is component multi-volume archive. By creating an archive from several parts, you can record its parts on several media.

Main types of archiver programs

Currently, several dozen archiver programs are used, which differ in the list of functions and operating parameters, but the best of them have approximately the same characteristics. Of the most popular programs we can distinguish: Zip (and its modification WinZip), WinRAR, Arj (and its varieties), G-Zip, 7-Zip.

Archive programs also allow you to create archives that do not require any programs to extract files from, since the archive files themselves can contain an unpacking program. Such archive files are called self-extracting. A self-extracting archive file is a bootable, executable module that is capable of independently unzipping the files it contains without using an archiver program.

Self-extracting archive got the name SFX archive(SelF-eXtracting). Archives of this type are usually created in EXE file format.

Many archiver programs unpack files by dumping them onto disk, but there are also those that are designed to create a packaged executable module (program). As a result of such packaging, a program file is created with the same name and extension, which, when loaded into RAM, self-extracts and runs immediately. At the same time, it is possible inverse conversion program file in unpacked format. Such archivers include programs Upx, PKLITE, LZEXE.

The EXPAND program, which is part of the operating utilities Windows systems, used to unpack files software products supplied by Microsoft.

Ways to manage the archiver program

The archiver program is controlled in one of the following ways:

• - by using command line, in which a launch command is generated containing the name of the archiver program, the control command and its configuration keys, as well as the names of the archive and source files;
• - using a built-in shell and dialog panels that appear after starting the program and allow control using menus and function keys, which creates more comfortable working conditions for the user;
• - by using context menu Conductor in operating system Windows.

The volume of digital media used is steadily growing. The amount of data that is transferred from one computer to another is no longer calculated in megabytes, as it was a few years ago, but in gigabytes and even terabytes.

It would seem that with such a large amount of information, the problem of lack of free space on the carrier should have completely disappeared. However, even today you can often find yourself in a situation where your beloved Nero refuses to burn a DVD, citing a lack of free space on the laser disc. In this case, you have to resort to archiving files and selecting the optimal format with the maximum compression ratio.

Archiving files is also used when backup data. Backup programs have recently become widespread precisely because the size of hard drives has increased. When a storage medium fails, a huge amount of data is lost, so creating backup copy- this is the same usual precaution as using an antivirus.

Files are also usually archived so that they take up less space on your hard drive. Compression is also necessary when sending files via e-mail, copying information to other computers, etc.

Used to archive files special programs- archivers. These are programs designed to pack files by compressing the information stored in them. Compression is the process of converting the information contained in a file into a form that removes all unnecessary information, resulting in a smaller file size. Such “extra” data in files can be repeating characters, constant bits, etc. Accordingly, compression methods may be different.

The degree of information compression depends on several reasons:

• First, the type of data being compressed matters a lot. Graphic and text files are best compressed. For them, the compression ratio can be from five to forty percent. Files of executable programs, load modules, and multimedia files are compressed worse.
• Secondly, the compression method is of great importance.
• Thirdly, it is also important which archiver is used. When choosing the type of archiver, they are usually guided by the following considerations: so that the compression ratio is as high as possible, and the time spent packing and unpacking files is as little as possible.

Today, the most common are four archivers - WinRar, WinAce, 7Zip and WinZip. As for the latest program, it does not stand up to criticism.

Despite its wide popularity and high-profile advertising campaign, thanks to which the program migrated to hundreds of thousands of computers, WinZip loses to its competitors in all respects. Therefore, we will not consider it in this review.

WinRar 3.50 Beta 1

WinRar can be associated with the following file types: RAR, ZIP, CAB, ARJ, LZH, ACE, 7-Zip, TAR, GZip, UUE, BZ2, JAR, ISO, Z.

The program supports files of almost unlimited size (up to 8,589,934,591 GB). However, to work with files larger than 4 GB you need to work in file system NTFS.

When choosing optimal settings For compression there are several points to consider:

• Although WinRAR supports the ZIP format, in most cases it is recommended to choose RAR. This will provide more high level compression. You can compress files in ZIP if you are not sure that the computer on which the files will be decompressed will have a program installed that can be used to decompress RAR files.
• You need to decide which compression method is best to use. The higher the compression ratio, the more time it will take to archive, so you need to consider the purpose for which the data is being archived. If this is long-term storage, of course, it makes sense to wait and get an archive with the maximum compression level, but if you just need to send several documents by mail, the Normal compression level is also suitable for you.

If you need to achieve maximum file compression, use the Create solid archive option. However, it also has its drawbacks. Firstly, it will take longer to unpack such files than to extract them from a regular archive. Imagine that you have two hundred files in your archive. If it is created in the usual way, you can easily extract one of the files. If you used solid archive, it will matter how the file you need is archived. If it was in the middle of the second hundred, then to unpack it the program will need to unpack 150 files before it gets to it. Creating archives in this way can also entail great losses, because if the archive is damaged, you will lose all the files that were in it. In the case of packaging in the usual way, you will be able to extract, if not all, but most of the files from the damaged archive.

If you need to create large archive, this can take quite a long time. WinRar allows you to determine approximately how long it will take to complete a particular task. The Benchmark and hardware test option is intended for this. Another reason to use this option is to define possible errors, which may occur when archiving a particular configuration on a computer due to a hardware failure.

Among other WinRar settings, one can note the ability to create self-extracting archives indicating the unpacking path. Such files do not require an archiver program on the computer on which they are planned to be unzipped. Such archives are called SFX-archives. Their disadvantage compared to regular ones archive files is larger in size, since they, in addition to the actual packed files, also contain an executive EXE module.

The contents of a RAR archive can be made invisible. To do this, in the program settings, in the Archiving with Password window, you need to check the box next to the Encrypt File Names line.

You can also set a password to open the archive.

As a result of an error transferring the archive via local network or downloading it from the Internet, or due to a hardware failure or virus attack, the archive may be damaged. WinRar allows you to determine the integrity of the data by testing the archive using the Test Archived Files option.

To minimize the chance of data loss, when creating WinRar archives It is recommended to use the Put Recovery Record option (this checkbox can be found on the General tab of the archive creation window).

If this has been done, then if the archive is damaged, it can be restored.

In addition, in WinRar, you can reduce the likelihood of damage to the RAR archive by specifying the size of the recovery information when creating it. To do this, run the Commands > Protect Archive From Damage command in the Winrar window. In this case, the volume of Recovery Record cannot exceed ten percent of the total archive size.

To restore damaged RAR archives, you must select required file in the WinRar window and execute the command Tools > Repair.

WinRAR can be integrated into the context menu, and it supports not only the Explorer menu, but also other programs, for example the popular file manager Total Commander. This makes it possible to quickly archive files using default settings and without opening a program window. By the way, the default settings can be changed in accordance with the requirements you place on your archives. This can be done by opening the WinRar window and running the Options > Settings command. In this window, you need to go to the Compression tab and click the Create Default button. The settings specified in this window will be used for quick archiving.

If you need to change the archiving settings, this can also be done using the context menu. To do this, select the Add to Archive... command. Here you can set the format and compression level, specify the archive name and select other archiving parameters.

WinRar allows you to save user-specified settings to a file with the Reg extension. This file can later be imported into the program to reuse the given configuration. This file stores information such as the history of archives that were recently created, default compression settings, etc.

Another one convenient option Winrar - the ability to create your own bookmarks - Favorities. Very often it is necessary to regularly archive the same folders on your hard drive. By adding information about the location of these folders to bookmarks, you can quickly navigate to them in the program window and archive the necessary files and subdirectories.