MP3

After that, MP3 algorithms become public domain and all of these counter-productive legal hassles go away. Companies, which offer a special business version of their distribution, add special support packages and special tools to administrate higher numbers of installations or do administrative tasks more easily. The Fraunhofer patents expire April 2010. The business model of commercial suppliers is generally dependent on charging for support, especially for business users. With Thomson and Sivel both owning separate patents which they claim are needed by the codec, the legal status of MP3 remains unclear. GNU/Linux users are often organised in so called Linux User Groups or abbreviated LUG. Motorola also recently signed with Audio MPEG to license MP3. Technical support is provided by commercial suppliers and by other Linux users, usually in online forums, newsgroups and mailing lists.

[3] previously sued Thomson for patent infringement on MP3 technology[4], but those disputes were resolved in November 2005 with Sisvel granting Thomson an MP3 license. Complete distributions exist for most of these architectures, but most distributions focus on the "Intel" PC market. [2] and its US subsidiary Audio MPEG, Inc. But eventually, people started trying to port it to other platforms, and now Linux is available on many CPU architectures, among them:. Sisvel S.p.A. As originally envisioned by Linus Torvalds, Linux was strictly an x86 application. Thus while patent fees have been an issue for companies attempting to use MP3, they have not meaningfully impacted users, allowing the format to grow in popularity. Linux also integrates well with Python, Perl, PHP and Ruby.

Furthermore, while attempts have been made to discourage distribution of encoder binaries, Thomson has stated that individuals using free MP3 encoders are not required to pay fees. They are interpreted line-by-line as commands entered in the shell. Additionally, patent holders declined to enforce license fees on open source decoders, allowing many free MP3 decoders to develop. These are applications that are written without the need for compilation of the code. In spite of the patent restrictions, the perpetuation of the MP3 format continues; the reasons for this appear to be the network effects caused by:. Another option for linux programming is writing shell scripts. For information about licensing fees see here and here. Some of the most popular are Anjuta, Code::Blocks, KDevelop, NetBeans IDE, Glade (actually a user interface designer), Eclipse, the famous Emacs and Vim.

Until the key patents expire, open source / free software encoders and players appear to be illegal for commercial use in countries that recognize software patents. There are also a number of IDEs available for Linux. Microsoft, the makers of the Windows operating system, chose to move away from MP3 to their own proprietary Windows Media formats to avoid the licensing issues associated with the patents. GCC supports C, C++ and Java (for example by using GCJ) among other languages. These patent issues significantly slowed the development of unlicensed MP3 software and led to increased focus on creating and popularizing alternatives such as WMA and Ogg Vorbis. The GNU Compiler Collection (GCC) comes with the vast majority of distributions. To make, sell and/or distribute products using the [MPEG Layer-3] standard and thus our patents, you need to obtain a license under these patents from us.". A number of compilers are available for Linux.

The letter claimed that unlicensed products "infringe the patent rights of Fraunhofer and THOMSON. In a corporate setting essentially the same can be done using a Citrix server, rdesktop to access a Microsoft Terminal Services server, or with NX technology. In September 1998, the Fraunhofer Institute sent a letter to several developers of MP3 software stating that a license was required to "distribute and/or sell decoders and/or encoders". At its simplest one or more people needing occasional access to Windows applications can share remote access to a single Windows PC for that purpose using VNC. See Software patents under the European Patent Convention. This is a good solution where applications are unable to be migrated, or an item of hardware such as a dongle, custom decoder card, or some USB devices will only run under Windows. Thomson has been granted software patents in EU countries and by the European Patent Office [1], but it is unclear whether or not they would be enforced by courts there. A fourth alternative is to run the applications on a Windows machine but use remote access software such as VNC to view it on the Linux desktop.

Thomson has been actively enforcing these patents. Aside from the performance difficulties, virtual machine approaches to running Windows applications cannot integrate Windows programs into the Linux desktop, as they must instead run inside the virtual Windows desktop. Thomson Consumer Electronics controls licensing of the MPEG-1/2 Layer 3 patents in countries that recognize software patents, including the United States and Japan, but not EU countries. Full CPU emulators (such as QEMU or the slower counterpart Bochs) can be used, though to run a Windows program these emulators will also require a copy of Windows. MP3, which was designed and tuned for use alongside MPEG-1/2 Video, generally performs poorly on monaural data at less than 48 kbit/s or in stereo at less than 80 kbit/s. VMware is a proprietary hardware virtualisation program that can run Windows in this way with near-perfect functionality, however this approach can carry a considerable speed and performance penalty. Thomson claims that its mp3PRO codec achieves CD quality at 64 kbit/s, but listeners have reported that a 64 kbit/s mp3PRO file compares in quality to a 112 kbit/s MP3 file and does not come reasonably close to CD quality until about 80 kbit/s. A third alternative for running Windows applications within Linux is to use a virtual machine program and run the desired application along with the entire virtual Windows operating system.

The developers of the patent-free Ogg Vorbis codec claim that their algorithm surpasses MP3, RealAudio and WMA sound quality, and the listening tests mentioned above support that claim. Since a legal copy of the Microsoft implementation of the Windows API is needed, use of Win4Lin requires a copy of Windows. Though proponents of newer codecs such as WMA and RealAudio have asserted that their respective algorithms can achieve CD quality at 64 kbit/s, listening tests have shown otherwise; however, the quality of these codecs at 64 kbit/s is definitely superior to MP3 at the same bitrate. A similar alternative to running Windows applications inside Linux is to use the proprietary Win4Lin software, which converts Microsoft's version of the Windows API to run inside Linux rather than reimplementing it from scratch. What is considered 'CD quality' is quite subjective; for some 128kbit/s MP3 is sufficient, while for others 200kbit/s or higher MP3 is necessary. Although compatibility is improving, in many cases week-by-week, applications that make use of non-standard programming practices can experience problems. At high bitrates (128kbit/s+), most people do not hear significant differences. Since these programs are written without use of any Microsoft code, they do not require a Windows license.

At 64kbit/s, AAC-HE and mp3pro performed marginally better than other codecs. Many Windows programs run on Linux at approximately the same speed using these programs, and in some cases run even faster. At 128kbit/s, Ogg Vorbis, AAC, MPC and WMA Pro tied for first place with LAME MP3 a little behind. The popular Wine software, along with the commercial derivatives Crossover Office and Transgaming's Cedega create an application compatibility layer by reimplementing the Windows API inside of Linux. Listening tests have attempted to find the best-quality lossy audio codecs at certain bitrates. There are several ways to run applications written for Microsoft Windows on Linux, with varying levels of success. These include:. Since nearly all settings are stored in ordinary text files they can be configured by any text editor.

While they are not similar to MP3, they are good examples of other compression schemes available. There are also many command line utilities for configuring programs. There are also some lossless audio compression methods used on the Internet. Others, like Linuxconf, Gnome System Tools, and Webmin, are not distribution-specific. The Fraunhofer Gesellschaft owns many of the basic patents underlying these codecs, with Dolby Labs, Sony, Thomson Consumer Electronics, and AT&T holding other key patents. The easiest way to do this is by using tools provided by distributions such as Debian's debconf, Mandriva's Control Center, or SUSE's YaST. mp3PRO, MP3, AAC, and MP2 are all members of the same technological family and depend on roughly similar psychoacoustic models. There are a number of ways to change these settings.

Many other lossy audio codecs exist, including:. A few programs use a configuration database instead of files. Typically, the average volume and clipping information about audio track is stored in the metadata tag. Configuration of most system wide settings are stored in a single directory called /etc, while user-specific settings are stored in hidden files in the user's home directory. The most popular and widely used solution for storing replay gain is known simply as "Replay Gain". However, the fastest approach is probably that of Workspot, which uses VNC to provide a free Linux desktop demo online. The idea is to normalize the volume (not the volume peaks) of audio files, so that the volume does not change between consecutive tracks. Ubuntu have a separate "Live" version of their distribution which runs from CD.

A few standards for encoding the gain of an MP3 file have been proposed. MEPIS also runs from CD like Knoppix, and both can be installed onto a PC like any other Linux distribution. As compact discs and other various sources are recorded and mastered at different volumes, it is useful to store volume information about a file in the tag so that at playback time, the volume can be dynamically adjusted. The approach by Knoppix, which runs Linux directly from a CD without disturbing the PC's hard drive, is probably the most successful demonstration tool to date. APEv2 can coexist with ID3 tags in the same file, but it can also be used by itself. Many commercial distributions are hard to install, but with work, allow someone to re-use an old machine to see what the Linux desktop is like. APEv2 was originally developed for the MPC file format (see the APEv2 specification). Commercial exhibitions provide Linux demonstrations to potential new users, especially corporate buyers.

The most widespread standard tag formats are currently the ID3 ID3v1 and ID3v2 tags, and the more recent APEv2 tag. Linux User Groups, or LUGs, still provide the primary face-to-face forum for demonstration of Linux. A "tag" is data stored in an MP3 (as well as other formats) that contains metadata such as the title, artist, album, track number or other information about the MP3 file to be added to the file itself. So-called "live CDs" that simply boot from CD and automatically load the necessary drivers for the user's respective system promise to change that. Therefore, for the most part, comparison of decoders is almost exclusively based on how computationally efficient they are (i.e., how much memory or CPU time they use in the decoding process). The difficulty in quickly demonstrating Linux on the computer of a potential new user remains still an obstacle, slowing its adoption as a personal computing platform. The MP3 file has a standard format which is a frame consisting of 384, 576, or 1152 samples (depends on MPEG version and layer) and all the frames have associated header information(32 bits) and side information(9, 17, or 32 bytes, depending on MPEG version and stereo/mono).The header and side information help the decoder to decode the associated huffman encoded data correctly. After everything is done, the virtual machine can be booted just as if it were an independent computer.

Most decoders are "bitstream compliant", meaning that the uncompressed output they produce from a given MP3 file will be the same (within a specified degree of rounding tolerance) as the output specified mathematically in the standard document. The virtual machine software will simulate an isolated environment onto which the Linux system is installed. Decoding, on the other hand, is carefully defined in the standard. Technology of virtual machines (such as Virtual PC or VMware) also enables Linux to be run inside another OS such as Microsoft Windows. It must be kept in mind that an encoder that is proficient at encoding at higher bitrates (such as LAME, which is in widespread use for encoding at higher bitrates) is not necessarily as good at other, lower bitrates. Similar approaches include coLinux. Comparisons are widely available, so it is easy for a prospective user of an encoder to research the best choice. A Linux boot loader will boot the Linux system when the PC is restarted and the user chooses to boot Linux.

As a result, there are many different MP3 encoders available, each producing files of differing quality. The difference is that it is not necessary for the user to leave Windows, since Linux is installed to the Windows hard-disk partition. This is the domain of psychoacoustics, which aims at understanding how human acoustical perception works (both in our ears and in our brain). The software provides all the needed features; it is a real Linux distribution. This is done to limit the temporal spread of quantization noise accompanying the transient. After downloading the installer (more than 100MB), the user can install Linux just like any other Windows application. If there is a transient 192 samples are taken instead of 576. Consider WinLinux, for example.

Implementers of the standard were supposed to devise their own algorithms suitable for removing parts of the information in the raw audio (or rather its MDCT representation in the frequency domain).During encoding 576 time domain samples are taken and is transformed to 576 frequency domain samples. Some let the user install Linux on top of their current system. The decoding algorithm and file format, as a contrast, are well defined. Some beginners (especially those familiar with Microsoft Windows and Mac OS) may still feel that making the shift can be hard but many solutions have been created to solve this problem. The MPEG-1 standard does not include a precise specification for an MP3 encoder. Many distribution companies now are sparing no effort to provide users with advanced, easy and specific installations. Nevertheless, a well-tuned MP3 encoder can perform competitively even with these restrictions. It is famous for its ability to automatically partition a hard drive using the Disk Druid utility.

In technical terms, MP3 is limited in the following ways:. Anaconda, one of the more popular installers, is used by Red Hat Linux, Fedora Core and other distributions to simplify the installation process. Newer audio compression formats such as Vorbis and AAC no longer have these limitations. Many distributions also support booting over a network, so an installation on a properly configured machine can be done remotely. There are several limitations inherent to the MP3 format that cannot be overcome by using a better encoder. The cost savings achieved by using thin clients can be invested in greater computing power or storage on the server. Non-standard bitrates up to 640 kbit/s can be achieved with the LAME encoder and the --freeformat option, however only few MP3 players can play those files. Variations on this mode include using local drives and computing power to run applications.

Some encoders utilize this technique to a great extent. The clients can be ordinary PCs with the addition of the network bootloader on a drive or network interface controller. This method compares to a sound activated tape recorder that reduces tape consumption by not recording silence. A Linux Terminal Server is a single machine to which many clients can connect this way, so one obtains the benefit of installing Linux on many machines for the cost of installing on one. This technique makes it possible to use more bits for parts of the sound with higher dynamics (more sound movement) and fewer bits for parts with lower dynamics, further increasing quality and decreasing storage space. Clients can boot over the network from the server and display results and pass information to the server where all the applications run. Audio in MP3 files are divided into frames (which have their own bit rate) so it is possible to change the bit rate dynamically as the file is encoded (although not originally implemented, VBR is in extensive use today). Still another mode of installation of Linux is to install on a powerful computer to use as a server and to use ordinary less powerful machines (perhaps without hard drives, and having less memory and slower CPUs) as thin clients over the network.

Variable bit rates (VBR) are also possible. Similarly, some minimal distributions, such as tomsrtbt, can be run directly from as little as 1 floppy disk without needing to change the hard drive contents. MPEG-2 and [the non-official] MPEG-2.5 includes some additional bit rates: 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 kbit/s. With this, one boots from the CD and can use Linux without making any modification to the contents of the hard drive. 44.1 kHz is almost always used (coincides with the sampling rate of compact discs), and 128 kbit/s has become the de facto "good enough" standard, although 192 Kbit/s is becoming increasingly popular over peer-to-peer file sharing networks. Other distributions, such as Knoppix, can be run directly from a "live CD" running entirely in RAM, rather than installing it to the hard drive. Bit rates available in MPEG-1 Layer 3 are 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 and 320 kbit/s, and the available sample frequencies are 32, 44.1 and 48 kHz. After a basic system is installed, more software can be added by downloading it from the Internet or using CDs.

In the early days of MP3 encoding, a fixed bit rate was used for the entire file. Some distributions, such as Debian, can be installed from a small set of floppy disks. The general rule is that more information is included from the original sound file when a higher bit rate is used, and thus the higher the quality during play back. Such a CD can be burned from a downloaded ISO image, purchased alone for a low price, or can be obtained as part of a box set that may also include manuals and additional commercial software. The bit rate is variable for MP3 files. The most common method of installing Linux, supported by all major distributions, is by booting from a CD that contains the installation program and installable software. For these operations, the concerns mentioned above are not necessarily relevant, as long as appropriate software (such as mp3DirectCut and MP3Gain) is used to prevent extra decoding-encoding steps. Further, personal computers that come with Linux distributions already installed are readily available from numerous vendors, including large mainstream vendors like Hewlett-Packard and Dell.

Some simple editing operations, such as cutting sections of audio, may be performed directly on the encoded MP3 data without necessitating reencoding. Also it is not normally necessary to feed a stack of driver CDs into a Linux installation as most hardware is supported out of the box. Lossless formats produce the best possible result, at the expense of a lower compression ratio. It is unnecessary to file license numbers and enter them during installation. The losses produced by multiple stages of coding may also compound each other, becoming more evident when the signal is reencoded after processing. Many distributions are at least as easy to install as a comparable version of Windows. Lossless formats are strongly preferred for material that will be edited, mixed, or otherwise processed because the perceptual assumptions made by lossy encoders may not hold true after processing. In the past, difficulty of installation was a barrier to wide adoption of Linux-based systems, but the process has been made easy in recent years.

If your aim is to archive sound files with no loss of quality (or work on the sound files in a studio for example), then you should use Lossless compression algorithms, currently capable of compressing 16-bit PCM audio to 38% while leaving the audio identical to the original, such as Lossless Audio LA, Apple Lossless, FLAC, Windows Media Audio 9 Lossless (wma) and Monkey's Audio (among others). The paper Why Open Source Software / Free Software (OSS/FS)? Look at the Numbers! identifies many quantitative studies of open source software, on topics including market share and reliability, with many studies specifically examining Linux. The numbers given above are rough guidelines that work for many people, but in the field of lossy audio compression the only true measure of the quality of a compression process is to listen to the results. The large number of choices of Linux distributions can also confuse users and software vendors. Merely changing the conditions of listening, such as the audio playing system or environment, can expose unwanted distortions caused by lossy compression. However, some observers claim that the intervals between Linux distribution releases are no worse, and often better, than the project management "schedule slipping" that occurs with other operating systems and with software systems in general. Individual acoustic perception may vary, so it is not evident that a certain psychoacoustic model can give satisfactory results for everyone. Linux distributions have been criticized for unpredictable development schedules, thus making enterprise users less comfortable with Linux than they might be with other systems (Marcinkowski, 2003).

A given bit rate suffices for some listeners but not for others. However, Relevantive, the renowned Berlin-based organization specializing in providing consultation to companies on the usability of software and Web services, concluded that the usability of Linux for a set of desktop-related tasks is "equal to Windows XP." Since then, there have been numerous independent studies and articles [10] [11] [12] that show that a modern Linux desktop using Gnome or KDE is on par with or superior to Microsoft Windows. It is important to note that quality of an audio signal is subjective. Microsoft-sponsored studies such as those by IDC and Gartner have argued that Linux had a higher total cost of ownership (TCO) than Windows. A 128 kbit/s MP3 produced by a good encoder might sound better than a 192 kbit/s MP3 file produced by a bad encoder. There have been conflicting studies of Linux's usability and cost in the past. It is therefore misleading to speak of 128 kbit/s or 192 kbit/s quality, except in the context of a particular encoder or of the best available encoders. Deliberately non-portable hardware drivers like Winmodems and Winprinters have been a general problem.

Good encoders produce acceptable quality at 128 to 160 Kibit/s and near-transparency at 160 to 192 kbit/s, while low quality encoders may never reach transparency, not even at 320 kbit/s. Often, this development requires reverse engineering of some sort, as certain manufacturers remain secretive and refuse to provide the hardware or firmware specifications for their products. Many early encoders that are no longer widely used:. Though some vendors provide device drivers, many device drivers must be developed by volunteers after the release of the product. A few possible encoders:. Support for certain new and obscure hardware remains an issue. Different encoders may achieve this with varying degrees of success. Linux is rapidly gaining popularity as a desktop operating system as it is increasingly used in schools and workplaces and more people are becoming familiar with it.

Due to the fact that their lossy encoding loses information, MP3 algorithms work hard to ensure that the parts lost cannot be detected by human listeners by modeling the general characteristics of human hearing (e.g., due to noise masking). Linux is past that stage now, with numerous manufacturers installing Linux and many organizations having five or more years experience with Linux - since installation evolved to graphical user interfaces - or Unix, which has been around for decades. Tests may be biased against older formats in favour of new ones by using older encoders based on out-of-date technologies, or even buggy encoders for the old format. Because of reluctance to change and the fact that many computers still come with Microsoft Windows pre-installed, there has been a slow initial adoption of new desktop operating systems. When comparing compression schemes, it is important to use encoders that are of equivalent quality. Most distributions of Linux have two or more means of software installation, and more office and end-user applications now come with an automated installation program. They would contend that more realistic rates would be as follows:. However, general applications like spreadsheets, word processors, and browsers are available for Linux in profusion.

Many people consider these quoted rates as being heavily skewed in favour of Layer 2 and Layer 3 recordings. Equivalents of some specific programs may not be available. However, as different encoders use different models, it is difficult to draw absolute comparisons of this kind. Users might have to switch application software, and there may be fewer options, as in the case of computer games. The differences between the layers are caused by the different psychoacoustic models used by them; the Layer 1 algorithm is typically substantially simpler, therefore a higher bit rate is needed for transparent encoding. For example, Gentoo Linux, a source-based distribution, is time-consuming to install, but can be more usable for advanced users than stereotypical beginner-friendly distributions, such as Mandriva or Ubuntu. Fraunhofer Gesellschaft (FhG) publish on their official webpage the following compression ratios and data rates for MPEG-1 Layer 1, 2 and 3, intended for comparison:. It is worth noting that an operating system's usability is subjective and dependent on the background knowledge and needs of its users.

Obviously, imperfections in an MP3 encode will be much less apparent on low-end computer speakers than on a good stereo system connected to a computer or -- especially -- using high-quality headphones. It used to be easier to find local technical support for Windows or Mac OS than for Linux in some places but with local Linux User Groups or LUGs appearing everywhere this has changed. Yet other listeners, and the same listeners in other environments (such as in a noisy moving vehicle or at a party) will consider the quality acceptable. Many older programs with text user interfaces (TUI) have wild inconsistencies between them, but they maintain loyal followings. However, listening tests show that with a bit of practice many listeners can reliably distinguish 128 kbit/s MP3s from CD originals; in many cases reaching the point where they consider the MP3 audio to be of unacceptably low quality. On the command shell, many usability hangups from early Unix days generally remain, such as the difficulty in finding some commands, and the inability to undo many operations such as file deletion. For average signals with good encoders, many listeners accept the MP3 bit rate of 128 kibit/s as near enough to compact disc quality for them, providing a compression ratio of approximately 11:1. GUI configuration tools and control panels are available for many system settings and services, but editing of plain-text configuration files is often required.

As well as the bit rate of the encoded file, the quality of MP3 files depend on the quality of the encoder and the difficulty of the signal being encoded. The area of hardware and services configuration is where user experience is most varied. A good demonstration of compression artifacts is provided by the sound of applause: it is hard to compress because it is random, therefore the failings of the encoder are more obvious, and are audible as ringing. Additionally, proprietary software for other operating systems may be run through compatibility layers, such as Wine. With too low a bit rate, "compression artifacts" (i.e., sounds that were not present in the original recording) may appear in the reproduction. A growing number of proprietary software vendors are supporting Linux, and open source development for Linux is also steadily increasing. MP3 files encoded with a lower bit rate will generally play back at a lower quality. While some very specific application may not be available for Linux, there usually exists a replacement, often of better quality.

By contrast, uncompressed audio as stored on a compact disc has a bit rate of about 1400 kbit/s. Applications running within graphical desktop environments such as GNOME and KDE in Linux are very similar to those running on other operating systems. Typically rates chosen are between 128 and 256 kilobit per second. Linux and other free software projects have been frequently criticized for not going far enough in terms of ensuring usability, and Linux was once considered more difficult to use than Windows or the Macintosh, although this has changed. Because MP3 is a lossy format, it is able to provide a number of different options for its "bit rate"—that is, the number of bits of encoded data that are used to represent each second of audio. The Linux market is among the fastest growing and is projected to exceed $35.7 billion by 2008 [9](this statistic is not comparable to capitalised operating systems like Windows - since Linux is free to use). The use of formats that supports DRM is in an attempt to prevent piracy of copyright protected materials, but any computer savvy person can easily rip the DRM from a song file turning it into a file that is not locked to any computer. However, argued advantages of Linux, such as lower cost, fewer security vulnerabilities [8] , and lack of vendor lock-in, have spurred a growing number of high-profile cases of mass adoption of Linux by corporations and governments.

Commercial online music distribution services (like the iTunes Music Store) usually prefer other/proprietary music file formats that support Digital Rights Management (DRM) to control and restrict the use of digital music. According to market research company IDC, in 2002, only 25% of servers and 2.8% of desktop computers were already running Linux. Due to the vastly increased spread of MP3s through the Internet some major record labels reacted by filing a lawsuit against Napster to protect their Copyrights (see also intellectual property). Its market share of desktops is rapidly growing. Controversies regarding peer-to-peer file sharing of MP3 files have flourished in recent years — largely because high compression enables sharing of files that would otherwise be too large and cumbersome to share. Once viewed as an operating system only computer professionals and aficionados could use, Linux distributions have become user-friendly, with many graphical interfaces and applications. Those programs made it very easy for the average user to playback, create, share, and collect MP3s. Graphical Linux software exists for almost any area and in some areas there is a greater quality and quantity of software available than for proprietary operating systems.

MP3 popularity was mostly due to, and interchangeable with, the successes of companies and software packages like Nullsoft's Winamp (released in 1997), mpg123, and Napster (released in 1999). In desktop environments like GNOME and KDE, Linux may be used with a user interface that is similar to that of Mac OS, Microsoft Windows, or other desktop environments, and its traditional Unix-like command line interface. In the first half of 1995 through the late 1990s, MP3 files began flourishing on the Internet. Linux is rapidly gaining popularity as a desktop operating system. Other founding members include Jon Luini, Brandee Selck, and Ahin Savara. As of June 2005, the 3 fastest supercomputers in the world (as recorded by the Top500) run Linux. IUMA was started by Rob Lord (who later headed pioneering Nullsoft) and Jeff Patterson, both from the University of California, Santa Cruz, in 1993. Linux is increasingly common as an operating system for supercomputers, most recently on 64-bit AMD Opterons in the Cray XD1.

IUMA was the Internet's first high-fidelity music web site, hosting thousands of authorized MP2 recordings before MP3 or the web was popularized. Linux is also expanding into telecommunications equipment through efforts such as Carrier Grade Linux. The Internet Underground Music Archive (IUMA) is generally recognized as the start of the on-line music revolution. The TomTom satellite navigation system also uses an embedded version of the Linux kernel. Initially the only encoder available for MP2 production was the Xing Encoder, accompanied by the program CDDA2WAV, a CD ripper that transformed CD audio tracks to computer data files. A large number of network firewalls and routers, including several from Linksys and Netgear, use Linux internally, taking advantage of its advanced firewalling and routing capabilities. In October 1993, MP2 (MPEG-1 Audio Layer 2) files appeared on the Internet and were often played back using the Xing MPEG Audio Player, and later in a program for Unix by Tobias Bading called MAPlay, which was initially released on February 22nd, 1994 (MAPlay was also ported to the Microsoft Windows). The popular TiVo digital video recorder also uses a customized version of Linux.

Because of the relatively small hard drives back in that time (~500 MB) the technology was essential to store music for listening pleasure on a computer. In handheld devices, it is an increasingly popular alternative to the Windows CE and Palm OS operating systems. With the first real-time software MP3 player Winplay3 (released September 9th, 1995) many people were able to encode and playback MP3 files on their PCs. In mobile phones, Linux has become a major competitor to the proprietory Symbian OS software. The filename extension .mp3 was chosen by the Fraunhofer team on July 14, 1995 (previously, the files had been named .bit). Its low cost makes it particularly useful in set-top boxes and for devices such as the Simputer, a computer aimed mainly at low-income populations in developing nations. Later on, on July 7, 1994 the Fraunhofer Society released the first software MP3 encoder called l3enc. Linux is also often used in embedded systems.

Some other real time implementation of MPEG Audio encoders were available for the purpose of digital broadcasting (radio DAB, television DVB) towards consumer receivers and set top boxes. Sony has previously released a PS2 Linux kit for their PlayStation 2 video game console. Working in non real time on a number of operating systems it was able to demonstrate the first real time hardware decoding (DSP based) of compressed audio. The multi-billion dollar video game industry will see widespread Linux use with the 2006 launch of the Sony PlayStation 3 video game console which will run Linux out of the box. A reference simulation software written in C language known as ISO 11172-5 was developed by the members of the ISO MPEG Audio committee in order to produce bit compliant MPEG Audio files (Layer 1, Layer 2, Layer 3). Additionally, Linux has a plethora of database software such as MySQL, Sybase ASE (linux application) , mSQL and others. Some more serious and critical audio excerpts (glockenspiel, triangle, accordion, ...) were taken from the EBU V3/SQAM reference compact disc and have been used by professional sound engineers to assess the subjective quality of the MPEG Audio formats. A prominent example of this software combination in use is MediaWiki — the software primarily written for Wikipedia.

This song was chosen because of its softness and simplicity, making it easier to hear imperfections in the compression format during playbacks. Linux is the cornerstone of the so-called LAMP server-software combination (Linux, Apache, MySQL, Perl/PHP/Python) that has achieved widespread popularity among Web developers, making it one of the most common platforms on the Web. Karlheinz Brandenburg used a CD recording of Suzanne Vega's song Tom's Diner to assess the MP3 compression algorithm. Linux has made considerable gains in server and special-purpose markets, such as image rendering and Web services, and is now making inroads into the high volume desktop market. Compression ratios with this reference are higher, which demonstrates the problem of the term compression ratio for lossy encoders. This stereotype has been dispelled in recent years by the increased user-friendliness and broad adoption of many Linux distributions. Sometimes the Digital Audio Tape (DAT) SP parameters are used (48 kHz, 2x16 bit). Because of this, and because of being attracted by access to the internals of the system, Linux users have traditionally tended to be more technologically oriented than users of Microsoft Windows and Mac OS, sometimes revelling in the tag of "hacker" or "geek".

Nevertheless, there are often published compression rates that use the CD parameters as references (44.1 kHz, 2 channels at 16 bits per channel or 2x16 bit). In the past, a user needed significant knowledge of computers in order to install and configure Linux. Compression efficiency of encoders is typically defined by the bit rate because compression rate depends on the bit depth and sampling rate of the input signal. The source code for the Linux kernel used to be maintained using the software application called BitKeeper but, partly because a license dispute, it is now maintained via Git, the new directory content manager created by Linus Torvalds himself. Further work on MPEG audio was finalized in 1994 as part of the second suite of MPEG standards, MPEG-2, more formally known as international standard ISO/IEC 13818-3, originally published in 1995. This distribution contained over fifty-five million source lines of code, and the study estimated that it would have cost 1.9 billion dollars (year 2000 dollars) to develop by conventional proprietary means. All algorithms were finalized in 1992 as part of MPEG-1, the first standard suite by MPEG, which resulted in the international standard ISO/IEC 11172-3, published in 1993. In a later study, Counting potatoes: the size of Debian 2.2, the same analysis was performed for Debian GNU/Linux version 2.2.

Johnston (US), Gerhard Stoll (Germany), Yves-François Dehery (France), Karlheinz Brandenburg (Germany) took ideas from Musicam and ASPEC, added some of their own ideas and created MP3, which was designed to achieve the same quality at 128 kbit/s as MP2 at 192 kbit/s. Slightly over half of the code in that distribution was licensed under the GPL. Further, on a working group consisting of J.D. Had all this software been developed by conventional proprietary means, it would have cost 1.08 billion dollars (year 2000 dollars) to develop in the United States. Stoll (Layer II). Using the Constructive Cost Model (COCOMO), the study estimated that this distribution required about eight thousand person-years of development time. van de Kerkhof (Layer I) and G. The Linux kernel contained 2.4 million lines of code, or 8% of the total.

Under the chairmanship of Professor Mussmann (University of Hannover) the editing of the standard was made under the responsibilities of L. More Than a Gigabuck: Estimating GNU/Linux's Size, a study of Red Hat Linux 7.1, found that this particular distribution contained 30 million source lines of code (SLOC). Its technologies and ideas were fully incorporated into the definition of ISO MPEG Audio Layer I and Layer II and further on of the Layer III (MP3) format. A variety of Linux distribution screenshots can be viewed here. The Musicam format based on subband coding was key to settle the basis of the MPEG Audio compression format (sampling rates, structure of frames, headers, number of samples per frame). A typical general-purpose distribution includes the Linux kernel, some GNU libraries and tools, command-line shells, and thousands of application software packages, from office suites and the graphical X Window System to compilers, text editors, and scientific tools. The Musicam technique, as proposed by Philips (The Netherlands), CCETT (France), IRT (Germany) was chosen due to its simplicity and error robustness, as well as its low computational power associated to the encoding of high quality compressed audio. Over 450 distributions are available [7].

In 1991, there were two proposals available: Musicam (known as Layer 2), and ASPEC (Adaptive Spectral Perceptual Entropy Coding). Distributions are created for many different purposes, including localization, architecture support, real-time applications, and embedded systems, and many deliberately include only free software. EU-147 ran from 1987 to 1994. They include additional system software and application programs, as well as certain processes to install these systems on a computer. This project was financed by the European Union as a part of the EUREKA research program where it was commonly known as EU-147. These are compiled by individuals, loose-knit teams, and various professional organizations. MPEG-1 Audio Layer 2 encoding began as the Digital Audio Broadcast (DAB) project managed by Egon Meier-Engelen of the DFVLR (later on called DLR = Deutsche Luft und Raumfahrt = German Aerospace Agency) in Germany. Linux is predominantly used as part of a Linux distribution (commonly called a 'distro').

Nevertheless, any succession is not likely to happen for a significant amount of time due to MP3's overwhelming popularity (MP3 enjoys extremely wide popularity and support, not just by end-users and software but by hardware such as DVD and CD players). The most comprehensive coverage of this suit is given by Groklaw. In terms of the MPEG specifications, AAC (Advanced audio coding) from MPEG-4 is to be the successor of the MP3 format, although there has been a significant movement to create and popularize other audio formats. A few of Novell's press releases seem to demonstrate serious problems with SCO's claims:. MP3 Surround is backward compatible with standard stereo MP3, and file sizes are similar. To date, no proof of SCO's claims of copied code in Linux has been provided and SCO's claims have varied widely. MP3 Surround, a version of the format supporting 5.1 channels for surround sound, was introduced in December 2004. This controversy has involved lawsuits by SCO against Novell, DaimlerChrysler (partially dismissed in July, 2004), and AutoZone, and by Red Hat and others against SCO.

The MP3 format uses, at its heart, a hybrid transformation to transform a time domain signal into a frequency domain signal:. Additionally, SCO sent letters to a number of companies warning that their use of Linux without a license from SCO may be actionable, and claimed in the press that they would be suing individual Linux users. MP3 audio can be compressed with different bit rates, providing a range of tradeoffs between data size and sound quality. In March 2003, the SCO Group (SCO) filed a lawsuit against IBM claiming that IBM had contributed some portions of SCO's copyrighted code to the Linux kernel in violation of IBM's license to use Unix. A number of techniques are employed in MP3 to determine which portions of the audio can be discarded, including psychoacoustics. The distinction between Torvalds' kernel and entire Linux-based systems that contain the kernel is a perennial source of confusion, and the naming remains controversial. It provides a representation of pulse-code modulation-encoded (PCM) audio data in a much smaller size by discarding portions that are considered less important to human hearing (similar to JPEG, a lossy compression for images). Torvalds, the creator of the Linux kernel, has said that he finds calling Linux in general GNU/Linux "just ridiculous." Still, some distributions do use this name — notably Debian GNU/Linux — while most people simply refer to the system as Linux.

MP3 is a compression format. Because the GNU libraries and programs, an essential part of nearly all Linux distributions, stem from a long-standing free operating system project that predates the Linux kernel, Richard Stallman and the Free Software Foundation ask that the combined system (regardless of distribution) be referred to as GNU/Linux or a Linux-based GNU system. . See also List of words of disputed pronunciation for a fuller technical discussion of the various ways "Linux" is pronounced. In popular usage, MP3 also refers to files of sound or music recordings stored in the MP3 format on computers. Note that in English, "Linux" and "Minix" are usually pronounced with a short /ɪ/ sound that is different from Torvalds's phonemically Finland-Swedish pronunciation of these words (which is somewhere between what would be considered short and long in English). It was designed to greatly reduce the amount of data required to represent audio, yet still sound like a faithful reproduction of the original uncompressed audio to most listeners. An audio file of Torvalds saying "Hello, this is Linus Torvalds, and I pronounce Linux as /lɪnʊks/" also exists [6].

MPEG Audio Layer 3, more commonly referred to as MP3, is a popular digital audio encoding and lossy compression format invented and standardized in 1991 by a team of engineers working in the framework of the ISO/IEC MPEG audio committee under the chairmanship of Professor Hans Musmann (University of Hannover - Germany). In 1992, Torvalds explained [5] (IPA pronunciations added to quote in braces):. the majority of home users not knowing or not caring about the software patent controversy, which is in general irrelevant to their choice of the MP3 format for personal use. Other variations are also possible, but less frequently heard. the lack of DRM-protection technology, which makes MP3 files easy to edit, copy and distribute over networks,. The first pronunciation is considered more correct, while the second has become popular for sounding more natural in English. the wide variety of existing software and hardware that takes advantage of the file format,. Linux is most commonly pronounced either to rhyme with minix [ˈlɪnəks], or to sound like lie nix [ˈlaɪnəks].

the large quantity of music now available in the MP3 format,. In September 2005, Intellectual Property Australia, the trademark regulator in Australia, rejected an application to trademark Linux. the fact that these alternatives do not universally provide a definite advantage over MP3,. LMI has also sought to enforce the Linux trademark in countries other than the US. familiarity with the format, not knowing alternatives exist,. Reg No: 1916230) is owned by Linus Torvalds, registered for "Computer operating system software to facilitate computer use and operation." The licensing of the trademark is now handled by the Linux Mark Institute (LMI). Apple Lossless. The Linux trademark (U.S.

Wavpack. In 1997, Linus Torvalds stated, "Making Linux GPL'd was definitely the best thing I ever did." [4] Other subsystems use other licenses, although all of them share the property of being free/open-source; for example, several libraries use the LGPL (a more-permissive variant of the GPL), and the X Window System uses the permissive (non-copyleft) MIT License. TTA. The GPL requires that all source code modifications and derived works also be licensed under the GPL, and is sometimes referred to as a "share and share-alike" (or copyleft) license. SHN, also known as Shorten. The Linux kernel, along with most of the GNU components, is licensed under the GNU General Public License (GPL) version 2 (not or later). Monkey's Audio. Originally, Linus was going to call it Freax for "free" and with the often-used X in the names of Unix-like systems.

FLAC stands for 'Free Lossless Audio Codec'. (The name Linux was derived from Linus' Minix.) The name was later trademarked (see below). Speex, free software and patent free codec based on CELP specifically designed for speech and VoIP. He was the one to invent the name Linux for the directory from which Torvalds' project was first available for download [3]. RealAudio from RealNetworks, frequently in use for streaming on websites;. Lemmke was working for the Helsinki University of Technology (TKK), located in Espoo near Helsinki, as an administrator of ftp.funet.fi, an FTP server which belongs to the Finnish University and Research Network (FUNET), which has numerous organizations as its members, amongst them the TKK and the University of Helsinki. AMR-WB+ Enhanced Adaptive Multi Rate WideBand codec, optimized for cellular and other limited bandwidth use;. The name "Linux" was coined, not by Torvalds, but by Ari Lemmke.

QDesign, used in QuickTime at low bitrates;. Tux the penguin is the logo and mascot of Linux (although there are other, less common representations,such as theOS-tan), based on an image created by Larry Ewing in 1996. Windows Media Audio (WMA) from Microsoft. The task of producing an integrated system, which combines all of these basic components along with graphical interfaces (such as GNOME or KDE, which in turn are based on the X Window System) and application software, is now performed by Linux distribution vendors / organizations. MPEG-4 AAC, used by Apple's iTunes Music Store and iPod. Today, Torvalds continues to direct the development of the kernel, while other subsystems such as the GNU components are developed separately. ATRAC, used in Sony's Minidisc;. The Linux system quickly surpassed Minix in functionality; Torvalds and other early Linux kernel developers adapted their kernel to work with the GNU components and user-space programs to create a complete, fully functional, free operating system.

AC-3, used in Dolby Digital and DVD;. Initial versions of Linux also required an operating system to be present in order to boot from a hard disk, but soon there were independent bootloaders, the most well known being lilo. mp3PRO from Thomson Multimedia combining MP3 with SBR;. A computer running Minix was originally necessary in order to configure, compile, and install Linux. MPC, also known as Musepack (formerly MP+), a derivative of MP2;. By the 0.01 release, Linus had implemented enough POSIX system calls to make Linux run the GNU Bash shell; after this bootstrapping procedure, development accelerated rapidly. Ogg Vorbis from the Xiph.org Foundation, a free software and patent free codec. Raymond's essay The Cathedral and the Bazaar discusses the development model of the Linux kernel and similar software.

MPEG-1/2 Audio Layer 2 (MP2), MP3's predecessor;. Eric S. Encoder/decoder overall delay is not defined, which means lack of official provision for gapless playback; gaps may be introduced between tracks, although this can be avoided to a degree by using LAME to encode. Since then, thousands of developers from around the world have participated in the project. Joint stereo is done on a frame-to-frame basis. The first version of the Linux kernel (0.01) was released to the Internet on September 17, 1991, with the second version following shortly thereafter in October [2]. No scale factor band for frequencies above 15.5/15.8 kHz. After that, it gradually evolved into an entire operating system kernel intended as a foundation for POSIX-compliant systems.

Time resolution can be too low for highly transient signals. When Linus needed to read and write files to disk, this task-switching terminal emulator was extended with an entire filesystem handler. Bitrate is limited to a maximum of 320 kbit/s. The terminal emulator was running two threads: one for sending and one for receiving characters from the serial port. ACM Producer Pro. Linux started out as a terminal emulator written in IA-32 assembler and C, which was compiled into binary form and booted from a floppy disk so that it would run outside of any operating system. BladeEnc. However, Tanenbaum did not permit others to extend his operating system, leading Torvalds to develop a replacement for Minix.

Xing. Torvalds originally used Minix, a simplified Unix-like system written by Andrew Tanenbaum for teaching operating system design. ISO dist10 reference code. Meanwhile, in 1991, another kernel — eventually dubbed "Linux" — was begun as a hobby by Finnish university student Linus Torvalds while attending the University of Helsinki. Fraunhofer Gesellschaft: Some encoders are good, some have bugs. However, due to a lack of cooperation from the Berkeley programmers, Stallman decided instead to use the Mach microkernel, which subsequently proved unexpectedly difficult, and the Hurd's development proceeded slowly. It is (in contrast to others) a fully LGPL'd MP3 encoder, with excellent speed and quality, rivaling even MP3's technological successors. According to Thomas Bushnell, the initial Hurd architect, their early plan was to adapt the BSD 4.4-Lite kernel and, in hindsight, "It is now perfectly obvious to me that this would have succeeded splendidly and the world would be a very different place today" [1].

LAME first created by Mike Cheng in early 1998. The GNU project began developing their own kernel, the Hurd, in 1990 (after an abandoned attempt called Trix). Layer 3: excellent at 224...320 Kbit/s, very good at 192...224 Kbit/s, good at 128...192 Kbit/s. By the beginning of the 1990s, GNU had produced or collected nearly all of the necessary components of this system—libraries, compilers, text editors, a Unix-like shell, and other software—except for the lowest level, the kernel. Layer 2: excellent at 256...384 kbit/s, very good at 224...256 Kbit/s, good at 192...224 Kbit/s. The goal of GNU was to develop a complete Unix-like operating system composed entirely of free software. Layer 1: excellent at 384 kbit/s. In 1983, Richard Stallman founded the GNU project, which today provides an essential part of most Linux systems (see also GNU/Linux, below).

Layer 3: 112...128 kbit/s, compression 12:1...10:1. . Layer 2: 192...256 kbit/s, compression 8:1...6:1. It is deployed in applications ranging from embedded systems (such as mobile phones and personal video recorders) to personal computers to supercomputers. Layer 1: 384 kbit/s, compression 4:1. Linux was originally developed for Intel 386 microprocessors and now supports all popular computer architectures (and several obscure ones). Aliasing reduction postprocessing. Proponents and analysts attribute this success to its vendor independence (the opposite of vendor lock-in), low cost, security, and reliability.

36 or 12 tap MDCT; size can be selected independent for sub-band 0...1 and 2...31. Since then, Linux has gained the support of major corporations such as IBM, Sun Microsystems, Hewlett-Packard, and Novell for use in servers and is gaining popularity in the desktop market. 32-band polyphase quadrature filter. Initially, Linux was primarily developed and used by individual enthusiasts. Most broadly, a Linux distribution bundles large quantities of application software with the core system, and provides more user-friendly installation and upgrades. In the narrowest sense, the term Linux refers to the Linux kernel, but it is commonly used to describe entire Unix-like operating systems (also known as GNU/Linux) that are based on the Linux kernel combined with libraries and tools from the GNU Project and other sources.

It is one of the most prominent examples of free software and of open-source development: unlike proprietary operating systems such as Windows and Mac OS, all of its underlying source code is available to the public for anyone to freely use, modify, improve, and redistribute. Linux is a computer operating system and its kernel. Greene, The Register, retrieved December 22, 2005. Mandrake 8.1 easier than Win-XP by Thomas C.

Desktop Linux: Ready for Prime Time? by Emmett Dulaney, Redmond Magazine, June 2005, retrieved on 21 December 2005. Wheeler. Why Open Source Software / Free Software (OSS/FS)? Look at the Numbers! by David A. González-Barahona et al.

Counting potatoes: the size of Debian 2.2 by Jesús M. Wheeler. More Than a Gigabuck: Estimating GNU/Linux's Size by David A. Retrieved January 19, 2004 from [14].

Linux Torvalds Q&A. (2004). Mackenzie, K. Retrieved January 16, 2004 from [13].

Linux breaks desktop barrier in 2004: Torvalds. (2004). R. Gedda.

Glyn Moody: Rebel Code: Linux and the Open Source Revolution, Perseus Publishing, ISBN 0-713-99520-3. Sparc (Sun4). SuperH (Sega Dreamcast). IBM System/390.

PowerPC (Macintosh). PA-RISC (HP workstations). MIPS (DECstation, SGI Indy....). Motorola 68K (Sun3, Amiga, Atari, early Mac, Apollo....).

Alpha. ARM (handhelds, embedded systems). Both AMD and Intel versions of "64-bit x86". Intel/AMD x86 (the "normal PC").

2003-Nov-18 Novell Statement on SCO claims regarding a non-compete clause in Novell-SCO contracts. 2003-Jun-06 Novell Statement on SCO Contract Amendment. 2003-May-30 Novell Statement re: SCO press conference allegations. 2003-May-28 Novell Challenges SCO Position, Reiterates Support for Linux.

2003-May-15 Novell Statement on SCO Contract Amendment (good news for Linux users).