Hello Kitty

The card was released to teach young girls how to shop. After that, MP3 algorithms become public domain and all of these counter-productive legal hassles go away. Since 2004 the little cat has been featured on a MasterCard debit card from Legend Credit Inc. The Fraunhofer patents expire April 2010. On USA television, the American-produced Hello Kitty and Friends aired 13 episodes on CBS in 1991. With Thomson and Sivel both owning separate patents which they claim are needed by the codec, the legal status of MP3 remains unclear. It was first released in English in November 2002. Motorola also recently signed with Audio MPEG to license MP3.

Hello Kitty's Paradise ran for 16 episodes between 1993 and 1994. [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. On Japanese television, Hello Kitty (and pals) have starred in at least one anime series of their own. [2] and its US subsidiary Audio MPEG, Inc. Several Hello Kitty cartoons/animes targeted towards young children have been produced. Sisvel S.p.A. These are some of them:. 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.

Several electronic games have been produced where Kitty appears as the main character. 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. She is now a phenomenon adorning over 22,000 products and accounting for half of Sanrio's $1 billion yearly revenue. Additionally, patent holders declined to enforce license fees on open source decoders, allowing many free MP3 decoders to develop. The very first product bearing Hello Kitty's image was a small clear vinyl coin purse which sold for 240 yen (today, roughly US$2.27, or €1.77). 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:. Though a large proportion of the merchandise are stationery products, other goods range from foods and clothing to computers and cars, and in Japan, its popularity has penetrated every aspect of Japanese daily life. For information about licensing fees see here and here.

Although originally aimed at the pre-adolescent female market, the Hello Kitty logo now adorns almost every product that one can imagine to have its logo on it. 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. Singer Lisa Loeb has admitted to being a fan, and has even dedicated a whole album in homage to Hello Kitty, called Hello Lisa. 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. Many American celebrities have contributed to the character's popularity: Mariah Carey, Cameron Diaz, Heidi Klum, Steven Tyler, Carmen Electra, Mandy Moore, and Nicky Hilton have all been spotted with Hello Kitty goods. 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. Hello Kitty was once featured in an advertising campaign of the retail chain Target. 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.".

Now products featuring the character can be found in virtually any American department store. The letter claimed that unlicensed products "infringe the patent rights of Fraunhofer and THOMSON. She really came to her own during the late 1990s when several celebrities such as Mariah Carey adopted her as a fashion statement. 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". children's ambassador for UNICEF since 1983. See Software patents under the European Patent Convention. Hello Kitty has been marketed in the United States from the beginning and has held the position of U.S. 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.

It has also been noted that the character shows a resemblance to the character Miffy, designed in 1955 by Dick Bruna and that the line drawing style is not original. Thomson has been actively enforcing these patents. There has been some suggestion that Hello Kitty has its origins in Maneki Neko, and that the name Hello Kitty itself is a translation of Maneki Neko, which means beckoning cat in English. 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. Rarer variations feature other accessories such as strings of flowers. 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. Hello Kitty usually wears a bow beneath her left ear but she can often be seen with a five petal flower instead. 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.

The current designer, Yuko Yamaguchi, explains that the lack is so that she expresses no emotion. 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. The official answer from Sanrio as to why Hello Kitty has no mouth (see external links below) is that she speaks from the heart, in no one particular language. 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. She has all the normal facial features except she has no mouth. 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. Like most Sanrio characters, Hello Kitty is drawn in a cute style (see: Kawaii). At high bitrates (128kbit/s+), most people do not hear significant differences.

Charmmy Kitty was given to Hello Kitty by her father, George White and boyfriend Dear Daniel. At 64kbit/s, AAC-HE and mp3pro performed marginally better than other codecs. Charmmy resembles Hello Kitty but has more cat-like features. At 128kbit/s, Ogg Vorbis, AAC, MPC and WMA Pro tied for first place with LAME MP3 a little behind. Since 2004 she has even had a pet cat of her own called Charmmy Kitty, and a pet hamster called Sugar. Listening tests have attempted to find the best-quality lossy audio codecs at certain bitrates. Hello Kitty's fictional world includes a whole array of friends and family members. These include:.

When Hello Kitty's boyfriend "Dear Daniel" was created in 1999, designers took his name from the 1971 film, Melody, which starred Mark Lester as a character called Daniel, and features songs by the Bee Gees. While they are not similar to MP3, they are good examples of other compression schemes available. Kitty's name came from one of the cats that Alice kept in the book Through the Looking-Glass by Lewis Carroll. There are also some lossless audio compression methods used on the Internet. Hello Kitty was given an English pedigree because British culture was popular with Japanese girls at the time of her creation. 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. who still holds the position. mp3PRO, MP3, AAC, and MP2 are all members of the same technological family and depend on roughly similar psychoacoustic models.

The second designer, Setsuko Yonekubo, took over for five years until 1980 when the task was given to Yuko Yamaguchi. Many other lossy audio codecs exist, including:. Shimizu left the company about a year later. Typically, the average volume and clipping information about audio track is stored in the metadata tag. Hello Kitty was originally created by Sanrio designer Ikuko Shimizu in 1974. The most popular and widely used solution for storing replay gain is known simply as "Replay Gain". . The idea is to normalize the volume (not the volume peaks) of audio files, so that the volume does not change between consecutive tracks.

Copyrighted in 1976, Hello Kitty is now a globally known trademark. A few standards for encoding the gain of an MP3 file have been proposed. It is presented as a personified white cat, with the most distinctive feature being a bow or some other decoration on her left ear. 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. Hello Kitty (ハローキティ Harōkiti) is one of the many fictional characters produced by the Japanese company Sanrio, and has long been the most popular one out of the company's characters. APEv2 can coexist with ID3 tags in the same file, but it can also be used by itself. Very close to her twin sister Mimmy. APEv2 was originally developed for the MPC file format (see the APEv2 specification).

Description: A bright and kind-hearted kitten, good at baking cookies and loves Mama's apple pie. The most widespread standard tag formats are currently the ID3 ID3v1 and ID3v2 tags, and the more recent APEv2 tag. Best school subjects: English, music, visual arts, and pie eating. 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. Collects: Small cute things like sweets, stars, goldfish, etc. 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). Favorite word: "Friendship". 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.

mum or Mary). 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. Favorite food: Apple pie made by Mama (A.K.A. Decoding, on the other hand, is carefully defined in the standard. Good at: Baking cookies. 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. Weight: That of three shiny apples. Comparisons are widely available, so it is easy for a prospective user of an encoder to research the best choice.

Height: That of five apples. As a result, there are many different MP3 encoders available, each producing files of differing quality. Place of birth: Suburban London. This is the domain of psychoacoustics, which aims at understanding how human acoustical perception works (both in our ears and in our brain). Blood type: A (Negative). This is done to limit the temporal spread of quantization noise accompanying the transient. Birthday: November 1, 1974. If there is a transient 192 samples are taken instead of 576.

Name: Kitty White. 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. Occasionally the phrase "What the Hello Kitty" is heard as a euphemism for "What the hell". The decoding algorithm and file format, as a contrast, are well defined. The yowling noises from within suggests that they were made from real cats. The MPEG-1 standard does not include a precise specification for an MP3 encoder. On the episode "Thirty Minutes Over Tokyo" of the TV series The Simpsons, the family travels to Japan and passes by the Hello Kitty merchandise factory. Nevertheless, a well-tuned MP3 encoder can perform competitively even with these restrictions.

A merging of Sanrio characters with the Cthulhu Mythos results in the webcomic, Hello Cthulhu [1]. In technical terms, MP3 is limited in the following ways:. Hello Kitty no Ohanabatake, a Hello Kitty's Flower Shop (Famicom). Newer audio compression formats such as Vorbis and AAC no longer have these limitations. Hello Kitty World (Famicom). There are several limitations inherent to the MP3 format that cannot be overcome by using a better encoder. Hello Kitty: Roller Rescue (Nintendo GameCube, PlayStation 2, Xbox). 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.

Hello Kitty: Happy Party Pals (Nintendo Game Boy Advance, THQ / Webfoot Technologies). Some encoders utilize this technique to a great extent. This method compares to a sound activated tape recorder that reduces tape consumption by not recording silence. 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. 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).

Variable bit rates (VBR) are also possible. 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. 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. 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.

In the early days of MP3 encoding, a fixed bit rate was used for the entire file. 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. The bit rate is variable for MP3 files. 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.

Some simple editing operations, such as cutting sections of audio, may be performed directly on the encoded MP3 data without necessitating reencoding. Lossless formats produce the best possible result, at the expense of a lower compression ratio. The losses produced by multiple stages of coding may also compound each other, becoming more evident when the signal is reencoded after processing. 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.

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 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. Merely changing the conditions of listening, such as the audio playing system or environment, can expose unwanted distortions caused by lossy compression. Individual acoustic perception may vary, so it is not evident that a certain psychoacoustic model can give satisfactory results for everyone.

A given bit rate suffices for some listeners but not for others. It is important to note that quality of an audio signal is subjective. 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. 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.

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. Many early encoders that are no longer widely used:. A few possible encoders:. Different encoders may achieve this with varying degrees of success.

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). 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. When comparing compression schemes, it is important to use encoders that are of equivalent quality. They would contend that more realistic rates would be as follows:.

Many people consider these quoted rates as being heavily skewed in favour of Layer 2 and Layer 3 recordings. However, as different encoders use different models, it is difficult to draw absolute comparisons of this kind. 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. 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:.

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. 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. 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. 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.

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. 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. With too low a bit rate, "compression artifacts" (i.e., sounds that were not present in the original recording) may appear in the reproduction. MP3 files encoded with a lower bit rate will generally play back at a lower quality.

By contrast, uncompressed audio as stored on a compact disc has a bit rate of about 1400 kbit/s. Typically rates chosen are between 128 and 256 kilobit per second. 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 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.

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. 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). 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. Those programs made it very easy for the average user to playback, create, share, and collect MP3s.

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 the first half of 1995 through the late 1990s, MP3 files began flourishing on the Internet. Other founding members include Jon Luini, Brandee Selck, and Ahin Savara. IUMA was started by Rob Lord (who later headed pioneering Nullsoft) and Jeff Patterson, both from the University of California, Santa Cruz, in 1993.

IUMA was the Internet's first high-fidelity music web site, hosting thousands of authorized MP2 recordings before MP3 or the web was popularized. The Internet Underground Music Archive (IUMA) is generally recognized as the start of the on-line music revolution. 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. 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).

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. 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. The filename extension .mp3 was chosen by the Fraunhofer team on July 14, 1995 (previously, the files had been named .bit). Later on, on July 7, 1994 the Fraunhofer Society released the first software MP3 encoder called l3enc.

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. 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. 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). 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.

This song was chosen because of its softness and simplicity, making it easier to hear imperfections in the compression format during playbacks. Karlheinz Brandenburg used a CD recording of Suzanne Vega's song Tom's Diner to assess the MP3 compression algorithm. Compression ratios with this reference are higher, which demonstrates the problem of the term compression ratio for lossy encoders. Sometimes the Digital Audio Tape (DAT) SP parameters are used (48 kHz, 2x16 bit).

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). 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. 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. 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.

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. Further, on a working group consisting of J.D. Stoll (Layer II). van de Kerkhof (Layer I) and G.

Under the chairmanship of Professor Mussmann (University of Hannover) the editing of the standard was made under the responsibilities of L. 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. 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). 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.

In 1991, there were two proposals available: Musicam (known as Layer 2), and ASPEC (Adaptive Spectral Perceptual Entropy Coding). EU-147 ran from 1987 to 1994. This project was financed by the European Union as a part of the EUREKA research program where it was commonly known as EU-147. 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.

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). 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. MP3 Surround is backward compatible with standard stereo MP3, and file sizes are similar. MP3 Surround, a version of the format supporting 5.1 channels for surround sound, was introduced in December 2004.

The MP3 format uses, at its heart, a hybrid transformation to transform a time domain signal into a frequency domain signal:. MP3 audio can be compressed with different bit rates, providing a range of tradeoffs between data size and sound quality. A number of techniques are employed in MP3 to determine which portions of the audio can be discarded, including psychoacoustics. 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).

MP3 is a compression format. . In popular usage, MP3 also refers to files of sound or music recordings stored in the MP3 format on computers. 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.

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). 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. the lack of DRM-protection technology, which makes MP3 files easy to edit, copy and distribute over networks,. the wide variety of existing software and hardware that takes advantage of the file format,.

the large quantity of music now available in the MP3 format,. the fact that these alternatives do not universally provide a definite advantage over MP3,. familiarity with the format, not knowing alternatives exist,. Apple Lossless.

Wavpack. TTA. SHN, also known as Shorten. Monkey's Audio.

FLAC stands for 'Free Lossless Audio Codec'. Speex, free software and patent free codec based on CELP specifically designed for speech and VoIP. RealAudio from RealNetworks, frequently in use for streaming on websites;. AMR-WB+ Enhanced Adaptive Multi Rate WideBand codec, optimized for cellular and other limited bandwidth use;.

QDesign, used in QuickTime at low bitrates;. Windows Media Audio (WMA) from Microsoft. MPEG-4 AAC, used by Apple's iTunes Music Store and iPod. ATRAC, used in Sony's Minidisc;.

AC-3, used in Dolby Digital and DVD;. mp3PRO from Thomson Multimedia combining MP3 with SBR;. MPC, also known as Musepack (formerly MP+), a derivative of MP2;. Ogg Vorbis from the Xiph.org Foundation, a free software and patent free codec.

MPEG-1/2 Audio Layer 2 (MP2), MP3's predecessor;. 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. Joint stereo is done on a frame-to-frame basis. No scale factor band for frequencies above 15.5/15.8 kHz.

Time resolution can be too low for highly transient signals. Bitrate is limited to a maximum of 320 kbit/s. ACM Producer Pro. BladeEnc.

Xing. ISO dist10 reference code. Fraunhofer Gesellschaft: Some encoders are good, some have bugs. It is (in contrast to others) a fully LGPL'd MP3 encoder, with excellent speed and quality, rivaling even MP3's technological successors.

LAME first created by Mike Cheng in early 1998. Layer 3: excellent at 224...320 Kbit/s, very good at 192...224 Kbit/s, good at 128...192 Kbit/s. Layer 2: excellent at 256...384 kbit/s, very good at 224...256 Kbit/s, good at 192...224 Kbit/s. Layer 1: excellent at 384 kbit/s.

Layer 3: 112...128 kbit/s, compression 12:1...10:1. Layer 2: 192...256 kbit/s, compression 8:1...6:1. Layer 1: 384 kbit/s, compression 4:1. Aliasing reduction postprocessing.

36 or 12 tap MDCT; size can be selected independent for sub-band 0...1 and 2...31. 32-band polyphase quadrature filter.