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MP3

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MPEG Audio Layer III
Filename extension .mp3[1]
Internet media type audio/mpeg,[2] audio/MPA,[3] audio/mpa-robust[4]
Initial release 1993[5]
Type of format Audio compression format, audio file format
Standard(s) ISO/IEC 11172-3,[5]
ISO/IEC 13818-3[6]

MPEG Audio Layer III,[4] more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression. It is a common audio format for consumer audio storage, as well as a de facto standard of digital audio compression for the transfer and playback of music on digital audio players.

MP3 is an audio-specific format that was designed by the Moving Picture Experts Group (MPEG) as part of its MPEG-1 standard and later extended in MPEG-2 standard. The first MPEG subgroup – Audio group was formed by several teams of engineers at Fraunhofer IIS, University of Hannover, AT&T-Bell Labs, Thomson-Brandt, CCETT, and others.[7] MPEG-1 Audio (MPEG-1 Part 3), which included MPEG-1 Audio Layer I, II and III was approved as a committee draft of ISO/IEC standard in 1991,[8][9] finalised in 1992[10] and published in 1993 (ISO/IEC 11172-3:1993[5]). Backwards compatible MPEG-2 Audio (MPEG-2 Part 3) with additional bit rates and sample rates was published in 1995 (ISO/IEC 13818-3:1995).[6][11]

The use in MP3 of a lossy compression algorithm is designed to greatly reduce the amount of data required to represent the audio recording and still sound like a faithful reproduction of the original uncompressed audio for most listeners. An MP3 file that is created using the setting of 128 kbit/s will result in a file that is about 1/11 the size[note 1] of the CD file created from the original audio source. An MP3 file can also be constructed at higher or lower bit rates, with higher or lower resulting quality.

The compression works by reducing accuracy of certain parts of sound that are considered to be beyond the auditory resolution ability of most people. This method is commonly referred to as perceptual coding.[13] It uses psychoacoustic models to discard or reduce precision of components less audible to human hearing, and then records the remaining information in an efficient manner.

Contents

History

Development

The MP3 lossy audio data compression algorithm takes advantage of a perceptual limitation of human hearing called auditory masking. In 1894, Alfred Marshall Mayer reported that a tone could be rendered inaudible by another tone of lower frequency.[14] In 1959, Richard Ehmer described a complete set of auditory curves regarding this phenomenon.[15] Ernst Terhardt et al. created an algorithm describing auditory masking with high accuracy.[16] This work added to a variety of reports from authors dating back to Fletcher, and to the work that initially determined critical ratios and critical bandwidths.

The psychoacoustic masking codec was first proposed in 1979, apparently independently, by Manfred R. Schroeder, et al.[17] from AT&T-Bell Labs in Murray Hill, NJ, and M. A. Krasner[18] both in the United States. Krasner was the first to publish and to produce hardware for speech (not usable as music bit compression), but the publication of his results as a relatively obscure Lincoln Laboratory Technical Report did not immediately influence the mainstream of psychoacoustic codec development. Manfred Schroeder was already a well-known and revered figure in the worldwide community of acoustical and electrical engineers, but his paper was not much noticed, since it described negative results due to the particular nature of speech and the linear predictive coding (LPC) gain present in speech. Both Krasner and Schroeder built upon the work performed by Eberhard F. Zwicker in the areas of tuning and masking of critical bands,[19][20] that in turn built on the fundamental research in the area from Bell Labs of Harvey Fletcher and his collaborators.[21] A wide variety of (mostly perceptual) audio compression algorithms were reported in IEEE's refereed Journal on Selected Areas in Communications.[22] That journal reported in February 1988 on a wide range of established, working audio bit compression technologies, some of them using auditory masking as part of their fundamental design, and several showing real-time hardware implementations.

The immediate predecessors of MP3 were "Optimum Coding in the Frequency Domain" (OCF),[23] and Perceptual Transform Coding (PXFM).[24] These two codecs, along with block-switching contributions from Thomson-Brandt, were merged into a codec called ASPEC, which was submitted to MPEG, and which won the quality competition, but that was mistakenly rejected as too complex to implement. The first practical implementation of an audio perceptual coder (OCF) in hardware (Krasner's hardware was too cumbersome and slow for practical use), was an implementation of a psychoacoustic transform coder based on Motorola 56000 DSP chips.

As a doctoral student at Germany's University of Erlangen-Nuremberg, Karlheinz Brandenburg began working on digital music compression in the early 1980s, focusing on how people perceive music. He completed his doctoral work in 1989.[25] MP3 is directly descended from OCF and PXFM, representing the outcome of the collaboration of Brandenburg - working as a postdoc at AT&T-Bell Labs with James D. (JJ) Johnston of AT&T-Bell Labs - with the Fraunhofer Institut for Integrated Circuits, Erlangen, with relatively minor contributions from the MP2 branch of psychoacoustic sub-band coders. In 1990, Brandenburg became an assistant professor at Erlangen-Nuremberg. While there, he continued to work on music compression with scientists at the Fraunhofer Society (in 1993 he joined the staff of the Fraunhofer Institute).[25]

The song Tom's Diner by Suzanne Vega was the first song used by Karlheinz Brandenburg to develop the MP3. Brandenburg adopted the song for testing purposes, listening to it again and again each time refining the scheme, making sure it did not adversely affect the subtlety of Vega's voice.

Standardization

In 1991, there were only two proposals available that could be completely assessed for an MPEG audio standard: Musicam (Masking pattern adapted Universal Subband Integrated Coding And Multiplexing) and ASPEC (Adaptive Spectral Perceptual Entropy Coding). The Musicam technique, as proposed by Philips (the Netherlands), CCETT (France) and Institut für Rundfunktechnik (Germany) was chosen due to its simplicity and error robustness, as well as its low computational power associated with the encoding of high quality compressed audio.[26] The Musicam format, based on sub-band coding, was the basis of the MPEG Audio compression format (sampling rates, structure of frames, headers, number of samples per frame).

Much of its technology and ideas were incorporated into the definition of ISO MPEG Audio Layer I and Layer II and the filter bank alone into Layer III (MP3) format as part of the computationally inefficient hybrid filter bank. Under the chairmanship of Professor Musmann (University of Hannover) the editing of the standard was made under the responsibilities of Leon van de Kerkhof (Layer I) and Gerhard Stoll (Layer II).

ASPEC was the joint proposal of AT&T Bell Laboratories, Thomson Consumer Electronics, Fraunhofer Society and CNET.[27] It provided the highest coding efficiency.

A working group consisting of Leon van de Kerkhof (The Netherlands), Gerhard Stoll (Germany), Leonardo Chiariglione (Italy), Yves-François Dehery (France), Karlheinz Brandenburg (Germany) and James D. Johnston (USA) took ideas from ASPEC, integrated the filter bank from Layer 2, 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.

All algorithms for MPEG-1 Audio Layer I, II and III were approved in 1991[8][9] and finalized in 1992[10] as part of MPEG-1, the first standard suite by MPEG, which resulted in the international standard ISO/IEC 11172-3 (a.k.a. MPEG-1 Audio or MPEG-1 Part 3), published in 1993.[5] Further work on MPEG audio[28] 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 (a.k.a. MPEG-2 Part 3 or backwards compatible MPEG-2 Audio or MPEG-2 Audio BC[11]), originally published in 1995.[6][29] MPEG-2 Part 3 (ISO/IEC 13818-3) defined additional bit rates and sample rates for MPEG-1 Audio Layer I, II and III. The new sampling rates are exactly half that of those originally defined for MPEG-1 Audio. MPEG-2 Part 3 also enhanced MPEG-1's audio by allowing the coding of audio programs with more than two channels, up to 5.1 multichannel.[28] There is also MPEG-2.5 audio, a proprietary unofficial extension developed by Fraunhofer IIS. It enables MP3 to work satisfactorily at very low bitrates and added lower sampling frequencies.[30][31] MPEG-2.5 was not developed by MPEG and was never approved as an international standard.

MPEG Audio Layer III versions[5][6][9][30][31][32]
Version International Standard[*] First public release date (First edition) Latest public release date (edition)
MPEG-1 Audio Layer III ISO/IEC 11172-3 (MPEG-1 Part 3) 1993  
MPEG-2 Audio Layer III ISO/IEC 13818-3 (MPEG-2 Part 3) 1995 1998
MPEG-2.5 Audio Layer III nonstandard, proprietary    

 

  • Note: The ISO standard ISO/IEC 11172-3 (a.k.a. MPEG-1 Audio) defined three formats: the MPEG-1 Audio Layer I, Layer II and Layer III. The ISO standard ISO/IEC 13818-3 (a.k.a. MPEG-2 Audio) defined extended version of the MPEG-1 Audio – MPEG-2 Audio Layer I, Layer II and Layer III. MPEG-2 Audio (MPEG-2 Part 3) should not be confused with MPEG-2 AAC (MPEG-2 Part 7 – ISO/IEC 13818-7).[11]

Compression efficiency of encoders is typically defined by the bit rate, because compression ratio depends on the bit depth and sampling rate of the input signal. Nevertheless, compression ratios are often published. They may use the Compact Disc (CD) parameters as references (44.1 kHz, 2 channels at 16 bits per channel or 2×16 bit), or sometimes the Digital Audio Tape (DAT) SP parameters (48 kHz, 2×16 bit). Compression ratios with this latter reference are higher, which demonstrates the problem with use of the term compression ratio for lossy encoders.

Karlheinz Brandenburg used a CD recording of Suzanne Vega's song "Tom's Diner" to assess and refine the MP3 compression algorithm. This song was chosen because of its nearly monophonic nature and wide spectral content, making it easier to hear imperfections in the compression format during playbacks. Some jokingly refer to Suzanne Vega as "The mother of MP3".[33] Some more critical audio excerpts (glockenspiel, triangle, accordion, etc.) 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 particular track has an interesting property in that the two channels are almost, but not completely, the same, leading to a case where Binaural Masking Level Depression causes spatial unmasking of noise artifacts unless the encoder properly recognizes the situation and applies corrections similar to those detailed in the MPEG-2 AAC psychoacoustic model.

Going public

A reference simulation software implementation, written in the C language and later known as ISO 11172-5, was developed (in 1991–1996) by the members of the ISO MPEG Audio committee in order to produce bit compliant MPEG Audio files (Layer 1, Layer 2, Layer 3). It was approved as a committee draft of ISO/IEC technical report in March 1994 and printed as document CD 11172-5 in April 1994.[34] It was approved as a draft technical report (DTR/DIS) in November 1994,[35] finalized in 1996 and published as international standard ISO/IEC TR 11172-5:1998 in 1998.[36] The reference software in C language was later published as a freely available ISO standard.[37] 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. 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.

On July 7, 1994, the Fraunhofer Society released the first software MP3 encoder called l3enc.[38] The filename extension .mp3 was chosen by the Fraunhofer team on July 14, 1995 (previously, the files had been named .bit).[1] With the first real-time software MP3 player Winplay3 (released September 9, 1995) many people were able to encode and play back MP3 files on their PCs. Because of the relatively small hard drives back in that time (~ 500–1000 MB) lossy compression was essential to store non-instrument based (see tracker and MIDI) music for playback on computer.

Internet

In the second half of 1994, MP3 files began to spread on the Internet. The popularity of MP3s began to rise rapidly with the advent of Nullsoft's audio player Winamp, released in 1997. In 1998, the first portable solid state digital audio player MPMan, developed by SaeHan Information Systems which is headquartered in Seoul, South Korea, was released and the Rio PMP300 was sold afterwards, despite legal suppression efforts by the RIAA.[39]

In November 1997, the website mp3.com was offering thousands of MP3s created by independent artists for free.[39] The small size of MP3 files enabled widespread peer-to-peer file sharing of music ripped from CDs, which would have previously been nearly impossible. The first large peer-to-peer filesharing network, Napster, was launched in 1999.

The ease of creating and sharing MP3s resulted in widespread copyright infringement. Major record companies argued that this free sharing of music reduced sales, and called it "music piracy". They reacted by pursuing lawsuits against Napster (which was eventually shut down and later sold) and against individual users who engaged in file sharing.

Despite the popularity of the MP3 format, online music retailers often use other proprietary formats that are encrypted or obfuscated in order to make it difficult to use purchased music files in ways not specifically authorized by the record companies. Attempting to control the use of files in this way is known as Digital Rights Management. Record companies argue that this is necessary to prevent the files from being made available on peer-to-peer file sharing networks. This has other side effects, though, such as preventing users from playing back their purchased music on different types of devices. However, the audio content of these files can usually be converted into an unencrypted format. For instance, users are often allowed to burn files to audio CD, which requires conversion to an unencrypted audio format.

Unauthorized MP3 file sharing continues on next-generation peer-to-peer networks. Some authorized services, such as Beatport, Bleep, Juno Records, eMusic, Zune Marketplace, Walmart.com, Rhapsody, the legal incarnation of Napster, and Amazon.com sell unrestricted music in the MP3 format.

Encoding audio

The MPEG-1 standard does not include a precise specification for an MP3 encoder, but does provide example psychoacoustic models, rate loop, and the like in the non-normative part of the original standard.[40] At present, these suggested implementations are quite dated. Implementers of the standard were supposed to devise their own algorithms suitable for removing parts of the information from the audio input. As a result, there are many different MP3 encoders available, each producing files of differing quality. Comparisons are widely available, so it is easy for a prospective user of an encoder to research the best choice. It must be kept in mind that an encoder that is proficient at encoding at higher bit rates (such as LAME) is not necessarily as good at lower bit rates.

During encoding, 576 time-domain samples are taken and are transformed to 576 frequency-domain samples. If there is a transient, 192 samples are taken instead of 576. This is done to limit the temporal spread of quantization noise accompanying the transient. (See psychoacoustics.)

Decoding audio

Decoding, on the other hand, is carefully defined in the standard. Most decoders are "bitstream compliant", which means that the decompressed output – that 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 ISO/IEC high standard document (ISO/IEC 11172-3). Therefore, comparison of decoders is usually based on how computationally efficient they are (i.e., how much memory or CPU time they use in the decoding process).

Audio quality

When performing lossy audio encoding, such as creating an MP3 file, there is a trade-off between the amount of space used and the sound quality of the result. Typically, the creator is allowed to set a bit rate, which specifies how many kilobits the file may use per second of audio. The higher the bit rate, the larger the compressed file will be, and, generally, the closer it will sound to the original file.

With too low a bit rate, compression artifacts (i.e., sounds that were not present in the original recording) may be audible in the reproduction. Some audio is hard to compress because of its randomness and sharp attacks. When this type of audio is compressed, artifacts such as ringing or pre-echo are usually heard. A sample of applause compressed with a relatively low bit rate provides a good example of compression artifacts.

Besides the bit rate of an encoded piece of audio, the quality of MP3 files also depends on the quality of the encoder itself, and the difficulty of the signal being encoded. As the MP3 standard allows quite a bit of freedom with encoding algorithms, different encoders may feature quite different quality, even with identical bit rates. As an example, in a public listening test featuring two different MP3 encoders at about 128 kbit/s,[41] one scored 3.66 on a 1–5 scale, while the other scored only 2.22.

Quality is dependent on the choice of encoder and encoding parameters.[42]

The simplest type of MP3 file uses one bit rate for the entire file — this is known as Constant Bit Rate (CBR) encoding. Using a constant bit rate makes encoding simpler and faster. However, it is also possible to create files where the bit rate changes throughout the file. These are known as Variable Bit Rate (VBR) files. The idea behind this is that, in any piece of audio, some parts will be much easier to compress, such as silence or music containing only a few instruments, while others will be more difficult to compress. So, the overall quality of the file may be increased by using a lower bit rate for the less complex passages and a higher one for the more complex parts. With some encoders, it is possible to specify a given quality, and the encoder will vary the bit rate accordingly. Users who know a particular "quality setting" that is transparent to their ears can use this value when encoding all of their music, and generally speaking not need to worry about performing personal listening tests on each piece of music to determine the correct bit rate.

Perceived quality can be influenced by listening environment (ambient noise), listener attention, and listener training and in most cases by listener audio equipment (such as sound cards, speakers and headphones).

A test given to new students by Stanford University Music Professor Jonathan Berger showed that student preference for MP3 quality music has risen each year. Berger said the students seem to prefer the 'sizzle' sounds that MP3s bring to music.[43]

Bit rate

Several bit rates are specified in the MPEG-1 Audio Layer III standard: 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 and 320 kbit/s, and the available sampling frequencies are 32, 44.1 and 48 kHz.[31] Additional extensions were defined in MPEG-2 Audio Layer III: bit rates 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 kbit/s and sampling frequencies 16, 22.05 and 24 kHz.[31]

A sample rate of 44.1 kHz is almost always used, because this is also used for CD audio, the main source used for creating MP3 files. A greater variety of bit rates are used on the Internet. The rate of 128 kbit/s is commonly used,[44] at a compression ratio of 11:1, offering adequate audio quality in a relatively small space. As Internet bandwidth availability and hard drive sizes have increased, higher bit rates up to 320 kbit/s are widespread.

Uncompressed audio as stored on an audio-CD has a bit rate of 1,411.2 kbit/s,[note 2] so the bitrates 128, 160 and 192 kbit/s represent compression ratios of approximately 11:1, 9:1 and 7:1 respectively.

Non-standard bit rates up to 640 kbit/s can be achieved with the LAME encoder and the freeformat option, although few MP3 players can play those files. According to the ISO standard, decoders are only required to be able to decode streams up to 320 kbit/s.[45]

MPEG-1 and MPEG-2 Audio Layer III
available bit rates (kbit/s)[9][30][31][32][46]
MPEG-1
Audio Layer III
MPEG-2
Audio Layer III
nonstandard proprietary
MPEG-2.5 Audio Layer III
- 8 8
- 16 16
- 24 24
32 32 32
40 40 40
48 48 48
56 56 56
64 64 64
80 80 80
96 96 96
112 112 112
128 128 128
- 144 144
160 160 160
192 - -
224 - -
256 - -
320 - -
MPEG-1 and MPEG-2 Audio Layer III
available sampling rates (Hz)[9][30][31][32]
MPEG-1
Audio Layer III
MPEG-2
Audio Layer III
nonstandard proprietary
MPEG-2.5 Audio Layer III
- - 8000 Hz
- - 11025 Hz
- - 12000 Hz
- 16000 Hz -
- 22050 Hz -
- 24000 Hz -
32000 Hz - -
44100 Hz - -
48000 Hz - -

VBR

MPEG audio may use variable bitrate (VBR), accomplished via bitrate switching on a per-frame basis, but only layer III decoders must support it.[31][47][48][49] VBR is used when the goal is to achieve a fixed level of quality. The final file size of a VBR encoding is less predictable than with constant bitrate. Average bitrate is VBR implemented as a compromise between the two – the bitrate is allowed to vary for more consistent quality, but is controlled to remain near an average value chosen by the user, for predictable file sizes. Although an MP3 decoder must support VBR to be standards compliant, historically some decoders have bugs with VBR decoding, particularly before VBR encoders became widespread.

Layer III audio can also use a "bit reservoir", a partially full frame's ability to hold part of the next frame's audio data, allowing temporary changes in effective bitrate, even in a constant bitrate stream.[31][47]

File structure

Mp3filestructure.svg

An MP3 file is made up of multiple MP3 frames, which consist of a header and a data block. This sequence of frames is called an elementary stream. Frames are not independent items ("byte reservoir") and therefore cannot be extracted on arbitrary frame boundaries. The MP3 Data blocks contain the (compressed) audio information in terms of frequencies and amplitudes. The diagram shows that the MP3 Header consists of a sync word, which is used to identify the beginning of a valid frame. This is followed by a bit indicating that this is the MPEG standard and two bits that indicate that layer 3 is used; hence MPEG-1 Audio Layer 3 or MP3. After this, the values will differ, depending on the MP3 file. ISO/IEC 11172-3 defines the range of values for each section of the header along with the specification of the header. Most MP3 files today contain ID3 metadata, which precedes or follows the MP3 frames; as noted in the diagram.

Design limitations

There are several limitations inherent to the MP3 format that cannot be overcome by any MP3 encoder. Newer audio compression formats such as AAC, WMA Pro and Vorbis are generally void of a number of these limitations.[50] In technical terms, some limitations include:

  • Time resolution can be too low for highly transient signals and may cause smearing of percussive sounds.[51]
  • Due to the tree structure of the filter bank, pre-echo problems are made worse, as the combined impulse response of the two filter banks does not, and cannot, provide an optimum solution in time/frequency resolution.[51]
  • The combining of the two filter banks' outputs creates aliasing problems that must be handled partially by the "aliasing compensation" stage; however, that creates excess energy to be coded in the frequency domain, thereby decreasing coding efficiency.[citation needed]
  • Frequency resolution is limited by the small long block window size, which decreases coding efficiency.[51]
  • There is no scale factor band for frequencies above 15.5/15.8 kHz.[original research?]
  • Joint stereo is done only on a frame-to-frame basis.[51]
  • Internal handling of the bit reservoir increases encoding delay.[citation needed]
  • Encoder/decoder overall delay is not defined, which means there is no official provision for gapless playback. However, some encoders such as LAME can attach additional metadata that will allow players that can handle it to deliver seamless playback.
  • The data stream can contain an optional checksum, but the checksum only protects the header data, not the audio data.

ID3 and other tags

Main articles: ID3 and APEv2 tag

A "tag" in an audio file is a section of the file that contains metadata such as the title, artist, album, track number or other information about the file's contents. The MP3 standards do not define tag formats for MP3 files, nor is there a standard container format that would support metadata and obviate the need for tags.

However, several de facto standards for tag formats exist. As of 2010, the most widespread are ID3v1 and ID3v2, and the more recently introduced APEv2. These tags are normally embedded at the beginning or end of MP3 files, separate from the actual MP3 frame data. MP3 decoders normally either read info from the tags, or just treat them as ignorable, non-MP3 junk data.

Playing & editing software often contains tag editing functionality, but there are also tag editor applications dedicated to the purpose.

Aside from metadata pertaining to the audio content, tags may also be used for DRM.[citation needed]

Volume normalization

Since volume levels of different audio sources can vary greatly, due to the loudness war and other factors, it is sometimes desirable to adjust the playback volume of audio files such that a consistent average loudness is perceived. This normalization, while similar in purpose, is distinct from dynamic range compression.

ReplayGain is one standard for measuring and storing the loudness of an MP3 file in its metadata tag, enabling a ReplayGain-compliant player to automatically adjust the overall playback volume for each file. MP3Gain may be used to reversibly modify files based on ReplayGain measurements so that adjusted playback can be achieved on players without ReplayGain capability.

Licensing and patent issues

Many organizations have claimed ownership of patents related to MP3 decoding or encoding. These claims have led to a number of legal threats and actions from a variety of sources, resulting in uncertainty about which patents must be licensed in order to create MP3 products without committing patent infringement in countries that allow software patents.

The various MP3-related patents expire on dates ranging from 2007 to 2017 in the U.S.[52] The initial near-complete MPEG-1 standard (parts 1, 2 and 3) was publicly available on December 6, 1991 as ISO CD 11172.[53][54] In the United States, patents cannot claim inventions that were already publicly disclosed more than a year prior to the filing date, but for patents filed prior to June 8, 1995, submarine patents made it possible to extend the effective lifetime of a patent through application extensions. Patents filed for anything disclosed in ISO CD 11172 a year or more after its publication are questionable; if only the known MP3 patents filed by December 1992 are considered, then MP3 decoding may be patent free in the US by September 2015 when U.S. Patent 5,812,672 expires which had a PCT filing in Oct 1992.[55][56][57]

Technicolor (formerly called Thomson Consumer Electronics) claims to control MP3 licensing of the Layer 3 patents in many countries, including the United States, Japan, Canada and EU countries.[58] Technicolor has been actively enforcing these patents.[59]

MP3 license revenues generated about €100 million for the Fraunhofer Society in 2005.[60]

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". The letter claimed that unlicensed products "infringe the patent rights of Fraunhofer and Thomson. 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."[61]

However, there exist both free and/or proprietary alternatives, with free formats such as Vorbis, FLAC, and others. Microsoft's usage of its own proprietary Windows Media format allows it to avoid licensing issues associated with these patents by avoiding usage of the MP3 format entirely. Until the key patents expire, unlicensed encoders and players could be infringing in countries where the patents are valid.

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:

  • familiarity with the format
  • the large quantity of music now available in the MP3 format
  • the wide variety of existing software and hardware that takes advantage of the file format and does not support the alternatives
  • the lack of DRM restrictions, which makes MP3 files easy to edit, copy and play in different portable digital players (Apple, Creative, Samsung, etc.)
  • the majority of home users not knowing or not caring about the patents' existence and often not considering such legal issues when choosing their music format for personal use

Additionally, patent holders declined to enforce license fees on free and open source decoders, which allows many free MP3 decoders to develop.[citation needed]

Sisvel S.p.A. and its U.S. subsidiary Audio MPEG, Inc. previously sued Thomson for patent infringement on MP3 technology,[62] but those disputes were resolved in November 2005 with Sisvel granting Thomson a license to their patents. Motorola also recently signed with Audio MPEG to license MP3-related patents.

In September 2006, German officials seized MP3 players from SanDisk's booth at the IFA show in Berlin after an Italian patents firm won an injunction on behalf of Sisvel against SanDisk in a dispute over licensing rights. The injunction was later reversed by a Berlin judge,[63] but that reversal was in turn blocked the same day by another judge from the same court, "bringing the Patent Wild West to Germany" in the words of one commentator.[64]

In February 2007, Texas MP3 Technologies sued Apple, Samsung Electronics and Sandisk in eastern Texas federal court, claiming infringement of a portable MP3 player patent that Texas MP3 said it had been assigned. Apple and Sandisk both settled the claims against them in January 2009.[65] Samsung settled as well.[66]

Alcatel-Lucent has asserted several MP3 coding and compression patents, allegedly inherited from AT&T-Bell Labs, in litigation of its own. In November 2006, before the companies' merger, Alcatel sued Microsoft for allegedly infringing seven patents. On February 23, 2007, a San Diego jury awarded Alcatel-Lucent US $1.52 billion in damages for infringement of two of them.[67] The court subsequently tossed the award, however, finding that one patent had not been infringed and that the other was not even owned by Alcatel-Lucent; it was co-owned by AT&T and Fraunhofer, who had licensed it to Microsoft, the judge ruled.[68] That defense judgment was upheld on appeal in 2008.[69] See Alcatel-Lucent v. Microsoft for more information.

Alternative technologies

Many other lossy and lossless audio codecs exist. Among these, mp3PRO, AAC, and MP2 are all members of the same technological family as MP3 and depend on roughly similar psychoacoustic models. The Fraunhofer Gesellschaft owns many of the basic patents underlying these codecs as well, with others held by Dolby Labs, Sony, Thomson Consumer Electronics, and AT&T. In addition, there is also the open source file format Vorbis that has been available free of charge and without any known patent restrictions.

See also

 

Author:Bling King
Published:May 20th 2012
Modified:Feb 24th 2013
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There is no such thing as time
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     Upon further ponderance I have come to the conclusion that time does not exist except in the law of physics. I have come to this conclusion through the observation of how things change and why they change at the pace in which they change. To me it seems that every change that takes place  in the universe is not dictated by time but rather physics. It is the law of physics that dictates the rate and speed at which all things change. For example if you have a car  that is traveling at 100 miles an hour the speed at  which the car travels is all dictated by physical changes and therfor controlled by the law of physics..Therfor it seems that for any change to take place all you need is physics and the law of physics that governs the physical changes. Time does not need be a factor and bears no relavance. As long as we have the law of physics everything will happen in accordance with those laws.

The composition of time
Posted by Bling King

   

    Time has 3 components. A front a middle and a rear. In the front time has what appears to be something of perspectual perspectualness that will move things forward at a set forth proponent. This part of time is easy to see and witness. However it is not easy to predict at which point time will make forward momentum happen. It would seem that this forward momentum is always in inactment but I would disagree with this. To me it seems more as if time interacts with things on its own accord leaving somethings unchanged for long standing periods of time. An example of this would be how time occasionally interacts with the speed of light. The speed of light remains constant but occasionally time will manifest itself into the equation and make modifications of the speed that light travels. For instance light will move forward forthwittingly at a billion miles a second but if it encounters any kind of resistance then time will inject itself and change the speed at which it was moving. Which leads me to the assumption that in order for time to inject itself into any equation a proponent has to take place that makes a physical change that would cause time to interject itself. If no physical change takes place than time has also not been a factor.

    The middle proponent of time is the area in which time is manipulating  the change that takes...Read More

👄What turns me on
Posted by Bling King

    I get turned on by some funny stuff. I'm not really into like full blown kinkiness or at least I wouldn't consider myself to be a kinky person but I do have a few fetishes. Some of them are a little out of the ordinary. For instance I have this one fetish about being tied up  and thrown in the ocean and then rescued by a mermaid. I think this fantasy comes from when I was a kid and I used to dream of mermaids and always wanted to meet one. Well one day its gonna happen. Now don't go telling me mermaids don't exist. You don't know cause they are in fact real and as soon as I meet one I will prove it to you. As far as some of my other turn ons  I guess what really gets me excited is people who  tell other people to shut the fuck up. I love when a woman just looks at a man and tells him to shut his mouth. To me thats a big turn on because the woman seems assertive like a dominatrix or something. If she will be assertive in a conversation she will be assertive in the bedroom or so I  would like to believe.

Time is a dialectable derelict
Posted by Bling King

To fathom the fortrighteousness of time one has to contemplate the personification of forthwittial forthwittil. Time forthwittingly will only listen to the commands of its on inner personification to which there is no directional direction or so it would seem but on further inquisitories I have come to realize that there is a forthwittingly forthwittal of which time has pronounced and those commands seem to speak to the nature of to which time corresponds. To review these pronouncements for your own bemusement look at time as if you had it captured it  in a bottle. What would happen? We know on the inside of the bottle time would force the inner workings of the bottle to correspond to times diabolical commands. Causing everything to change to times everlescent rules. however on the outside of the bottle things would not change, everything would stay in constant neutrality or would it? The question remains if there was no time would things still be allowed to happen and if so at what pace and what would dictate the pace at which things would change. There seems to be no rule in place for the dictation of the pace change which takes place. So it would seem that time has decided that factor somehow within itself. There could be a correlation at which things change and the pace being dictated by physics and the amount the physical world can be allowed to change within its own accord of set boundaries. To actually find...Read More

Free from time constraints
Posted by Bling King

 

 

 

There was a time when time did not matter. The thing that was an utmost relevance now was of no matter. The diffrence it made seemed miniscule and now it is constantly dictating everything that takes place before me. What is this thing that controls and makes everything manifest itself to its constraints and why and how does it do this. Time is nothing but the utmost miracle before us. Something that has always had to exist for anything ever to take place. There is no changing its course there is no variance in its absolute everlasting existance. To control time would be the utmost  crown jewel of all accomplishments if indeed it could ever be controlled. The only way I ever see time being manipulated to change its values is to speed up everything that time has interacted with. In order to do such a thing you would have to understand the nature of the objects in question and how they are effected by time. For instance a speeding car will slow down in time without constant force being distrubuted by the engine. To slow down the car one only has to take their foot off the accelarator and gradually time will do the rest but if you could freeze time at the speed at which the car was traveling then time would not  exist because the...Read More

the truth about time
Posted by Bling King

        I have looked at time many times and I have noticed a few components. There is a precise proponent that ushers in a manifestation. Whenever something new is going to happen you can look at that event which is about to take place and precisely predict exactly when it has started. Once you realize a manifestation has taken place you can precisely predict its out come. If you know that a manifestation has started to take place then you will know you are being guided through the realm precisely by the forces of an enlightenment. Throughout time this manifestation will remain constant starting with a beginning and an end and ending in a preconcieved enlightenment. Sometimes an enlightenment can take weeks and some times an enlightenment can take centuries. It depends on how many times that enlightenment has been benounced to the realm. 

 

nothing
Posted by Bling King

I suspect a suffcient of sufficence of suffiacantel suffiance of suffiance of absurdity of absurdanace. In all actual actuality there is an  actual actuality of actualityness in retrospect to the retorospective respect in which every person who has an intellectual intellect can see that the world is a prominance of prominance in which the order will reside as long as the order is maintained. Once that order is relinquished chaos will ensue. For chaos to be a calamity there only needs to be a perspectual perspective of perspectance that escalates the chaos to that height. What would cause that is a person or persons in the realm of the realmatical realmatics looking beyond thier own existance to the existance of there forfathers to see what has become of thier existance. If you look at your own existance for what it is you will see that it is neither logical nor illogical for it makes all the sense of a sensimatical sensematic. As long as you have a reason for your own existance then it is fruitful for you to exist. Once that reason or reasons are gone you will no longer care whether it is you live or die. In the realm in which we live is a prospectus prospectant of prospectantin which all will ensue. To change the prospectus prospectus you need to look to the realm and see what the prospectus prospectant is and manifest it to your own liking. My...Read More

The conclusive conclusion
Posted by Bling King

In all actual reality the realm is manifested of certain procedural procedures that come forth frequently to forthrightous forthrightenous. In the place of predicament I have found that I can properly place things in the procedural sequence unbenowst to people of the realm. In order to conflict the conflictions you have to equate the equation of equationalness in to proper equations. Very simple but also very tedious. You do this by equating the equation into percise preciseness. An example of an equation would be a placement of perdicament of a certain event in which you wish it to be. The next manifestation I could manifest is a manifestual manifestation of manifests of a sequance of certainal circumstances. Put together a sequence by asking the sequence in order to manifest itself and then tell the manifestations to happen in frequence in which they will unfold.

The Unattainable future
Posted by Bling King

     If the future is a grain of sand and its falling through an hour glass nothing in the world can stop it. It will eniquivaocalby blind as to where its going when it comes to its rest it has befallen its fate and will remain where it lay for an eternity knowing nothing about itself or it's surroundings. I am that grain of sand. Nothing ever can change my destiny for only time here makes a diffrence.. To benounce the future is the only way to change ones fortune. The time it takes to make an equivical change remains the utmost mystery of the universe.

🤯In the eyes of myself
Posted by Bling King

 

 

There where three men. All who seemed frightened. They stood on the edge of the canyon looking on as a fourth man tumbled to his death. We could have saved him said one of the men. He should have saved himself said another. The third man just look at them bewildered and brought a handgun to his own head and pulled the trigger. Blood spattered. The two men watched as he slumped to the ground. The first man screamed and the second threw himself to the side of the man on the ground. Why?!! he screamed. It was the only sound heard. Sobbing he looked at the man standing and said you did this! You and your frigging righteous speech about the lives we leave and the sacrifice we must make. Your the devil. I am not the devil said the standing man only the truth. The truth about what? The other man screamed. Your life he said and he jumped.

The man heard a ringing and he sat up slowly. It was over the dream but his thoughts where still on the side of the canyon. How did this happen. How did it all just fade away? The dream came and went in an instant leaving his mind boggled and his eyes heavy. I knew I was there thought the man but how? It was all to familiar the...Read More

The story Elijah and Ellen
Posted by Bling King

The story of Elijah and Ellan. This is the story of Elijah and Ellan. Ellan is a beutiful temptress and Elijah is a dutiful servant of Ellan's. Together the pair fell in love and soon became a duo of in excessible excession. They frolicked in the sun under the rare occurance of rain they took shelter in the arms of each other. One day while hiding from the glares of the sun under an oak tree that provided an abundance of shade they looked into each others souls and realized there where no people suited for each other then the two of them where suited for each other. They basked in the notion that they where the most two compatible souls on the planet. As they where thinking this a giant unforseen acclamaited acclamation occurred. The planet began to tremble and shake beneath them and the stars came out. The sun hid amongst the clouds and everything from start to finish began to take shape. There where huge explosions and giant surges of wind and rain. The two began to run for their shelter knowing at the exact moment the trembling and violent agressions of unacclaimated weather started that they most likely wouldn't make it to see another sunrise. The planet was exploding with molten lava and the tempertures where unbearable as for the two of them could remember they had never seen a winter climate and didn't expect they ever would. The planet had been warming out of...Read More

today was a day of dismal despair
Posted by Bling King

Things have gone down hill drastically now for a very long time. We seem to be some what defeated but yet i know we still have some power and prominance. We are fighting an up hill battle and there is no way forward from here from what i can see. We are trudging along a path that goes nowhere.

⚔️The Greatest Warrior of All Time
Posted by Bling King

 

 

Today i conquered and beat all adverseries there where to beat. Tomorrow new adversaries will arise. I will be ready, there is never a shortage of enemies who wish to dethrone me from the top of the world. I didn't get here by being passive and yeilding to the oppostion. I got here by defeating them both mentally and physically and in entiriety.

In a time of desilute despair
Posted by Bling King

     There was a time when I was in desilute despair. The only thing I had was me myself and I to fall back on. I looked at the person who was my opponent and I knew one of  us was going to die and I was going to do everytrhing I could to make dam sure it wasn't me. I pulled my six shooter from its holster and aimed at the guy looking at me  about 30 yards away. He also went for his gun and in lightning speed he was laid sprawled out on the dirt bleeding and moaning. I had heard a shot but new that it had come from my own gun. He never even got a shot off. I was unscathed and again undeafeted. Anybody who ever tried to kill me was dead and their where over 30 who had tried and failed to kill yours truly.

Gravity
Posted by Bling King

Gravity is the force of nature that pulls cellestrial bodies toward one another. The cause of gravity is the enertia of a bodies movement through space and time. This happens by an object preconcievably traveling through the cosmos at an alarming rate of acceleration. The faster an object travels the more enertia it will build up and then will therefore have a greater ability to move. the more it moves the more other objects will cling to it. the way this can be proved is by taking an object and hurtling it towards another object the two objects would collide do to the enertia pulling them towards each other. Thy would not stay on their current trajectory but their paths would alter towards one another in a greater force than their initial gravitational pull. the best test to accomodate this theory would be tow baseballs flying through the air at speeds over one hundred miles an hour. The baseballs would not interject themselves with one another normally but at this speed would do so do to the balls enertia pulling them towards one another.

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