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112-491: Although originally designed for audio files, such as MP3 , it is commonly used to point media players to audio and video sources, including online sources. M3U was originally developed by Fraunhofer for use with their WinPlay3 software, but numerous media players and software applications now support the format. Careless handling of M3U playlists has been the cause of vulnerabilities in many music players such as VLC media player , iTunes , Winamp , and many others. There

224-482: A psychoacoustic coding-algorithm exploiting the masking properties of the human ear. Further optimization by Schroeder and Atal with J.L. Hall was later reported in a 1979 paper. That same year, a psychoacoustic masking codec was also proposed by M. A. Krasner, who published and produced hardware for speech (not usable as music bit-compression), but the publication of his results in a relatively obscure Lincoln Laboratory Technical Report did not immediately influence

336-514: A 75–95% reduction in size, depending on the bit rate . In popular usage, MP3 often refers to files of sound or music recordings stored in the MP3 file format (.mp3) on consumer electronic devices. Originally defined in 1991 as the third audio format of the MPEG-1 standard, it was retained and further extended—defining additional bit rates and support for more audio channels —as the third audio format of

448-435: A Neve 80-68 mixing console because Wright wanted the album's acoustic sound to be as natural as possible. Staley instructed that Pro Tools not be used within the studio; as Wright explained, "Layne absolutely had a working knowledge of his sonic preferences in the studio - and felt analog sounded better for the band's sound." The album's tracks were mostly recorded within one or two takes. The album's acoustic guitar sound

560-460: A bit rate, which specifies how many kilobits per second of audio is desired. The higher the bit rate, the larger the MP3 data stream will be, and, generally, the closer it will sound to the original recording. 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

672-461: A broadcasting system using COFDM modulation was demonstrated on air and in the field with Radio Canada and CRC Canada during the NAB show (Las Vegas) in 1991. The implementation of the audio part of this broadcasting system was based on a two-chip encoder (one for the subband transform, one for the psychoacoustic model designed by the team of G. Stoll (IRT Germany), later known as psychoacoustic model I) and

784-423: 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. Another predecessor of

896-483: A core part of the MP3 algorithm. Ernst Terhardt and other collaborators constructed an algorithm describing auditory masking with high accuracy in 1982. 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. In 1985, Atal and Schroeder presented code-excited linear prediction (CELP), an LPC-based perceptual speech-coding algorithm with auditory masking that achieved

1008-460: 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. MP3 is directly descended from OCF and PXFM, representing the outcome of the collaboration of Brandenburg — working as a postdoctoral researcher at AT&T-Bell Labs with James D. Johnston ("JJ") of AT&T-Bell Labs — with

1120-534: 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, the 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). Over time this concern has become less of an issue as CPU clock rates transitioned from MHz to GHz. Encoder/decoder overall delay

1232-482: A home computer as full recordings (as opposed to MIDI notation, or tracker files which combined notation with short recordings of instruments playing single notes). A hacker named SoloH discovered the source code of the "dist10" MPEG reference implementation shortly after the release on the servers of the University of Erlangen . He developed a higher-quality version and spread it on the internet. This code started

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1344-478: A large reduction in file sizes when compared to uncompressed audio. The combination of small size and acceptable fidelity led to a boom in the distribution of music over the Internet in the late 1990s, with MP3 serving as an enabling technology at a time when bandwidth and storage were still at a premium. The MP3 format soon became associated with controversies surrounding copyright infringement , music piracy , and

1456-463: A lesser quality setting for lectures and human speech applications and reduces encoding time and complexity. 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. An in-depth study of MP3 audio quality, sound artist and composer Ryan Maguire 's project "The Ghost in

1568-489: A perceptual limitation of human hearing called auditory masking . In 1894, the American physicist Alfred M. Mayer reported that a tone could be rendered inaudible by another tone of lower frequency. In 1959, Richard Ehmer described a complete set of auditory curves regarding this phenomenon. Between 1967 and 1974, Eberhard Zwicker did work in the areas of tuning and masking of critical frequency-bands, which in turn built on

1680-531: A proposal to collaborate on new material. Wright reacted positively and booked ten days at the London Bridge Studio. Despite Cantrell's assurances, the band did not have any planned tracks before the session began. Drummer Sean Kinney had said, "After playing loud music for a year, we'd come home and the last thing we wanted to do was crank up the amps right away. That stuff was written on buses and whenever we had downtime. We did Jar of Flies to see how it

1792-403: A public listening test featuring two early MP3 encoders set at about 128 kbit/s, 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. This observation caused a revolution in audio encoding. Early on bit rate was the prime and only consideration. At the time MP3 files were of the very simplest type: they used

1904-439: A quarter of MPEG-1 sample rates. For the general field of human speech reproduction, a bandwidth of 5,512 Hz is sufficient to produce excellent results (for voice) using the sampling rate of 11,025 and VBR encoding from 44,100 (standard) WAV file. English speakers average 41–42 kbit/s with -V 9.6 setting but this may vary with the amount of silence recorded or the rate of delivery (wpm). Resampling to 12,000 (6K bandwidth)

2016-501: A real-time decoder using one Motorola 56001 DSP chip running an integer arithmetics software designed by Y.F. Dehery's team (CCETT, France). The simplicity of the corresponding decoder together with the high audio quality of this codec using for the first time a 48 kHz sampling rate , a 20 bits/sample input format (the highest available sampling standard in 1991, compatible with the AES/EBU professional digital input studio standard) were

2128-454: A set of songs about rugged individualism turned into exile." The album's title originates from a science experiment that Cantrell conducted in third grade. The experiment consisted of maintaining two jars full of flies. The flies in one jar would be overfed, while the flies in the other jar would be underfed. The flies that were overfed reproduced rapidly, but then died from overcrowding. The flies that were underfed managed to survive throughout

2240-619: A significant data compression ratio for its time. IEEE 's refereed Journal on Selected Areas in Communications reported on a wide variety of (mostly perceptual) audio compression algorithms in 1988. The "Voice Coding for Communications" edition published in February 1988 reported 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 genesis of

2352-436: A specified directory (for example, a flash drive , or CD-ROM). The m3u file should contain only one string: the path to the directory. After starting, the media player will play all contents of the directory: Here is another example, using relative format. The M3U file is placed in the same directory as the music, and directories must be preserved when moving the playlist to another device if subdirectories are used. This method

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2464-493: Is application/vnd.apple.mpegurl , registered in 2009 and only referring to the playlist format as used in HLS applications. The current proposal for the HLS playlist format acknowledges two media types which it treats as equivalent: application/vnd.apple.mpegurl and audio/mpegurl . Likewise, these are the two types recommended for HLS use by Microsoft. For non-HLS applications, no media types were standardized or registered with

2576-447: Is 1152 samples, divided into two granules of 576 samples. These samples, initially in the time domain, are transformed in one block to 576 frequency-domain samples by MDCT. MP3 also allows the use of shorter blocks in a granule, down to a size of 192 samples; this feature is used when a transient is detected. Doing so limits the temporal spread of quantization noise accompanying the transient (see psychoacoustics ). Frequency resolution

2688-529: Is M3U8, which uses UTF-8 -encoded characters. M3U8 files are the basis for the HTTP Live Streaming (HLS) format originally developed by Apple to stream video and radio to iOS devices, and which is now a popular format for adaptive streaming in general. The 2015 proposal for the HLS playlist format uses UTF-8 exclusively and does not distinguish between the "m3u" and "m3u8" file name extensions. The only Internet media type registered for M3U and M3U8

2800-525: Is a coding format for digital audio developed largely by the Fraunhofer Society in Germany under the lead of Karlheinz Brandenburg . 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; for example, compared to CD-quality digital audio , MP3 compression can commonly achieve

2912-583: Is an example of a M3U playlist file for " Jar of Flies " album by " Alice in Chains " that was created by Mp3tag with the following custom option settings: The following tag editor software allows users to edit the ID3 tags in MP3 files, and has support for creating M3U files. The following media player software supports playing M3U files. MP3 MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III )

3024-424: Is compressed, artifacts such as ringing or pre-echo are usually heard. A sample of applause or a triangle instrument with a relatively low bit rate provides good examples of compression artifacts. Most subjective testings of perceptual codecs tend to avoid using these types of sound materials, however, the artifacts generated by percussive sounds are barely perceptible due to the specific temporal masking feature of

3136-423: Is limited by the small long block window size, which decreases coding efficiency. Time resolution can be too low for highly transient signals and may cause smearing of percussive sounds. 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. Additionally,

3248-491: Is more flexible, as it does not rely on the file path staying the same. This is the same file as above, saved as sample.m3u in C:\Documents and Settings\User\My Music\ This format in an M3U allows copying to another device for playback. All files and directories referred to must also be copied. Here is a mixed example: Notes: References to other M3U playlists, for example, are generally not well-supported. The following

3360-513: Is no formal specification for the M3U format; it is a de facto standard. An M3U file is a plain text file that specifies the locations of one or more media files. The file is saved with the "m3u" filename extension if the text is encoded in the local system's default non-Unicode encoding (e.g., a Windows codepage ), or with the "m3u8" extension if the text is UTF-8 encoded. Each entry carries one specification. The specification can be any one of

3472-432: 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. When performing lossy audio encoding, such as creating an MP3 data stream, there is a trade-off between the amount of data generated and the sound quality of the results. The person generating an MP3 selects

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3584-520: Is selected by the LAME parameter -V 9.4. Likewise -V 9.2 selects a 16,000 sample rate and a resultant 8K lowpass filtering. Older versions of LAME and FFmpeg only support integer arguments for the variable bit rate quality selection parameter. The n.nnn quality parameter (-V) is documented at lame.sourceforge.net but is only supported in LAME with the new style VBR variable bit rate quality selector—not average bit rate (ABR). Jar of Flies Jar of Flies

3696-406: Is that, in any piece of audio, some sections are easier to compress, such as silence or music containing only a few tones, 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 advanced MP3 encoders, it is possible to specify a given quality, and

3808-419: Is the most advanced MP3 encoder. LAME includes a variable bit rate (VBR) encoding which uses a quality parameter rather than a bit rate goal. Later versions (2008+) support an n.nnn quality goal which automatically selects MPEG-2 or MPEG-2.5 sampling rates as appropriate for human speech recordings that need only 5512 Hz bandwidth resolution. In the second half of the 1990s, MP3 files began to spread on

3920-510: Is the third studio EP by American rock band Alice in Chains . It was released on January 25, 1994, by Columbia Records . The band's second acoustic EP, after 1992's Sap , it was the first acoustic EP in music history to debut at No. 1 on the Billboard 200 chart, with the first week sales exceeding 141,000 copies in the United States. The self-produced record was written and recorded over

4032-499: The Best Hard Rock Performance . In November 2011, Jar of Flies was ranked No. 4 on Guitar World magazine's top ten list of guitar albums of 1994. It was featured on Guitar World magazine's "Superunknown: 50 Iconic Albums That Defined 1994" list in 2014. In April 2014, Jar of Flies was ranked No. 12 on Rolling Stone ' s "40 Best Records From Mainstream Alternative's Greatest Year" list. In May 2014,

4144-555: 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 the 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

4256-575: 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 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 to produce bit-compliant MPEG Audio files (Layer 1, Layer 2, Layer 3). It

4368-570: The Fraunhofer Institute for Integrated Circuits , Erlangen (where he worked with Bernhard Grill and four other researchers – "The Original Six" ), 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 's Heinrich Herz Institute . In 1993, he joined

4480-469: The IANA , but a number of media types are nonetheless associated with the historical and ongoing use of the M3U and M3U8 formats for general playlists: These types, plus application/vnd.apple.mpegurl and application/vnd.apple.mpegurl.audio , are supported for HLS applications by (for example) Microsoft's Windows 10 and Internet Explorer 9, and LG's WebOS . This is an example of an extended M3U file on

4592-497: The Institute for Broadcast Technology (Germany), and Matsushita (Japan), was chosen due to its simplicity and error robustness, as well as for its high level of computational efficiency. The MUSICAM format, based on sub-band coding , became the basis for the MPEG Audio compression format, incorporating, for example, its frame structure, header format, sample rates, etc. While much of MUSICAM technology and ideas were incorporated into

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4704-580: The Internet , often via underground pirated song networks. The first known experiment in Internet distribution was organized in the early 1990s by the Internet Underground Music Archive , better known by the acronym IUMA. After some experiments using uncompressed audio files, this archive started to deliver on the native worldwide low-speed Internet some compressed MPEG Audio files using the MP2 (Layer II) format and later on used MP3 files when

4816-463: The MPEG-2 ideas and implementation but was named MPEG-2.5 audio since MPEG-3 already had a different meaning. This extension was developed at Fraunhofer IIS, the registered patent holder of MP3, by reducing the frame sync field in the MP3 header from 12 to 11 bits. As in the transition from MPEG-1 to MPEG-2, MPEG-2.5 adds additional sampling rates exactly half of those available using MPEG-2. It thus widens

4928-476: The Nyquist–Shannon sampling theorem . Frequency reproduction is always strictly less than half of the sampling rate, and imperfect filters require a larger margin for error (noise level versus sharpness of filter), so an 8 kHz sampling rate limits the maximum frequency to 4 kHz, while a 48 kHz sampling rate limits an MP3 to a maximum 24 kHz sound reproduction. MPEG-2 uses half and MPEG-2.5 only

5040-535: The Recording Industry Association of America (RIAA), making Jar of Flies one of the band's most successful releases. In Canada, Jar of Flies was certified double platinum for sales of 200,000 copies. In the United Kingdom, the album was certified silver after selling 60,000 copies there. Following Alice in Chains' extensive 1993 world tour for Dirt , bassist Mike Starr getting fired during

5152-447: The bitstream , called an audio frame, which is made up of 4 parts, the header , error check , audio data , and ancillary data . The MPEG-1 standard does not include a precise specification for an MP3 encoder but does provide examples of psychoacoustic models, rate loops, and the like in the non-normative part of the original standard. MPEG-2 doubles the number of sampling rates that are supported and MPEG-2.5 adds 3 more. When this

5264-499: 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

5376-442: The 32 sub-band filterbank of Layer II on which the format is based. Besides the bit rate of an encoded piece of audio, the quality of MP3-encoded sound also depends on the quality of the encoder algorithm as well as the complexity of the signal being encoded. As the MP3 standard allows quite a bit of freedom with encoding algorithms, different encoders do feature quite different quality, even with identical bit rates. As an example, in

5488-598: The EP "darkly gorgeous", and Steve Huey stated " Jar of Flies is a low-key stunner, achingly gorgeous and harrowingly sorrowful all at once." The album was nominated for a Grammy Award for Best Recording Package in 1995, but lost to Buddy Jackson for "Tribute to the Music of Bob Wills and the Texas Playboys" performed by Asleep at the Wheel . The single "I Stay Away" was nominated for

5600-468: The EP was placed at No. 5 on Loudwire ' s "10 Best Hard Rock Albums of 1994" list. In April 2019, the EP was ranked No. 42 on Rolling Stone ' s "50 Greatest Grunge Albums" list. Jar of Flies served as inspiration for Strung Out 's 2018 acoustic EP, Black Out the Sky . Cane Hill 's lead vocalist Elijah Witt said that Jar of Flies was a major influence on the band's 2019 acoustic EP, Kill

5712-404: 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. The data stream can contain an optional checksum . Joint stereo is done only on a frame-to-frame basis. In short, MP3 compression works by reducing

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5824-570: The MP3 format and technology is to be found in the perceptual codec MUSICAM based on an integer arithmetics 32 sub-bands filter bank, driven by a psychoacoustic model. It was primarily designed for Digital Audio Broadcasting (digital radio) and digital TV, and its basic principles were disclosed to the scientific community by CCETT (France) and IRT (Germany) in Atlanta during an IEEE- ICASSP conference in 1991, after having worked on MUSICAM with Matsushita and Philips since 1989. This codec incorporated into

5936-573: The MP3 format. It is nonetheless ubiquitous and especially advantageous for low-bit-rate human speech applications. 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 an extended version of 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). LAME

6048-500: The MP3 technology is fully described in a paper from Professor Hans Musmann, who chaired the ISO MPEG Audio group for several years. In December 1988, MPEG called for an audio coding standard. In June 1989, 14 audio coding algorithms were submitted. Because of certain similarities between these coding proposals, they were clustered into four development groups. The first group was ASPEC, by Fraunhofer Gesellschaft , AT&T , France Telecom , Deutsche and Thomson-Brandt . The second group

6160-402: The MP3" isolates the sounds lost during MP3 compression. In 2015, he released the track "moDernisT" (an anagram of "Tom's Diner"), composed exclusively from the sounds deleted during MP3 compression of the song "Tom's Diner", the track originally used in the formulation of the MP3 standard. A detailed account of the techniques used to isolate the sounds deleted during MP3 compression, along with

6272-615: The MPEG-1 Audio Layer III standard, MP3 files with a bit rate below 32 kbit/s might be played back sped-up and pitched-up. Earlier systems also lack fast forwarding and rewinding playback controls on MP3. MPEG-1 frames contain the most detail in 320 kbit/s mode, the highest allowable bit rate setting, with silence and simple tones still requiring 32 kbit/s. MPEG-2 frames can capture up to 12 kHz sound reproductions needed up to 160 kbit/s. MP3 files made with MPEG-2 do not have 20 kHz bandwidth because of

6384-502: The SourceForge website until it became the de facto CBR MP3 encoder. Later an ABR mode was added. Work progressed on true variable bit rate using a quality goal between 0 and 10. Eventually, numbers (such as -V 9.600) could generate excellent quality low bit rate voice encoding at only 41 kbit/s using the MPEG-2.5 extensions. MP3 uses an overlapping MDCT structure. Each MPEG-1 MP3 frame

6496-537: The Windows platform. Sample.mp3 and Example.ogg are the media files. 123 and 321 are the lengths in seconds. A length of -1 or 0 may be used when the media file is a streaming file, as there is no actual, predefined length value. The value after the length is the title to be shown, which is generally the same as the location of the file which is on the second line. On the macOS and Linux platforms, Unix paths are used. This example shows how to create an m3u file linking to

6608-428: The accuracy of certain components of sound that are considered (by psychoacoustic analysis) to be beyond the hearing capabilities of most humans. This method is commonly referred to as perceptual coding or psychoacoustic modeling. The remaining audio information is then recorded in a space-efficient manner using MDCT and FFT algorithms. The MP3 encoding algorithm is generally split into four parts. Part 1 divides

6720-458: The album's sessions. To reflect the recording's acoustic climate, Kinney sometimes used brushes to obtain a softer feel. AKG 414 microphones were used for overhead registration, while D-12s were used for the floor and rack toms, and Sennheiser MD 421s were placed on the kick drum. 451s and 57s were mounted on the top side of the snare drum, while a 441 was fitted on the bottom side. The characteristic syncopated drum opening in "No Excuses"

6832-476: The assessment of music compression codecs. The subband coding technique was found to be efficient, not only for the perceptual coding of high-quality sound materials but especially for the encoding of critical percussive sound materials (drums, triangle ,...), due to the specific temporal masking effect of the MUSICAM sub-band filterbank (this advantage being a specific feature of short transform coding techniques). As

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6944-435: The audio signal into smaller pieces, called frames, and an MDCT filter is then performed on the output. Part 2 passes the sample into a 1024-point fast Fourier transform (FFT), then the psychoacoustic model is applied and another MDCT filter is performed on the output. Part 3 quantifies and encodes each sample, known as noise allocation, which adjusts itself to meet the bit rate and sound masking requirements. Part 4 formats

7056-404: The available frequency fidelity in half while likewise cutting the bit rate by 50%. 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. An MP3 coded with MPEG-2 results in half of the bandwidth reproduction of MPEG-1 appropriate for piano and singing. A third generation of "MP3" style data streams (files) extended

7168-431: 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. 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

7280-551: The compression format during playbacks. 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. Some more critical audio excerpts ( glockenspiel , triangle, accordion , etc.) were taken from

7392-561: The conceptual motivation for the project, was published in the 2014 Proceedings of the International Computer Music Conference. Bit rate is the product of the sample rate and number of bits per sample used to encode the music. CD audio is 44100 samples per second. The number of bits per sample also depends on the number of audio channels. The CD is stereo and 16 bits per channel. So, multiplying 44100 by 32 gives 1411200—the bit rate of uncompressed CD digital audio. MP3

7504-512: The course of just one week at the London Bridge Studio in Seattle . The tracks " No Excuses ", " I Stay Away " and " Don't Follow " were released as singles to promote the EP. Jar of Flies was nominated for two Grammy Awards in 1995: Best Recording Package and Best Hard Rock Performance for "I Stay Away". The EP was well received by critics and has been certified quadruple platinum by

7616-665: The definition of MPEG Audio Layer I and Layer II, the filter bank alone and the data structure based on 1152 samples framing (file format and byte-oriented stream) of MUSICAM remained in the Layer III (MP3) format, as part of the computationally inefficient hybrid filter bank. Under the chairmanship of Professor Musmann of the Leibniz University Hannover , the editing of the standard was delegated to Leon van de Kerkhof (Netherlands), Gerhard Stoll (Germany), and Yves-François Dehery (France), who worked on Layer I and Layer II. ASPEC

7728-444: The dominance of acoustic instruments in Jar of Flies , the album is often considered a continuation of the sound adopted by the band on the 1992 EP Sap . The album demonstrates the band's wide range by offering a variety of tracks with an acoustic texture, featuring elements of blues rock and jangle pop . Steve Huey of AllMusic stressed that "the mood is still hopelessly bleak, but

7840-597: The encoder will adjust the bit rate accordingly. Users that desire 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 the listening environment (ambient noise), listener attention, listener training, and in most cases by listener audio equipment (such as sound cards, speakers, and headphones). Furthermore, sufficient quality may be achieved by

7952-479: The extended M3U format as a base for their HTTP Live Streaming (HLS) which was documented in an Independent Submission Stream RFC in 2017 as RFC 8216 . Therein, a master playlist references segment playlists which usually contain URLs for short parts of the media stream. Some tags only apply to the former type and some only to the latter type of playlist, but they all begin with #EXT-X- . The Unicode version of M3U

8064-475: The file- ripping and sharing services MP3.com and Napster , among others. With the advent of portable media players (including "MP3 players"), a product category also including smartphones , MP3 support remains near-universal and a de facto standard for digital audio. The Moving Picture Experts Group (MPEG) designed MP3 as part of its MPEG-1 , and later MPEG-2 , standards. MPEG-1 Audio (MPEG-1 Part 3), which included MPEG-1 Audio Layer I, II, and III,

8176-598: The first ever EP and first Alice in Chains release to top the charts. It was the only EP ever to gain this distinction until 2004, when the Collision Course mashup EP by Jay-Z and Linkin Park also achieved the number one spot ten years later, and Bad Meets Evil 's EP Hell: The Sequel in 2011. Jar of Flies sold 2,037,853 copies during its first year and was later certified triple platinum in 1995 and quadruple platinum in 2022. Paul Evans of Rolling Stone called

8288-478: The first generation of MP3 defined 14 × 3 = 42 interpretations of MP3 frame data structures and size layouts. The compression efficiency of encoders is typically defined by the bit rate because the 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

8400-429: The following: Each entry ends with a line break which separates it from the following one. Furthermore, some devices only accept line breaks represented as CR LF , but do not recognize a single LF . The M3U file can also include comments, prefaced by the "#" character. In extended M3U , "#" also introduces extended M3U directives which are terminated by a colon ":" if they support parameters. Apple used

8512-485: The fundamental research in the area from Harvey Fletcher and his collaborators at Bell Labs . Perceptual coding was first used for speech coding compression with linear predictive coding (LPC), which has origins in the work of Fumitada Itakura ( Nagoya University ) and Shuzo Saito ( Nippon Telegraph and Telephone ) in 1966. In 1978, Bishnu S. Atal and Manfred R. Schroeder at Bell Labs proposed an LPC speech codec , called adaptive predictive coding , that used

8624-615: The joint stereo coding of MUSICAM and created the MP3 format, which was designed to achieve the same quality at 128  kbit/s as MP2 at 192 kbit/s. The algorithms for MPEG-1 Audio Layer I, II and III were approved in 1991 and finalized in 1992 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. Files or data streams conforming to this standard must handle sample rates of 48k, 44100, and 32k and continue to be supported by current MP3 players and decoders. Thus

8736-471: The main reasons to later adopt the characteristics of MUSICAM as the basic features for an advanced digital music compression codec. During the development of the MUSICAM encoding software, Stoll and Dehery's team made thorough use of a set of high-quality audio assessment material selected by a group of audio professionals from the European Broadcasting Union, and later used as a reference for

8848-513: The mainstream of psychoacoustic codec-development. The discrete cosine transform (DCT), a type of transform coding for lossy compression, proposed by Nasir Ahmed in 1972, was developed by Ahmed with T. Natarajan and K. R. Rao in 1973; they published their results in 1974. This led to the development of the modified discrete cosine transform (MDCT), proposed by J. P. Princen, A. W. Johnson and A. B. Bradley in 1987, following earlier work by Princen and Bradley in 1986. The MDCT later became

8960-409: The music we made at that time to be released. But the record label heard it and they really liked it. For us, it was just the experience of four guys getting together in the studio and making some music." The album's sessions lasted 14–18 hours a day, and recording was complete within seven days. Assistant engineer Jonathan Plum described the sessions as "exhaustive". The album was recorded on tape on

9072-424: The name of the kid on the cover. The first pressing of the compact disc for Jar of Flies included plastic flies visible on the front view of the clear spine. It earned a Grammy nomination for Best Recording Package. The record received a multi-format reissue for its 30th anniversary in 2024. One of them was a vinyl record with the carcasses of real flies pressed into it and limited to 100 copies. Jar of Flies

9184-537: The poignant, introspective tone produces a sense of acceptance that's actually soothing, in a funereal sort of way. Jerry Cantrell's arrangements keep growing more detailed and layered; while there are a few noisy moments, most of Jar of Flies is bathed in a clean, shimmering ambience whose source is difficult to pin down". Paul Evans of Rolling Stone stated that Staley's vocals on the tracks "Swing on This" and "Rotten Apple" "ow[e] as much to Styx and Kansas as Jerry Cantrell’s guitars do to Black Sabbath ", and that

9296-417: The previous generation for a total of 9 varieties of MP3 format files. The sample rate comparison table between MPEG-1, 2, and 2.5 is given later in the article. MPEG-2.5 is supported by LAME (since 2000), Media Player Classic (MPC), iTunes, and FFmpeg. MPEG-2.5 was not developed by MPEG (see above) and was never approved as an international standard. MPEG-2.5 is thus an unofficial or proprietary extension to

9408-414: The recording industry approved re-incarnation of Napster , and Amazon.com sell unrestricted music in the MP3 format. An MP3 file is made up of MP3 frames, which consist of a header and a data block. This sequence of frames is called an elementary stream . Due to the "bit reservoir", frames are not independent items and cannot usually be extracted on arbitrary frame boundaries. The MP3 Data blocks contain

9520-596: The reproduction of Vega's voice. Accordingly, he dubbed Vega the "Mother of MP3". Instrumental music had been easier to compress, but Vega's voice sounded unnatural in early versions of the format. Brandenburg eventually met Vega and heard Tom's Diner performed live. In 1991, two available proposals were assessed for an MPEG audio standard: MUSICAM ( M asking pattern adapted U niversal S ubband I ntegrated C oding A nd M ultiplexing) and ASPEC ( A daptive S pectral P erceptual E ntropy C oding). The MUSICAM technique, proposed by Philips (Netherlands), CCETT (France),

9632-440: The same bit rate for the entire file: this process is known as constant bit rate (CBR) encoding. Using a constant bit rate makes encoding simpler and less CPU-intensive. However, it is also possible to optimize the size of the file by creating files where the bit rate changes throughout the file. These are known as variable bit rate. The bit reservoir and VBR encoding were part of the original MPEG-1 standard. The concept behind them

9744-866: The sampling rate, MPEG-2 layer III removes all frequencies above half the new sampling rate that may have been present in the source audio. As shown in these two tables, 14 selected bit rates are allowed in MPEG-1 Audio Layer III standard: 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256 and 320 kbit/s, along with the 3 highest available sampling rates of 32, 44.1 and 48  kHz . MPEG-2 Audio Layer III also allows 14 somewhat different (and mostly lower) bit rates of 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 kbit/s with sampling rates of 16, 22.05 and 24  kHz which are exactly half that of MPEG-1. MPEG-2.5 Audio Layer III frames are limited to only 8 bit rates of 8, 16, 24, 32, 40, 48, 56 and 64 kbit/s with 3 even lower sampling rates of 8, 11.025, and 12 kHz. On earlier systems that only support

9856-514: The scope of MP3 to include human speech and other applications yet requires only 25% of the bandwidth (frequency reproduction) possible using MPEG-1 sampling rates. While not an ISO-recognized standard, MPEG-2.5 is widely supported by both inexpensive Chinese and brand-name digital audio players as well as computer software-based MP3 encoders ( LAME ), decoders (FFmpeg) and players (MPC) adding 3 × 8 = 24 additional MP3 frame types. Each generation of MP3 thus supports 3 sampling rates exactly half that of

9968-399: The shot, so I utilized lots of different gels over the lights to achieve the final look." Schenck's assistant took several trips to a nearby horse stable where he caught hundreds of flies using a butterfly net. On January 27, 2019, two days following the album's 25th anniversary, Schenck published rare outtakes from the album cover shoot on his Instagram account and said that he has forgotten

10080-428: The staff of Fraunhofer HHI. An acapella version of the song " Tom's Diner " by Suzanne Vega was the first song used by Brandenburg to develop the MP3 format. It was used as a benchmark to see how well MP3's compression algorithm handled the human voice. Brandenburg adopted the song for testing purposes, listening to it again and again each time he refined the compression algorithm, making sure it did not adversely affect

10192-509: The standard was fully completed. The popularity of MP3s began to rise rapidly with the advent of Nullsoft 's audio player Winamp , released in 1997, which still had in 2023 a community of 80 million active users. 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

10304-413: The subsequent MPEG-2 standard. MP3 as a file format commonly designates files containing an elementary stream of MPEG-1 Audio or MPEG-2 Audio encoded data, without other complexities of the MP3 standard. Concerning audio compression , which is its most apparent element to end-users, MP3 uses lossy compression to encode data using inexact approximations and the partial discarding of data, allowing for

10416-508: The tour for his drug use, and Ozzy Osbourne bassist Mike Inez joining the band, the members returned home to Seattle after the end of their Lollapalooza tour and found themselves evicted from their residence after failing to pay the rent. Homeless, the band then moved into the London Bridge Studio in Seattle. During Alice in Chains' June–August 1993 appearance at Lollapalooza, guitarist Jerry Cantrell called producer Toby Wright with

10528-485: The vocal tracks were recorded within one or two takes via a Neumann M-49 microphone. Cantrell performed the lead vocals in the track "Don't Follow". Wright described Cantrell as an "awesome" singer, and stressed that "you couldn't have done all those harmonies without him." The album's sessions concluded on September 14. Wright mixed the album at Scream Studios in Los Angeles , California from September 17–22. Due to

10640-530: The vocals "evoke pathos as well as anger." Tom Sinclair of Entertainment Weekly noted that "No Excuses" has a '70s-influenced style and described "Swing on This" as "postmodern boogie-woogie ". The album's lyrics are dark and gloomy, with Huey writing that " Jar of Flies is about living with the consequences, full of deeply felt reflections on loneliness, self-imposed isolation , and lost human connections ." Jon Pareles of The New York Times observed that "Alice in Chains prizes solitude on Jar of Flies ,

10752-690: The widespread CD ripping and digital music distribution as MP3 over the internet. 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 (a.k.a. MPEG-2 Part 3 or backward compatible MPEG-2 Audio or MPEG-2 Audio BC ), originally published in 1995. MPEG-2 Part 3 (ISO/IEC 13818-3) defined 42 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 in MPEG-1 Audio. This reduction in sampling rates serves to cut

10864-429: The year. Concerning the anecdote, Staley said "I guess there's a message in there somewhere. Evidently that experiment had a big impact on Jerry." Rocky Schenck photographed the album cover in his dining room on September 8, 1993. As he recalled, "The band had come up with the idea for the title and wanted the cover to be a young boy looking into a jar filled with flies. I remember they asked me to use 'crazy colors' in

10976-483: Was MUSICAM , by Matsushita , CCETT , ITT and Philips . The third group was ATAC (ATRAC Coding), by Fujitsu , JVC , NEC and Sony . And the fourth group was SB-ADPCM , by NTT and BTRL. The immediate predecessors of MP3 were "Optimum Coding in the Frequency Domain" (OCF), and Perceptual Transform Coding (PXFM). These two codecs, along with block-switching contributions from Thomson-Brandt, were merged into

11088-434: Was a result of Kinney's improvised experimentation with side-stick drumming. Wright was not an advocate of the technique and said that they "eventually wound up with some bongos and some smaller drums set up over the hi-hat that we incorporated into that groove ." Staley wrote much of the album's lyrics within the studio and arranged the album's vocal harmonies. Wright recalled the pace of Staley's work as quick, and that

11200-477: Was able to demonstrate the first real-time hardware decoding (DSP based) of compressed audio. Some other real-time implementations of MPEG Audio encoders and decoders were available for digital broadcasting (radio DAB , television DVB ) towards consumer receivers and set-top boxes. On 7 July 1994, the Fraunhofer Society released the first software MP3 encoder, called l3enc . The filename extension .mp3

11312-487: Was approved as a committee draft for an ISO / IEC standard in 1991, finalized in 1992, and published in 1993 as ISO/IEC 11172-3:1993. An MPEG-2 Audio (MPEG-2 Part 3) extension with lower sample and bit rates was published in 1995 as ISO/IEC 13818-3:1995. It requires only minimal modifications to existing MPEG-1 decoders (recognition of the MPEG-2 bit in the header and addition of the new lower sample and bit rates). The MP3 lossy compression algorithm takes advantage of

11424-596: Was approved as a committee draft of the ISO/IEC technical report in March 1994 and printed as document CD 11172-5 in April 1994. It was approved as a draft technical report (DTR/DIS) in November 1994, finalized in 1996 and published as international standard ISO/IEC TR 11172-5:1998 in 1998. The reference software in C language was later published as a freely available ISO standard. Working in non-real time on several operating systems, it

11536-454: Was chosen by the Fraunhofer team on 14 July 1995 (previously, the files had been named .bit ). With the first real-time software MP3 player WinPlay3 (released 9 September 1995) many people were able to encode and play back MP3 files on their PCs. Because of the relatively small hard drives of the era (≈500–1000 MB ) lossy compression was essential to store multiple albums' worth of music on

11648-401: Was designed to encode this 1411 kbit/s data at 320 kbit/s or less. If less complex passages are detected by the MP3 algorithms then lower bit rates may be employed. When using MPEG-2 instead of MPEG-1, MP3 supports only lower sampling rates (16,000, 22,050, or 24,000 samples per second) and offers choices of bit rate as low as 8 kbit/s but no higher than 160 kbit/s. By lowering

11760-590: 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. 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 ,

11872-457: Was particularly focused on. Wright recalled that "at some points we overdubbed some acoustics with micing those acoustics, but when they were recording live off the floor, I'd use whatever pick-ups [Cantrell] had in his guitars at the time, trying to keep that sound as close to acoustic-sounding as possible. So that it sounded like it was an acoustic guitar instead of an electrified acoustic guitar ." Cantrell played using Ovation guitars during

11984-413: Was produced. This version of the album includes a lyric sheet, a biography and discography of the band, the music videos for "No Excuses" and "I Stay Away" and fragments of interviews with the musicians. In addition, 2,500 copies were made of a double EP including Jar of Flies and Sap . The album entered the Billboard 200 chart at number one; with first week sales of over 141,000 copies, becoming

12096-552: Was released on January 25, 1994, by Columbia Records . The album was promoted by two singles, "No Excuses" and "I Stay Away", both of which received music videos. "No Excuses" reached #1 on the Album Rock Tracks chart, becoming the first single by the band to do so. Cantrell admitted that "we couldn't believe that it did so well," and that "the success of Jar of Flies showed us that we could do what we liked and that other people would like it too." A limited edition Enhanced CD

12208-456: Was sold afterward in 1998, despite legal suppression efforts by the RIAA . In November 1997, the website mp3.com was offering thousands of MP3s created by independent artists for free. 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 ,

12320-455: Was the joint proposal of AT&T Bell Laboratories, Thomson Consumer Electronics, Fraunhofer Society, and CNET . It provided the highest coding efficiency. A working group consisting of van de Kerkhof, Stoll, Leonardo Chiariglione ( CSELT VP for Media), Yves-François Dehery, Karlheinz Brandenburg (Germany) and James D. Johnston (United States) took ideas from ASPEC, integrated the filter bank from Layer II, added some of their ideas such as

12432-467: Was to record with [bassist] Mike Inez. We just went into the studio with no songs written, to check out the chemistry. It all fell into place. The sounds and the tones were really good. We thought it would be a waste not to put that material out." The first session took place on September 7, 1993. Vocalist Layne Staley said the band "just wanted to go into the studio for a few days with our acoustic guitars and see what happened. We never really planned on

12544-571: Was written, the suggested implementations were quite dated. Implementers of the standard were supposed to devise algorithms suitable for removing parts of the information from the audio input. As a result, many different MP3 encoders became available, each producing files of differing quality. Comparisons were widely available, so it was easy for a prospective user of an encoder to research the best choice. Some encoders that were proficient at encoding at higher bit rates (such as LAME ) were not necessarily as good at lower bit rates. Over time, LAME evolved on

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