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MP1
MPEG-1 Audio Layer I, commonly abbreviated to MP1, is a lossy audio codec and one of three audio formats included in the MPEG-1 standard. For files only containing MP1 audio, the file extension .mp1 is used. It is a deliberately simplified version of MPEG-1 Audio Layer II (MP2), created for applications where lower compression efficiency could be tolerated in return for a less complex algorithm that could be executed with simpler hardware requirements. While supported by most media players, the codec is considered largely obsolete due to wider acceptance of the more complex Layer II (MP2) and Layer III (MP3) MPEG-1 codecs. A limited version of MPEG-1 layer I was also used by the Digital Compact Cassette Digital Compact Cassette (DCC) is a magnetic tape sound recording format introduced by Philips and Matsushita Electric in late 1992 and marketed as the successor to the standard analog Compact Cassette. It was also a direct competitor to Son ... format, in the form of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPEG-1 Audio Layer II
MP2 (formally MPEG-1 Audio Layer II or MPEG-2 Audio Layer II, sometimes incorrectly called Musicam) is a lossy audio compression format. It is standardised as one of the three audio codecs of MPEG-1 alongside MPEG-1 Audio Layer I (MP1) and MPEG-1 Audio Layer III (MP3). The MP2 abbreviation is also used as a common file extension for files containing this type of audio data, or its extended variant MPEG-2 Audio Layer II. MPEG-1 Audio Layer II was developed by Philips, CCETT and IRT as the MUSICAM algorithm, as part of the European-funded Digital Audio Broadcasting (DAB) project. Alongside its use on DAB broadcasts, the codec has been adopted as the standard audio format for Video CD and Super Video CD media, and also for HDV. On the other hand, MP3 (which was developed by a rival collaboration led by Fraunhofer Society called ASPEC) gained more widespread acceptance for PC and Internet applications. MP2 compresses less than MP3, but therefore also has less computational ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Compact Cassette
Digital Compact Cassette (DCC) is a magnetic tape sound recording format introduced by Philips and Matsushita Electric in late 1992 and marketed as the successor to the standard analog Compact Cassette. It was also a direct competitor to Sony's MiniDisc (MD), but neither format toppled the then-ubiquitous analog cassette despite their technical superiority, and DCC was discontinued in October 1996. Another competing format, the Digital Audio Tape (DAT), had by 1992 also failed to sell in large quantities to consumers, although it was popular as a professional digital audio storage format. The DCC form factor is similar to the analog compact cassette (CC), and DCC recorders and players can play back either type: analog as well as DCC. This backward compatibility was intended to allow users to adopt digital recording without rendering their existing tape collections obsolete, but because DCC recorders couldn't record (only play back) analog cassettes, it effectively forced con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lossy Compression
In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. Higher degrees of approximation create coarser images as more details are removed. This is opposed to lossless data compression (reversible data compression) which does not degrade the data. The amount of data reduction possible using lossy compression is much higher than using lossless techniques. Well-designed lossy compression technology often reduces file sizes significantly before degradation is noticed by the end-user. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication or to reduce transmission times or storage needs). The most widely used lossy compression algorithm is the discrete cosine transform (DCT), first published by N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio File Format
An audio file format is a file format for storing digital audio data on a computer system. The bit layout of the audio data (excluding metadata) is called the audio coding format and can be uncompressed, or audio compression (data), compressed to reduce the file size, often using lossy compression. The data can be a raw bitstream in an audio coding format, but it is usually embedded in a container format or an audio data format with defined storage layer. Format types It is important to distinguish between the audio coding format, the Container format (digital), container containing the Raw audio format, raw audio data, and an audio codec. A codec performs the encoding and decoding of the raw audio data while this encoded data is (usually) stored in a container file. Although most audio file formats support only one type of audio coding data (created with an audio codec, audio coder), a multimedia container format (as Matroska or Audio Video Interleave, AVI) may support multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elementary Stream
An elementary stream (ES) as defined by the MPEG communication protocol is usually the output of an audio encoder or video encoder. An ES contains only one kind of data (e.g. audio, video, or closed caption). An elementary stream is often referred to as "elementary", "data", "audio", or "video" bitstreams or streams. The format of the elementary stream depends upon the codec or data carried in the stream, but will often carry a common header when packetized into a packetized elementary stream. Header for MPEG-2 video elementary stream General layout of MPEG-1 audio elementary stream The digitized sound signal is divided up into blocks of 384 samples in Layer I and 1152 samples in Layers II and III. The sound sample block is encoded within an audio frame: * header * error check * audio data * ancillary data The header of a frame contains general information such as the MPEG Layer, the sampling frequency, the number of channels, whether the frame is CRC protected, whether ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO/IEC 11172-3
MPEG-1 is a standard for lossy compression of video and audio. It is designed to compress VHS-quality raw digital video and CD audio down to about 1.5 Mbit/s (26:1 and 6:1 compression ratios respectively) without excessive quality loss, making video CDs, digital cable/satellite TV and digital audio broadcasting (DAB) practical. Today, MPEG-1 has become the most widely compatible lossy audio/video format in the world, and is used in a large number of products and technologies. Perhaps the best-known part of the MPEG-1 standard is the first version of the MP3 audio format it introduced. The MPEG-1 standard is published as ISO/ IEC 11172, titled ''Information technology—Coding of moving pictures and associated audio for digital storage media at up to about 1.5 Mbit/s''. The standard consists of the following five ''Parts'': #Systems (defining a format for storage and synchronization of video, audio, and other data together in a single file—later dubbed the MPEG pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO/IEC 13818-3
ISO/IEC JTC 1, entitled "Information technology", is a joint technical committee (JTC) of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC). Its purpose is to develop, maintain and promote standards in the fields of information and communications technology (ICT). JTC 1 has been responsible for many critical IT standards, ranging from the Joint Photographic Experts Group (JPEG) image formats and Moving Picture Experts Group (MPEG) audio and video formats to the C and C++ programming languages. History ISO/IEC JTC 1 was formed in 1987 as a merger between ISO/TC 97 (Information Technology) and IEC/TC 83, with IEC/SC 47B joining later. The intent was to bring together, in a single committee, the IT standardization activities of the two parent organizations in order to avoid duplicative or possibly incompatible standards. At the time of its formation, the mandate of JTC 1 was to develop base standards in information t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lossy Audio Compression
In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression reduces bits by identifying and eliminating Redundancy (information theory), statistical redundancy. No information is lost in lossless compression. Lossy compression reduces bits by removing unnecessary or less important information. Typically, a device that performs data compression is referred to as an encoder, and one that performs the reversal of the process (decompression) as a decoder. The process of reducing the size of a data file is often referred to as data compression. In the context of data transmission, it is called source coding: encoding is done at the source of the data before it is stored or transmitted. Source coding should not be confused with channel coding, for error detection and correction or line coding, the means ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPEG-1
MPEG-1 is a Technical standard, standard for lossy compression of video and Audio frequency, audio. It is designed to compress VHS-quality raw digital video and CD audio down to about 1.5 Mbit/s (26:1 and 6:1 compression ratios respectively) without excessive quality loss, making video CDs, digital Cable television, cable/Satellite television, satellite TV and digital audio broadcasting (DAB) practical. Today, MPEG-1 has become the most widely compatible lossy audio/video format in the world, and is used in a large number of products and technologies. Perhaps the best-known part of the MPEG-1 standard is the first version of the MP3 audio format it introduced. The MPEG-1 standard is published as International Organization for Standardization, ISO/International Electrotechnical Commission, IEC 11172, titled ''Information technology—Coding of moving pictures and associated audio for digital storage media at up to about 1.5 Mbit/s''. The standard consists of the follow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Media Player (application Software)
Media player software is a type of application software for playing multimedia computer files like audio and video files. Media players commonly display standard media control icons known from physical devices such as tape recorders and CD players, such as play ( ), pause ( ), fastforward (⏩️), rewind (⏪), and stop ( ) buttons. In addition, they generally have progress bars (or "playback bars"), which are sliders to locate the current position in the duration of the media file. Mainstream operating systems have at least one default media player. For example, Windows comes with Windows Media Player, Microsoft Movies & TV and Groove Music, while macOS comes with QuickTime Player and Music. Linux distributions come with different media players, such as SMPlayer, Amarok, Audacious, Banshee, MPlayer, mpv, Rhythmbox, Totem, VLC media player, and xine. Android comes with YouTube Music for audio and Google Photos for video, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sub-band Coding
In signal processing, sub-band coding (SBC) is any form of transform coding that breaks a signal into a number of different frequency bands, typically by using a fast Fourier transform, and encodes each one independently. This decomposition is often the first step in data compression for audio and video signals. SBC is the core technique used in many popular lossy audio compression algorithms including MP3. Encoding audio signals The simplest way to digitally encode audio signals is pulse-code modulation (PCM), which is used on audio CDs, DAT recordings, and so on. Digitization transforms continuous signals into discrete ones by sampling a signal's amplitude at uniform intervals and rounding to the nearest value representable with the available number of bits. This process is fundamentally inexact, and involves two errors: '' discretization error,'' from sampling at intervals, and ''quantization error,'' from rounding. The more bits used to represent each sample, the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio File Formats
An audio file format is a file format for storing digital audio data on a computer system. The bit layout of the audio data (excluding metadata) is called the audio coding format and can be uncompressed, or compressed to reduce the file size, often using lossy compression. The data can be a raw bitstream in an audio coding format, but it is usually embedded in a container format or an audio data format with defined storage layer. Format types It is important to distinguish between the audio coding format, the container containing the raw audio data, and an audio codec. A codec performs the encoding and decoding of the raw audio data while this encoded data is (usually) stored in a container file. Although most audio file formats support only one type of audio coding data (created with an audio coder), a multimedia container format (as Matroska or AVI) may support multiple types of audio and video data. There are three major groups of audio file formats: * Uncompressed audi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
