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Audio Codecs
An audio codec is a device or computer program capable of encoding or decoding a digital data stream (a codec) that encodes or decodes audio. In software, an audio codec is a computer program implementing an algorithm that compresses and decompresses digital audio data according to a given audio file or streaming media audio coding format. The objective of the algorithm is to represent the high-fidelity audio signal with a minimum number of bits while retaining quality. This can effectively reduce the storage space and the bandwidth required for transmission of the stored audio file. Most software codecs are implemented as libraries which interface to one or more multimedia players. Most modern audio compression algorithms are based on modified discrete cosine transform (MDCT) coding and linear predictive coding (LPC). In hardware, audio codec refers to a single device that encodes analog audio as digital signals and decodes digital back into analog. In other words, it cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Codec
A codec is a computer hardware or software component that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder on a signal or data stream, and hence is a type of codec. ''Endec'' is a portmanteau of encoder/decoder. A coder or encoder encodes a data stream or a signal for transmission or storage, possibly in encrypted form, and the decoder function reverses the encoding for playback or editing. Codecs are used in videoconferencing, streaming media, and video editing applications. History Originally, in the mid-20th century, a codec was a hardware device that coded analog signals into digital form using pulse-code modulation (PCM). Later, the term was also applied to software for converting between digital signal formats, including companding functions. Examples An audio codec converts analog audio signals into digital signals for transmissi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AC'97
AC'97 (''Audio Codec '97;'' also MC'97 for ''Modem Codec '97'') is an audio codec standard developed by Intel Architecture Labs and various codec manufacturers in 1997. The standard was used in motherboards, modems, and sound cards. The specification covers two types of components, and the AC-Link digital interface between them: # an AC'97 ''digital controller'' (DC97), which is typically built into the southbridge of the chipset, and # an AC'97 audio and/or modem ''codec'', available from several vendors, which contains the analog components of the architecture. AC'97 defines a high-quality, 16- or 24- bit audio architecture with 5.1 surround sound support for the PC. AC'97 supports a 96 kHz sampling rate at 24-bit stereo resolution and a 48 kHz sampling rate at 24-bit stereo resolution for multichannel recording and playback. Integrated audio is implemented with the AC'97 Codec on the motherboard, a communications and networking riser card, or an audio/modem r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Codec
A video codec is software or Computer hardware, hardware that data compression, compresses and Uncompressed video, decompresses digital video. In the context of video compression, ''codec'' is a portmanteau of ''encoder'' and ''decoder'', while a device that only compresses is typically called an ''Encoder (digital), encoder'', and one that only decompresses is a ''decoder''. The compressed data format usually conforms to a standard video coding format. The compression is typically lossy, meaning that the compressed video lacks some information present in the original video. A consequence of this is that decompressed video has lower quality than the original, uncompressed video because there is insufficient information to accurately reconstruct the original video. There are complex relationships between the video quality, the amount of data used to represent the video (determined by the bit rate), the complexity of the encoding and decoding algorithms, sensitivity to data losses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcoding
Transcoding is the direct digital-to-digital conversion of one encoding to another, such as for video data files, audio files (e.g., MP3, WAV), or character encoding (e.g., UTF-8, ISO/IEC 8859). This is usually done in cases where a target device (or workflow) does not support the format or has limited storage capacity that mandates a reduced file size, "Advancements in Compression and Transcoding: 2008 and Beyond", Society of Motion Picture and Television Engineers (SMPTE), 2008, webpageSMPTE-spm or to convert incompatible or obsolete data to a better-supported or modern format. In the analog video world, transcoding can be performed just while files are being searched, as well as for presentation. For example, Cineon and DPX files have been widely used as a common format for digital cinema, but the data size of a two-hour movie is about 8 terabytes (TB). That large size can increase the cost and difficulty of handling movie files. However, transcoding into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Open-source Codecs
This is a listing of open-source codecs—that is, open-source software implementations of audio or video coding formats, audio codecs and video codecs respectively. Many of the codecs listed implement media formats that are restricted by patents and are hence not open formats. For example, x264 is a widely used open source implementation of the heavily patent encumbered MPEG-4 AVC video compression standard. Video codecs * x264 – H.264/MPEG-4 AVC implementation. x264 is not a codec (encoder/decoder); it is just an encoder (it cannot decode video). *OpenH264 – H.264 baseline profile encoding and decoding *OpenVVC an VVC /H.266 Real Time- Decoder for Mac OS, Windows, Linux and Android and special Version of FFmpeg, which was used for Ateme Satellite Broadcast Test. * x265 – An encoder based on the High Efficiency Video Coding (HEVC/H.265) standard. * Xvid – MPEG-4 Part 2 codec, compatible with DivX * libvpx – VP8 and VP9 implementation; formerly a propriet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Codecs
The following is a list of compression formats and related codecs. Audio compression formats Non-compression * Linear pulse-code modulation (LPCM, generally only described as PCM) is the format for uncompressed audio in media files and it is also the standard for CD-DA; note that in computers, LPCM is usually stored in container formats such as WAV, AIFF, or AU, or as raw audio format, although not technically necessary. ** FFmpeg * Pulse-density modulation (PDM) ** Direct Stream Digital (DSD) is standard for Super Audio CD *** foobar2000 Super Audio CD Decoder (based on MPEG-4 DST reference decoder) *** FFmpeg (based on dsd2pcm) * Pulse-amplitude modulation (PAM) Lossless compression * Actively used ** Most popular *** Free Lossless Audio Codec (FLAC) **** libFLAC **** FFmpeg *** Apple Lossless Audio Codec (ALAC) **** Apple QuickTime **** libalac **** FFmpeg **** Apple Music *** Monkey's Audio (APE) **** Monkey's Audio SDK **** FFmpeg (decoder only) *** OptimFRO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Audio Coding Formats
The following tables compare general and technical information for a variety of audio coding formats. For listening tests comparing the perceived audio quality of audio formats and codecs, see the article Codec listening test. General information Notes # The 'Music' category is merely a guideline on commercialized uses of a particular format, not a technical assessment of its capabilities. For example, MP3 and AAC dominate the personal audio market in terms of market share, though many other formats are comparably well suited to fill this role from a purely technical standpoint. # First public release date is first of either specification publishing or source releasing, or in the case of closed-specification, closed-source codecs, is the date of first binary releasing. Many developing codecs have pre-releases consisting of pre-1.0 versions and perhaps 1.0 release candidates (RCs), although 1.0 may not necessarily be the release version. # Latest stable version is that of sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear PCM
Pulse-code modulation (PCM) is a method used to digitally represent analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the amplitude of the analog signal is sampled at uniform intervals, and each sample is quantized to the nearest value within a range of digital steps. Alec Reeves, Claude Shannon, Barney Oliver and John R. Pierce are credited with its invention. Linear pulse-code modulation (LPCM) is a specific type of PCM in which the quantization levels are linearly uniform. This is in contrast to PCM encodings in which quantization levels vary as a function of amplitude (as with the A-law algorithm or the μ-law algorithm). Though ''PCM'' is a more general term, it is often used to describe data encoded as LPCM. A PCM stream has two basic properties that determine the stream's fidelity to the original analog signal: the sampling rate, which is the number of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
I²C
I2C (Inter-Integrated Circuit; pronounced as "" or ""), alternatively known as I2C and IIC, is a synchronous, multi-master/multi-slave, single-ended, serial communication bus invented in 1980 by Philips Semiconductors (now NXP Semiconductors). It is widely used for attaching lower-speed peripheral integrated circuits (ICs) to processors and microcontrollers in short-distance, intra-board communication. The I2C bus can be found in a wide range of electronics applications where simplicity and low manufacturing cost are more important than speed. PC components and systems which involve I2C include serial presence detect (SPD) EEPROMs on dual in-line memory modules (DIMMs) and Extended Display Identification Data (EDID) for monitors via VGA, DVI, and HDMI connectors. Common I2C applications include reading hardware monitors, sensors, real-time clocks, controlling actuators, accessing low-speed DACs and ADCs, controlling simple LCD or OLED displays, changing computer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial Peripheral Interface Bus
Serial Peripheral Interface (SPI) is a de facto standard (with many #Variations, variants) for Comparison of synchronous and asynchronous signalling, synchronous serial communication, used primarily in embedded systems for short-distance wired communication between integrated circuits. SPI follows a master–slave (technology), master–slave architecture, where a master device Signaling (telecommunications), orchestrates communication with one or more slave devices by driving the clock signal, clock and chip select signals. Some devices support changing master and slave roles on the fly. Motorola's original specification (from the early 1980s) uses four logic signals, aka lines or wires, to support full duplex communication. It is sometimes called a ''four-wire'' serial bus to contrast with Serial Peripheral Interface#Three-wire, three-wire variants which are half duplex, and with the ''two-wire'' I²C and 1-Wire serial buses. Typical #Applications, applications include interf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
