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Apple’s lossless ALAC nu open source | AVblog - hifi, audio, video, luidsprekers, HDTV, tv, HDMI
Apple heeft haar lossless audioformaat ALAC volledig vrij gegeven – waardoor het nu voor iedere fabrikant en software-leverancier mogelijk is om dit formaat te ondersteunen. ALAC is een manier om muziekbestanden te verkleinen zonder kwaliteitsverlies. Identiek aan het origineel, alleen een stuk kleiner. Het is daarmee direct te vergelijken met het populaire FLAC formaat, dat altijd al vrij te gebruiken was. Het verschil tussen FLAC en ALAC is de manier van comprimeren; het resultaat (de geluidskwaliteit) is hetzelfde. Met het open-source maken van ALAC kan dit formaat flink aan populariteit winnen: omdat deze – in tegenstelling tot FLAC – breed door Apple wordt ondersteund zal de aantrekkingskracht van ontwikkelaars groot zijn.
Music Served: Extracting Music from your PC | Stereophile.com
Computer in the listening room? Two primary questions face an audiophile who wants to integrate a PC into his high-end system. First is which file format to use for ripping the music from his CDs (see sidebar).MP3 vs AAC vs FLAC vs CD | Stereophile.com
As Wes Phillips recently reported on this website , CD sales are down and legal downloads of audio files are up. Stereophile has been criticized more than once for not paying enough attention to the subjects of MP3 and other compressed file formats, such as AAC , and for offering no guidance at all to readers about how to get the best sound quality from compressed downloads. The reason is simple: Although they are universally described in the mainstream press as being of "CD quality," MP3s and their lossy-compressed ilk do not offer sufficient audio quality for serious music listening. This is not true of lossless-compressed formats such as FLAC , ALC , and WMA lossless—in fact, it was the release of iTunes 4.5, in late 2003, which allowed iPods to play lossless files, that led us to welcome the ubiquitous Apple player to the world of high-end audio. But lossy files achieve their conveniently small size by discarding too much of the music to be worth considering.
AAC – DivX Plus HD: 5.1 channel surround sound audio | DivX.com
Advanced Audio Coding (AAC) is the preferred audio format for high definition videos and is a substantial improvement on the well-known MP3 format. AAC has become the standard for high-quality digital audio and DivX Plus® video supports AAC audio tracks with 5.1 channel surround sound to deliver a cinematic experience with your home theater setup. Smaller files Given the same file size, AAC audio tracks can achieve better sound quality than MP3 audio tracks so you can achieve matching quality while reducing the data rate and audio stream in your DivX Plus file. This will take up less space than before, making for smaller files or the option to encode video with higher quality. Where storage or bandwidth is constrained, AAC's High Efficiency modes provide technologies like spectral band replication that allows you to come close to CD-quality sound at roughly half the data rate that MP3 would require.WavPack is a completely open audio compression format providing lossless, high-quality lossy, and a unique hybrid compression mode. Although the technology is loosely based on previous versions of WavPack, the new version 4 format has been designed from the ground up to offer unparalleled performance and functionality. In the default lossless mode WavPack acts just like a WinZip compressor for audio files. However, unlike MP3 or WMA encoding which can affect the sound quality, not a single bit of the original information is lost, so there's no chance of degradation. This makes lossless mode ideal for archiving audio material or any other situation where quality is paramount. The compression ratio depends on the source material, but generally is between 30% and 70%.
WavPack Audio Compression
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 format or streaming media audio format. The object of the algorithm is to represent the high-fidelity audio signal with minimum number of bits while retaining the quality. This can effectively reduce the storage space and the bandwidth required for transmission of the stored audio file . Most codecs are implemented as libraries which interface to one or more multimedia players . In hardware, "audio codec" refers to a single device that encodes analog audio as digital signals and decodes digital back into analog.
Audio codec - Wikipedia, the free encyclopedia
Vorbis is a free software / open source project headed by the Xiph.Org Foundation (formerly Xiphophorus company). The project produces an audio format specification and software implementation ( codec ) for lossy audio compression . Vorbis is most commonly used in conjunction with the Ogg container format [ 7 ] and it is therefore often referred to as Ogg Vorbis . Vorbis is a continuation of audio compression development started in 1993 by Chris Montgomery . [ 8 ] [ 9 ] Intensive development began following a September 1998 letter from the Fraunhofer Society announcing plans to charge licensing fees for the MP3 audio format . [ 10 ] [ 11 ] Vorbis project started as part of the Xiphophorus company's Ogg project (also known as OggSquish multimedia project). [ 12 ] [ 13 ] Chris Montgomery began work on the project and was assisted by a growing number of other developers.
Vorbis - Wikipedia, the free encyclopedia
Ogg is a free , open container format maintained by the Xiph.Org Foundation . The creators of the Ogg format state that it is unrestricted by software patents [ 4 ] and is designed to provide for efficient streaming and manipulation of high quality digital multimedia . The Ogg container format can multiplex a number of independent streams for audio , video , text (such as subtitles ), and metadata .
Ogg - Wikipedia, the free encyclopedia
MPEG-4 Part 14 - Wikipedia, the free encyclopedia
MPEG-4 Part 14 or MP4 (formally ISO / IEC 14496-14:2003 ) is a multimedia container format standard specified as a part of MPEG-4 . It is most commonly used to store digital video and digital audio streams, especially those defined by MPEG , but can also be used to store other data such as subtitles and still images. Like most modern container formats, MPEG-4 Part 14 allows streaming over the Internet . A separate hint track is used to include streaming information in the file. The only official filename extension for MPEG-4 Part 14 files is .mp4 .
Free Lossless Audio Codec - Wikipedia, the free encyclopedia
FLAC ( / ˈ f l æ k / ; Free Lossless Audio Codec ) is a codec ( compressor-decompressor or coder-decoder ) which allows digital audio to be losslessly compressed such that file size is reduced without any information being lost. Digital audio compressed by FLAC's algorithm can typically be reduced to 50–60% of its original size, and decompressed into an identical copy of the original audio data. FLAC is an open format with royalty-free licensing and a reference implementation which is free software .The following tables compare general and technical information for a variety of audio formats and audio compression formats. For listening tests comparing the perceived audio quality of audio formats and codecs, see the article Codec listening test . broadcast audio codecs: Systembase, APT, AVT, Harris Corporation , MAYAH, Prodys, Qbit; wireless headphones: iSkin , JayBird Gear, DTS discs for movies The 'Music' category is merely a guideline on commercialized uses of a particular format, not a technical assessment of its capabilities. (For example, in terms of marketshare, MP3 and AAC dominate the personal audio market, 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.