 ОБНОВЛЕНИЕ КОДЕКОВ |
 Аудио словарь |
- AAC
Like MP3, Advanced Audio Coding is an audio encoding scheme specified by the MPEG-2 standard. Although it is part of MPEG-2 standard, it is not compatible with the MPEG Layer scheme or MP3. AAC was design by researchers from a number of companies and can be licensed from Dolby Laboratories.
AAC encoding is more efficient than MP3, resulting in smaller file sizes for audio of similar quality. AAC can also provide many more audio channels than MP3, as well as a wider range of sampling rates for better sound quality than is possible with MP3.
Although AAC by itself has not yet been widely used, it has been used as the basis for several proprietary secure formats, and it will be used in the audio portion of the MPEG-4 standard.
- AC3
AC-3 is a high-quality, low-complexity multichannel audio compression system proposed by the Dolby Laboratories. AC-3 is approved by the ATSC and free specifications are available. AC-3 is also called Dolby Digital 5.1, the six channels are Left, Right, Center, Surround Left, Surround Right, Low Frequency Effects (<120Hz). The total encoded bit stream fits in 384Kbps. Also known as Dolby Digital, it’s a digital audio format from Dolby Labs™. It can support up to 5.1 channels of audio.
- Analog Audio
A continuously varying representation of sound waves. In most analog audio systems, a continuously varying voltage signal represents the sound wave.
- AHRA
Audio Home Recording Act of 1992 allows comsumers to create copies of recordings for personal, non-commercial use.
- ATRAC3
Sony's Adaptive Transform Acoustic Coding 3 format is an improved version of the ATRAC encoding shceme used by MiniDisc Players. It archieves nearly the same level of compression and sound quality as MP3 at the same bitrate. Currently, the ATRACT3 format is primarly used by Sony's portable players. Sony said that ATRAC3 will be SDMI compliant.
- ATSC
The Advanced Television Systems Committee (ATSC) is an international organization of 200 members that is establishing voluntary technical standards for advanced television systems. ATSC Digital TV Standards include digital high definition television (HDTV), standard definition television (SDTV), data broadcasting, multichannel surround-sound audio, and Satellite direct-to-home broadcasting.
- a2b music
A proprietary, secure music distribution system developed by AT&T. It uses AAC for compression.
- Bitrate
The number of bits per given time interval, used as a measure of information flow. Digital audio bitrate is often given in units of kbps (kilo bits per second).
- Buffer
A temporary storage of space used as a reserve to insure a smooth flow of data.
- CBR
Constant BitRate Encoding, the more commonly used method that allocates tht same number of bits per second of audio throughout the entire track. The advantage of this method is that the size of the finished MP3 can be calculated exactly before encoding it just by knowing the length of the track and the bitrate it will be encoded at. The main disadvantage of CBR is that it requires the encoder to use the same amount of information to represent both complex and very simple sections of audio. In a simple section of audio, such as silence, the encoder must waste bits, although it might not have enough bits later to completely represent an important, complex section of audio.
- Compression
Representing data in a more efficient format so it takes up less space when stored and/or requires less bandwidth when transmitted.
- Decoding
The process of converting a compressed audio format, like MP3, back into a form that can be played back.
- Digital Audio
Audio that has been sapled to get a number of data points that apporximate the original analog sound waves. Digital audio must be converted back to analog form for playback.
- Digital Audio Extraction (DAE)
Reading digital audio directly from a CD, as opposed to playing it back and sampling the analog signal. DAE is also called 'ripping'.
- Digital Rights Management (DRM)
A system that can track and manage listening and ownership of digital content.
- DMCA
Digital Millenium Copyright Act. Legistation that modified copyright law to make provisions for digital audio, including Webcasting.
- Dolby Surround and Dolby Pro Logic
Dolby Surround is a matrix process that enables any stereo (two-channel) medium, analog or digital, to carry four-channel audio. The encoded audio stream is fully compatible with mono and stereo playback. The four channels are Left, Right, Center, Surround. Dolby Pro Logic enhances Dolby Surround decoder by increasing the separation of Center and Surround channels from Left and Right channels.
- Encoding
The process of transforming audio into a compressed format, such as from WAV to MP3.
- EPAC
Enhanced Perceptual Audio Coder. An audio encoding method developed by Lucent Technologies.
- ID3 Tag
A means of saving limited descriptive information, including title, artist, album, year of release, genre and comments along with an MP3 track.
- Liquid Audio
A widely used but proprietary digital audio system that uses MPEG-2 AAC.
- Lossy compression
A type of data compression that does not keep all information is said to be 'lossy'. Many popular digital audio formats, including MP3, use lossy compression.
- Normalization
The process of adjusting the volume level on tracks as they are encoded, so that their peak levels fall within a similar range.
- OGM
OGM stands for OGg Media which is the name of the Ogg container implementation by Tobias Waldvogel. OGM can be used as an alternative to the AVI container and it can contain Ogg Vorbis, MP3 and AC3 audio, all kinds of video formats, chapter information and subtitles.
- PCM
Pulse Code Modulation. An uncompressed encoding method for digital audio, which is the way audio is stored on music CDs.
- Playlist
A listing of songs quequed up to be played in order. A playlist can also be configured or/and saved for reuse.
- Plug-in
A software module that can be used to add additional functionality to and existing program. The Winamp player uses plug-ins to add special audio or visual effects.
- RealAudio
A popular streaming format for audio and video developed by RealNetworks. The format's use is trageted toward low bitrate streaming.
- RIAA
Recording Industry Association of America. A trade organization that represent music industry financial and legal interests. Among other things, it works to influence legislation, protect the intellctual property rights of artists and record companies, and fight music piracy worldwide.
- Ripping
Is a process of reading the digital information that represents music from the CD. (a slang for digital audio extraction).
- Sampling
The process of repeatedly measuring and storing a digital representation of an analog signal.
- SDMI
Secure Digital Music Initiative is a forum for members of recording, consumer electronics, and computer technology industries to develop a standard framework for secure music distribution and use.
- SmartMedia
A type of small memory card used by many portable MP3 players for storage.
- Sound recording
Legal term for particular recording made of a song by a performer. The copyright for a sound recording is often owned by a recording company.
- Space-shifting
Moving or copying content between different media, formats, or devices.
- Streaming audio
Streaming is a method of transferring multimedia, such as audio or video in one continuous feed from sender or receiver. A streaming server parcels out a little at a time to everyone who is connected to it, and those receiving the stream can play it as it arrives without having to wait for a whole file to download. Streaming audio can be used to create a net radio station.
- VBR
Variable BitRate Encoding attempts to address this shortcoming. It dynamically allocates extra bits during complex sections of the audio track and uses fewer when it can get away with it during simpler sections of the audio. The end result is an MP3 file with a consistent quality level throughout the entire track. The disadvantage is that, it is impossible to predict the size of the finnished MP3 file. As a result, some MP3 players have difficulty with VBR-encoded files because they can't determine the play time of the track.
- VQF (TwinVQ)
The VQF format is the much-shortened name for Transformdomain Weighted Interleave Vector Quantization format, also called TwinVQ. It was developed by Nippon Telegraph and Telephone (NTT) and produces audio files with better compression and better sound quality than MP3. However, compared to MP3, VQF requires substantially greater time for the encoding process. Support for VQF has waned as of late, but MPEG-4 audio will incorporate the technology.
- WAV
An uncompressed sound file format for PCs.
- Windows Media Audio (WMA)
Is part of Microsoft's Windows Media audio and video software, which includes a digital rights management system to secure the files. WMA quality remains quite high even at low bitrates, and Microsoft claims WMA can reproduce CD-quality audio as low as 64kbps, or roughly twice the compression of MP3. WMA is downloadable format, and in conjunction with Microsoft's Advanced Streaming Format (ASF), WMA can also be streamed to listeners. In fact, Windows Media competes directly with the more established RealAudio format and is quickly gaining in popularity. Many portable devices already support WMA, and the format is sure to be a major player in the future of digital audio.
|
|
 |
|
|
| Регистрация на сайте предоставит Вам много дополнительных возможностей по наполнению сайта информацией. Самостоятельно публиковать новости и статьи, вы сможете оставлять комментарии. |
|
|
 |
|
