Opus (audio format)

OpusOpus audio format.opus
Comparison of audio coding formats. Streaming media. xHE-AAC.

Lossy compression

lossylossy data compressioncompressed
Data files using lossy compression are smaller in size and thus cost less to store and to transmit over the Internet, a crucial consideration for streaming video services such as Netflix and streaming audio services such as Spotify. A study conducted by the Audio Engineering Library concluded that lossy compression formats such as MP3s have distinct effects on timbral and emotional characteristics, tending to strengthen negative emotional qualities and weaken positive ones. The study further noted that the trumpet is the instrument most affected by compression, while the horn is least.

Apple Lossless

ALAC.m4aApple Lossless Audio Codec
Audio Interchange File Format (AIFF). Comparison of audio coding formats. Free Lossless Audio Codec (FLAC). Monkey's Audio. TTA. WavPack. Windows Media Audio 9 Lossless. Apple Lossless Audio Codec Project. ALAC – technical features. Apple - iTunes - Import. Article showing different rates of compression for different types of music.

Data compression

compressionvideo compressioncompressed
In addition to the direct applications (MP3 players or computers), digitally compressed audio streams are used in most video DVDs, digital television, streaming media on the internet, satellite and cable radio, and increasingly in terrestrial radio broadcasts. Lossy compression typically achieves far greater compression than lossless compression (data of 5 percent to 20 percent of the original stream, rather than 50 percent to 60 percent), by discarding less-critical data. The innovation of lossy audio compression was to use psychoacoustics to recognize that not all data in an audio stream can be perceived by the human auditory system.

Comparison of video container formats

Comparison of (audio/video) container formatscontainer files
Comparison of audio coding formats. Enhanced podcast.

Comparison of audio coding formats

audio
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. 1) The 'Music' category is merely a guideline on commercialized uses of a particular format, not a technical assessment of its capabilities.

Podcast

podcastspodcastingpodcaster
Vorbis may produce better audio quality with a smaller file size than alternative codecs such as AAC or MP3. However, this has not been proven conclusively. Ogg Vorbis is not bound by patents and is considered "free software" in the sense that no corporate entity owns the rights to the format. Some people feel that this is a safer container for their multimedia content for this reason. However, oggcasters can generally not reach as wide of an audience as more traditional podcasters. This is mainly due to the lack of native Ogg Vorbis support in Microsoft's Internet Explorer and Apple's Safari web browser, and the lack of Ogg Vorbis support in many mobile audio devices.

Metadata

meta datameta-datacommunications metadata
Digital audio formats such as digital audio files superseded music formats such as cassette tapes and CDs in the 2000s. Digital audio files could be labelled with more information than could be contained in just the file name. That descriptive information is called the audio tag or audio metadata in general. Computer programs specializing in adding or modifying this information are called tag editors. Metadata can be used to name, describe, catalogue and indicate ownership or copyright for a digital audio file, and its presence makes it much easier to locate a specific audio file within a group, typically through use of a search engine that accesses the metadata.

Digital container format

container formatcontainercontainer formats
Older formats such as AVI do not support new codec features like B-frames, VBR audio or VFR video natively. The format may be "hacked" to add support, but this creates compatibility problems. 4) Support for advanced content, such as chapters, subtitles, meta-tags, user-data. 5) Support of streaming media. Comparison of (audio/video) container formats. Open source codecs and containers. FFmpeg, cross-platform, open source, audio and video codec suite/library. List of multimedia (audio/video) codecs. Comparison of video codecs. Comparison of audio coding formats. Archive format. Metafile.

MPEG-2

MPEG2DVDH.262 / MPEG-2 Part 2 video
MPEG-2 AAC. multichannel encoding with up to 48 channels. Part 1: Systems – describes synchronization and multiplexing of video and audio. (It is also known as ITU-T Rec. H.222.0. ) See MPEG transport stream and MPEG program stream. Part 2: Video – video coding format for interlaced and non-interlaced video signals (Also known as ITU-T Rec. H.262). Part 3: Audioaudio coding format for perceptual coding of audio signals. A multichannel-enabled extension and extension of bit rates and sample rates for MPEG-1 Audio Layer I, II and III of MPEG-1 audio. Part 4: Describes procedures for testing compliance. Part 5: Describes systems for Software simulation.

VLC media player

VLClibVLCVLC for iOS
Container formats: ASF, AVI, FLAC, FLV, Fraps, Matroska, MP4, MPJPEG, MPEG-2 (ES, MP3), Ogg, PS, PVA, QuickTime File Format, TS, WAV, WebM. Audio coding formats: AAC, AC-3, DV Audio, FLAC, MP3, Speex, Vorbis. Streaming protocols: HTTP, MMS, RTSP, RTP, UDP. Video coding formats: Dirac, DV, H.263, H.264/MPEG-4 AVC, H.265/MPEG-H HEVC, MJPEG, MPEG-1, MPEG-2, MPEG-4 Part 2, Theora, VP5, VP6, VP8, VP9. Comparison of video player software. List of codecs. List of music software.

MPEG-4

MPEG44MP4
MPEG-4 is a method of defining compression of audio and visual (AV) digital data. It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG) (ISO/IEC JTC1/SC29/WG11) under the formal standard ISO/IEC 14496 – Coding of audio-visual objects. Uses of MPEG-4 include compression of AV data for web (streaming media) and CD distribution, voice (telephone, videophone) and broadcast television applications.

Audible (store)

AudibleAudible.comAudible Studios
Audible audio files are compatible with hundreds of audio players, PDAs, mobile phones and streaming media devices. Devices that do not have AudibleAir capability (allowing users to download content from their library directly into their devices) require a Windows PC or Macintosh to download the files. Additionally, titles can be played on the PC (using iTunes, Windows Media Player, or AudibleManager). Titles cannot be burned to CD with AudibleManager. According to Audible's website, they can be burned to CD using Apple's iTunes and some versions of Nero.

Psychoacoustics

psychoacousticpsychoacoustic modelpsychoacoustical
Such compression is a feature of nearly all modern lossy audio compression formats. Some of these formats include Dolby Digital (AC-3), MP3, Opus, Ogg Vorbis, AAC, WMA, MPEG-1 Layer II (used for digital audio broadcasting in several countries) and ATRAC, the compression used in MiniDisc and some Walkman models. Psychoacoustics is based heavily on human anatomy, especially the ear's limitations in perceiving sound as outlined previously. To summarize, these limitations are: Given that the ear will not be at peak perceptive capacity when dealing with these limitations, a compression algorithm can assign a lower priority to sounds outside the range of human hearing.

Bit rate

bitratedata ratedata transfer rate
bitrate available through the open-source Opus codec. 8 kbit/s telephone quality using speech codecs. 32–500 kbit/s lossy audio as used in Ogg Vorbis. 256 kbit/s Digital Audio Broadcasting (DAB) MP2 bit rate required to achieve a high quality signal. 400 kbit/s–1,411 kbit/s lossless audio as used in formats such as Free Lossless Audio Codec, WavPack, or Monkey's Audio to compress CD audio. 1,411.2 kbit/s Linear PCM sound format of CD-DA. 5,644.8 kbit/s DSD, which is a trademarked implementation of PDM sound format used on Super Audio CD. 6.144 Mbit/s E-AC-3 (Dolby Digital Plus), an enhanced coding system based on the AC-3 codec. 9.6 Mbit/s DVD-Audio, a digital format for delivering high-fidelity

Winamp

Bento BrowserWinamp 5.58Winamp3
Playback formats: Winamp supports music playback using MP3, MIDI, MOD, MPEG-1 audio layers 1 and 2, AAC, M4A, FLAC, WAV, and WMA. Winamp was one of the first widely used music players on Windows to support playback of Ogg Vorbis by default. It supports gapless playback for MP3 and AAC and ReplayGain for volume leveling across tracks. CD support includes playing and importing music from audio CDs, optionally with CD-Text, and burning music to CDs. The standard version limits maximum burn speed and datarate; the "Pro" version removes these limitations. Winamp supports playback of Windows Media Video and Nullsoft Streaming Video.

Audio Lossless Coding

ALS
Streaming. Error correction mechanisms. Optional storage in MP4 file format. Can be multiplexed with video data using MP4 file format. An MPEG-4 Audio profile "ALS Simple Profile". Lossless Predictive Audio Compression (predecessor). Lossless Transform Audio Compression (pre-predecessor). MPEG-4 SLS (MPEG-4 Scalable Lossless Coding). MPEG-4. MPEG-4 ALS homepage - Technical University Berlin. MPEG-4 Audio Lossless Coding (ALS) - MultimediaWiki. MPEG-4 ALS: Performance, Applications, and Related Standardization Activities - NTT (2007). Technical papers describing design of residual coding and quantization algorithms in MPEG-4 ALS codec. Announcement on ACN Newswire.