Replay Gain: Difference between revisions

From Hydrogenaudio Knowledgebase
m (Replaygain moved to Replay Gain: official spelling)
(name change)
 
(43 intermediate revisions by 15 users not shown)
Line 1: Line 1:
'''Replaygain''' is the name of a technique invented to achieve the same playback volume of audio files. It specifies the reference level of 89dB and an algorithm to measure the '''perceived''' loudness of audio data.
#REDIRECT [[ReplayGain]]
 
Replaygain is different from [[Normalization|peak normalization]]. In peak normalization, you merely ensure that the peak amplitude reaches a certain level. This does not ensure equal loudness. The replaygain technique measures the ''effective power'' (i.e. taking RMS after an ''Equal Loudness contour'') of the waveform, and amplifies the waveform accordingly. The result is that replaygained waveforms are usually more uniformly amplified that peak-normalized waveforms.
 
 
==Implementations==
 
There are different replaygain implementations, each with its own uses and strength. Most of them use [[metadata]] to indicate the level of the volume change (Volume is adjusted on playback; needs player/decoder support) others modify the audio data itself. Generally it is recommended to use an implementation which uses the metadata and does not touch the audio itself.
 
In a metadata based solution, information on both types of replaygain can be stored, and the desired playback effect can be switched back and forth in the appropriate player. However, if the audio data is permanently modified, only one type of replaygain can be chosen. Furthermore, if the audio data is modified, you may not be able to restore the original data, especially if the replaygain technique produces a negative amplification.
 
Replaygain has significant advantages over normalizing. It allows the loudness of a song to be consistant over an entire collection of audio, similar to (but more accurate than) RMS normalizing (this is called 'Track Gain', or 'Radio Gain' in earlier parlance). However, it also allows the loudness of an album to be consistant over a entire music collection, allowing the dynamics of album to remain (This is called 'Album Gain', or 'Audiophile Gain' in earlier parlance). This is usually very important in classical CDs, as there may be quiet segments and loud segments written into different tracks.
 
 
===MP3Gain===
[[MP3Gain]] is an implementation of Replaygain. It either modifies target data reversibly, or attaches metadata.
 
* Format: [[MP3]]
* Method: Audio / Meta
* Limitations: Limited to 1.5dB steps mode, may become irreversible
* http://mp3gain.sourceforge.net/
 
 
===[[LAME]]===
 
* Method: Header ([http://gabriel.mp3-tech.org/mp3infotag.html mp3infotag])
* Notes:
** Tags added during encoding; not supported by any player yet; Track Gain only
** ReplayGaining MP3's are usually done using MP3Gain (see [[Replaygain#MP3Gain|above]]) or [[Replaygain#foobar2000 replaygain scanner|foobar2000]]
* http://lame.sourceforge.net/
 
 
===[[MPC]] replaygain===
 
* Method: Header (similar to Meta data method)
* Notes: Replaygain values are stored in the header and replaygain is part of the Musepack specifications; therefore any Musepack decoder that does not support replaygain can be considered broken.
* http://rarewares.org/mpc.html
 
 
===VorbisGain===
 
* Format: [[Ogg Vorbis]]
* Method: Meta (in [[Vorbis comment]])
* http://www.sjeng.org/vorbisgain.html
** new compiles of VorbisGain at [http://www.rarewares.org/ogg.html www.rarewares.org]
:'''''Note:''' Andavari has provided a very useful script to integrate VorbisGain, which is a CLI tool, into Windows Explorer. Please [[Ogg Vorbis#ReplayGain|check this section]].
 
===FLAC / METAFLAC===
 
* Format: [[FLAC]]
* Method: Meta (in [[Vorbis comment]])
* http://flac.sf.net
 
 
===WavPack / WVGAIN===
 
* Format: [[WavPack]]
* Method: Meta (in [[APEv2]] tag)
* http://www.wavpack.com
 
 
===Wavegain===
 
* Format: waveform
* Method: Audio
* Limitations: Irreversible
* http://www.rarewares.org/files/others/wavegain.zip
 
 
===[[foobar2000]] replaygain scanner===
 
* Format:
** [[MP3]]: Values written to [[APEv2]] or [[ID3v2]] tags.
** [[MPC]]: Values written to header.
** [[Ogg Vorbis]]: Values written to [[Vorbis comment]].
** [[WavPack]]: Values written to [[APEv2]] tags.
** [[AAC]]: Values written to [[APEv2]] tags.
** [[MP4]]: Uses its own itunes-compatible tagging system (though itunes does not support replaygain).
** [[FLAC]]: Values written to [[Vorbis comment]].
** [[APE]]: Values written to [[APEv2]] tags.
** Modules ([[MOD]] etc.): Optionally saved into [[APEv2]] tags; otherwise the foobar2000 database is used.
** All other formats are supported but the replaygain values are saved to the foobar2000 database.
 
* You can also choose to only have the replaygain values saved in the foobar2000 database and leave the files untouched.
 
* http://foobar2000.org
 
===[[MediaMonkey]]===
 
* Format:
** [[MP3]]: Values written to [[APEv2]] or [[ID3v2]] tags.
** [[Ogg Vorbis]]: Values written to [[Vorbis comment]].
** [[WMA]]: Values stored in MediaMonkey's MDB database.
** [[FLAC]]: Values written to [[Vorbis comment]].
** [[APE]]: Values written to [[APEv2]] tags.
** [[WAV]]: Values stored in MediaMonkey's MDB database.
* In addition to tags, all ReplayGain values are also stored in MediaMonkey's MDB database
* Does not support Album/Audiophile replaygain
* Also capable of (irreversibly) changing the volume of MP3 tracks, similar to [[MP3Gain]]
* http://www.mediamonkey.com
 
==Players support==
 
Replaygain being present in the specs of FLAC, MPC, and APE formats, any player that support those formats usually support replaygain.
 
The situation with MP3 is rather different, as it was not part of the MP3 specs. The APEv2 tags metadata implementation is somewhat becoming the de-facto standard.
 
 
===Windows===
 
* [[Foobar2000]] supports replaygain in all possible aspects.
* [[Winamp]]
** MP3 replaygain support with adequate plugins (e.g. [http://otachan.com/in_!mpg123.html Otachan's in_!mpg123] - if you can't read japanese, you can find details [http://www.hydrogenaudio.org/forums/index.php?showtopic=18530 in this thread])
** [[Ogg Vorbis]] replaygain support
* [[MediaMonkey]] supports track replaygain only
* [[XMPlay]] recently implemented replaygain
 
''...and probably others.''
 
 
===Linux===
 
* [[XMMS]]. Reads replaygain from [[FLAC]], [[MPC]], [[Ogg Vorbis]] ..
:For [[MP3]], use the CVS version of the [http://xmms-mad.sourceforge.net/ xmms-mad]  mp3 plugin (it's not yet released as binary, furthermore not available in distribs' versions for now. Meanwhile binaries are available here: [http://perso.crans.org/~krempp/xmms-mad/ custom binaries])
* [[amarok]]. By using the amarok-script [http://kde-apps.org/content/show.php?content=26073 ReplayGain]
:And possibly others, since [http://developer.kde.org/~wheeler/taglib.html TagLib] added support for [[APEv2]] tags in [[MP3]] files, players using this library (like [[amaroK]] and [[JuK]]) might support that kind of replaygain tags in the near future.
* [http://www.sacredchao.net/quodlibet Quod Libet] reads replaygain from [[Ogg Vorbis]], [[MP3]], [[FLAC]], and [[MPC]].
:Requires support to be enabled (via the appropriate python bindings and libraries) for the above formats. Does not support replaygain values stored in [[APEv2]] tags in [[MP3]]s. Replaygain values are stored in RVA2 id3v2.4 frames. See the [http://www.sacredchao.net/quodlibet/wiki/Development/ID3Notes Quod Libet RVA2 / ReplayGain notes].
* [http://www.musicpd.org/ Music Player Daemon] (MPD) reads replaygain from [[Ogg Vorbis]], [[FLAC]], and [[MPC]].
:Foobar2000 style TXXX frames in [[MP3]]s are also supported in the latest development releases.
 
===Portable devices===
 
Current development builds of [http://www.rockbox.org/ Rockbox] for the iRiver H100 and H300 series players support replaygain for some encoder formats.  This is a rapidly evolving feature.  There are no other portable players known to support replaygain.
 
The iPod features ''Soundcheck'', which seems to produce roughly the same normalization gains as replaygain, but doesn't provide an Album Gain.
 
===Hi-Fi===
 
Slim Devices a company owened by Logitech Inc, supports Replaygain on both of their hi-end audiophile players, known as the [[Slim Devices Transporter|Transporter]] and the [[Slim Devices Squeezebox|Squeezebox]].
 
==External links==
* [http://replaygain.hydrogenaudio.org Original Replay Gain website]
* [http://en.wikipedia.org/wiki/Replay_Gain Replay Gain] at Wikipedia
* [http://www.bobulous.org.uk/misc/Replay-Gain.html Replay Gain using Foobar 2000] (how-to).
 
 
[[Category:Technical]]
[[Category:Metadata]]

Latest revision as of 17:17, 27 July 2011

Redirect to: