Replay Gain - Revision history

Notat: name change

2011-07-27T17:17:05Z

name change

Show changes

Notat: Replay Gain -> ReplayGain

2011-07-27T17:14:56Z

Replay Gain -> ReplayGain

Show changes

Mjb: missing space restored

2011-07-05T00:16:02Z

missing space restored

← Older revision		Revision as of 00:16, 5 July 2011
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	'''Replay Gain''' is the name of a technique invented to achieve the same perceived playback loudness of audio files. It defines an algorithm to measure the '''perceived''' loudness of audio data.		'''Replay Gain''' is the name of a technique invented to achieve the same perceived playback loudness of audio files. It defines an algorithm to measure the '''perceived''' loudness of audio data.

	Replay Gain allows the loudness of each song within a collection of songs to be consistent. This is called 'Track Gain'(or 'Radio Gain' in earlier parlance). It also allows the loudness of a specific sub-collection (an "album") to be consistent with the rest of the collection, while allowing the dynamics from song to song on the album to remain intact. This is called 'Album Gain' (or 'Audiophile Gain' in earlier parlance). This is especially important when listening to classical music albums, because quiet tracks need to remain a certain degree quieter than the louder ones.		Replay Gain allows the loudness of each song within a collection of songs to be consistent. This is called 'Track Gain' (or 'Radio Gain' in earlier parlance). It also allows the loudness of a specific sub-collection (an "album") to be consistent with the rest of the collection, while allowing the dynamics from song to song on the album to remain intact. This is called 'Album Gain' (or 'Audiophile Gain' in earlier parlance). This is especially important when listening to classical music albums, because quiet tracks need to remain a certain degree quieter than the louder ones.

	Replay Gain is different from [[Normalization\|peak normalization]]. Peak normalization merely ensures that the peak amplitude reaches a certain level. This does not ensure equal loudness. The Replay Gain technique measures the ''effective power'' of the waveform (i.e. the RMS power after applying an "equal loudness contour"), and then adjusts the amplitude of the waveform accordingly. The result is that Replay Gained waveforms are usually more uniformly amplified then peak-normalized waveforms.		Replay Gain is different from [[Normalization\|peak normalization]]. Peak normalization merely ensures that the peak amplitude reaches a certain level. This does not ensure equal loudness. The Replay Gain technique measures the ''effective power'' of the waveform (i.e. the RMS power after applying an "equal loudness contour"), and then adjusts the amplitude of the waveform accordingly. The result is that Replay Gained waveforms are usually more uniformly amplified then peak-normalized waveforms.

Notat: new specification is complete

2011-04-15T15:04:21Z

new specification is complete

← Older revision		Revision as of 15:04, 15 April 2011
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	== See also ==		== See also ==
	* [[~~Replay Gain~~ specification]] ~~(under development)~~		* [[ReplayGain specification]]

	== External links ==		== External links ==
			* [http://en.wikipedia.org/wiki/Replay_Gain Replay Gain] at Wikipedia
	* [http://www.replaygain.org/ Replay Gain - A Proposed Standard], the original proposal, now out of date with respect to current practice		* [http://www.replaygain.org/ Replay Gain - A Proposed Standard], the original proposal, now out of date with respect to current practice
	* [http://en.wikipedia.org/wiki/Replay_Gain Replay Gain] at Wikipedia
	* [http://www.bobulous.org.uk/misc/Replay-Gain.html Replay Gain using foobar2000] (how to use Replay Gain in Windows using foobar2000).		* [http://www.bobulous.org.uk/misc/Replay-Gain.html Replay Gain using foobar2000] (how to use Replay Gain in Windows using foobar2000).
	* [http://www.bobulous.org.uk/misc/Replay-Gain-in-Linux.html Replay Gain in Linux] (how to use Replay Gain in Linux using foobar2000 and Wine, or using metaflac or vorbisgain).		* [http://www.bobulous.org.uk/misc/Replay-Gain-in-Linux.html Replay Gain in Linux] (how to use Replay Gain in Linux using foobar2000 and Wine, or using metaflac or vorbisgain).

Mjb: /* foobar2000 Replay Gain scanner */ Since there's no help page for the fb2k ReplayGain Scanner preferences, I'd like to make "Target MP3 alteration volume level" more Google-able.

2011-02-04T04:17:47Z

foobar2000 Replay Gain scanner: Since there's no help page for the fb2k ReplayGain Scanner preferences, I'd like to make "Target MP3 alteration volume level" more Google-able.

← Older revision		Revision as of 04:17, 4 February 2011
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	=== [[foobar2000]] Replay Gain scanner ===		=== [[foobar2000]] Replay Gain scanner ===
	* Format:		* Format:
	** [[MP3]]: Values written to [[ID3v2]] (default) or [[APEv2]] tags. A separate function can be invoked to apply the tagged Track or Album Gain to the MP3 global gain fields (as MP3Gain does, but requiring tags first), and to rewrite the tags to account for the peak change and compensate for the difference from 89 dB. The 89 dB reference level for tags isn't configurable, but the reference level applied to the global gain fields is.		** [[MP3]]: Values written to [[ID3v2]] (default) or [[APEv2]] tags. A separate function can be invoked to apply the tagged Track or Album Gain to the MP3 global gain fields (as MP3Gain does, but requiring tags first), and to rewrite the tags to account for the peak change and compensate for the difference from 89 dB. The 89 dB reference level for tags isn't configurable, but the reference level applied to the global gain fields is (it's under Preferences > Advanced > Tools > ReplayGain Scanner > Target MP3 alteration volume level).
	** [[Musepack]]: Values written to header.		** [[Musepack]]: Values written to header.
	** (Ogg) [[Vorbis]]: Values written to [[Vorbis comment]].		** (Ogg) [[Vorbis]]: Values written to [[Vorbis comment]].

Notat: new section for target loudness. other clarifications and comments.

2011-01-18T22:33:53Z

new section for target loudness. other clarifications and comments.

← Older revision		Revision as of 22:33, 18 January 2011
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	'''Replay Gain''' is the name of a technique invented to achieve the same playback ~~volume~~ of audio files. It specifies the reference level of 83dB (with the expectation that players would add 6dB at playback time)<ref>However, the ''de facto'' standard has been for the reference level to simply be 89dB and for players not to add anything extra.[http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=52991&view=findpost&p=475019]</ref> and an algorithm to measure the '''perceived''' loudness of audio data.		'''Replay Gain''' is the name of a technique invented to achieve the same perceived playback loudness of audio files. It defines an algorithm to measure the '''perceived''' loudness of audio data.

	Replay Gain allows the loudness of each song within a collection of songs to be consistent. This is called 'Track Gain', or 'Radio Gain' in earlier parlance. It also allows the loudness of a specific sub-collection (an "album") to be consistent with the rest of the collection, while allowing the dynamics from song to song on the album to remain intact. This is called 'Album Gain', or 'Audiophile Gain' in earlier parlance. This is ~~usually~~ important when listening to classical music albums, because quiet tracks need to remain a certain degree quieter than the louder ones.		Replay Gain allows the loudness of each song within a collection of songs to be consistent. This is called 'Track Gain'(or 'Radio Gain' in earlier parlance). It also allows the loudness of a specific sub-collection (an "album") to be consistent with the rest of the collection, while allowing the dynamics from song to song on the album to remain intact. This is called 'Album Gain' (or 'Audiophile Gain' in earlier parlance). This is especially important when listening to classical music albums, because quiet tracks need to remain a certain degree quieter than the louder ones.

	Replay Gain is different from [[Normalization\|peak normalization]]. Peak normalization merely ensures that the peak amplitude reaches a certain level. This does not ensure equal loudness. The Replay Gain technique measures the ''effective power'' of the waveform (i.e. the RMS power after applying an "equal loudness contour"), and then adjusts the amplitude of the waveform accordingly. The result is that Replay Gained waveforms are usually more uniformly amplified then peak-normalized waveforms.		Replay Gain is different from [[Normalization\|peak normalization]]. Peak normalization merely ensures that the peak amplitude reaches a certain level. This does not ensure equal loudness. The Replay Gain technique measures the ''effective power'' of the waveform (i.e. the RMS power after applying an "equal loudness contour"), and then adjusts the amplitude of the waveform accordingly. The result is that Replay Gained waveforms are usually more uniformly amplified then peak-normalized waveforms.

			==Target loudness==
			The target loudness of almost all Replay Gain utilities is 89 dB SPL (an early departure from the proposal, endorsed by its author<ref>[http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=83397&view=findpost&p=721854 Does Replay gain work differtly in Media monkey]</ref>) — the Replay Gain proposal and SMPTE recommendation are 6dB lower.<ref>[http://www.mars.org/mailman/public/mad-dev/2004-February/000993.html Replay Gain discussion at mad-dev]</ref>

	==Clipping==		==Clipping==
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	== See also ==		== See also ==
	* [[Replay Gain specification]]		* [[Replay Gain specification]] (under development)

	== External links ==		== External links ==
	* [http://replaygain~~.hydrogenaudio~~.org ~~Original~~ Replay Gain ~~website~~]		* [http://www.replaygain.org/ Replay Gain - A Proposed Standard], the original proposal, now out of date with respect to current practice
	* [http://en.wikipedia.org/wiki/Replay_Gain Replay Gain] at Wikipedia		* [http://en.wikipedia.org/wiki/Replay_Gain Replay Gain] at Wikipedia
	* [http://www.bobulous.org.uk/misc/Replay-Gain.html Replay Gain using foobar2000] (how to use Replay Gain in Windows using foobar2000).		* [http://www.bobulous.org.uk/misc/Replay-Gain.html Replay Gain using foobar2000] (how to use Replay Gain in Windows using foobar2000).

Mjb: /* MediaMonkey */ album gain support clarifications

2010-12-30T04:44:41Z

MediaMonkey: album gain support clarifications

← Older revision		Revision as of 04:44, 30 December 2010
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	** [[MPC]]: Internal gain Structure.		** [[MPC]]: Internal gain Structure.
	* In addition to tags, all Replay Gain values are also stored in MediaMonkey's MDB database		* In addition to tags, all Replay Gain values are also stored in MediaMonkey's MDB database
	* ~~Does not support~~ Album/Audiophile Replay Gain (~~Added to new [[MediaMonkey]] version~~ 3		* Album/Audiophile Replay Gain not supported until v3.0 (Dec 2007); support during burning & ripping added in 3.1 (Jun 2009)
	* Also capable of (irreversibly) changing the volume of MP3 tracks, similar to [[MP3Gain]]		* Also capable of (irreversibly) changing the volume of MP3 tracks, similar to [[MP3Gain]]
	* http://www.mediamonkey.com		* http://www.mediamonkey.com/

	=== [[Winamp]] Replay Gain scanner===		=== [[Winamp]] Replay Gain scanner===

Mjb: /* MediaMonkey */ I think we established that the 89dB target with 0dB preamp is the de facto standard, rather than the 83dB target with 6dB preamp called for by the spec, so it's OK as-is

2010-12-30T04:30:43Z

MediaMonkey: I think we established that the 89dB target with 0dB preamp is the de facto standard, rather than the 83dB target with 6dB preamp called for by the spec, so it's OK as-is

← Older revision		Revision as of 04:30, 30 December 2010
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	=== [[MediaMonkey]] ===		=== [[MediaMonkey]] ===
	* Default behaviour is non-compliant with the ReplayGain standard http://replaygain.hydrogenaudio.org/calibration.html
	** Issue: Uses a reference value of 89dB rather than standard's 83dB
	** Workaround for v3.2.2: change values to 83dB at
	*** in Options \| Volume Levelling, all three '''Target Volume Level''' settings
	*** in Options \| Portable/Audio Devices for each device, Auto-Conversion, the '''Level volume when synchronizing''' setting.

	* Format:		* Format:
	** [[MP3]]: Values written to [[APEv2]] or [[ID3v2]] tags.		** [[MP3]]: Values written to [[APEv2]] or [[ID3v2]] tags.

Mjb: /* MP3Gain */ formatting

2010-12-29T12:28:33Z

MP3Gain: formatting

← Older revision		Revision as of 12:28, 29 December 2010
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	** <code>MP3GAIN_UNDO +###,+###,N</code> - the global gain adjustment to restore the original values in the left and right channels, respectively, followed by an indicator of whether to wrap at the extremes (<code>N</code> means no, <code>W</code> means yes). The adjustment values are 3 digits, zero-padded, preceded by a sign (<code>+</code> or <code>-</code>).		** <code>MP3GAIN_UNDO +###,+###,N</code> - the global gain adjustment to restore the original values in the left and right channels, respectively, followed by an indicator of whether to wrap at the extremes (<code>N</code> means no, <code>W</code> means yes). The adjustment values are 3 digits, zero-padded, preceded by a sign (<code>+</code> or <code>-</code>).
	** <code>REPLAYGAIN_TRACK_GAIN +#.###### dB</code> - The value is always 9 characters including the sign and decimal point. Examples: <code>+0.424046</code> and <code>-10.38500</code>		** <code>REPLAYGAIN_TRACK_GAIN +#.###### dB</code> - The value is always 9 characters including the sign and decimal point. Examples: <code>+0.424046</code> and <code>-10.38500</code>
	** <code>REPLAYGAIN_TRACK_PEAK #.###### dB</code> - The value is always 8 characters including the decimal point. Example: 0.149923		** <code>REPLAYGAIN_TRACK_PEAK #.###### dB</code> - The value is always 8 characters including the decimal point. Example: <code>0.149923</code>
	** <code>REPLAYGAIN_ALBUM_GAIN +#.###### dB</code> - The value is always 9 characters including the sign and decimal point. Optional.		** <code>REPLAYGAIN_ALBUM_GAIN +#.###### dB</code> - The value is always 9 characters including the sign and decimal point. Optional.
	** <code>REPLAYGAIN_ALBUM_PEAK #.###### dB</code> - The value is always 8 characters including the decimal point. Optional.		** <code>REPLAYGAIN_ALBUM_PEAK #.###### dB</code> - The value is always 8 characters including the decimal point. Optional.

Mjb: /* MP3Gain */ +format details and clarifications

2010-12-29T12:24:42Z

MP3Gain: +format details and clarifications

← Older revision		Revision as of 12:24, 29 December 2010
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	=== MP3Gain ===		=== MP3Gain ===
	[[MP3Gain]] is an implementation of Replay Gain. It can be used to just analyze files & recommend changes or to also modify the gain. If modifying the gain, it always modifies the audio data. It can add somewhat precise metadata, including undo info. The gain can be modified to any target dB, or it can be changed by a specified amount. For balance correction, user-specified changes can even be made on just one channel in simple L/R stereo-mode files (not joint stereo).		[[MP3Gain]] is an implementation of Replay Gain. It can be used to just analyze files & recommend changes or to also modify the gain. If modifying the gain, it always modifies the global gain fields in the MP3 audio data. It can add somewhat precise metadata, including undo info. The gain can be modified to any target dB, or it can be changed by a specified amount. For balance correction, user-specified changes can even be made on just one channel in simple L/R stereo-mode files (not joint stereo).

	* Format: [[MP3]]		* Format: [[MP3]]
	* Method: Audio + Meta, or Audio only		* Method: Audio + Meta (in APE tag), or Audio only
	* Limitations: ~~Audio~~ data modifications are limited to 1.5dB steps, may become irreversible (however, that's a very rare condition; see the [http://www.hydrogenaudio.org/forums/lofiversion/index.php/t34154.html "mp3gain is NOT lossless" forum thread])		* APE tag fields (ASCII bytes):
			** <code>MP3GAIN_MINMAX ###,###</code> - minimum & maximum global gain values for this file. 3 digits, zero-padded if necessary.
			** <code>MP3GAIN_ALBUM_MINMAX ###,###</code> - minimum & maximum global gain values across a set of files scanned as an album. Optional.
			** <code>MP3GAIN_UNDO +###,+###,N</code> - the global gain adjustment to restore the original values in the left and right channels, respectively, followed by an indicator of whether to wrap at the extremes (<code>N</code> means no, <code>W</code> means yes). The adjustment values are 3 digits, zero-padded, preceded by a sign (<code>+</code> or <code>-</code>).
			** <code>REPLAYGAIN_TRACK_GAIN +#.###### dB</code> - The value is always 9 characters including the sign and decimal point. Examples: <code>+0.424046</code> and <code>-10.38500</code>
			** <code>REPLAYGAIN_TRACK_PEAK #.###### dB</code> - The value is always 8 characters including the decimal point. Example: 0.149923
			** <code>REPLAYGAIN_ALBUM_GAIN +#.###### dB</code> - The value is always 9 characters including the sign and decimal point. Optional.
			** <code>REPLAYGAIN_ALBUM_PEAK #.###### dB</code> - The value is always 8 characters including the decimal point. Optional.
			* Limitations: Although the metadata, if written, contains precise adjustment & peak values, the audio data modifications are limited to 1.5dB steps and may become irreversible (however, that's a very rare condition; see the [http://www.hydrogenaudio.org/forums/lofiversion/index.php/t34154.html "mp3gain is NOT lossless" forum thread])
	* http://mp3gain.sourceforge.net/		* http://mp3gain.sourceforge.net/