Variable Bitrate - Revision history

MarkH: clarify that lossless compression (capable of reducing the size of arbitrary uncompressed data) is necessarily VBR

2014-07-28T20:57:00Z

clarify that lossless compression (capable of reducing the size of arbitrary uncompressed data) is necessarily VBR

← Older revision		Revision as of 20:57, 28 July 2014
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	Some codecs limited to [[Constant Bitrate]] (CBR) include [[AC3]] (in theory it can encode to VBR, but no high quality encoder offers that feature), [[DTS]] (same thing as AC3, no publicly available VBR encoder), [[Real Audio]] and [[ATRAC3]].		Some codecs limited to [[Constant Bitrate]] (CBR) include [[AC3]] (in theory it can encode to VBR, but no high quality encoder offers that feature), [[DTS]] (same thing as AC3, no publicly available VBR encoder), [[Real Audio]] and [[ATRAC3]].

	~~Most~~ [[lossless]] ~~codecs are~~ VBR.		All [[lossless]] compression is VBR.

	To help players seek and show correct durations, VBR formats often include metadata at the beginning of the file to indicate the total duration and provide a "seek table" of the offsets, within the file, of a set number of points, each a fixed duration apart. For example, the seek table may have 100 offsets to represent 1%, 2%, 3%, etc. of the way toward the total duration. This feature is sometimes also used in CBR formats, so that tags don't confound file-size based estimates of duration and seek points.		To help players seek and show correct durations, VBR formats often include metadata at the beginning of the file to indicate the total duration and provide a "seek table" of the offsets, within the file, of a set number of points, each a fixed duration apart. For example, the seek table may have 100 offsets to represent 1%, 2%, 3%, etc. of the way toward the total duration. This feature is sometimes also used in CBR formats, so that tags don't confound file-size based estimates of duration and seek points.

	[[Category:Technical]]		[[Category:Technical]]

70.176.62.130: WAV and AIFF are not lossless, they are strictly uncompressed (RAW).

2013-11-13T14:20:20Z

WAV and AIFF are not lossless, they are strictly uncompressed (RAW).

← Older revision		Revision as of 14:20, 13 November 2013
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	Some codecs limited to [[Constant Bitrate]] (CBR) include [[AC3]] (in theory it can encode to VBR, but no high quality encoder offers that feature), [[DTS]] (same thing as AC3, no publicly available VBR encoder), [[Real Audio]] and [[ATRAC3]].		Some codecs limited to [[Constant Bitrate]] (CBR) include [[AC3]] (in theory it can encode to VBR, but no high quality encoder offers that feature), [[DTS]] (same thing as AC3, no publicly available VBR encoder), [[Real Audio]] and [[ATRAC3]].

	Most [[lossless]] codecs are VBR. ~~[[PCM]] (as commonly stored in [[WAV]] or [[AIFF]] containers) is not.~~		Most [[lossless]] codecs are VBR.

	To help players seek and show correct durations, VBR formats often include metadata at the beginning of the file to indicate the total duration and provide a "seek table" of the offsets, within the file, of a set number of points, each a fixed duration apart. For example, the seek table may have 100 offsets to represent 1%, 2%, 3%, etc. of the way toward the total duration. This feature is sometimes also used in CBR formats, so that tags don't confound file-size based estimates of duration and seek points.		To help players seek and show correct durations, VBR formats often include metadata at the beginning of the file to indicate the total duration and provide a "seek table" of the offsets, within the file, of a set number of points, each a fixed duration apart. For example, the seek table may have 100 offsets to represent 1%, 2%, 3%, etc. of the way toward the total duration. This feature is sometimes also used in CBR formats, so that tags don't confound file-size based estimates of duration and seek points.

	[[Category:Technical]]		[[Category:Technical]]

Mjb: +seek table basics

2011-10-21T12:12:38Z

+seek table basics

← Older revision		Revision as of 12:12, 21 October 2011
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	Most [[lossless]] codecs are VBR. [[PCM]] (as commonly stored in [[WAV]] or [[AIFF]] containers) is not.		Most [[lossless]] codecs are VBR. [[PCM]] (as commonly stored in [[WAV]] or [[AIFF]] containers) is not.

			To help players seek and show correct durations, VBR formats often include metadata at the beginning of the file to indicate the total duration and provide a "seek table" of the offsets, within the file, of a set number of points, each a fixed duration apart. For example, the seek table may have 100 offsets to represent 1%, 2%, 3%, etc. of the way toward the total duration. This feature is sometimes also used in CBR formats, so that tags don't confound file-size based estimates of duration and seek points.

	[[Category:Technical]]		[[Category:Technical]]

Mjb: PCM is VBR?

2010-06-16T08:48:18Z

PCM is VBR?

← Older revision		Revision as of 08:48, 16 June 2010
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	Some codecs limited to [[Constant Bitrate]] (CBR) include [[AC3]] (in theory it can encode to VBR, but no high quality encoder offers that feature), [[DTS]] (same thing as AC3, no publicly available VBR encoder), [[Real Audio]] and [[ATRAC3]].		Some codecs limited to [[Constant Bitrate]] (CBR) include [[AC3]] (in theory it can encode to VBR, but no high quality encoder offers that feature), [[DTS]] (same thing as AC3, no publicly available VBR encoder), [[Real Audio]] and [[ATRAC3]].

	~~All~~ [[lossless]] codecs are~~, by nature,~~ VBR.		Most [[lossless]] codecs are VBR. [[PCM]] (as commonly stored in [[WAV]] or [[AIFF]] containers) is not.


	[[Category:Technical]]		[[Category:Technical]]

Speckmade at 16:44, 14 June 2007

2007-06-14T16:44:07Z

← Older revision		Revision as of 16:44, 14 June 2007
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	In '''Variable Bitrate''' ('''VBR''') coding, the user chooses the desired quality level and/or a range of allowable [[bitrate]]s. Then the encoder tries to maintain the selected quality during the whole stream by choosing the optimal amount of data to represent each frame of audio. The main advantage is that the user is able to specify the quality level and conserve as much space as possible, but the inconvenience is that the final file size is quite unpredictable.		In '''Variable Bitrate''' ('''VBR''') coding, the user chooses the desired quality level and/or a range of allowable [[bitrate]]s. Then the encoder tries to maintain the selected quality during the whole stream by choosing the optimal amount of data to represent each frame of audio. The main advantage is that the user is able to specify the quality level and conserve as much space as possible, but the inconvenience is that the final file size is quite unpredictable.

	Most modern encoders are able to perform VBR encoding, including (but not limited to) nearly all popular [[MP3]], [[AAC]], [[~~Ogg~~ Vorbis]], [[Musepack]], and [[WMA]] encoders.		Most modern encoders are able to perform VBR encoding, including (but not limited to) nearly all popular [[MP3]], [[Advanced Audio Coding\|AAC]], (Ogg) [[Vorbis]], [[Musepack]], and [[Windows Media Audio\|WMA]] encoders.

	Some codecs limited to [[~~CBR~~]] include [[AC3]] (in theory it can encode to VBR, but no high quality encoder offers that feature), [[DTS]] (same thing as AC3, no publicly available VBR encoder), [[Real Audio]] and [[ATRAC3]].		Some codecs limited to [[Constant Bitrate]] (CBR) include [[AC3]] (in theory it can encode to VBR, but no high quality encoder offers that feature), [[DTS]] (same thing as AC3, no publicly available VBR encoder), [[Real Audio]] and [[ATRAC3]].

	All [[lossless]] codecs are, by nature, VBR.		All [[lossless]] codecs are, by nature, VBR.

Speckmade: VBR moved to Variable Bitrate

2007-06-13T16:04:51Z

VBR moved to Variable Bitrate

← Older revision	Revision as of 16:04, 13 June 2007
(No difference)

Pepoluan: remove link to frame

2006-10-11T16:58:25Z

remove link to frame

← Older revision		Revision as of 16:58, 11 October 2006
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	In '''Variable Bitrate''' ('''VBR''') coding, the user chooses the desired quality level and/or a range of allowable [[bitrate]]s. Then the encoder tries to maintain the selected quality during the whole stream by choosing the optimal amount of data to represent each [[frame]] of audio. The main advantage is that the user is able to specify the quality level and conserve as much space as possible, but the inconvenience is that the final file size is quite unpredictable.		In '''Variable Bitrate''' ('''VBR''') coding, the user chooses the desired quality level and/or a range of allowable [[bitrate]]s. Then the encoder tries to maintain the selected quality during the whole stream by choosing the optimal amount of data to represent each frame of audio. The main advantage is that the user is able to specify the quality level and conserve as much space as possible, but the inconvenience is that the final file size is quite unpredictable.

	Most modern encoders are able to perform VBR encoding, including (but not limited to) nearly all popular [[MP3]], [[AAC]], [[Ogg Vorbis]], [[Musepack]], and [[WMA]] encoders.		Most modern encoders are able to perform VBR encoding, including (but not limited to) nearly all popular [[MP3]], [[AAC]], [[Ogg Vorbis]], [[Musepack]], and [[WMA]] encoders.

Pepoluan at 08:04, 2 September 2006

2006-09-02T08:04:23Z

← Older revision		Revision as of 08:04, 2 September 2006
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	All [[lossless]] codecs are, by nature, VBR.		All [[lossless]] codecs are, by nature, VBR.


			[[Category:Technical]]

Mjb: wikilink bitrate

2006-05-17T23:10:31Z

wikilink bitrate

← Older revision		Revision as of 23:10, 17 May 2006
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	In '''Variable Bitrate''' ('''VBR''') coding, the user chooses the desired quality level and/or a range of allowable ~~bitrates~~. Then the encoder tries to maintain the selected quality during the whole stream by choosing the optimal amount of data to represent each [[frame]] of audio. The main advantage is that the user is able to specify the quality level and conserve as much space as possible, but the inconvenience is that the final file size is quite unpredictable.		In '''Variable Bitrate''' ('''VBR''') coding, the user chooses the desired quality level and/or a range of allowable [[bitrate]]s. Then the encoder tries to maintain the selected quality during the whole stream by choosing the optimal amount of data to represent each [[frame]] of audio. The main advantage is that the user is able to specify the quality level and conserve as much space as possible, but the inconvenience is that the final file size is quite unpredictable.

	Most modern encoders are able to perform VBR encoding, including (but not limited to) nearly all popular [[MP3]], [[AAC]], [[Ogg Vorbis]], [[Musepack]], and [[WMA]] encoders.		Most modern encoders are able to perform VBR encoding, including (but not limited to) nearly all popular [[MP3]], [[AAC]], [[Ogg Vorbis]], [[Musepack]], and [[WMA]] encoders.

Pepoluan: minor formatting (boldify VBR keywords per wiki formatting guidelines)

2006-05-16T06:42:33Z

minor formatting (boldify VBR keywords per wiki formatting guidelines)

← Older revision		Revision as of 06:42, 16 May 2006
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	In Variable Bitrate (VBR) coding, the user chooses the desired quality level and/or a range of allowable bitrates. Then the encoder tries to maintain the selected quality during the whole stream by choosing the optimal amount of data to represent each [[frame]] of audio. The main advantage is that the user is able to specify the quality level and conserve as much space as possible, but the inconvenience is that the final file size is quite unpredictable.		In '''Variable Bitrate''' ('''VBR''') coding, the user chooses the desired quality level and/or a range of allowable bitrates. Then the encoder tries to maintain the selected quality during the whole stream by choosing the optimal amount of data to represent each [[frame]] of audio. The main advantage is that the user is able to specify the quality level and conserve as much space as possible, but the inconvenience is that the final file size is quite unpredictable.

	Most modern encoders are able to perform VBR encoding, including (but not limited to) nearly all popular [[MP3]], [[AAC]], [[Ogg Vorbis]], [[Musepack]], and [[WMA]] encoders.		Most modern encoders are able to perform VBR encoding, including (but not limited to) nearly all popular [[MP3]], [[AAC]], [[Ogg Vorbis]], [[Musepack]], and [[WMA]] encoders.