Transparency - Revision history

46.208.193.99 at 13:50, 4 April 2016

2016-04-04T13:50:57Z

← Older revision		Revision as of 13:50, 4 April 2016
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	In [[psychoacoustics]], '''transparency''' is the ideal result of [[lossy]] data compression. If a lossily compressed result is perceptually indistinguishable from the uncompressed input, then the compression can be declared to be transparent. In other words, transparency is the situation where [[artifact]]s are nonexistant or imperceptible.		In [[psychoacoustics]], '''transparency''' is the ideal result of [[lossy]] data compression. If a lossily compressed result is perceptually indistinguishable from the uncompressed input, then the compression can be declared to be transparent. In other words, transparency is the situation where [[artifact]]s are nonexistant or imperceptible.

	Transparency depends most on the listener's familiarity with artifacts, and to a lesser extent, the compression method, [[bitrate]] used, input characteristics, listening conditions, and listening equipment. It also depends, on the particular music piece or sound under examination. Some audio samples, when compressed with certain algorithms under certain conditions, are known to cause artifacts of a specific kind (see, for example, the samples from the [http://lame.sourceforge.net/quality.php Lame MP3 Encoder Quality and Listening Test Information web page]).		Transparency depends most on the listener's familiarity with artifacts, and to a lesser extent, the compression method, [[bitrate]] used, input characteristics, listening conditions, and listening equipment. It also depends on the particular music piece or sound under examination. Some audio samples, when compressed with certain algorithms under certain conditions, are known to cause artifacts of a specific kind (see, for example, the samples from the [http://lame.sourceforge.net/quality.php Lame MP3 Encoder Quality and Listening Test Information web page]).

	Judging transparency can be difficult due to observation bias, in which subjective like/dislike of a certain compression methodology emotionally influences ~~his/her~~ judgment. This bias is commonly referred to as ''placebo,'' although this use is slightly different from the medical use of the term.		Judging transparency can be difficult due to observation bias, in which subjective like/dislike of a certain compression methodology emotionally influences the listener's judgment. This bias is commonly referred to as ''placebo,'' although this use is slightly different from the medical use of the term.

	By definition, there is no way to prove whether a certain compression methodology is transparent. To scientifically prove that a compression method is ''not'' transparent, one should either show that the particular compression method results in a measurable and easily perceived artifact, or use double-blind tests where the high anchor is the original uncompressed audio. For such tests the [[ABX]] method is normally used, and the audio samples should be chosen so as to make the detection of artifacts more obvious.		By definition, there is no way to prove whether a certain compression methodology is transparent. To scientifically prove that a compression method is ''not'' transparent, one should either show that the particular compression method results in a measurable and easily perceived artifact, or use double-blind tests where the high anchor is the original uncompressed audio. For such tests the [[ABX]] method is normally used, and the audio samples should be chosen so as to make the detection of artifacts more obvious.

IgorC at 03:27, 5 December 2012

2012-12-05T03:27:13Z

← Older revision		Revision as of 03:27, 5 December 2012
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	* MP3-encoded files are generally considered artifact-free at bitrates at/above 192kbps.		* MP3-encoded files are generally considered artifact-free at bitrates at/above 192kbps.
	* Vorbis ogg files are supposedly artifact-free at bitrates at/above 160kbps.		* Vorbis ogg files are supposedly artifact-free at bitrates at/above 160kbps.
	* AAC-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at ~~150kbps, a~~ lower ~~bitrate~~ than both Vorbis ogg and MP3.		* AAC- and Opus-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at lower bitrates than both Vorbis ogg and MP3.
	* Opus-encoded files are typically considered to be transparent or very nearly transparent at/above: 32kbps for speech, 144kbps for music and complex audio.

	With the present competition between compression formats (open and proprietary) and encoder implementations (GPL'd, proprietary), any claims of transparency at any given bitrate should always be considered with some skepticism.		With the present competition between compression formats (open and proprietary) and encoder implementations (GPL'd, proprietary), any claims of transparency at any given bitrate should always be considered with some skepticism.

	[[Category:Listening Tests]]		[[Category:Listening Tests]]

64.72.223.160: grammar

2012-11-22T18:03:51Z

grammar

← Older revision		Revision as of 18:03, 22 November 2012
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	* Vorbis ogg files are supposedly artifact-free at bitrates at/above 160kbps.		* Vorbis ogg files are supposedly artifact-free at bitrates at/above 160kbps.
	* AAC-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at 150kbps, a lower bitrate than both Vorbis ogg and MP3.		* AAC-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at 150kbps, a lower bitrate than both Vorbis ogg and MP3.
	* Opus-encoded files are typically considered to be transparent or very nearly transparent at/above 32kbps for speech ~~and~~ 144kbps for music and ~~most~~ complex audio.		* Opus-encoded files are typically considered to be transparent or very nearly transparent at/above: 32kbps for speech, 144kbps for music and complex audio.

	With the present competition between compression formats (open and proprietary) and encoder implementations (GPL'd, proprietary), any claims of transparency at any given bitrate should always be considered with some skepticism.		With the present competition between compression formats (open and proprietary) and encoder implementations (GPL'd, proprietary), any claims of transparency at any given bitrate should always be considered with some skepticism.

	[[Category:Listening Tests]]		[[Category:Listening Tests]]

64.72.223.160: (1) See the AAC page for the 150kbps number. It's already on HA's wiki. (2) See Opus-Codec.org for their comparison graphic.

2012-11-22T18:01:13Z

(1) See the AAC page for the 150kbps number. It's already on HA's wiki. (2) See Opus-Codec.org for their comparison graphic.

← Older revision		Revision as of 18:01, 22 November 2012
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	* MP3-encoded files are generally considered artifact-free at bitrates at/above 192kbps.		* MP3-encoded files are generally considered artifact-free at bitrates at/above 192kbps.
	* Vorbis ogg files are supposedly artifact-free at bitrates at/above 160kbps.		* Vorbis ogg files are supposedly artifact-free at bitrates at/above 160kbps.
	* AAC-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at lower ~~bitrates~~ than both Vorbis ogg and MP3.		* AAC-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at 150kbps, a lower bitrate than both Vorbis ogg and MP3.
			* Opus-encoded files are typically considered to be transparent or very nearly transparent at/above 32kbps for speech and 144kbps for music and most complex audio.

	With the present competition between compression formats (open and proprietary) and encoder implementations (GPL'd, proprietary), any claims of transparency at any given bitrate should always be considered with some skepticism.		With the present competition between compression formats (open and proprietary) and encoder implementations (GPL'd, proprietary), any claims of transparency at any given bitrate should always be considered with some skepticism.

	[[Category:Listening Tests]]		[[Category:Listening Tests]]

Nessuno: Edited a typo.

2012-09-11T13:18:19Z

Edited a typo.

← Older revision		Revision as of 13:18, 11 September 2012
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	In [[psychoacoustics]], '''transparency''' is the ideal result of [[lossy]] data compression. If a lossily compressed result is perceptually ~~indistinguishible~~ from the uncompressed input, then the compression can be declared to be transparent. In other words, transparency is the situation where [[artifact]]s are nonexistant or imperceptible.		In [[psychoacoustics]], '''transparency''' is the ideal result of [[lossy]] data compression. If a lossily compressed result is perceptually indistinguishable from the uncompressed input, then the compression can be declared to be transparent. In other words, transparency is the situation where [[artifact]]s are nonexistant or imperceptible.

	Transparency depends most on the listener's familiarity with artifacts, and to a lesser extent, the compression method, [[bitrate]] used, input characteristics, listening conditions, and listening equipment. It also depends, on the particular music piece or sound under examination. Some audio samples, when compressed with certain algorithms under certain conditions, are known to cause artifacts of a specific kind (see, for example, the samples from the [http://lame.sourceforge.net/quality.php Lame MP3 Encoder Quality and Listening Test Information web page]).		Transparency depends most on the listener's familiarity with artifacts, and to a lesser extent, the compression method, [[bitrate]] used, input characteristics, listening conditions, and listening equipment. It also depends, on the particular music piece or sound under examination. Some audio samples, when compressed with certain algorithms under certain conditions, are known to cause artifacts of a specific kind (see, for example, the samples from the [http://lame.sourceforge.net/quality.php Lame MP3 Encoder Quality and Listening Test Information web page]).

Saratoga: don't explain how to scientifically prove something is true that is also subjective since that would be nonsense

2012-09-10T23:57:54Z

don't explain how to scientifically prove something is true that is also subjective since that would be nonsense

← Older revision		Revision as of 23:57, 10 September 2012
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	In [[psychoacoustics]], '''transparency''' is the ideal result of [[lossy]] data compression. If a lossily compressed result is perceptually indistinguishible from the uncompressed input, then the compression can be declared to be transparent. In other words, transparency is the situation where [[artifact]]s are nonexistant or imperceptible.		In [[psychoacoustics]], '''transparency''' is the ideal result of [[lossy]] data compression. If a lossily compressed result is perceptually indistinguishible from the uncompressed input, then the compression can be declared to be transparent. In other words, transparency is the situation where [[artifact]]s are nonexistant or imperceptible.

	Transparency depends most on the listener's familiarity with artifacts, and to a lesser extent, the compression method, [[bitrate]] used, input characteristics, listening conditions, and listening equipment. It also depends~~, of course~~, on the particular music piece or sound under examination. Some audio samples, when compressed with certain algorithms under certain conditions, are known to cause artifacts of a specific kind (see, for example, the samples from the [http://lame.sourceforge.net/quality.php Lame MP3 Encoder Quality and Listening Test Information web page]).		Transparency depends most on the listener's familiarity with artifacts, and to a lesser extent, the compression method, [[bitrate]] used, input characteristics, listening conditions, and listening equipment. It also depends, on the particular music piece or sound under examination. Some audio samples, when compressed with certain algorithms under certain conditions, are known to cause artifacts of a specific kind (see, for example, the samples from the [http://lame.sourceforge.net/quality.php Lame MP3 Encoder Quality and Listening Test Information web page]).

	Judging transparency can be difficult due to observation bias, in which subjective like/dislike of a certain compression methodology emotionally influences his/her judgment. This bias is commonly referred to as ''placebo,'' although this use is slightly different from the medical use of the term.		Judging transparency can be difficult due to observation bias, in which subjective like/dislike of a certain compression methodology emotionally influences his/her judgment. This bias is commonly referred to as ''placebo,'' although this use is slightly different from the medical use of the term.

	By definition, there is no way to prove whether a certain compression methodology is transparent~~, since transparency is a perceptual, subjective phenomenon~~. To scientifically prove that a compression method is ''not'' transparent, one should either show that the particular compression method results in a measurable and easily perceived artifact, or use double-blind tests where the high anchor is the original uncompressed audio. For such tests the [[ABX]] method is normally used, and the audio samples should be chosen so as to make the detection of artifacts more obvious.		By definition, there is no way to prove whether a certain compression methodology is transparent. To scientifically prove that a compression method is ''not'' transparent, one should either show that the particular compression method results in a measurable and easily perceived artifact, or use double-blind tests where the high anchor is the original uncompressed audio. For such tests the [[ABX]] method is normally used, and the audio samples should be chosen so as to make the detection of artifacts more obvious.

	Non-lossy compression algorithms are assumed to be transparent: a non-lossy compression methodology should never introduce any artifact.		Non-lossy compression algorithms are assumed to be transparent: a non-lossy compression methodology should never introduce any artifact.

Saratoga at 23:51, 10 September 2012

2012-09-10T23:51:30Z

← Older revision		Revision as of 23:51, 10 September 2012
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	In [[psychoacoustics]], '''transparency''' is the ideal result of [[lossy]] data compression. If a lossily compressed result is perceptually indistinguishible from the uncompressed input, then the compression can be declared to be transparent. In other words, transparency is the situation where [[artifact]]s are nonexistant or imperceptible.		In [[psychoacoustics]], '''transparency''' is the ideal result of [[lossy]] data compression. If a lossily compressed result is perceptually indistinguishible from the uncompressed input, then the compression can be declared to be transparent. In other words, transparency is the situation where [[artifact]]s are nonexistant or imperceptible.

	Transparency~~, like sound quality, is subjective. It~~ depends most on the listener's familiarity with artifacts, and to a lesser extent, the compression method, [[bitrate]] used, input characteristics, listening conditions, and listening equipment. It also depends, of course, on the particular music piece or sound under examination. Some audio samples, when compressed with certain algorithms under certain conditions, are known to cause artifacts of a specific kind (see, for example, the samples from the [http://lame.sourceforge.net/quality.php Lame MP3 Encoder Quality and Listening Test Information web page]).		Transparency depends most on the listener's familiarity with artifacts, and to a lesser extent, the compression method, [[bitrate]] used, input characteristics, listening conditions, and listening equipment. It also depends, of course, on the particular music piece or sound under examination. Some audio samples, when compressed with certain algorithms under certain conditions, are known to cause artifacts of a specific kind (see, for example, the samples from the [http://lame.sourceforge.net/quality.php Lame MP3 Encoder Quality and Listening Test Information web page]).

	Judging transparency can be difficult due to observation bias, in which subjective like/dislike of a certain compression methodology emotionally influences his/her judgment. This bias is commonly referred to as ''placebo,'' although this use is slightly different from the medical use of the term.		Judging transparency can be difficult due to observation bias, in which subjective like/dislike of a certain compression methodology emotionally influences his/her judgment. This bias is commonly referred to as ''placebo,'' although this use is slightly different from the medical use of the term.

Gigapod at 11:57, 26 November 2006

2006-11-26T11:57:16Z

← Older revision		Revision as of 11:57, 26 November 2006
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	Judging transparency can be difficult due to observation bias, in which subjective like/dislike of a certain compression methodology emotionally influences his/her judgment. This bias is commonly referred to as ''placebo,'' although this use is slightly different from the medical use of the term.		Judging transparency can be difficult due to observation bias, in which subjective like/dislike of a certain compression methodology emotionally influences his/her judgment. This bias is commonly referred to as ''placebo,'' although this use is slightly different from the medical use of the term.

	By definition, there is no way to prove whether a certain compression methodology is transparent, since transparency is a perceptual, subjective phenomenon. To scientifically prove that a compression method is ''not'' transparent, one should either show that the particular compression method ~~causes~~ a ~~given~~ measurable and easily perceived artifact, or use double-blind tests where the high-anchor is the original uncompressed audio. ~~The~~ [[ABX]] method is normally used, and the audio samples should be chosen so as to make the detection of artifacts more obvious.		By definition, there is no way to prove whether a certain compression methodology is transparent, since transparency is a perceptual, subjective phenomenon. To scientifically prove that a compression method is ''not'' transparent, one should either show that the particular compression method results in a measurable and easily perceived artifact, or use double-blind tests where the high anchor is the original uncompressed audio. For such tests the [[ABX]] method is normally used, and the audio samples should be chosen so as to make the detection of artifacts more obvious.

	Non-lossy compression algorithms are assumed to be transparent: a non-lossy compression methodology should never introduce any artifact.		Non-lossy compression algorithms are assumed to be transparent: a non-lossy compression methodology should never introduce any artifact.

Gigapod at 11:54, 26 November 2006

2006-11-26T11:54:48Z

← Older revision		Revision as of 11:54, 26 November 2006
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	* AAC-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at lower bitrates than both Vorbis ogg and MP3.		* AAC-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at lower bitrates than both Vorbis ogg and MP3.

	With the present competition between compression formats (open and proprietary) and encoder implementations (GPL'd, proprietary), any claims of transparency at any given bitrate should always be ~~taken~~ with some skepticism.		With the present competition between compression formats (open and proprietary) and encoder implementations (GPL'd, proprietary), any claims of transparency at any given bitrate should always be considered with some skepticism.

	[[Category:Listening Tests]]		[[Category:Listening Tests]]

Gigapod at 11:49, 26 November 2006

2006-11-26T11:49:17Z

← Older revision		Revision as of 11:49, 26 November 2006
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	Non-lossy compression algorithms are assumed to be transparent: a non-lossy compression methodology should never introduce any artifact.		Non-lossy compression algorithms are assumed to be transparent: a non-lossy compression methodology should never introduce any artifact.

	Transparency at the lowest possible bitrate also seems to be used as a measure of the quality or degree of sophistication and tuning of a compression algorithm:		Transparency at the lowest possible bitrate also seems to be used as a measure of the quality or degree of sophistication and tuning of a lossy compression algorithm:
	* MP3-encoded files are generally considered artifact-free at bitrates at/above 192kbps.		* MP3-encoded files are generally considered artifact-free at bitrates at/above 192kbps.
	* Vorbis ogg files are supposedly artifact-free at bitrates at/above 160kbps.		* Vorbis ogg files are supposedly artifact-free at bitrates at/above 160kbps.
	* AAC-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at lower bitrates than both Vorbis ogg and MP3.		* AAC-encoded files, depending on the particular encoder implementation, are claimed to be artifact-free at lower bitrates than both Vorbis ogg and MP3.

	With the present competition between compression formats (open and proprietary) and encoder implementations (GPL'd, proprietary), any claims of transparency at any given bitrate should always be taken with ~~a grain of salt~~.		With the present competition between compression formats (open and proprietary) and encoder implementations (GPL'd, proprietary), any claims of transparency at any given bitrate should always be taken with some skepticism.

	[[Category:Listening Tests]]		[[Category:Listening Tests]]