Difference between revisions of "Lossy"

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'''Lossy''' compression is a form of compression that takes advantage of the characteristics of human perception.
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'''Lossy''' compression is a form of compression that significantly reduce multimedia file size by throwing away information imperceptible to humans.
  
=Does Lossy Encoding Preserve Surround Information?=
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Human audio perception is not perfect. Lossy compression takes advantage of this characteristic. By selective discarding, much unnecessary information is thrown away. The amount of information discarded is usually adjustable, giving a compromise between smaller size with less quality and larger size with higher quality.
  
Depending on the encoder and settings, degradation of surround imaging may happen. Use higher [[bitrate]]. Mid/Side stereo of [[LAME]] or [[AAC]] does not destroy surround information. Also [[MPC]] preserves surround information with standard settings reasonably well. The lower the [[bitrate]], the worse you can expect the surround imaging become.
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The downside to this is that waveform reconstructed from compressed information will never exactly match the original waveform.
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== Does Lossy Encoding Preserve Surround Information? ==
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Depending on the encoder and settings, degradation of surround imaging may happen. Use higher [[bitrate]] to prevent this from happening. Mid/Side stereo of [[LAME]] or [[Advanced Audio Coding|AAC]] does not destroy surround information. Also [[Musepack|MPC]] preserves surround information with standard settings reasonably well. The lower the [[bitrate]], the worse you can expect the surround imaging become.
  
 
* [http://www.hydrogenaudio.org/forums/index.php?act=ST&f=15&t=4639 More discussion]
 
* [http://www.hydrogenaudio.org/forums/index.php?act=ST&f=15&t=4639 More discussion]
  
=List of common lossy formats=
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== List of common lossy formats ==
* [[MP3]]
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* [[Advanced Audio Coding]] (AAC, also improperly known as [[MP4]] or [[M4A]])
* [[Ogg Vorbis]]
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* [[AAC]] (also improperly known as [[MP4]] or [[M4A]])
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* [[MPC]]/[[Musepack]]/[[MPPlus]] (MP+)
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* [[MP2]]
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* [[AC3]]
 
* [[AC3]]
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* [[ATRAC3]]
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* [[DTS]]
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* [[MP2]]
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* [[MP3]]
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* [[Musepack]] (also known as MPC, formerly known as MPEGplus or MP+)
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* [[Opus]]
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* (Ogg) [[Vorbis]]
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* [[QDesign]]
 
* [[Speex]] (speech only)
 
* [[Speex]] (speech only)
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* [[VQF]]
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* [[Windows Media Audio]] (WMA)
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== See Also ==
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* [[Choosing the best codec]]
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* [[Lossless]]
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[[Category:Codecs|*]]

Revision as of 02:48, 15 December 2016

Lossy compression is a form of compression that significantly reduce multimedia file size by throwing away information imperceptible to humans.

Human audio perception is not perfect. Lossy compression takes advantage of this characteristic. By selective discarding, much unnecessary information is thrown away. The amount of information discarded is usually adjustable, giving a compromise between smaller size with less quality and larger size with higher quality.

The downside to this is that waveform reconstructed from compressed information will never exactly match the original waveform.

Does Lossy Encoding Preserve Surround Information?

Depending on the encoder and settings, degradation of surround imaging may happen. Use higher bitrate to prevent this from happening. Mid/Side stereo of LAME or AAC does not destroy surround information. Also MPC preserves surround information with standard settings reasonably well. The lower the bitrate, the worse you can expect the surround imaging become.

List of common lossy formats

See Also