Difference between revisions of "Lossless and lossy"

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'''Lossless''' describes a way of compressing data which still keeps all the data. If you have a compressed file, you can use it to create an exact copy of the source file.
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'''Lossless''' is a way of [[compress]]ing data which is fully reversible, i.e., does not "throw away" data. A losslessly compressed file can be used to create an exact copy of the source file.
  
'''Lossy''' is the opposite to Lossless. Some data is discarded. This makes the file a lot smaller, but reduces the [[quality]] of the audio slightly.
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'''Lossy''' is the opposite of lossless. A certain amount of data is discarded; how much is usually dependent upon a quality or [[bit rate]] setting of the codec. This makes the file (or stream) much smaller that lossless compression, but reduces the quality.  It is impossible to [[transcode]] from one lossy format to another without further degrading quality.
  
{| class="wikitable" width="100%"
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==Lossless Codecs==
!Lossy !!Lossless
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{{Mmwiki|Category:Lossless Video Codecs|Category:Lossless Audio Codecs}}
|-
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* [[WAVE]] (WAVE is technically a container format, but usually contains lossless PCM audio.)
| width=50% | [[MP3]], [[Vorbis]], [[AAC]], [[WMA]], All [[codecs|video codecs]].
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* [[FLAC]]
| width=50% | [[WAVE]], [[FLAC]]
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* [[WavPack]]
|}
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* [[HuffYUV]] video codec
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==Lossy Codecs==
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* [[MP3]]
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* [[Vorbis]]
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* [[AAC]]
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* [[AC3]]
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* [[WMA]]
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* [[Speex]]  
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* Most [[video codec]]s
  
 
[[Category:Glossary]]
 
[[Category:Glossary]]

Latest revision as of 05:22, 16 May 2019

Lossless is a way of compressing data which is fully reversible, i.e., does not "throw away" data. A losslessly compressed file can be used to create an exact copy of the source file.

Lossy is the opposite of lossless. A certain amount of data is discarded; how much is usually dependent upon a quality or bit rate setting of the codec. This makes the file (or stream) much smaller that lossless compression, but reduces the quality. It is impossible to transcode from one lossy format to another without further degrading quality.

Lossless Codecs

  • WAVE (WAVE is technically a container format, but usually contains lossless PCM audio.)
  • FLAC
  • WavPack
  • HuffYUV video codec

Lossy Codecs