Lossless: Difference between revisions
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'''Lossless compression''' is a compression methodology in which the result of the compression can be restored faithfully, i.e. bit-by-bit identical with the uncompressed data. | '''Lossless compression''' is a compression methodology in which the result of the compression can be restored faithfully, i.e. bit-by-bit identical with the uncompressed data. | ||
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The difference between 'mere' ZIP/RAR is that lossless compression algorithms are especially tuned and designed for the characteristics of Waveform data, thus achieving compression far greater than can be achieved by generic compression utilities. | The difference between 'mere' ZIP/RAR is that lossless compression algorithms are especially tuned and designed for the characteristics of Waveform data, thus achieving compression far greater than can be achieved by generic compression utilities. | ||
As lossless compression preserves all information of the original Waveform file, audio compressed with lossless compression will unavoidably be larger than audio compressed with [[lossy]] compression. However, this disadvantage is more than offset by lossless' ability to be [[transcoding|transcoded]] to other lossless format <u>without</u> any quality degradation. | |||
=Popular lossless formats= | |||
* [[Apple Lossless]] ([[ALAC]]) | * [[Apple Lossless]] ([[ALAC]]) | ||
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=Oddball Formats= | |||
There are several old lossless formats that aren't really deserving of having an article all for themselves. Reasons are: lack of widespread support, lack of features, bad efficiency and, most importantly, it seems noone is really interested in them. | There are several old lossless formats that aren't really deserving of having an article all for themselves. Reasons are: lack of widespread support, lack of features, bad efficiency and, most importantly, it seems noone is really interested in them. | ||
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Note that currently '''no single format can be considered best for all applications'''. Rather, the best format depends on the ''intended use'', as well as a number of other factors (such as licensing and file structure). For example, Shorten and FLAC are widely used for sharing live music because of their cross-platform support and speed. Monkey's Audio is popular among Windows users for its superior compression ratio. | Note that currently '''no single format can be considered best for all applications'''. Rather, the best format depends on the ''intended use'', as well as a number of other factors (such as licensing and file structure). For example, Shorten and FLAC are widely used for sharing live music because of their cross-platform support and speed. Monkey's Audio is popular among Windows users for its superior compression ratio. | ||
=Comparisons= | |||
''Note the specific assumptions and limitations of each comparison; in particular, results are sensitive to the music selected''' | |||
; http://web.inter.nl.net/users/hvdh/lossless/lossless.htm : Includes an interesting graph of encode/decode speeds vs. file size on the All Albums page | ; http://web.inter.nl.net/users/hvdh/lossless/lossless.htm : Includes an interesting graph of encode/decode speeds vs. file size on the All Albums page | ||
Revision as of 06:03, 5 January 2006
Lossless compression is a compression methodology in which the result of the compression can be restored faithfully, i.e. bit-by-bit identical with the uncompressed data.
In a nutshell, it is somewhat like compressing a Waveform file with ZIP or RAR.
The difference between 'mere' ZIP/RAR is that lossless compression algorithms are especially tuned and designed for the characteristics of Waveform data, thus achieving compression far greater than can be achieved by generic compression utilities.
As lossless compression preserves all information of the original Waveform file, audio compressed with lossless compression will unavoidably be larger than audio compressed with lossy compression. However, this disadvantage is more than offset by lossless' ability to be transcoded to other lossless format without any quality degradation.
Popular lossless formats
Oddball Formats
There are several old lossless formats that aren't really deserving of having an article all for themselves. Reasons are: lack of widespread support, lack of features, bad efficiency and, most importantly, it seems noone is really interested in them.
Most of those would have disappeared by now, but they are being preserved for posterity at rjamorim's ReallyRareWares
- Advanced Digital Audio (ADA)
- Marian's a-Pac
- AudioZip
- Dakx WAV
- Entis Lab MIO
- LiteWave
- Pegasus SPS
- RKaudio
- Split2000
- Sonarc
- VocPack
- WavArc
- WaveZip/MUSICompress
Note that currently no single format can be considered best for all applications. Rather, the best format depends on the intended use, as well as a number of other factors (such as licensing and file structure). For example, Shorten and FLAC are widely used for sharing live music because of their cross-platform support and speed. Monkey's Audio is popular among Windows users for its superior compression ratio.
Comparisons
Note the specific assumptions and limitations of each comparison; in particular, results are sensitive to the music selected'
- http://web.inter.nl.net/users/hvdh/lossless/lossless.htm
- Includes an interesting graph of encode/decode speeds vs. file size on the All Albums page
- Lossless comparison
- A comparision focusing more on codec features and less on absolute encoding efficiency. Also features a table comparing most popular codecs based on their features.
- http://home.wanadoo.nl/~w.speek/comparison.htm
- Performance Comparison of Lossless Audio Compressors - Compares file size, encode speed, decode speed for APE, FLAC, LPAC, WavPack, Shorten (SHN), RKAU, OptimFROG, LA, WMA Lossless. Updated 5-2003