Alla data in cui scrivo:
* http://sourceforge.net/projects/lame/
* http://www.dors.de/razorlame/index.php
Il testo che segue è tratto da http://wiki.hydrogenaudio.org/index.php?title=LAME
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Best quality: "archiving"
* -b 320.
This is the strongest setting for MP3, with the lowest risk of artifacts. With the exception of a few situations, quality is rarely better than the highest VBR profiles described below. However, 'archiving' music using a lossy format like MP3 is never recommended – no matter how transparent the resulting files might be. The alternative is to use Lossless formats like WavPack, FLAC etc. that allow true archiving bit for bit like on original CD.
High quality: HiFi, home or quiet listening
* -V3 --vbr-new (~175 kbps),
* -V2 --vbr-new (~190 kbps),
* -V1 --vbr-new (~210 kbps) or
* -V0 --vbr-new (~230 kbps) are recommended.
These settings will produce transparent encoding (transparent = most people cannot distinguish the MP3 from the original in an ABX blind test). Audible differences between these presets exist, but are extremely rare.
Portable: background noise and low bitrate requirement, small sizes
* -V6 --vbr-new (~115 kbps),
* -V5 --vbr-new (~130 kbps) or
* -V4 --vbr-new (~160 kbps) are recommended for this use.
-V6 --vbr-new produces an acceptable quality, while -V4--vbr-new should be close to perceptual transparency.
Very low bitrate, small sizes: eg. for voice, radio, mono encoding etc.
For very low bitrates, up to 100kbps, ABR is most often the best solution. Use --abr (e.g. --abr 80).
--preset voice is only available in the command line front-end, and is there for compatibility. It is currently mapped to --abr 56 -mm, so that means that the recommendation would be to encode in mono, and use ABR.
PIU' IN DETTAGLIO...
VBR (variable bitrate) settings
VBR: variable bitrate mode.
Use variable bitrate modes when the goal is to achieve a fixed level of quality using the lowest possible bitrate.
VBR is best used to target a specific quality level, instead of a specific bitrate. The final file size of a VBR encode is less predictable than with ABR, but the quality is usually better.
Usage: -V(number) where number is 0-9, 0 being highest quality, 9 being the lowest.
Example: -V2
ABR (average bitrate) settings
ABR: average bitrate mode.
A compromise between VBR and CBR modes, ABR encoding varies bits around a specified target bitrate. Use ABR when you need to know the final size of the file but still want to allow the encoder some flexibility to decide which passages need more bits. Usage: --preset where (desired averaged bitrate in kbit/s) can be any value between 8 - 320 , like eg. 9, 17, 80, 128, 133, 200 etc. Example: --preset 200
CBR (constant bitrate) settings
CBR: constant bitrate mode.
CBR encoding is not efficient. Whereas VBR and ABR modes can supply more bits to complex music passages and save bits on simpler ones, CBR encodes every frame at the same bitrate. CBR is only recommended for usage in streaming situations where the upper bitrate must be strictly enforced. Usage: -b where (bitrate in kbit/s) must be chosen from the following values: 8, 16, 24, 32, 40, 48, 64, 80, 96, 112, 128, 160, 192, 224, 256, or 320.
Example: -b 192
