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The mp3encode package encodes MPEG layer I, II and III audio files.
This is the reference implementation so don't expect spectacular performance.
Driving encode is pretty simple although it may take some practice to
work out an optimal compression rate. AIFF files are the only type of files that
seem to work with this version so you may need to install a port like "sox" to
convert your file types. I use the "nas" port to record and edit all of my audio
files but so long as you have a valid AIFF file it shouldn't matter what you
use.
Although the source code includes a decoder I have decided not to port
it because we already have a couple of top class MPEG decoders in the ports
collection.
Psychoacoustic model 2 is the only supported model in layer III
encoding. A bit-rate of 128 kilobits/s is adequate for most forms of music but
you may need to turn down the compression to 160 kilobits/s if the music is
particularly atmospheric.
Vocal spoken recordings are best encoded using a 32 kilobits/s bit-rate
with layer II (layer III makes you sound like a Dalek under digital water) with
a 32 kHz sample rate in mono. Using this method I have managed to get about 5
minutes of AM radio quality audio into around 1 MB.
If anyone finds any bugs in this software please let me know and include
patches to fix them.
Share and enjoy,
Joel...
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