In order to compress a software painstakingly, eventually still did not find a don't money GUI tools, depressed, another idea, why not use Linux command line tool to compress ah, so found this tool on the Internet lame
First of all, of course, using homebrew to install lame
Dangchengchengdemacbook-pro:js dangchengcheng$ Brew Install lame
==> Downloading https://homebrew.bintray.com/bottles/lame-3.99.5.yosemite.bottle.1.tar.gz
######################################################################## 100%
==> Pouring lame-3.99.5.yosemite.bottle.1.tar.gz
Linux can be installed with the Apt-get install lame or yum install lame
The installation was successful.
In fact, compressing the audio file is nothing more than reducing the sampling rate, so lame will use the-B parameter to compress the audio in most cases.
Dangchengchengdemacbook-pro:img dangchengcheng$ lame-b Music2.mp3 Music4.mp3
LAME 3.99.5 64bits (http://lame.sf.net)
Resampling:input 44.1 khz output khz
Using polyphase lowpass Filter, transition band:5484 Hz-5677 Hz
Encoding Music2.mp3 to Music4.mp3
Encoding as-kHz j-stereo MPEG-2 Layer III (16x) Kbps qval=3
Frame | CPU Time/estim | REAL Time/estim | Play/cpu | ETA
7273/7295 (100%) | 0:03/0:03| 0:04/0:04| 74.073x| 0:00
-------------------------------------------------------------------------------------------------------------
Kbps LR MS% long switch short%
32.0 3.3 96.7 91.2 5.0 3.8
ReplayGain: -8.9db
Dangchengchengdemacbook-pro:img dangchengcheng$
The result of the final compression is satisfactory, from 4.2M to 1.1M
Mac Compression mp3 audio file/linux applicable