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用JAVA写的MP3,MP2,MP1解码源代码

+--------------------------------------+
| JMPG123 MPEG Audio Libray            |
| copyright (c) 1998 by Michael Hipp   |
+--------------------------------------+

 It's my first java project and even my first
 real object oriented program at all, so forgive me
 if some of the stuff is done ugly. 

 Currently, only support for Layer2,Layer3 audio streams.
 Layer3 needs some more debugging. MPEG-2 isn't tested.

 Output is always to the standard out with stereo,
 16 bit and BIG endian. If you use the native part to
 decode: the output endian is system dependend. This
 will change in the future!

Simple performance tests: (solaris/Dual Sun Ultra 2 with 300MHz)
  mpg123 (raw C)                 = 100%   (precision=float)
  jmpg123 (sunwjit JIT compiler) = 622%   (precision=double)
  jmpg123 (interpreted)          = 3436%  (precision=double)

Possible Options: (no options: write audio to audio system)
  -s : write audio to STDOUT 
  -t : only decoding no output
  -native: use native functions for 'SubBandSynthesis' and 'Dct64' 

Native Libs:
  in the directories jmpg/libnative.linux/ and jmpg/libnative.solaris/ 
  you can find the precompiled libs for Linux and Solaris.
  You must put the appropriate path in your library path environment
  value. (eg LD_LIBRARY_PATH )
  You may wanna build this part yourself. Check jmpg/lib/native/ and
  jmpg/audio/native/ in this case.

  You need the libaudionative.so library if you wanna play the samples
  directly to your hardware. Else you must use the '-s' option and
  redirect the standard output to a special (system depended) audio player.

Running with jmpg.jar:
  Add the file jmpg.jar to your CLASSPATH environment. Ie:
  (tcsh/csh): setenv CLASSPATH $CLASSPATH\:/home/myjavauser/java/jmpg.jar
  (bash)    : export CLASSPATH=$CLASSPATH\:/home/myjavauser/java/jmpg.jar

Running in a default environment:
  Uncompress the jar-file and copy the jmpg/ directory into a directory,
  which is part of your 
  CLASSPATH or add the parent directory of jmpg/ to your CLASSPATH.

Running:
  Then call:
    java jmpg.jmpg123 -t <a_test_mpeg.mp3>
  This will decode the MPEG without playing.
  For real playing remove the '-t' option or replace it by '-s'.
  As mentioned above, only '-t' or '-s' is 100% pure java. Else
  the program tries to load the nativeAudio library to
  play directly to the audio hardware.