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fix point版本的Ogg Vorbis decoder

Fixed Point (integer) based Ogg Vorbis audio decoder
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The integerisation work is (C) 2002 by Nicolas Pitre <[e-mail]>
See lib/COPYING for license terms.

Please make sure you correctly set the best optimisation flags for your CPU
in the Makefile before compiling.

This is a decoder only.  The resulting binary is "decoder" which should be
presented an Ogg bitstream on its stdin and raw 16bit samples will be output
on stdout.  For convenience I included the code for a little program called
"vplay" that is able to play raw audio streams on Linux.

To play a 44100Hz stereo Ogg Vorbis file, simply do:

	decoder < bitstream.ogg | vplay -b 16 -s 44100 -S

A more complete player such as ogg123 should link against this code with
little effort.

***** WARNING ***** WARNING ***** WARNING ***** WARNING *****
This fixed point Vorbis decoding library does NOT pretend to be
"Ogg Vorbis Compliant".  It does work with current available encoders,
but that's all.  Unless the full Vorbis specifications are available,
future encoders may break this decoder while still being in compliance
with the specs.  Be warned.
***** WARNING ***** WARNING ***** WARNING ***** WARNING *****

For a fully compliant fixed point decoder guaranteed not to break in the
future, please look for the Tremor decoder licensed by Xiph.Org.

To generate the original fully-compliant floating point decoder, simply
comment  out the definition of FIXED_POINT in fixp.h.  This is handy to
compare results if some streams appear not to play correctly.  I'll be
interested in any Vorbis stream that doesn't produce the same result
with both modes so to fix this decoder.


Nicolas Pitre
[e-mail]
Jun 24, 2002