Introduction
============
Congratulations! You are about to experience exceptionally high-quality
MPEG audio.
This plug-in is a replacement for the default MPEG audio decoder that
comes with Winamp. MAD is a high-quality MPEG audio decoder with support
for output resolutions from 8 to 32 bits.
For more information about MAD and the MAD plug-in, please visit:
http://www.mars.org/home/rob/proj/mpeg/mad-plugin/
License
=======
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your option)
any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details:
http://www.mars.org/home/rob/misc/GPL2.html
The source code for this plug-in is available from the same place you
obtained this plug-in. If you choose to redistribute this plug-in, you
must accompany it with the complete source code or an offer to obtain the
source in accordance with section 3 of the GPL.
Recommendations
===============
In order to get the most from this plug-in, it is recommended that you
have a high-quality audio setup, including a nice sound card and good
speakers. You can still benefit from MAD's high quality dithered output
with any sound card, but to best enjoy the fine detail in the sound MAD
produces, a high-end sound card with a 24-bit DAC is recommended.
Configuration
=============
1. Start Winamp.
2. Configure the plug-in from Winamp's Preferences panel under the
Plug-ins/Input section. Choose the highest output resolution supported
by your sound card (usually 8 or 16 bits, but possibly 24 or 32 for
high-end cards.)
3. Disable the Nullsoft MPEG audio decoder plug-in by deleting the file
association extension list (version 2.7), unchecking the "Use for MP1,
MP2, and MP3 files" option (version 2.666), or unchecking the "Layer
III", "Layer II", and "Layer I" options (version 2.33 or 2.34) in its
configuration.
Alternatively, you could move the file in_mp3.dll out of your Winamp
Plugins directory (usually C:\Program Files\Winamp\Plugins) and restart
Winamp.
4. Play MP3, MP2, or MP1 files and enjoy high quality sound.
Frequently Asked Questions
==========================
Q. I can't get it to work. I get an error message whenever I try to play
something. What's wrong?
A. You have probably selected an output resolution unsupported by your
sound card. Try 16 bits instead.
Note: SB Live! cards do not support 24- or 32-bit output.
Q. On some files, Winamp seems to play as normal except I hear no sound.
What's wrong?
A. The most likely cause for this is that the files were encoded with CRC
protection, but the checksums are wrong. Some early encoders were known
to create such files. MAD has to assume the CRCs are valid, so it
thinks every frame in the file is corrupt, and plays silence instead.
If you open the file info dialog and view the "Statistics" tab, you
will probably see the number of CRC errors accumulating at the same
rate as the number of decoded frames.
You will have to fix these files before MAD will play them.
Q. What is "Auto clipping attenuation"?
A. This version of the MAD plug-in has the ability to attenuate (weaken)
the digital signal reproduced from the MPEG audio data, so that it does
not experience distortion from clipping. Clipping occurs when the
signal is so strong that it exceeds the maximum representable
amplitude, known as "full scale."
You can attenuate the signal manually from the file info dialog, or you
can have the signal attenuated automatically whenever clipping
occurs. If you choose to attenuate automatically, you can further
control how aggressively the signal is attenuated. The default setting
should be appropriate for most circumstances, but you can adjust it in
case the signal is attenuated too abruptly or not quickly enough.
Changes
=======
Changes since 0.14.1b:
- fixed a possible crash due to bad Xing header information
- eliminated the error dialog when trying to open a (bad) file
- increased the size of the info dialog box in preparation for an ID3v2
tag editor
Changes since 0.14.0b:
- none visible; the plug-in is now linked with the new libid3tag
library, which will eventually enable full ID3v2 support
Changes since 0.13.0b:
- a new, improved dithering algorithm has been implemented
- streaming can now be disabled (to use other plug-ins with better
streaming support)
Changes since 0.12.5b:
- the last complete audio frame should now always be decoded
- Xing VBR headers are now detected and read if "Fast playing time
calculation" is enabled
- visuals for 24- and 32-bit output should now display correctly
- corrected a problem decoding MPEG-2 Layer III intensity stereo
Changes since 0.12.4b:
- several more performance improvements
Changes since 0.12.3b:
- many performance improvements
- alias reduction is now performed on mixed short blocks
Changes since 0.12.2b:
- added decoding statistics to file info dialog
- title formatting is greatly enhanced, and includes the ability to
use conditional constructs
- output can now be attenuated to eliminate clipping
- MAD now supports the MPEG 2.5 format
Changes since 0.12.1b:
- several performance improvements
Changes since 0.7.3b:
- fixed a potential problem related to a thread conflict
- changed the version numbering to coincide with the MAD source releases
- created a PiMP installer executable
Changes since 0.7.2a:
- fixed a problem that could cause Winamp to crash if the File Info box
is dismissed before the MPEG Audio length is calculated
- fixed some ID3v2-induced problems related to determining the correct
sample rate, et al.
Changes since 0.7.1a:
- a different method for packing stereo PCM samples is used which *may*
be somewhat faster than before
- fixed several seek-related issues; should no longer get a "blip" sound
- slightly improved error handling on bad frames
Known Issues
============
- there are buffering issues related to streaming support
- the ID3v2 tag editor is missing
- using DSP effects (including the equalizer) will negate the effects of
dithering
Acknowledgments
===============
The author would like to thank the following individuals for their
support, suggestions, beta testing, debugging, and indeed for proposing
the idea to write this plug-in in the first place:
kaiwei
David Shin
The following individuals have also made notable contributions:
Matt Parnell
John Stewart
Feedback
========
Please send bug reports, comments, and suggestions to the author:
Rob Leslie <rob@mars.org>
