AviSynth C Interface
Version 0.15
Copyright 2004 Kevin Atkinson under the GPL 2.0

This is the version 0.15 of a compiler neutral C API for AviSynth 2.5.
The latest version can be found at
http://kevin.atkinson.dhs.org/avisynth_c/.

AviSynth 2.5.3 includes an older version of my C API.  To install the
newer version simply overwrite avisynth_c.dll with the one from the
never version.  avisynth_c.dll can usually be found in the windows
system directory.

To install the C ABI with older versions simply copy avisynth_c.dll
into the plugin directory or load with with LoadPlugin like you
would any normal AviSynth plugin.

If you are using AviSynth 2.5.3 or better filters written with this
interface can be loaded like any other filter.  With early versions of
AviSynth use:
   LoadCPlugin(filename)

The API is defined in the C header "avisynth_c.h".  This header uses
two common extensions to C which are also part of the C99 and C++
standard: "//" comments, and inline functions.  Gcc and Visual C fully
supports these extensions.  Since "extern C" linkage is used the C API
can be used by any C++ compiler, even ones that are not API compatible
with VC++.

Please see "example.html" for an illustrative example of how to use
the C ABI and "abi.html" for a complete reference to the ABI.  The
file "examples.c" contians some additional examples.  The examples dll
was created using gcc 3.2.3.

The example file defines the following filters:
  DoNothing(clip): does absolutely nothing
  DuplicateN(clip, num): replaces all frames in the clip with frame 
                         with frame number num.
  InvertLuma(clip): Inverts the luma channel.  Requires YUY2 or YV12
  InvertLumaInPlace(clip): Same as InvertLuma but does not make
                           a copy of the clip.

To use it use
  LoadCPlugin("PATH TO EXAMPLES DLL\examples.dll")

Please note that it is VERY important to free all AVI_Clip when you are
done with it.  This is because if you don't AviSynth may crash on
exit.

Also note that a future version of the C ABI is very likely to use the
stdcall calling convention for better compatibility with languages
like Visual Basic.  Naturally this will break binary compatibility.
To maintain source code compatibility always use AVSC_CC when defining
callback functions.

Changes from 0.14 to 0.15 (January 1, 2004)

  * Bug Fixes
  * Wrote example.html and abi.html

Changes From 0.13 to 0.14 (September 10, 2003)

  * Implemented avs_create_script_environment
  * Added avs_copy_video_frame
  * Minor API Changes

Changes From 0.12 to 0.13 (September 7, 2003)

  * Bug Fixes
  * Added constants for use with avs_get_cpu_flags
  * Clarified copyright notice

Changes From 0.11 to 0.12

  * Bug Fixes

Changes From 0.10 to 0.11 (August 12, 2003)

  * Bug Fixes
  * Minor API Changes
  * Added YV12 support to the examples.

Everything in the distribution is Copyright 2003 Kevin Atkinson.

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.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA, or visit
http://www.gnu.org/copyleft/gpl.html.

As a special exception, I give you permission to link to the Avisynth
C interface with independent modules that communicate with the
Avisynth C interface solely through the interfaces defined in
avisynth_c.h, regardless of the license terms of these independent
modules, and to copy and distribute the resulting combined work under
terms of your choice, provided that every copy of the combined work is
accompanied by a complete copy of the source code of the Avisynth C
interface and Avisynth itself (with the version used to produce the
combined work), being distributed under the terms of the GNU General
Public License plus this exception.  An independent module is a module
which is not derived from or based on Avisynth C Interface, such as
3rd-party filters, import and export plugins, or graphical user
interfaces.