Here is the code:-~
/* SimpleSample plugin for Avisynth -- a simple sample~
Copyright (C) 2002-2003 Simon Walters, All Rights Reserved~
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.~
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.~
The author can be contacted at:~
Simon Walters~
siwalters@hotmail.com~
V1.0 - 1st release.~
V1.0a - Revised version to put colourspace checking in the right place.~
V1.0b - Added detailed comments. // sh0dan~
*/
//following 2 includes needed~
#include "windows.h"~
#include "avisynth.h"~
/****************************~
* The following is the header definitions.~
* For larger projects, move this into a .h file~
* that can be included.~
****************************/~
class SimpleSample : public GenericVideoFilter { ~
// SimpleSample defines the name of your filter class.~
// This name is only used internally, and does not affect the name of your filter or similar.~
// This filter extends GenericVideoFilter, which incorporates basic functionality.~
// All functions present in the filter must also be present here.~
public:~
// This defines that these functions are present in your class.~
// These functions must be that same as those actually implemented.~
// Since the functions are "public" they are accessible to other classes.~
// Otherwise they can only be called from functions within the class itself.~
SimpleSample(PClip _child, IScriptEnvironment* env);~
// This is the constructor. It does not return eny value, and is always used, ~
// when an instance of the class is created.~
// Since there is no code in this, this is the definition.~
PVideoFrame __stdcall GetFrame(int n, IScriptEnvironment* env);~
// This is the function that AviSynth calls to get a given frame.~
// So when this functions gets called, the filter is supposed to return frame n.~
};~
/***************************~
* The following is the implementation ~
* of the defined functions.~
***************************/~
SimpleSample::SimpleSample(PClip _child, IScriptEnvironment* env) :
GenericVideoFilter(_child) {~
// This is the implementation of the constructor.~
// The child clip (source clip) is inherited by the GenericVideoFilter,~
// where the following variables gets defined:~
// PClip child; // Contains the source clip.~
// VideoInfo vi; // Contains videoinfo on the source clip.~
if (vi.IsPlanar()) // is input planar?~
env->ThrowError("SimpleSample: input to filter must be in YUY2 or RGB");~
// This filter does not not support planar images.~
}~
PVideoFrame __stdcall SimpleSample::GetFrame(int n, IScriptEnvironment* env) {~
// This is the implementation of the GetFrame function.~
// See the header definition for further info.~
PVideoFrame src = child->GetFrame(n, env);~
// Request frame 'n' from the child (source) clip.~
PVideoFrame dst = env->NewVideoFrame(vi);~
// Construct a frame based on the information of the current frame~
// contained in the "vi" struct.~
const unsigned char* srcp = src->GetReadPtr();~
// Request a Read pointer from the source frame.~
// This will return the position of the upperleft pixel in YUY2 images,~
// and return the lower-left pixel in RGB.~
// RGB images are stored upside-down in memory. ~
// You should still process images from line 0 to height.~
unsigned char* dstp = dst->GetWritePtr();~
// Request a Write pointer from the newly created destination image.~
// You can request a writepointer to images that have just been~
// created by NewVideoFrame. If you recieve a frame from PClip->GetFrame(...)~
// you must call env->MakeWritable(&frame) be recieve a valid write pointer.~
const int dst_pitch = dst->GetPitch();~
// Requests pitch (length of a line) of the destination image.~
// For more information on pitch see: http://www.avisynth.org/index.php?page=WorkingWithImages
const int dst_width = dst->GetRowSize();~
// Requests rowsize (number of used bytes in a line.~
// See the link above for more information.~
const int dst_height = dst->GetHeight();~
// Requests the height of the destination image.~
const int src_pitch = src->GetPitch();~
const int src_width = src->GetRowSize();~
const int src_height = src->GetHeight();~
int w, h;~
for (h=0; h < src_height;h++) { // Loop from top line to bottom line.~
for (w = 0; w < src_width; w++) // Loop from left side of the image to the right side.~
*(dstp + w) = *(srcp + w); // Copy each byte from source to destination.~
srcp = srcp + src_pitch; // Add the width of one line (in bytes) to the source image.~
dstp = dstp + dst_pitch; // Add the width of one line (in bytes) to the destination.~
}~
// end copy src to dst~
// As we now are finished processing the image, we return the destination image.~
return dst;~
}~
// This is the function that created the filter, when the filter has been called.~
// This can be used for simple parameter checking, so it is possible to create different filters,~
// based on the arguments recieved.~
AVSValue __cdecl Create_SimpleSample(AVSValue args, void* user_data, IScriptEnvironment* env) {~
return new SimpleSample(args[0].AsClip(),env); ~
// Calls the constructor with the arguments provied.~
}~
// The following function is the function that actually registers the filter in AviSynth~
// It is called automatically, when the plugin is loaded to see which functions this filter contains.~
extern "C" __declspec(dllexport) const char* __stdcall AvisynthPluginInit2(IScriptEnvironment* env) {~
env->AddFunction("SimpleSample", "c", Create_SimpleSample, 0);~
// The AddFunction has the following paramters:~
// AddFunction(Filtername , Arguments, Function to call,0);~
// Arguments is a string that defines the types and optional names of the arguments for you filter.~
// c - Video Clip~
// i - Integer number~
// f - Float number~
// s - String~
// b - boolean~
return "`SimpleSample' SimpleSample plugin";~
// A freeform name of the plugin.~
}~
