![avisynth loop avisynth loop](https://i.ytimg.com/vi/6Wysw_GCsnc/hqdefault.jpg)
This will go into the output frame of the AviSynth session: GlReadPixels(0,0,width,height,GL_RGB,GL_UNSIGNED_BYTE,img_data) īut, not before I grab all the pixel data from the rendered image using glReadPixels. So I enter the main loop after all settings are done:Īnd in the end of the display() function I exit the main loop: (this can only be done in OpenGLUT, regular GLUT does not support this) Because the whole thing is setup again in the next frame. Now, another hack I had to do is have the GLUT main loop render only one frame. This is done in each frame, sadly, but I wasn't able to make it work otherwise. GlutInitDisplayMode ( GLUT_RGB | GLUT_DOUBLE ) So I went with the "dirtier" solution of creating a window for the sake of off-screen redering (which kinda takes the "off" out of "offscreen"), but it works.įor easier setup I used GLUT (with an OpenGLUT impl.) and GLEE: I burned many hours trying to make BITMAPs work as offscreen redering contexts for OpenGL but with no avail. In Win32 case a drawing context can be either a bona fide actual window, or a memory-based BITMAP. In order to render anything, OpenGL must have a rendering context, for a rendering context you need an OS drawing context. GluBuild2DMipmaps( GL_TEXTURE_2D, 3, width,height, OK, now I have the input frame in my memory space and I can move on to make an OpenGL texture out of it: Unsigned char* line_dstp = texBuf + (height - 1 - y)*line_length Uchar* texBuf = (uchar*)malloc(width * height * 3) //"pure" RGB24 encodingĬonst unsigned char* srcp = src->GetReadPtr() //strange AviSynth RGB24 encoded dataĬonst unsigned char* line_srcp = srcp + y* src_pitch Frames come encoded as RGB 24bit, with a little twist: rows size in bytes is not width*3 as you'd expect it be, but AviSynth use a parameter called "Pitch" to determine row size in bytes. Reading the frame is pretty straightforward. Draw rendered 3D image to output frame (OpenGL+AviSynth).Paint frame as texture over 3D model (OpenGL).
#Avisynth loop code
I based my code on this example from NeHe. Open GL on the other hand is very well documented and "tutorialed". Here is the one I used, that basically does nothing but copy the input frame to the output frame.
#Avisynth loop how to
So I set out to integrate AviSynth with OpenGL to create a nice 3D transition effect for our movie clips.ĪviSynth API is not so well documented, but they have very good ground-up examples on how to DIY plugin. I had a little project at work recently, that involved creating movie clips using AviSynth.Īnd I was appalled by the shabbiness of existing transition plugins available freely for AviSynth, they always reminded me of 80s-like video editing.