struct inputdata
{
   vec2 video_size;
   vec2 texture_size;
   vec2 output_size;
   float frame_count;
   float frame_direction;
   float frame_rotation;
};

attribute vec4 a_position;
attribute vec2 a_texCoord;
uniform inputdata IN;
varying vec4 TexCoord[8];

void main()
{
const vec2 OGLSize = vec2( 1024.0, 512.0);
vec2 OGLInvSize = 1.0/OGLSize;
float dx = OGLInvSize.x;
float dy = OGLInvSize.y;

gl_Position = a_position;
TexCoord[0].xy = a_texCoord;
TexCoord[1] = TexCoord[0].xxxy + vec4( -dx, 0, dx,-2.0*dy); // A1 B1 C1
TexCoord[2] = TexCoord[0].xxxy + vec4( -dx, 0, dx,    -dy); //  A  B  C
TexCoord[3] = TexCoord[0].xxxy + vec4( -dx, 0, dx,      0); //  D  E  F
TexCoord[4] = TexCoord[0].xxxy + vec4( -dx, 0, dx,     dy); //  G  H  I
TexCoord[5] = TexCoord[0].xxxy + vec4( -dx, 0, dx, 2.0*dy); // G5 H5 I5
TexCoord[6] = TexCoord[0].xyyy + vec4(-2.0*dx,-dy, 0,  dy); // A0 D0 G0
TexCoord[7] = TexCoord[0].xyyy + vec4( 2.0*dx,-dy, 0,  dy); // C4 F4 I4
}