how to display AVI in Lesson 30

We need to see more of your code to be able to give you proper solutions, but my first guess is that you're clearing the color and depth buffer twice each frame.

You only need glClear(..) once at the beginning of DrawGLScene?!

This is my new version of DrawGLScene(). At the top, I call DrawAVI(). With this code, I am able to see the avi, but it is flashing. It's almost as if there is no synchronization. I've played with putting DrawAVI is various places, but nothing seems to help.

Thanks!

int DrawGLScene(GLvoid) // Here's Where We Do All The Drawing
{
int i;
static float offset = (float)0.01;
//====================================
// Call Video
//====================================
DrawAVI ();// Draw Our Scene

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

//set camera in hookmode
if (hook_toball1)
{
TVector unit_followvector=ArrayVel[0];
unit_followvector.unit();
gluLookAt(ArrayPos[0].X()+250,ArrayPos[0].Y()+250 ,ArrayPos[0].Z(), ArrayPos[0].X()+ArrayVel[0].X() ,ArrayPos[0].Y()+ArrayVel[0].Y() ,ArrayPos[0].Z()+ArrayVel[0].Z() ,0,1,0);

}
else { gluLookAt(pos.X(),pos.Y(),pos.Z(),up_pos.X()+dir.X(),up_pos.X()+dir.Y(),up_pos.Z()+dir.Z(), 0.0,1.0,0.0);
}

glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

glRotatef(camera_rotation,0,1,0);


glEnable(GL_TEXTURE_2D);
//render walls(planes) with texture
glBindTexture(GL_TEXTURE_2D, texture[3]);
glColor3f(1, 1, 1);
glBegin(GL_QUADS);

glTexCoord2f(1.0f, 0.0f); glVertex3f(-320,320,-320);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-320,-320,-320);
glTexCoord2f(0.0f, 1.0f); glVertex3f(320,-320,-320);
glTexCoord2f(0.0f, 0.0f); glVertex3f(320,320,-320);

glTexCoord2f(1.0f, 0.0f); glVertex3f(320,320,-320);
glTexCoord2f(1.0f, 1.0f); glVertex3f(320,-320,-320);
glTexCoord2f(0.0f, 1.0f); glVertex3f(320,-320,320);
glTexCoord2f(0.0f, 0.0f); glVertex3f(320,320,320);

glEnd();

//render floor (plane) with colours
glBindTexture(GL_TEXTURE_2D, texture[2]);
glBegin(GL_QUADS);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-800,-320,800);
glTexCoord2f(1.0f, 1.0f); glVertex3f(800,-320,800);
glTexCoord2f(0.0f, 1.0f); glVertex3f(800,-320,-800);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-800,-320,-800);
glEnd();



//render/blend explosions
glEnable(GL_BLEND);
glDepthMask(GL_FALSE);
glBindTexture(GL_TEXTURE_2D, texture[1]);
for(i=0; i<20; i++)
{
if(ExplosionArray._Alpha>=0)
{
glPushMatrix();
ExplosionArray._Alpha-=0.01f;
ExplosionArray._Scale+=0.03f;
glColor4f(1,1,0,ExplosionArray._Alpha);
glScalef(ExplosionArray._Scale,ExplosionArray._Scale,ExplosionArray._Scale);
glTranslatef((float)ExplosionArray._Position.X()/ExplosionArray._Scale, (float)ExplosionArray._Position.Y()/ExplosionArray._Scale, (float)ExplosionArray._Position.Z()/ExplosionArray._Scale);
glCallList(dlist);
glPopMatrix();
}
}

glDepthMask(GL_TRUE);
glDisable(GL_BLEND);
glDisable(GL_TEXTURE_2D);



return TRUE; // Keep Going
}

I made additional changes that helped, but it still has the flashing/flickering problem. This is the new DrawAVI():

void DrawAVI() {
// Grab A Frame From The AVI
GrabAVIFrame(frame);
if(bg) // Is Background Visible?
{
// Reset The Modelview Matrix
glBegin(GL_QUADS);
// Begin Drawing The Background (One Quad)
// Front Face
glTexCoord2f(1.0f, 1.0f); glVertex3f( 11.0f, 8.3f, -20.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-11.0f, 8.3f, -20.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-11.0f, -8.3f, -20.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f( 11.0f, -8.3f, -20.0f);
glEnd();
// Done Drawing The Background
}
}

I moved the call to DrawAVI() to just after the call to glRotatef(camera_rotation,0,1,0);

The randomness of the flickering was eliminated by removing the call to glTexSubImage2D() at the end of GrabAVIFrame()

void GrabAVIFrame(int frame)
// Grabs A Frame From The Stream
{
static int xScreenLocation = 0;
static int yScreenLocation = 0;
static int xScreenWidth = 0;
static int yScreenHeight = 0;

static int offset = 1;
LPBITMAPINFOHEADER lpbi; // Holds The Bitmap Header Information
lpbi = (LPBITMAPINFOHEADER)AVIStreamGetFrame(pgf, frame);
// Grab Data From The AVI Stream
pdata=(char *)lpbi+lpbi->biSize+lpbi->biClrUsed * sizeof(RGBQUAD);
// Pointer To Data Returned By AVIStreamGetFrame

// Convert Data To Requested Bitmap Format
xScreenLocation = 50;
yScreenLocation = 50;
xScreenWidth = width/2;
yScreenHeight = height/2;
DrawDibDraw (hdd, hDC, xScreenLocation, yScreenLocation, width/2, height/2, lpbi, pdata, 0, 0, width, height, 0);

// Swap The Red And Blue Bytes (GL Compatability)
flipIt(data);

// Update The Texture
// glTexSubImage2D (GL_TEXTURE_2D, 0, 0, 0, 256, 256, GL_RGB, //GL_UNSIGNED_BYTE, data);
}