It's pretty straightforward to calculate frame boundaries if the frame size is uniform and are packed correctly. For example, consider a single row of 10 frames consisting 50x50 images. For the 5th frame, the boundries would be {x=50*5,y=0,w=50,h=50}. The calculations would be slighty more complicated for animations packed into multiple rows.

For tools I use Tyler 2.0 to pack multiple bitmap files into a single one. I use it because it's simple and number of frames per row is configurable.

You can also use imagepacker which is more complicated and more powerful. You can output the frame rectangle of every frame in the animation.

I use Animation Shop 3(came with PSP7) from Jasc Software to take a gif and export all the individual frames to seperate files. There probably exist a free tool for doing this somewhere.

Check out this page for some more interesting tools.

Good Luck.

Its not to hard.
Are you using WIN32 API or DirectX?

I generally create a SPRITE structure that stores all the data about my SPRITE. Then I have a global.h file that has start and stop variables depending on the direction I'm facing. I think it would be easier just to show you.

//Set knight properties
blueknight.x = SCREEN_WIDTH/2;
blueknight.y = SCREEN_HEIGHT-100;
blueknight.width = 96;
blueknight.height = 96;
blueknight.curframe = 8;
blueknight.movex = 0;
blueknight.movey = 0;
blueknight.animcount = 0;
blueknight.animdelay = 2;

//Walking variables
const int WALKRIGHT[2] = {0,7};
const int WALKUP[2] = {8,15};
const int WALKNE[2] = {16,23};
const int WALKNW[2] = {24,31};
const int WALKDOWN[2] = {32, 39};
const int WALKSE[2] = {40, 47};
const int WALKSW[2] = {48, 55};
const int WALKLEFT[2] = {56, 63};
const int WALKCOLUMNS = 8;
const int SPEED = 5;

Notice I have an array the first variable is the start frame the second is the stop frame.

void PlayerControl::Walk(int direction)
{
if(currDirection != direction && !attack)
{
switch(direction)
{
case 1:
blueknight.curframe = WALKRIGHT[0];
startFrame = WALKRIGHT[0];
blueknight.movex = SPEED;
blueknight.movey = 0;
stopFrame = WALKRIGHT[1];
currDirection = 1;
attackDirection = 1;


if(attack)
{
Attack(attackDirection);
}
else
{
blueknight.y +=blueknight.movey;
blueknight.x +=blueknight.movex;
if(currDirection != STOP)
{
if(++blueknight.animcount >=blueknight.animdelay)
{
++blueknight.curframe;
if(blueknight.curframe>stopFrame)
{
blueknight.curframe = startFrame;
}
}
}
else if(currDirection == STOP)
{
blueknight.curframe = stopFrame;
}

RECT srcRect;
srcRect.left = (blueknight.curframe % WALKCOLUMNS) *blueknight.width;
srcRect.top = (blueknight.curframe/WALKCOLUMNS) * blueknight.height;
srcRect.right = (srcRect.left + blueknight.width);
srcRect.bottom = (srcRect.top + blueknight.height);

position.x = (float)blueknight.x;
position.y = (float)blueknight.y;
position.z = 0.0f;

sprite_handler->Draw(
blue_knight_walk_image,
&srcRect,
NULL,
&position,
D3DCOLOR_XRGB(255,255,255));
}//end else


This is probably hard to understand but I just took pieces of my code and posted it on here. You can't just call Draw like I did, because you have to Begin and End the sprite_handler first. This is an object that is called between Begin and End.

Look for a program called SpriteBuilder, it works awesome for combining multiple images.

You can download the trial version, and I think I only paid $29.99 for it. If you have a bunch of files you need to have combined, send them to adam_autum@iwon.com and I will combine them and send them back to you.