One way of considering it might help you, since we have no idea what you are attempting in terms of animation:
Sometimes putting the camera INSIDE the scene eases this kind of problem. For instance, if you texture the inside of a sphere, it naturally loops around, and all you need to do is rotate the camera.
If you are doing a walk cycle, you may find it easier to START the walk cycle in the center of the screen, so the looping occurs in the middle where you have more control
More information will give you better answers.
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