My infant son let out his first real giggles today, so I quickly grabbed my digicam (Canon S100) and recorded. I started out in portrait, then halfway through I rotated the camera to film in landscape so that the viewer can see what he's laughing at.

Is there any way to fix this, so that when it is viewed online, it all appears in the proper orientation (without rotating sideways halfway through)?

Please tell me I didn't muck up the video of his first laugh