Abstract: An orientation based, aspect-ratio switching video playback system selects from multiple video streams having corresponding content to automatically match the orientation of the device and play a version of the video filmed, produced and formatted for that orientation. Orientation changes may occur at any time during playback. When an orientation change is detected, the video playback system stores the current playback time, switches to the video stream optimized for the new orientation, and resumes playback from the stored playback time. Switching may be performed automatically and seamlessly to enable the viewer to continue watching the video in the new orientation, at the optimal aspect ratio for such orientation, using the full screen area without clipping any video content, and without interruption.