How to shoot movies with the Canon Eos Rebel T2i– and “movie recording has been stopped automatically”
If the camera stops recording after a short while with the error “movie recording has been stopped automatically”, you most likely have an internal memory buffer overrun (there is a bar chart visible warning you off that shortly before the camera stops). This may be due to you not using a Class (6) or faster SDHC card. Try first a low level format inside the camera, or get a faster memory card. (Per the manual below, a lowering to standard HD should not help!).
Note also: The camera stops the recording when the file size has reached 4GB (3.99 in Windows – FAT32 limit). It is left as an exercise for the reader when that point in time is. May be related to the fact that this camera is primarily meant for photos, not video. I felt I had to use the lowest HD setting with my untested SD card (the one that buffer overran slightly later with the earlier SD card: 1280*720, 60fps – which produces 1GB/3 minute).
Note finally: camera might stop also due to overheating.