How to recover 1.4GB video file that can't be read (Canon)

Try with recover_mp4_to_h264. It's a command line program, and will require a good reference file.

Usage as indicated:

recover_mp4_to_h264 in_good_similar.mp4 --avcc
recover_mp4_to_h264 in_corrupted.mp4 out_video.h264 [out_audio.aac | out_audio.wav | out_audio.mp3] [<recorder>]
recover_mp4_to_h264 in_corrupted.mp4 out_video.h264 [--aac | --pcm | --mp3] [<recorder>]