If you right-click on a video and select Properties, then the audio-video tab,
you will see the details of how the file was encoded.

With my very cheap Moviepix camera, the files are .MOV, the video is H.264/AVC,
1280 by 720, and the audio is MPEG-4 AAC. The files play back fine on my
computer, which has a Phenom II X2 processor running at 3.2 GHz. The Sysmonitor
screenlet says one CPU is running at about 60% during playback.

If you use Video Converter to convert to another format, the videos might play
back better on your computer.

I've actually switched from the Moviepix, which only worked really well when
shooting outdoors in sunlight. Now I am using a Samsung F30, which uses the same
encoding but names the files .MP4.