» Download MP4Box

To check video & audio information, download VideoSpec, MediaInfo.
To split .MP4 files (video) by size, watch this video.
To demux .MP4 files (video), watch this video.

Test results on Demuxing, Splitting (by size) & Joining MP4 files (video)
1. It works fine on Mac OSX 10.5.8, 10.6.8 and 10.7.1 (The extension must be .mp4)

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