I doubt in one thing. As described in ISO-14496-12 moov/mvhd/trak/mdia/minf/stbl/stsd should contain format specific box e.g. avc1 box described in ISO-14496-15 or mp42 described in ISO-14496-14. But it also contains fields in VideoSampleDescription from QuickTime Format specification such as 'version', 'revision_level','vendor', etc.
Could anyone explain this issue?