There is no default file format for PrP. You use whatever fits you or your client needs.
AVI and QuickTime are just wrappers for the various codecs that reside within. These codecs determine the degree and kind of compression used.
Many folks choose to use the industry standards of Prores (only available on the Mac) or DNxHD, developed by Avid. Both are available wrapped in QT.
I recently chose to master to OP1a AVC-I 100. This is wrapped in MXF which is 2x faster when exporting from PrP then any QT wrapped codec.
Though its not yet considered an industry standard.
Tom Daigon
PrP / After Effects Editor
http://www.hdshotsandcuts.com
https://www.youtube.com/watch?v=DxPrG3WUyz8
(Best viewed at 1080P and full screen)
HP Z820 Dual 2687
64GB ram
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