From what I've seen, the video on the Coffret LD set is from the same source used for the French THX LDs, German THX LDs and UK widescreen VHSs, and shares the same audio source as the UK widescreen VHSs in that it's time compressed so pitch is preserved but the dynamic range has been compressed so loud explosions don't have any real 'impact' and just merge into any other loud noises going on.