I know that Peter is building in some proxy generation, but I have been trying this out (as Streamclip is giving me poor results at the moment).
- import h264 HD file to timeline (no realtime playback BUT has muxed audio).
- render out a jpegAVI of that strip at a matched resolution (annoying to do this for each clip) at a moderate compression.
- import the newly rendered jpegAVI and place it above the original.
- Meta both together
- Play in REALTIME with synced audio.
- Edit program
- Perform colour corrections with Transfer Strips on top of each shot
- deactivate all the proxy versions of each strip (the hard part)
- render out high quality (yum).
I guess that you could slap all the shots onto the timeline and render a single clip out, bring it back and slice it up on the timeline then meta them individually.
Anyway this has all been about muxing and playback.