I do have an idea of how to sync up the beginning/end, but since Shadowplay records using variable frame rate, the audio will go out of sync with time.
I guess you could use something like Handbrake to re-encode the shadowplay recordings to a constant frame rate (and if you're using Lightworks or Premiere you'll have to do that anyway),
but I find it much more comfortable to use Sony Vegas Pro (13) which handles variable frame rate correctly, so I save one step of re-encoding.
However, if you're using a program that records in constant frame rate (dxtory/fraps can do that, iirc) or are willing to try and see how well this works once you "constant-ize" with handbrake,
this was my original suggestion:
- Start recording your desktop
If you enable a windows "areo" theme for your desktop (the ones with transparency), then you can get shadowplay to record your desktop. - Start your recording programm
- Make a constant noise (humm/sing/etc)
- Click the "record" button in your recording program
Now you have a semi-accurate (not quite clapboard-level but probably better than what most gaming channels use) sync point.
When you're done recording, you should do the inverse: Make noise, click stop recording, all while still recording video.
PS: Or just get a pop-filter/windbreaker for your mic