Space Kaijuu said:
Does anyone have any suggestions on the best way to adjust the audio so that it syncs up with the video?
(Only some?) capture cards sync audio to the video on-the-fly and don't always make a full accounting of "rounding errors" in it's sync-delays (both "+" and "-"). All other things being equal, this causes instances of drift that may or may not cancel out each other across the length of the stream. Editing can exacerbate these errors. This information (for mpeg, as best I know) is fully embedded in the audio stream (.MPA, .MP2).
Your first step might be to convert your audio to .WAV or some other format without time-adjust information and determine if that format remains in sync with your video. If so, you're done.
Failing that, your next step might be to confirm that your video is complete (no dropped or duplicated frames) for it to be your audio-anchor. Failing a "reference" video and/or if your audio is warbling throughout, then, scene by scene or even shot by shot, stretch or compress your audio segments with something like this:
The PaceMaker Plug-in v2.6
http://www.surina.net/pacemaker/
Such software can change the tempo of the audio to fit into the allowed video space. This one may not have fine enough adjustment or good enough quality, but it's freeware and will let you determine if this approach is practical. PaceMaker happens to be a plug-in for WinAmp (and MediaMonkey) but others are stand-alone programs.
Finally, always, always, cut your zoomed-in audio at the 0 dB points at descents, or at rises, uniformly:
When rejoined (at those points), you will never hear "clicks", "pops", or other poor-construction artifacts. If your audio editor doesn't let you visualize your edits this way, you're using the wrong audio editor.