ffmpeg capture of 1366 x 768 desktop is skewed but FaceTime cam capture is fine
Per FFmpeg's bug tracker, I was able to ascertain that the source of the problem is specific to the default resolution of the Mac AirBook: 1366 x 768.


  The linesize ... was 1376 ... but
  the buffer size was for a linesize of 1366.


After switching the AirBooks Built-In Display resolution, I am able to successfully capture a recognizable desktop movie:



To resolve this problem requires implementing a patch which I do not know how to do yet.