Osx ffmpeg avfoundation audio not syncing

Question

I am trying to record my screen sound and video using ffmpeg. I installed soundflower successfully and installed the correct audio devices. However, when using ffmpeg, the sound is accelerated and not synchronized with the video.

ffmpeg -f avfoundation -i "1:0" -y out.avi

I also tried the following options.

ffmpeg -vsync 2 -f avfoundation -i "1:0" -framerate 30 -y out.avi

ffmpeg -vsync 2 -f avfoundation -i "1:0" -frame_rate 30 -probesize 10M  -y out.avi

ffmpeg -async 1 -probesize 10M -f avfoundation -i "1:0" -r 15  -y out.avi

ffmpeg -async 15 -f avfoundation -i "1:0" -r 15  -y out.avi

I am using ffmpeg version 2.6.2 installed via homebrew.

If someone has a free solution that is not ffmpeg that works well from the command line, then I will also agree with that. Quicktime screen recording produces very large file sizes, so it is not suitable.