I did a similar thing with some old VHS. I used an SVHS VCR that had component output, a firewire digitizer, a firewire PCI card, a PC, and some Windows software to capture the raw video from the firewire card. There were zero audio sync issues.
Tearing at the top and bottom of the image is unavoidable. You just have to crop the top & bottom of the video. If you look carefully at the author's example video, you can see that the professional video was zoomed in slightly, indicating that it was cropped.
Tearing at the top and bottom of the image is unavoidable. You just have to crop the top & bottom of the video. If you look carefully at the author's example video, you can see that the professional video was zoomed in slightly, indicating that it was cropped.