Audio starts late

[ggarra13]

A commit made the audio start late. When the audio was added with the -a flag, all was still good. I didn't do a bisect, but audio was fine at least up to:

b476f32b5d121fec19615a125e8853512ac9c0de

[darbyjohnston]

I do see this with the movie you sent me, it looks like it happens with movies that have a timecode offset. I'll look into it.