Was able to drop an .avi file into Reaper and synch it to my audio fairly easily, because I played to the song on my iPhone while recording the video.
Had a bit of trouble getting ffmpeg libraries working... Went with AVI and MJPEG for rendering formats. Not great looking, but decent for YouTube. (I hope--have not uploaded it yet)
How come my avi video is an empty shell in Reaper? I've seen videos in which it looks like a sound file... with waveforms showing up.
Thx,
Rick