I wanted to figure out a way to quickly and easily combine an image file (jpg) and audio file (mp3) into a video file (mov) using the free media converter tool ffmpeg. This would allow me to upload my podcast episodes and songs to YouTube. After extensive googling and testing I found the combination that finally worked. And since I’m such a nice dude, I’ll share it with you:
Youtube trick.
Source: Combine Image File and Audio File Into Video – avconv / ffmpeg