Here are some examples of how to convert audio podcasts in mp3 format to YouTube videos in mp4 format with nice (and small to save bandwidth) black and white wave form visualisations. They require the ffmpeg command-line tool, and are one-liners that must be run from the Windows command prompt (see image above).
NB/ I used these one-liner scripts to convert Roy’s Rocket Radio to YouTube-able vids. This was, in fact, the easy part. The (agonisingly) slow part is uploading to YouTube. Check out my progress here. I’m guessing it will take a week or so to convert all, as of this moment, 170 shows.
ffmpeg -i YOURFILE.mp3 -filter_complex "[0:a]showwaves=s=640x480:mode=line:rate=25,format=yuv420p[v]" -map "[v]" -map 0:a YOURFILE.mp4
Replace YOURFILE with the file you want to convert.
All Files in a Directory
FOR /F "tokens=*" %G IN ('dir /b *.mp3') DO ffmpeg -i "%G" -filter_complex "[0:a]showwaves=s=640x480:mode=line:rate=25,format=yuv420p[v]" -map "[v]" -map 0:a "%~nG.mp4"
The command should be run in the directory containing the files you want to convert.
Sources (and More Examples)