That's right, usually the best quality audio you can get from youtube is in m4a format. The only problem I'm having is youtube sets the format inside the m4a to

That's right, usually the best quality audio you can get from youtube is in m4a format. The only problem I'm having is youtube sets the format inside the m4a to dash, which some stupid players (including iTunes) don't want to play. So I have to run something like ffmpeg.exe -i "Keith Wiley - The Fermi Paradox, Self-Replicating Probes, Interstellar Transport Bandwidth-AUk6ZlePtQA.m4a" -c:a copy 2.m4a to change the format in the file header to M4A.