MPEG and M4A explained
MPEG-1 and MPEG-2 program streams are the formats behind Video CDs and DVDs. They are decades old and very inefficient by modern standards.
M4A is an MP4 container holding only audio — usually AAC, sometimes Apple Lossless. The extension exists mainly so players know not to look for a video track.
- Where MPEG files come from
- DVD rips, old camcorders and broadcast archives.
- Where M4A is used
- iTunes purchases, Apple Music downloads, voice memos and audiobooks.