01 90 Proof.m4a -

Technical users can run ffprobe to analyze the stream, often discovering that the mdat (media data) is present, even if the container is broken.

Technical Spotlight: Rescuing "01 90 Proof.m4a" and Other Broken Recordings 01 90 Proof.m4a

Once you have a working file, use ffmpeg to re-encode it into a stable format: ffmpeg -i newfile.m4a -c:a aac output.m4a . Prevention: How to Save Files Forever Technical users can run ffprobe to analyze the

Install faad2 via Homebrew ( brew install faad2 ) and try converting the raw file, adjusting the sample rate if necessary. adjusting the sample rate if necessary.