How to recover a broken mp4 file: moov atom not found

I made a recording with ffmpeg -f alsa -ac 2 -i plughw:0,0 /tmp/audio.mp4 I then moved /tmp/audio.mp4 to another directory (/root/audio.mp4) without stopping ffmpeg leading to a broken .mp4 file: ffplay /root/audio.mp4 [...] [mov,mp4,m4a,3gp,3g2,mj2 @ 0x7f3524000b80] moov atom not found audio.mp4: Invalid data found when processing input **How to recover and read my .mp4 file?**