I am not able to reproduce this in AEM 6.2 (latest SP + CFP), I can see
dam:sha1, dam:size and dam:extracted are getting saved on metadata node
for all type of files including mp3/mp4. Is there any customization
around asset processing/handling done in your case? Can you please check
if there is any error in logs (error.log) logged during asset processing
(dam_update_asset) workflow? Share the same to understand the issue
better.Thanks,Ashutosh