Recovered .MP4 files are not playing

[Sherlock_Holmes]

Hi guys,

I have Panasonic HC-VX980M.
Its built-in storage (not SD card) was accidentally formatted.
Nothing has been recorded since then.
I tried to restore with Recoverit and R-Studio and files are restored in both apps.
However, recovered files are not playing.
Interestingly, if I try to compress any recovered video file (say 1GB in size) its compressed file size is about 350KB.

Does that mean the recovered files were not recovered indeed.
How to recover the video properly.

Thanks.

[butterw]

Files are not recovered, they are likely filed with 0s.

[davexnet]

Files are not recovered, they are likely filed with 0s.

Try testdisk
https://www.cgsecurity.org/wiki/TestDisk_Download

[Sherlock_Holmes]

Tried PhotoRec but it restored some files with 128KB in size.

[davexnet]

Tried PhotoRec but it restored some files with 128KB in size.

I think it depends on what the format did, how much of the disk did it overwrite .
A long format may overwrite every sector - In which case the files are gone.

However, there are quite a few products that claim to be able to get back data even after a format.
https://www.easeus.com/datarecoverywizardpro/

If your files compressed from 1GB to 350k (zip or 7z?) it means the file was mostly repetitive
data, most likely binary zeroes. You can look at them with a hex editor. Just scroll through it and see

[Sherlock_Holmes]

Thanks guys for your help.
I've gave up with this.