recover MP4 files

[khoelscher]

so I recorded video using OBS software in MKV format then remuxed them to MP4. I moved them to a Adobe Media watch folder to transcode the mp4 files. I moved in all the mkv files by mistake and without thinking selected all and deleted (doh!) nope, not in recycle bin - perm delete!

I used 'undeletefiles pro' program to recover the files. Found all the mp4 and mkv files. They all have data on them, but the mp4 are unplayable even with VLC player. Tried to remux again the recovered MKV files no luck

So question is how can I repair a "recovered" mp4 file? There about 36 files in all. From what I know the encoding or container for the mp4 would be corrupted . Any suggestions?

I will upload one such file here

thank you

[davexnet]

A quick look at your file with a hex editor (I used HxD) shows that it contains 99.9% binary zeroes.
Nothing to recover here

[khoelscher]

ok, it still shows different file sizes like there is something in the files...

[davexnet]

Unfortunately, the size is no indicator of a valid recovery.

Once a file is deleted, it usually first goes into the recycle bin (did you look there?)
then when it is deleted from the recycle bin the space is marked as free and
is immediately available to other programs and Windows itself as new files are written.

The chances of success are increased greatly if the disk
was not the system disk and/or you stopped writing anything to that particular volume.
The amount of overall free space also a factor.
Try Recuvu, I believe there's a free version

https://www.ccleaner.com/recuva/download

[khoelscher]

yeah, when i went to delete the files it said too big for recycle bin permanent delete? so yeah massive F up right there. I realize what i did a few min later and used a recovery program to fetch the files (and BTW, almost all the "free" programs will only find the files, you have to pay to recover, or it only recovers a tiny amount for free) So bassically, sounds like I am hosed here

[davexnet]

yeah, when i went to delete the files it said too big for recycle bin permanent delete? so yeah massive F up right there. I realize what i did a few min later and used a recovery program to fetch the files (and BTW, almost all the "free" programs will only find the files, you have to pay to recover, or it only recovers a tiny amount for free) So bassically, sounds like I am hosed here

Recuvu was/is a reputable undelete software, however, Piriform was acquired by CCleaner who, in turn, was
acquired by avast and their reputation has been damaged in recent times with some questionable
choices they made in their software.

The free version on the site is the same version I have on my XP box; it is fully functional.
I tested it by deleting a 68MB RAR file that was in 3 extents; undeleted it using Recuvu to a
second partition successfully (it unRars without error)

[khoelscher]

well I tried the cmd prompt recover method with FFMPEG/recover mp4, and uh, yeah. Dead. so thanks for the help but my brainfart screwed the pooch on this one!

C:\recover 2\recover\bin>recover_mp4.exe 23-08-27.mp4 result.h264 result.aac --lav
recover_mp4 v1.92 (C) 2011-2017 Dmitry Vasilyev <slydiman@mail.ru>
http://slydiman.me

Writing H264 video file 'result.h264'...
Video format: AVC video 1920x1080, High Profile, Level 4.0
Assuming max AVC/HEVC NAL unit size (IDR) 0x3FFFFF, (non IDR) 0xFFFFF
Used AVC templates: LAV/FFMPEG
Writing audio file 'result.aac'...
Audio format: Assuming audio stream is AAC, 44100Hz, 2ch, profile 2
Assuming min AAC chunk size 0x9E
Searching 'mdat' atom in '23-08-27.mp4'...
Cannot find 'mdat' atom in first 64MB of '23-08-27.mp4'
FATAL ERROR: The file '23-08-27.mp4' cannot be recovered. The entire file is filled by 00 byte!
Video=0.000
'result.h264' created, size 51 (0.000%)
Audio=0.000
'result.aac' created, size 0 (0.000%)

[abolibibelot]

This thread is rather old but since it hasn't been mentioned, it's worth adding for anyone reading this in the future : if the drive was a SSD what happened is not surprising — because of the TRIM command the deleted files are usually wiped within seconds of their deletion. Because of this (among other things), SSDs are dreadful for data recovery — this should be stressed and spread.


@davexnet

A quick look at your file with a hex editor (I used HxD) shows that it contains 99.9% binary zeroes.

More like 100.0%... (With WinHex : “Find hex values”, type “!00”, which searches any byte that is not “00”, not a single hit.)

Recuvu was/is a reputable undelete software, however, Piriform was acquired by CCleaner who, in turn, was acquired by avast and their reputation has been damaged in recent times with some questionable choices they made in their software.

It's spelled Recuva, and it hasn't been updated since 2016, but the current version (1.53.1087) is still very good at what it does for a free program, even outperforming reputed commercial data recovery softwares like R-Studio in some specific areas, as I reported on the R-TT forum (with zero feedback last time I checked) :
https://forum.r-tt.com/viewtopic.php?f=13&t=11090 (raw recovery of AVI files)
https://forum.r-tt.com/viewtopic.php?f=13&t=11186 (assessing the state of files and their recovery potential based on whether their clusters have been overwritten by another file)

The free version on the site is the same version I have on my XP box; it is fully functional.
I tested it by deleting a 68MB RAR file that was in 3 extents; undeleted it using Recuvu to a
second partition successfully (it unRars without error)

On a HDD this is quite trivial, since the clusters which belonged to a deleted file don't get overwritten until they get reallocated to an actual file, or unless the user explicitly requests it (by using a file shredder, or a hex editor, or doing a so-called “low level format”, or performing a write scan with a HDD testing program like HD Sentinel) ; and, on the NTFS filesystem, the MFT record (which contains the cluster allocation information among other things), likewise, usually remains accessible — except in specific cases, like files larger than 4GB (I'm not so sure why, but when such a large file gets deleted, its MFT record, although still present, loses the key cluster information data, so even if all the file's clusters are still intact they can no longer be retrieved through the analysis of the MFT ; in such cases, Recuva still displays the file's size — R-Studio displays “0 byte” which is yet another minor drawback of this otherwise excellent software — but with a warning saying “File's data could not be found on the disk” ; a raw recovery can still be attempted {*}, but it works well only if the file was not fragmented), or files which are so fragmented that they need several MFT records to store their cluster allocation data (I have also seen this happen for a few files much smaller than 4GB and not fragmented, with no obvious pattern).

https://www.cjoint.com/c/JLgbmX4GRCA
(On this screenshot from the analysis by Recuva of a formatted 3TB HDD, all files larger than 4GB appear as “Unrecoverable” with the comment “File's data could not be found on the disk”, except one, a ~9GB file which was located in the recycle bin of that partition. Not sure why, perhaps the deletion process works differently when a file is sent to the recycle bin and then the recycle bin is emptied, as opposed to being deleted right away with [SHIFT] + [SUPPR]. I could recover all those “unrecoverable” files with Photorec [for video files and most ISO images], or R-Studio with a custom file signature [for the less common BIN/CAB video games files] or WinHex and some guesswork [for a few tricky ones], except the last one, the ~19GB MKV which must have been overwritten.)


{*} I wrote this TL;DR on the subject a while back, one night I was really bored :
https://forum.videohelp.com/threads/399175-Raw-recovery-of-video-files-%28file-carving...ture-search%29