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Using Magic Lantern => General Help Q&A => Topic started by: ksn2632 on November 26, 2022, 11:27:52 PM

Title: .M00, .M01 Files duplicate of .MLV file? (MLV recovery/corruption)
Post by: ksn2632 on November 26, 2022, 11:27:52 PM
Hi everyone, I know there's been lots of posts on this topic, but after spending the past week trying out different solutions, I'm officially stumped and would appreciate any advice.

After wrapping up a shoot, I accidentally deleted one of my shots in camera while trying to view it. Went straight home and ran file recovery software on the CF card and was able to recover the MLV along with the .M## files with the headers missing. This was easy enough to fix using a hex editor; the problem however lied in the M00, M01, etc. files. When importing the MLV file alone in MLVapp, it played just fine, but when importing along with say the .M00 file, the total frames and duration looked correct (about double), but the clip itself (as in, what I'm actually seeing on screen) was the exact same as the MLV file on its own, but now played back at about 50% speed. I checked out the spanning files in the hex editor and found that all the data following the VIDF blocks were the same as in the .MLV (I verified this by copying chunks of code from the spanning files and searching for them in the MLV file's code; pretty much everything matched up). So basically I'm left with just the first 40ish seconds of the video I had originally shot, plus a bunch of duplicate files that were supposed to have the last couple minutes of footage.

Is the rest of the clip salvageable? How/why did this occur? Any and all advice is greatly appreciated  :'(
Title: Re: .M00, .M01 Files duplicate of .MLV file? (MLV recovery/corruption)
Post by: Danne on November 27, 2022, 10:54:10 AM
Is it possible to rename the .M00 to .MLV? Maybe header info in those as well.
Title: Re: .M00, .M01 Files duplicate of .MLV file? (MLV recovery/corruption)
Post by: ksn2632 on November 28, 2022, 02:26:03 AM
Hi, yes I have tried converting the .M00, .M01, and .M02 files to .MLV and the problem persists, they all show the exact same footage as the MLV ...
Title: Re: .M00, .M01 Files duplicate of .MLV file? (MLV recovery/corruption)
Post by: Danne on November 28, 2022, 09:51:20 AM
Any conclusions? Impossible to follow your answer. The way you describe it the M00 renamed to .MLV extracts exact same content as your first .MLV file in the sequence which indicates they are the exact same size and maybe just copies of the first .MLV.
Renaming test was to see if the M00, M01 etc could be extracted independently from each oter treated as single .MLV files.
Title: Re: .M00, .M01 Files duplicate of .MLV file? (MLV recovery/corruption)
Post by: ksn2632 on November 29, 2022, 12:04:37 AM
Quote from: Danne on November 28, 2022, 09:51:20 AM
Any conclusions? Impossible to follow your answer. The way you describe it the M00 renamed to .MLV extracts exact same content as your first .MLV file in the sequence which indicates they are the exact same size and maybe just copies of the first .MLV.
Renaming test was to see if the M00, M01 etc could be extracted independently from each oter treated as single .MLV files.

Sorry for the confusion; renaming the M00 alone does not work because it also has missing headers, but when attaching the header of a working MLV in a hex editor, then renaming the .M00 file to .MLV, I can play it back in MLVApp. So I am able get the M00, M01, etc. files working as independent MLV's, but as you say, they are all seemingly copies of the first MLV. Virtually the same file size and seemingly identical code in hex editor minus the headers and footers.

I'm guessing it might have something to do with the recovery process (?) I tested this out with a different CF card afterwards: shot about ~2 minutes of random footage, deleted it, and then recovered it. The MLV was fine but subsequent M## files showed the exact same content as the first.
Title: Re: .M00, .M01 Files duplicate of .MLV file? (MLV recovery/corruption)
Post by: ksn2632 on December 01, 2022, 10:43:13 AM
UPDATE: I figured out how to get back the rest of the footage  8)

I decided to start back from square one and recover the files from the CF card, but this time using a different file recovery software than I had before. What I used was FTK Imager, and when I scanned the CF card, it found a new folder that I had not seen before called "unallocated space". In it was about 60GB worth of files without extensions and with numerical names such as 0000010, 0003210, 0006410, and so on. I looked at the hex preview and sure enough, they had VIDF blocks. I exported a random file towards the end of the folder, brought it into MLVApp, and saw footage that I had not been seeing previously. Finally! The footage I was looking for was there all along, as I had thought. The funny thing though is that each of these files were 100MB (and there were hundreds of them). So in order to reconstruct the video, I had to open one file in a hex editor, copy all of the code, append it to the end of the very first file in the sequence (0000010), then rinse and repeat about a hundred times. It is a painstaking process to rebuild a 19GB clip 100MB at a time, but it was worth it. Grateful for the ML forum for providing me the information to help me recover this file; I otherwise would not have known how to manually edit the files using a hex editor, let alone think to do it. Hopefully this helps anyone in the future who finds them self in the same situation.