Recover of Magic Lantern .MLV - Incomplete Files

Using PhotoRec to recover lost data
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digitalre
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Joined: 06 Apr 2015, 01:31

Recover of Magic Lantern .MLV - Incomplete Files

#1 Post by digitalre »

Hey

I had a problem with my CF Card which i used in a Canon 5D MkIII with magic lantern recording .MLV files. All recorded ok in camera, but when I went to download the footage on my iMac the card was blank - no files, folders, etc.

So I used PhotoRec to recover the files which worked well, but the .mlv are only 3.6mb in size. When I import them into RAWMagic, I can see the correct ISO, Timecode etc, however the files are only 1 frame.

Any ideas on how to fix this?

Thanks

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cgrenier
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Re: Recover of Magic Lantern .MLV - Incomplete Files

#2 Post by cgrenier »

A manual data recovery with a disk editor is probably needed to find all the video frame (VIDF). If you want you can send an image of the memory card (TestDisk, Advanced, Image Creation, compress the image.dd file) or the card itself. Please send me a private email if you are interested.

benjaminallison
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Joined: 12 Aug 2016, 08:37

Re: Recover of Magic Lantern .MLV - Incomplete Files

#3 Post by benjaminallison »

Just wanted to follow up on this. I accidentally deleted files from my CF card using Magic Lantern's file manager. Photorec is restoring photos (CR2) just fine, but MLVs are being restored in 3.6MB chunks.

CF is a Komputerbay 64GB 1066x, which I formated in camera (Canon 5D Mark III) prior to shooting.

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cgrenier
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Re: Recover of Magic Lantern .MLV - Incomplete Files

#4 Post by cgrenier »

benjaminallison, do you have the problem with latest photorec 7.1-WIP ?

benjaminallison
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Re: Recover of Magic Lantern .MLV - Incomplete Files

#5 Post by benjaminallison »

Thanks so much for your reply.

Yeah 7.1-WIP is retrieving 3.6mb sized files.

Now, these files were deleted using Magic Lantern's File Manager. As soon as I realized what happened, I popped the card out, so nothing was written subsequent (but I'm not sure if that particular delete method messes with the data in some way).

I tried undelete using Testdisk, and while it can see the files and undelete them in (what appear to be) more accurate filesizes, the data seems to be mangled for some reason. :(

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cgrenier
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Re: Recover of Magic Lantern .MLV - Incomplete Files

#6 Post by cgrenier »

Can you do a test ? Put a small memory card in your camera, take a video. Do not delete this file.
Run PhotoRec, start a recovery, choose [Whole] instead of [Free]. If you have the same problem, please run testdisk, Advanced, Image Creation, upload the image.dd file on google drive (or similar) and send me the link.
I will try to find where the problem is.

benjaminallison
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Re: Recover of Magic Lantern .MLV - Incomplete Files

#7 Post by benjaminallison »

So some unexpected results. I recorded a brief clip to an SD card, didn't delete it. Photorec was able to find the file, however, the file it recovered was smaller than the original. The original is 363.3MB and the recovered version is 305.2MB

Interestingly, the recovered version is at least a valid MLV, unlike the deleted files on the CF card. It seems like it's just missing the last 16 frames or so.

Also, Photorec was also able to recover deleted MLVs on the SD card and render usable files (again, smaller sizes, missing some frames).

I'm not sure if the greater success is due to the differences in card formats (CF is FAT32, SD is NTFS).

I can try the same test on the CF card if that helps (now that I've made a Testdisk image, am I safe to write to the card, or should I still avoid writing to it?).

Additionally, I do have some MLVs that I moved off of the CF before the deletion mishap. Note sure if those would be helpful to help compare data patterns.

I've uploaded the text MLV's here: http://benjaminallison.com/test-files.zip

Original: M13-1123.MLV
Recovered: f0713728.mlv

I'm uploading the Testdisk image, I'll report back once it's available.

benjaminallison
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Joined: 12 Aug 2016, 08:37

Re: Recover of Magic Lantern .MLV - Incomplete Files

#8 Post by benjaminallison »

image.dd of CF image uploaded. Sending PM with the details.

benjaminallison
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Joined: 12 Aug 2016, 08:37

Re: Recover of Magic Lantern .MLV - Incomplete Files

#9 Post by benjaminallison »

Just checking in to see if there was any hope of recovery! I appreciate everything you're doing.

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