Author Topic: Recovering MLV Files From corrupt Memory Card? (Read 11182 times)

JChance · « **on:** March 21, 2016, 11:58:57 PM »

Hey everyone! I was shooting a documentary with my Canon 70D with ML on the Sandisk Extreme 128 GB Memory card and once it got full it said "Card cannot be accessed" I was wondering if there was a way to recover the MLV files? This is super important and I would love if it was possible.

please, please tell me its possible. I've attempted to use data recovery programs, but none of them support MLV files returning.

Walter Schulz · « **Reply #1 on:** March 22, 2016, 12:12:21 AM »

Is the card detected by your OS if inserted into cardreader?

JChance · « **Reply #2 on:** March 22, 2016, 12:23:28 AM »

The card is detected, but just says it Cannot be accessed and I have the options of "Initializing (which brings up Disk utility), Ignore, or eject.

When I use traditional data recovery it shows up as well. Even on the camera it says the card is unable to be accessed.

Walter Schulz · « **Reply #3 on:** March 22, 2016, 12:28:40 AM »

Give Photorec running under OS X or Linux a chance. Both OSs do have options to mount "unreadable" cards and Photorec supports MLV recovery.
Google will come up with some hints to do this. If unable to find a solution come back here.

JChance · « **Reply #4 on:** March 22, 2016, 02:21:13 AM »

Walter, you have saved my ass and helped me on so many occassions. I want you to know that you are so appreciated for all of the crazy amazing things you do!

will definitely give it a go

JChance · « **Reply #5 on:** March 22, 2016, 03:34:50 AM »

So photorec recovered them, but there seems to be no data on them? I cannot play them with MLrawviewer? This is how they show up (much smaller than actual mlv files?) or.. when they do happen to play from MLrawviewer they are just black screens.

This is how they show up

Maybe I picked the wrong directory? It's on my SD card so I don't know if thats ex2 or rdisk or what any of that means...

DeafEyeJedi · « **Reply #6 on:** March 22, 2016, 04:49:46 AM »

Did you try them in 'paranoid mode' yet as that has helped me previously...

JChance · « **Reply #7 on:** March 23, 2016, 05:46:45 PM »

Still extremely small 1.6mb files. Even with Paranoid (bruteforce mode) enabled

I'm a bit confused on the options to select, maybe thats it?

When I put my SD Card in there's rdisk1 and rdisk2, then it asks for No partition or NTFS etc. and I select No partition (whole disk). After that it asks ex1/ex2 or FAT,etc and I choose the FAT,etc. option

Is there a set plan on what to options to choose for corrupted Sandisk 128 GB memory cards?

Walter Schulz · « **Reply #8 on:** March 23, 2016, 06:35:34 PM »

Canon supports FAT file systems only.
Try again.

JChance · « **Reply #9 on:** March 23, 2016, 07:15:34 PM »

I selected the FAT etc. option each time. Does it matter if i select Partition or no partition? Furthermore does it matter if I selected Rdisk1 or rdisk2?

Walter Schulz · « **Reply #10 on:** March 23, 2016, 07:36:43 PM »

There is a Step-by-Step instruction covering most of your issues:
http://www.cgsecurity.org/wiki/PhotoRec_Step_By_Step

JChance · « **Reply #11 on:** March 24, 2016, 11:56:26 PM »

I tried all of that and all of the videos are still coming out extremely small

DeafEyeJedi · « **Reply #12 on:** March 25, 2016, 02:15:10 AM »

I've had this happened to me on several occasions as well and reached out the developer on this very exact issues to no avail.

He replied back and said to use the Paranoid mode which I did and still didn't help so not sure what's to do at this point.

JChance · « **Reply #13 on:** March 26, 2016, 03:41:47 PM »

This is really disheartening, should I just format the memory card and call it a loss?

There was 128 GB worth of documentary footage on it :/

DeafEyeJedi · « **Reply #14 on:** March 26, 2016, 05:45:23 PM »

Not sure yet. That's basically what I had to do with mine stuff even tho I had already rendered them earlier and held onto the DNG's but I like to archive MLV's.

Have you tried writing an email to the developer yet? Sometimes having more than one person reporting the same so called "bug" with the 1.6MB for each recovered MLV's may give him a good reason(s) to take a look into it.

Wouldn't hurt to try.

JChance · « **Reply #15 on:** March 28, 2016, 06:19:34 PM »

Sent him a message, hoping for the best.

Thanks everyone. Hopefully we can get a concrete answer from this

Tyronetheterrible · « **Reply #16 on:** March 29, 2016, 09:12:48 PM »

I was able to restore my MLV files from my SD cards on multiple occasions by selecting "Initialize" when the option appears, and "repair disk" in Disk Utility. Then I simply re-insert the SD card, and then they are accessible. This has always worked for me in my case.

JChance · « **Reply #17 on:** March 30, 2016, 08:56:06 AM »

ill definitely try it out! Thank you!

JChance · « **Reply #18 on:** April 06, 2016, 11:31:19 PM »

HA! IT WORKED! IT WORKED!

Tyronetheterrible · « **Reply #19 on:** April 07, 2016, 02:36:40 AM »

Glad to hear man!
I freaked out when I first ran into this issue, as I shot a full day's worth of an important project (knowing full well of the inherent risks to begin with of course), but it's nice to know there is this fail-safe for this particular issue.

JChance · « **Reply #20 on:** April 07, 2016, 09:09:38 AM »

It's extremely pleasing to know that the fix is so easy as well!

Can we update ML's troubleshooting with this info? It can help many shooters! Instead of photorec (which doesn't really work) you can do this method trouble-free

DeafEyeJedi · « **Reply #21 on:** April 07, 2016, 06:31:47 PM »

Nice to know and thanks for sharing this info guys. Totally agreed that this should be included to ML troubleshooting re: OS X.

droider · « **Reply #22 on:** October 14, 2017, 06:59:30 PM »

hi JChance,
i hope I'm not too late! Photorec is good solution, you should check this app. TestDisk is another option (but there is no GUI). Good luck!

jkanint · « **Reply #23 on:** December 06, 2017, 09:45:48 AM »

Here is the official guide from Sandisk: https://kb.sandisk.com/app/answers/detail/a_id/4985/~/data-recovery-for-memory-cards-and-flash-drives

P.S I am using TunesBro DiskGeeker. It works like a charm but it is a paid solution.

Hope this helps.

tyfreak · « **Reply #24 on:** September 22, 2019, 04:46:08 PM »

Hello everyone! I don't know, if this is a necro-posting, but I'll write.
Here is my sitiation: Canon 5D Mark III, 1.2.3, last build of Magic Lantern.
If you format CF card with loaded ML, you'll get FAT32 filesystem (I use 128gb Sandisk pro). Without ML you'll get exFAT. It doesn't matter, video automatically splits into 4gb chunks, m00, m01 etc. But! What has happend with my friend: he formatted card with ML loaded, shot one day, card was full. And then he pulled out SD with ML, and then he accidentally formatted CF, with ExFAT! Facepalm!..
FAT32 was formatted with exFAT. What I tried: R.saver (only saw ML-firmware files), photorec (photorec saved some MLV files 3.5mb length, all info was right, ie WB, shutter, but no video) and many other programs. It was pointless.
And I decided to dig deeper into card, with hex-editor. A opened document with byte-by-byte description of all MLV-segments, and journey begans!
After two days I found out one important thing: ML (or 5D himself), when in 4gb-chunks mode, continuously overwrites first VIDF-segment with headers for chunk-files (m00, m01...). What we have in perfect world:
MLVI...|some stuff, like WB, shutter, pixel shift...|VIDF-0..|videoframe0|VIDF1|videoframe1|... etc
What we have in FAT32:
MLVI...|some stuff, like WB, shutter, pixel shift...|VIDF-0..|videoframe0 - cut! after around 1024 bytes of videoframe0 we can see this:
MLVI...|some stuff, like WB, shutter, pixel shift...|MLVI name for chunk, ie MVIxx_yyy.M00|VIDF-1892|videoframe1892 - cut!
And etc, with all Mxx chunks. So, we have completely destroyed first frame. And if we look closely down the card, we'll find our cutted frames, but without headers.
And then I copy-pasted headers from the first VIDF to their right places, checked length (if we have one byte mismatch, all converters stops with errors), replaced first VIDF-frame with healthy frame from another video and saved all this files from hex-editor to PC. And it worked!
It was insane! I saw dreams, where I, in space, trying to rebuild MLV from numbers in stars.
What I want to say... And nothing to say! FAT32 sucks, photorec sucks, and I'm Neo, I can see RAW-video in hex-numbers!
P.S. Maybe this post will be useful for lost souls, who's trying to save their MLV-files from FAT32-trap:)) Load your hex-editors, friends!

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Author Topic: Recovering MLV Files From corrupt Memory Card? (Read 11182 times)