Why did my footage corrupt? BMPC 4K

Hey guys, really hoping someone can help me figure this out as I still need to shoot some footage this week and this camera is my only real option. So here is my problem explained in detail;

On Friday I shot about 300GB of Prores HQ footage on my BMPC 4K using a Kingston HoyerX savage 480 GB SSD. Formatted to exfat. I shot by powering the camera via a vmount battery only.after the shoot I connected the drive via SATA directly to my motherboard on my PC and dumped the footage. Checked the footage and it turned out fine, no issues. After that I put the SSD back in the camera and reformatted the drive to prep for the next day.

On Saturday I shot about 200 GB of Prores HQ footage on the same camera using the same drive formatted using the same format. Now most of the stuff was shot locked on a tripod indoors so I chose to power the camera via the power adapter straight into the wall since it’s easier that way. I also recognize that throughout the day I noticed I had the camera unplugged and let the batter get low while recording before plugging back in. Also when I check the footage on the camera it all plays back fine.

Here’s where I get confused. When I go to dump the footage it transferred rather fast which I found strange. The only reason I dumped the footage in the first place was because I had shot around an hour and 25 minutes of footage and I know that I can only fit about 90 minutes of 4K Prores footage on my 480 GB drive. So why is it showing up as only 200GB when I go to transfer it to PC? Weird. Anyways I dump the footage and attempt to play it in a number of media players and each time I open it there is no picture or sound. The timeline moves across as if the video is playing...but there’s nothing. Footage can’t be played in any media player, footage can’t be converted and it can’t be imported into any footage alediting software (AE, Premiere, Resolve...when I import to resolve the footage is solid red and it’s just static audio). I thought that was odd, so I unplugged the drive, plugged it back into the pc to try again and now my pc is asking me to format the drive every time I plug it in. At this point I have to leave to shoot more footage so I just hope that the footage that I had already dumped is okay, u plug the drive from the computer and put it back into my camera to format it. Now the camera says “no SSD”, however...it lets me format the SSD anyways. After it’s formatted it recognizes the SSD, and I move on to the next shoot (which ends up going fine, no problems with that footage).

At the end of the day I go back to check the corrupted footage and yep, it’s still screwed. I tried using a footage recovery tool, and noticed that it would work on a number of the clips...but what happened on some of the clips is at the beginning there were a couple seconds of footage from the day before...at the start of the footage that I shot the next day. Why is that?

I’ve given up hope in recovering the footage I’m just trying to figure out what could have caused this?
Does this sound like an SSD problem? Seemed not to happen again once I reformatted the drive and shot more footage on it.
Was it because I let the battery get low while filming?

Has anyone else had problems like this and if so how have you fixed it or how should I go about trying to fix it?

What exactly do mean by you let get the battery low? Was it low but the camera still running and you stopped recording and changed battery? Or did the camera go out during recording because the battery was finished?

To me it sounds like the camera was not able to finish writing the file so the file container MOV is missing some head/tail metadata. But if you say it copied too fast then it is likely that the file structure had been damaged severely, and you have only a copy with nothing in it and a pseudo size of 200GB.

What happens if you try to make a ZIP archive from this file? If it is mostly empty than you will get a very small zip.

Do you have only one file or several which do not playback? If you have several, is there one small enough to upload to wetransfer? So I could have a look at it and do some tests? I have no big hope as I'm not an data rescue expert, but it won't hurt to do some tests.

If it seems like the footage data is still there but inaccessible, then there is a specialized company in Spain who can repair footage. They need an intact file with the same file format settings from the camera for reference and can then recreate the metadata stream.

They have a tool to download which gives an estimation of repairability:
http://aeroquartet.com/movierepair/download

What exactly do mean by you let get the battery low? Was it low but the camera still running and you stopped recording and changed battery? Or did the camera go out during recording because the battery was finished?

To me it sounds like the camera was not able to finish writing the file so the file container MOV is missing some head/tail metadata. But if you say it copied too fast then it is likely that the file structure had been damaged severely, and you have only a copy with nothing in it and a pseudo size of 200GB.

What happens if you try to make a ZIP archive from this file? If it is mostly empty than you will get a very small zip.

Do you have only one file or several which do not playback? If you have several, is there one small enough to upload to wetransfer? So I could have a look at it and do some tests? I have no big hope as I'm not an data rescue expert, but it won't hurt to do some tests.

If it seems like the footage data is still there but inaccessible, then there is a specialized company in Spain who can repair footage. They need an intact file with the same file format settings from the camera for reference and can then recreate the metadata stream.

They have a tool to download which gives an estimation of repairability:
http://aeroquartet.com/movierepair/download

What I mean with the low battery was that I shot on the camera’s internal battery for a short while before I realized it was getting critically low (which happens very quickly on my camera). I have read about atleast one other person having a similar issue when shooting on the internal battery once it gets low and I guess I just wanted to know if that claim has any merit to it or if there is any connection there to the corrupt files.

I appreciate your desire to help me run some tests but the smallest clips I have are well over a couple Gigs. I’ve already done some file recovery tests and some of the files were able to be recovered via the GARUonline recovered, but that took only recovers 50% of the file. I looked into the one you linked and it looks like they’d be able to recover the footage, but they would charge over $1000 for the amount of footage I have in the file structure I have. Unfortunately that’s not an option as hear videos were for a fundraising event in two weeks and there isn’t much of a budget.

Basically I’ve already committed to having to reshoot the stuff I lost out on (which won’t be too bad), I just wanted to figure out what the problem was so I could address it on the next shoot since I have to use the same camera (I don’t have a backup camera).

Do you think it was a hard drive issue then? One that was simply fixed by reformatting?
Or do you think it was a power issue? Since the footage shot on the camera the day before and immediately after reformatting the drive had no issues when the camera was powered by a VMount.

I tend to agree we can assume that your problem came from the low power battery.

I've had this exact issue with my BMPC. I cannot confirm if it is due to low battery or not. It's happened to me twice, and on two separate approved SSD's. I've purchased the Blackmagic video assist as a backup recording device as I do not shoot in an environment where reshoots are always an option.

My internal battery does die quickly. Sometimes even on full charge it will display as 10% battery when playing media back.

It would be nice if Blackmagic could comment on whether or not the battery is related to the file corruption issue, and if it is, where to go to replace our batteries?

Feral McElreavy

I tend to agree we can assume that your problem came from the low power battery.

Okay that’s good to know. So with that in mind, I should be fine to power the camera via wall power or Vmount, just not using the cameras internal battery; correct?