corrupt memory card file

[musicguy]

I just bought a new Panasonic Lumix GH-2. On its maiden trip out, I made 4 videos with mts files ... then the battery ran out. I can copy the first three files to my computer, but the last one will not copy ("The file or directory is corrupted and unreadable.") I also cannot play this last file, when I try to play it (with VLC Media Player) from the card. It was a Transcend 16GB class 10 card. This last file was 1.3 GB; the earlier ones were bigger and copied fine.

What happened? I did not format the card ... should I have formatted the card in the camera, before use? Or is this problem due to the camera battery running out while it was taking this video? Is the GH-2 really so stupid that it would corrupt its own data file as its power is going down?

How can I recover this? This is actually a really important video, as I used this new camera as the main camera in a music video recording session. "CardRecovery" free scan says it finds 275 mts files (segments of files?) on the card, and they want me to buy their software to recovery these. Is this likely to work? Has anyone used it? Can one easily reconnect the hundreds of file segments? Or what other software should I use? It does not need to be free; I will gladly buy a piece of software if it has a good chance of working!

Thanks!

[aedipuss]

unlikely anything from that last file can be saved. when the battery ran out before finalizing the video the info files in the file weren't written. even if a "file recovery" program could get a file for you it wouldn't be recognizable as a video file.

[musicguy]

Thanks aedipuss.

I understand from you that this was due to the camera battery running out while I was filming. Wow. What a horrible camera design!

How do you professional videographers avoid this disaster from happening every time the battery runs out? Do you try to stop using batteries short of their end-of-life? Or is this just a Panasonic issue? I have other brands of cameras which do NOT have this issue. Or should I get a 120VAC adapter for use, instead of batteries, in indoor video shoots?

BTW, a bit more info that I forgot to write in my first email: Windows Explorer displays the missing file with its size etc. The camera does not find the file if I ask it to replay the video.

[davexnet]

Can you copy the file from Windows Explorer using drag and drop (or similar) ?

[musicguy]

Dave, Windows Explorer does list the file ... but, no, if I try to copy the file with Windows Explorer, I get the message "The file or directory is corrupted and unreadable."

[edDV]

Thanks aedipuss.

I understand from you that this was due to the camera battery running out while I was filming. Wow. What a horrible camera design!

How do you professional videographers avoid this disaster from happening every time the battery runs out? Do you try to stop using batteries short of their end-of-life? Or is this just a Panasonic issue? I have other brands of cameras which do NOT have this issue. Or should I get a 120VAC adapter for use, instead of batteries, in indoor video shoots?

A pro wouldn't run batteries dry except in emergencies. Statistical probability. You didn't choose SD flash for reliability.

DV tape would get the last frame, HDV would get the last GOP (0.5sec).

SD Flash has all the close file issues.

[musicguy]

I'm reading about the open-source photo recovery app called "PhotoRec" (http://www.cgsecurity.org/wiki/PhotoRec), although it's not clear to me yet if this app handles mts files. Does anyone have any experience with this app?

[musicguy]

edDV,

Thanks for your comment ("A pro wouldn't run batteries dry except in emergencies. Statistical probability. You didn't choose SD flash for reliability.").

I had figured the camera would shut itself down gracefully when it ran out of battery juice. (It must sense that the battery voltage is below a threshold ... then decide it is out of power ... then stop writing the file to the card ... then turn off the microprocessor etc. Wouldn't it?) But I guess that's a mistake, huh?

Alright, this makes it harder, if I need to manually watch the battery level of this camera. In this situation, I was simultaneously running three video cameras (the Panasonic GH-2 and two older Canons) as well as audio recording gear ... and the two Canons gracefully shutdown when they needed battery changes ... but the new Panasonic apparently didn't.

[davexnet]

Give photorec a try. It uses read only access, so it wont compromise it further.

I've seen other articles where users actually ran chkdsk /F on the drive - with some success.
I think you would have to consider this a last resort.

[musicguy]

Thanks, Dave. I'll be away next 24 hours, so will take this step when I return.

[edDV]

edDV,

Thanks for your comment ("A pro wouldn't run batteries dry except in emergencies. Statistical probability. You didn't choose SD flash for reliability.").

I had figured the camera would shut itself down gracefully when it ran out of battery juice. (It must sense that the battery voltage is below a threshold ... then decide it is out of power ... then stop writing the file to the card ... then turn off the microprocessor etc. Wouldn't it?) But I guess that's a mistake, huh?

Alright, this makes it harder, if I need to manually watch the battery level of this camera. In this situation, I was simultaneously running three video cameras (the Panasonic GH-2 and two older Canons) as well as audio recording gear ... and the two Canons gracefully shutdown when they needed battery changes ... but the new Panasonic apparently didn't.

AVCHD uses M2ts which is a packet based protocol. Packets don't always receive sequentially or match to GOPS so a power outage can leave gaps within a GOP, or missing GOPs in the sequence. Any recovery software needs to go back to the best GOP in the sequence.

The Lumix GH-2 also records MJPEG which is frame based. Suggest you record MJPEG when near the end of battery life or storage memory.

[musicguy]

Yeah! I used the open-source photo recovery app called "PhotoRec", and it WORKED. It recovered the corrupt file.

I also learned a bit more about why this happened, from reading other sites. Now, when I bought the camera two weeks ago, I also bought a spare battery. It was not Panasonic brand, but it was supposed to substitute ok for the particular Panasonic battery. It turned out hat I happened to be using the spare battery when this file corruption happened. Further info: the battery level does not appear in the camera screen when I use this spare ... so, even if I had been trying to watch the level and stop short of the end, I would not have known where I was re the battery level. Further, some people write on other sites that the Panasonic camera does not know when it was about to run out of juice, if it is not connected to a PANASONIC battery! ... and that's why it wasn't smart enough to know to stop writing to the card before it shutdown. Geez.

So what to do about this?
1. I'm going to get an AC Adapter, when they become available (Panasonic doesn't sell them in US yet).
2. And, for outdoor work, I guess Ill need to buy some real Panasonic batteries (when they become available in the US), even though they are three times as expensive as the generics.
3. And if I record outside with non-Panasonic batteries, I'll use mjpeg (as edDV suggests).

I'd be interested in comments.

[apprentice222]

Transcend are known for these kind of file errors.
I have two of these 16gb cards, sometimes i make about 30 pictures and a few movies with a Samsung WB500 camera. All ok at first, but sometimes out of the blue file corruption happens on some files. Preview on camera is not possible anymore, resulting in 'file error'. At computer the file is there, but unreadable. I am not sure if it's due to the use of 3rd party or faulty hardware. I think it has something to do with the Transcend card. Also because on a google search you can find other people with the same problems.