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[Thief^]

You seriously replied to a post on page 1 of a 163 page help thread?

[wierd]

Did that too, actually. Making the partition bigger than 8 gigs causes it to stop responding again.

Does the DS have issues with SDHC cards?  IIRC, cards bigger than 4gb are SDHC, and use a different LBA encoding mechanism.  I will look into that...

I checked Nintendo's website...

Does your 8gb card show up in thier tested cards list?

en-americas-support.nintendo.com/app/answers/detail/a_id/274/~/what-sd-cards-and-microsd-cards-are-compatible%3F

The card might not be fully compliant with the features nindendo expects of an SDcard that size.

[sirdanilot]

Hey guys I was wondering if any of you have experience with corrupted video files (.mts)

For an important project I filmed some things, however it appears that the people I bought my sd cards from cheated me (note to self: don't buy sd cards from street vendors in a third world country); the SD cards appear to be 16 GB but it seems that the actual space is much smaller (even though my computer shows them also as having 16 GB capacity). When you want to store videos on them above a certain memory thershold they get completely corrupted !

Now I did google some data recovery programs and so on, and I have also found a program called PhotoRec. However these programs are more geared towards saving files off corrupted hard drives and sd cards so you can get them on your PC. But I already have the video files on my PC, all I want is to de-corrupt them. The video files showw the appropriate size for the length of video but they cannot be opened in any video player or editor.

anyone know if it would be possible to recover these corrupt files and what programs I need?

[wierd]

sadly, I doubt your file is recoverable.

You cant recover data that does not exist;  these knockoff SDCards have hacked device firmwares that report a flash chip capacity bigger than what is actually inside. when written passed the actual drive capacity, data is simply discarded, or worse, starts overwriting previously written sectors.

[TheBiggerFish]

Yyyeeeeeup.  You're pretty much out of luck.

[sirdanilot]

sadly, I doubt your file is recoverable.

You cant recover data that does not exist;  these knockoff SDCards have hacked device firmwares that report a flash chip capacity bigger than what is actually inside. when written passed the actual drive capacity, data is simply discarded, or worse, starts overwriting previously written sectors.

Oh god....

Thing is, the cards used to work fine. At the beginnig of my project I shot some short videos and they were not corrupted (they probably didnt go over the actual limit of the card).
Once the problem started to arise, the first few videos on the card still worked (perhaps the first 2 or 3 GBs worth of them), but the latter ones were corrupted. I also have one video which is playable on windows media player until about halfway into the video, then it stops playing giving an error message, so that shows where the corruption begins.

Do you really think the data is not there? Because the corrupted files do have the size you'd expect of them, also when I transfer them to my hard drive. How can there be 'phantom data' on my computer, i.e. how can my computer not recognize that the file is not actually 3 GB?

[wierd]

Depending on what suckery the crooks used, one of two things happens when you use those cards.

1) when you write past the actual capacity of the chip inside the card, data is just dicarded, but windows still thinks it is being written because the card says the writes completed OK.  You have file chains created in the FAT/MFT of the drive, because it allocates clusters for the file, but the data does not exist. Files written at the start of the drive are just fine though, and can be salvaged.

2) When you write past the actual capacity of the chip in the card, instead of discarding the data, it starts overwriting the data at the start of the chip, destroying the data that was there. This corrupts files that used to be OK, by overwriting their data.

depending on which kind of firmware hack the crooks used, that is what has happened to your data.

[Thief^]

Sounds like #1.

But yes, the data is gone either way. The "corrupted" video files are filled with either garbage, all 0s, or a repeat of the data from the first part of the card.

Basically this:
Card is only 4GB (say) but reports 16GB.
The "file allocation table" (which records the name and size of a file along with where on the storage its data is recorded) is at the start of the drive, so any device  (PC/camera) will be able to add new files which appear to be in the non-existent extra 12GB of the drive, because they can be added to the file table fine (because it's always at the start).
However when the device tries to actually write the file data, it has to destroy some - the card is only 4GB. It will either silently destroy the data for existing files (overwrite), or for the new file (discard). From your description it sounds like you have the "discard" type.
The destroyed data is not recoverable - it physically no longer exists.
When you go to copy the file off the card, your PC will create a file that matches the size in the file table, and then tries to read the data for it. Because the data doesn't exist, the card "makes something up"... So the file is the right size, but it doesn't have the right data in. It's not "corrupt" as such - the data is not damaged, it's garbage - there's nothing of your original data there to recover.

Sorry.

[sirdanilot]

Oh god, so it is truly lost afteyr all ...

It's really too  bad , this was a cultural documentation project and these people put in so much effort for the things I filmed, but it was filmed in vain apparently. Its going to be hard to explain this to these people as they have no notion of these technical matters.

[i2amroy]

Look at it this way, you only got cheated out a small flash drive. I saw a picture of someone who purchased what appeared to be 2 350GB hard drives only to notice that they didn't appear to be making any sort of noise at all, popped open the casing, and discovered two 16GB flash drives wired up inside of empty HD cases.

It sucks, but it could always have been worse.

[Shadowlord]

I'm not an expert or anything, but I attempted to simplify the explanation:

The corrupt video isn't really lost, since it was never saved in the first place, because the card ran out of room to write video to but pretended it still could. The card was just lying and saying there was room, basically, and making it appear to be writing properly when it was really discarding what you were recording.

Although that's still technical. Perhaps "this card I bought pretended to be able to record more hours of video than it really could, and discarded most of what I recorded while telling me that it was still recording. It was only apparent when I tried to watch what I had recorded." Maybe mention who you got it from.

[i2amroy]

At a simplest level you could basically just say: "Someone cheated me and in the process destroyed what I've been recording. I'm very sorry, and will do my best to fix the problem.", which leaves out pretty much all the technical side of things while still covering the basic idea (which is that someone cheated you and destroyed your work by cheating you).

[TheBiggerFish]

That works.

[sirdanilot]

At a simplest level you could basically just say: "Someone cheated me and in the process destroyed what I've been recording. I'm very sorry, and will do my best to fix the problem.", which leaves out pretty much all the technical side of things while still covering the basic idea (which is that someone cheated you and destroyed your work by cheating you).

Yeah I'll just have to tell them I got cheated, basically.

It's so sad, but nothing can be done about it.

I also don't understand why the camera didn't write the videos to the internal memory when it noticed problems writing it onto the SD card, this camera has substantial internal memory (which I would have used had I known before I was cheated with my SD cards). However if you set it to write to internal memory before hand that should fix it. Other SD cards also worked fine however they are only 4 GB so after half an hour of recording I have to switch them which is extremely annoying and disrupts the things I want to film ('hold on there for a minute pal have to switch cards !' ).

[miauw62]

It didn't notice any problems writing to the sd card, that's the point