Frame Corruption Thoughts?

[bjonsson]

Hey guys,

Just had a shoot where we had occasional corruption . Corruption was not on the original CF's - only on Post and Back up Drives. Anyone else have this problem? I have been pointed to the CF reader and cable, but have not been able to recreate it. Thoughts? Any experience with this problem, then recreating it?

Should also note that we were using a FW800 reader - Lexar

Thanks in advance,

B

 

[Shane Betts]

This is why you must use something like R3D Data Manager. These errors do happen and Data Manager picks them up and fixes them. On the rare occasion (haven't seen it yet) where it can't, it tells the DIT who can then tell camera dept to reshoot. For such a cheap piece of software, it's absolutely imperative.

 

[Scott Snare]

My experience is that the CF readers overheat after 2 or 3 cards back to back. They should be cooled and rotated to minimize corrupt frames, bit check is always a good idea to insure the transfer.

 

[Dustin Cross]

How do you know the corruption wasn't on the original CF cards? Did you play all the footage from the original CF before downloading?

I just had a DIT call me about a commercial he did that had corrupt footage. He had a couple cards that were downloading slow. He did checksums and everything looked good, but the footage was corrupt. All the corrupt footage came from the slow cards. He pulled those cards out of rotation. The one CF reader went through 1.5TB of footage in two days and the only problem footage came from problem CF cards. No problem with a CF reader over heating with non stop use in 90+ degree temps for two days. CF cards go bad.

Make sure you do checksums, but you have to view footage on set to be certain there are no problems.


Dusty

 

[bjonsson]

How do you know the corruption wasn't on the original CF cards? Did you play all the footage from the original CF before downloading?

I just had a DIT call me about a commercial he did that had corrupt footage. He had a couple cards that were downloading slow. He did checksums and everything looked good, but the footage was corrupt. All the corrupt footage came from the slow cards. He pulled those cards out of rotation. The one CF reader went through 1.5TB of footage in two days and the only problem footage came from problem CF cards. No problem with a CF reader over heating with non stop use in 90+ degree temps for two days. CF cards go bad.

Make sure you do checksums, but you have to view footage on set to be certain there are no problems.


Dusty

We knew the cards were fine, because after we saw the corrupted footage from the post drive, we were able to go back to the last 5 cards we used. they were not overwritten as of yet - even after a few days. the footage was fine on the CF cards.

Also, an r3d stle check-sum program was used. Although it was checked with a Sum-Total procedure as opposed to an MD5.

 

[Dustin Cross]

Interesting. 16GB CF right? Lots of problems with 16GB CF.

Was all footage corrupt from original download or just some footage? Was corrupt footage from same card or did some cards have good footage and some corrupt?

Just trying to see if there is any way to figure out this problem.

 

[Jean Déraps]

I had a similar issue once, on 8 GB cards, and was using R3D Data Manager. The data had copied sucessfully on at least one of my disks (I was copying to 3 disks) so I was puzzled. I just disconnected the FW card reader and reconnected everything and all was fine. Perhaps the firewire connection was loose or something, or the CF card wasn't properly seated (and the connection became dicey with heat)?... It was the only time I've had this problem ever.

 

[Deanan]

We knew the cards were fine, because after we saw the corrupted footage from the post drive, we were able to go back to the last 5 cards we used. they were not overwritten as of yet - even after a few days. the footage was fine on the CF cards.

Also, an r3d stle check-sum program was used. Although it was checked with a Sum-Total procedure as opposed to an MD5.

It sounds very much like either a reader or a firewire cable.
To catch this type of problem, it's best to do the verify pass and compare two reads from the CF with R3DDM or do two separate copies and compare the checksums.