digital artifacts in p2 footage

V

vscomm

Member
Hello, all.
Came off of a 14 hour shoot day with the hvx200 (720 24pn) to find that every shot (around 200) has digital artifacts that sprinkle in every once in a while on single frames. Unbelievable. Erased all but one p2 card. The remaining p2 footage is fine when I load to edit system directly from camera via firewire.

The stuff that was transferred via laptop's pcmcia to external drive via USB has the artifacts. Been using this workflow for nearly a year and now this catastrophe. I'm assuming the footage got corrupt during the laptop transfer.

Any ways to "repair" the footage?
Has this happened to other people?
Any idea on avoiding this in future?

I gather that this is extremely rare. I can't find anyone with this problem. This is absolutely shocking to me.
thanks,
vscomm
 
Did you use a Mac to transfer the footage? If so, that's the problem.

The only workaround we've been told that may affect it is to always write-protect the cards before transferring footage.

For my work I won't use the Mac to transfer footage, I just don't trust it. Every case we've ever heard of this happening has been on the Mac, and the footage on the cards is always fine; it's after the Mac transfer that the glitches show up.

I've been using a Windows laptop for over two years with P2 and have never gotten a single dropout, a single glitch, or ever lost a frame.

This is not about "mac vs. PC", this is about acknowledging that in the real world, transferring on a Mac sometimes introduces glitches, and I recommend you look into getting a cheap Windows laptop to use as your transfer station if you want rock-solid predictable reliability.
 
The only repair would be by hand unless you still have the cards.
I could quote you a price for fixing it if it's critical footage.
 
Right, the only repair is by going through and copying bits from the prior or next frame to cover up the glitched bits.

If you still have the cards, transferring again will usually clean it up, either by transferring successfully or by glitching in different areas (which means that the previously-glitched stuff might transfer fine this time, so you could copy the new good frames over the old glitched frames).
 
I've been using a PC only for dumping the footage - always a pc - a two year old $800 Compaq with a pcmcia slot. Defragged all the time.

this laptop has no firewire - only USB 2.0. Could it be the usb or the cable? It's probably a cheap cable. But I never get transfer errors on the screen. The external drive is 8 month old maxtor used just for dumping to and nothing else. I've been using the same configuration for nearly a year on about 30 shoot days over this period.

I talked to panasonic and they coudn't help, saying "it could be anything." I could have said that!
 
I'm on PC and have the same problems (from FS-100 to PC). Figure it out, it was the fiwi cable.

Rudi
 
thanks, everyone. still don't know the prob and may not ever. It will take some time to try to repeat the problem. Nevertheless, there's got to be a way to check footage during the shoot that doesn't interrupt the flow too much. p2 viewer. It will just take more time and hassle. Or I could just invest in more p2 cards and play back from camera during shoot to check and never delete the cards until I successfully transfer them to hard drives.

TAPE IS EASIER AND FASTER! No archiving hassles either! I miss it. Not sure why this p2 thing is so sexy to people. I bought the HVX200 because it beat everything in it's class. If there were an hdv tape version that did the same things I would have been just as happy. Right now, I know I would have been happier! With tape I never came back to the studio with each and every take corrupted by artifacts or drop outs! Maybe one or two rarely. But a whole shoot day?
 
Look, there's something wrong with your system somewhere. I've never had a single corrupted frame or a single lost clip in over two years of using the system. I don't know what the fault was with your system but it's your system that did it. A bad drive, a bad cable, bad drivers, I don't know.

If you like tape, there are plenty of tape-based options out there too. But get to the source of the problem and solve it, instead of just indicting the whole system.
 
I've had an hvx for over a year have done hundreds of P2 transfers using a PC only and never a Mac. I've never had so much as a single pixel error. The only footage I've lost was user error when an assistant was backing up files then proceeded to delete the back up folder and the offloads folder. It was his first time with P2 and the footage wasn't particularly important anyways. The mac OS will always write a hidden folder "_mac OS folder" that us PC users can see (but is hidden to macs, I believe) The mac "corrupts" the card by adding files to a P2 card that it is not expecting in its file system leads to errors.
 
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The system is more prone to failures compared to tape based systems. If we could just leave the original footage on the p2 cards then we'd have something better. But that's cost prohibitive. I guess we'll see a day when we can do that. How can anybody argue that this is a better or safer way to secure your footage during a shoot? It's a cardinal sin to lose footage to something like this. A bad usb cable? Come on. Or a bad driver on a lap top? This only happens with this technology. So many more variables are thrown into the mix with p2. THAT MAKES IT A LESS STABLE SYSTEM. If I continue to use p2 I will have to handle the work flow with even finer kid gloves and replay footage constantly during the shoot. I think I will have to have enough p2 cards for the day and go back that evening and make sure everything transfers correctly. This introduces a whole new level of anxiety during each and every important shoot. You basically have to play back every frame of your footage. I NEVER HAD TO DO THIS WITH TAPE!!!!! Sure, tape will bring an occasional drop out.

Barry, I know you're an authority on this stuff, but this is just my opinion. I'm obviously frustrated. My DP and I have a combined 4 years working with p2. this is the first time confronting this. My DP still defends the system, but he doesn't have to answer to my client, does he.
 
I can tell you're frustrated. But you have to look at it from the perspective of reality -- something's wrong with your system. It is not the P2 system that's at fault. Something broke somewhere along the way with your system. There are 60,000 P2 cameras installed in some of the most demanding environments on the globe (major broadcasters) and these type of problems simply don't happen. It's far more reliable than tape ever was.

So, I say again -- diagnose your system. Find out where the bug is. It's not with your original footage. Heck, you say it happened on every card? Then it should be incredibly simple to narrow down where the problem is. Shoot some footage. Transfer it. Then do a binary compare between what you transferred, and what's still on your card. If there's any discrepancy at all, even one bit, then you know that your computer is to blame. Play the footage back while it's still on your card and you'll see it's faultless. So if your computer screwed up the copy, find out why and fix it.

Or, alternately, every P2 card you have is bad and they all failed to record properly, something I think would be mathematically impossible but hey, let's entertain it for a possibility. You'll know, because you can play the footage on the card and see whether it's working or not.

Either way, get to the root of the problem and place the blame where it belongs. Something in your chain of equipment failed. It isn't the cards or the camera, that much I can almost guarantee you. So it's either your computer, the drive you copied to, or (as Mac users have found) glitches from a bad cable...
 
No, it's not the camera or card. I had one card that wasn't deleted after the shoot. so I offloaded the footage directly from camera via 1394 to a firewire 800 dual drive and it looks fine.

so the problem lies in in my laptop, usb cable or the external drive I used on the shoot. My only problem with p2 is that we have to throw in so many more variables into the mix when we move our footage. If i continue with p2 i will have to take extra precious time (that people rarely have) to look over the shots to make sure they're good. I never had to do this with tape so much. I may stick with my hvx because of it's cost and quality. I think anybody reading this thread can learn from this - the workflow needs to be carefully executed and you need to review your footage. That takes extra time. p2 definitely requires more time for the added workflow. New users must understand this. it's not faster or more efficient than tape. (and I understand that tape may be becoming obsolete because of solid state and drive technology - so people better get used to it!).

happy thanksgiving!
chase
 
P2 clip artifacts

P2 clip artifacts

Here are a few screen grabs of some terrible artifacting we encountered on a recent shoot. Does this look similar to yours?

From the start, our work flow was impaired by a bunk P2 store unit. We ended up having to connect the camera directly to a new Apple laptop and dumping the data from our spent cards at various intervals throughout the day.

This is my first shoot using P2 cards, and though it seems pretty obvious that the files are corrupted somehow, I'm hoping the issue might be occurring during the transcoding process (re-wrapping) to Quicktime - I'm importing the clips with FCP 5.0.4 - File>Import>Panasonic P2.

Any advice/expertise would be greatly appreciated, and have a happy Thanksgiving!!!
 

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vscomm said:
p2 definitely requires more time for the added workflow. New users must understand this. it's not faster or more efficient than tape. (and I understand that tape may be becoming obsolete because of solid state and drive technology - so people better get used to it!).
Click to expand...

All I know is that I'd never go back to tape. P2 is much quicker for me than tape.

If you think tape is perfect, talk to my buddies whose DVX eats their tapes whenever they try to review footage with it.

On longer shoots I dump all my cards to a P2 Store and then transfer when it's full.

I use P2 Log Pro to quickly scan the clips to check if there are any problems.

I'm on a Mac and had the glitch problem until it was discovered that you need to write-protect your cards before inserting them.

I've never had a glitch since.

I've had issues transferring long periods of tape into my system where the drive would hiccup or something else would happen to drop a frame and then I'd have to start capturing all over again.
 
HVX FCP P2 artifacts

HVX FCP P2 artifacts

Alas, I too am getting artifacts in my footage! I've shot a lot of clips in 720/24p and had no problem until I switched over the 720/60 - there are lines scrolling throughout the footage. I've used the media management tool to try and delete extra frames but the lines will not go away. I've transferred the footage to a Mac Book Pro and it seems that the only footage that is affected is from one day in particular. However, I've got LOTS of footage from that day and really need it. Any suggestions? I'm a bit of newbie when it comes to variable frame rates and P2 so please bear with me - any ideas would be greatly appreciated.:huh:
 
I can quote you a $ on frame-by-frame restoration if you'd like. If the only data you have is corrupted, someone's going to have to go in and fix things in After Effects.
How are you transferring footage? Firewire cable, PCMCIA slot, P2 store.......?
 
In regards to using a Mac for transferring and the problems that can occur - is this a problem with Macs, or with P2 store and Macs? I've transferred directly from the camera to a Mac laptop many times using both the HVX and HPX, and I've never had a problem.
 
P2 transfer

P2 transfer

Hi guy's,

I was afraid in the beginning for the transfer with my HVX. I needed to
shoot a lot of 720PN and HD data. Now a have buyed a Mac Mini and a Terabite data consisting out of two hard drives. I build it in a compact alu box and I take it with me on set with an old 15 inch tft monitor. If I shoot and my 16 Gig P2 cards are full , I store it on the Terabite harddisks who are fixed in raid. Once the P2 cards empty I continiue shooting. I have final Cut on the mac mini and I can see wright away if the footage is good or corrupt. Up until now I had never problems with the mac mini or the P2 Cards. But you have to handle with care, thats's for sure. Digital data is more delicate than tapes. Do not move the cam or cable to muth during transfer. Once home you connect it to your Mac Pro and covert it with Final Cut. Simple as that.
 
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