GH4 Scary gh4 crash during long take

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dv416

Well-known member
Gh4, 2.5 firmware
Panny 12-35 lens
Shooting a CineD Custom profile in UHD 4k
Media: PNY UHS-1 U3 64gb card

Camera was in the middle of a long take. I attempt to cut the record and no response. None of the buttons are responding either. The timecode is still moving up by the second, but no buttons are responding. Turning the camera off does nothing. Eventually I decide to battery pull. I inspect the card and see that all of the previously parsed 4.26 gig files appear fine, but the most recent one was a corrupted "mdt" file. It is potentially salvageable, according to the "treasured" app / data recovery service (link here: http://aeroquartet.com/), however this still really concerns me.

Essentially, there was a serious "battery-pull" level of camera failure here with absolutely no indication there was anything wrong until the take was done and I pushed cut. In the past, when I have experienced errors, they come with a very obvious error-message and warning that the camera cut. I had none of that this time.

I checked the footage from our second camera, and this last take should have been about 6 minutes long, but the 1 gig corrupted file suggests only about 82 seconds were recorded before the failure. So even if the file is recovered, I don't think I'd get more than that 82 seconds. This error could have happened right at the beginning of the take and since the picture on screen didn't "freeze," nor did the timestamp freeze, I still wouldn't have known until I cut the record at the end. So, that I even got all but the last few minutes of the take seems just like random luck.

My theory is that it is a card / buffer issue. The shot was a highly detailed scene - shooting overhead on a burlap canvas (not unlike this: http://images.wisegeek.com/burlap-fabric.jpg). But even so, the card failure would have been totally random, as we had shot another video with this texture earlier in the day with no issues. Also, again - I usually get error messages on screen when there are card errors.

Has anyone experienced anything like this before?
 
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My initial take away from your post is if you are seeing errors with anything like the frequency that comes over from your description, you definitely need to get some decent media. You ask whether "…anyone experienced anything like this before?"

No, never. No errors, ever.

You don't specify your media.
 
Just had this happen last week for the first time ever. I was playing around, nothing in particular, and when I tried to power the camera off, it wouldn't. I had to pull the battery, and I wasn't recording, so I can't comment about any file damage.

Go figure...
 
estarkey7 said:
Just had this happen last week for the first time ever. I was playing around, nothing in particular, and when I tried to power the camera off, it wouldn't. I had to pull the battery, and I wasn't recording, so I can't comment about any file damage.

Go figure...
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Correct me if I'm wrong, but wasn't this an issue that happened occasionally with hacked GH2s. Since the GH4 hasn't been hacked, it can't be hacking, but I seem to remember the problems revolved around the speed of SD cards, which back then were much slower.

It could be faulty memory (mine, not the cards) but I'm putting it out there just in case.
 
stoneinapond said:
Correct me if I'm wrong, but wasn't this an issue that happened occasionally with hacked GH2s. Since the GH4 hasn't been hacked, it can't be hacking, but I seem to remember the problems revolved around the speed of SD cards, which back then were much slower.
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Yes, the GH4 is probably subject to similar internal data buffer management problems we encountered in hacking the GH2 to record at 100+ Mbps bitrates. The slower the SD card, the longer it takes to empty the data buffers, and a backlog can accumulate over time, particularly during a 4GB file spanning operation. The software-based H.264 encoder must share processor bandwidth with all other camera functions, and I found that auto-exposure and auto-focus functions could occasionally load down the CPU enough to cause sporatic recording failures. Incidents severe enough to require a battery pull were typically related to catastrophic buffer overflow, paralyzing the encoder and leaving it unable to properly close the file.
 
Sorry, yes it was a PNY UHS-1 U3 64gb card. Sustained write speeds of about 50+ MB/sec according to some reviewer on amazon. This is the recommended class from Panasonic.

Errors are extremely rare, but having shot on the Gh4 for a few years now, I have experienced them a few times, usually with clear alerts though, and usually due to using too slow media. But not always! I've had UHS-1 U3 buffer errors before. Just not without a warning, like this one. That is of course - if this error even is a write speed error, and not some other malfunction.
 
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We only use authentic SanDisk 64GB, & 128GB, 95 MB/s cards. Many of our takes are very long, & almost fill the cards. Have shot thousands of hours of footage on four different GH4s, & never had lock ups.
 
dv416 said:
it was a PNY UHS-1 U3 64gb card. Sustained write speeds of about 50+ MB/sec according to some reviewer on amazon. This is the recommended class from Panasonic.
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Excellent chance that is your "culprit". PNY makes pretty good memory for computers but with camera media does not have the quality control of SanDisk. Count me as another user of only genuine SanDisk media. I buy mine only from B&H, amazon has some vendors who "dance with the devil" in that "counterfeit" media has shown up there.
 
I had a similar issue with one of the 100mbps 1080p 60p modes on an older Sandisk extreme pro 30mb/s card.

Never had an issue with the 95mb/s or 80mb/s cards. Still though, would've thought that old Sandisk was fine. Definitely scared me as I do a lot events with it.
 
It's the GH4... We own two of them and both crash in the same manner occasionally. I hate that they do that.... I've lost so many good takes because of that flaw.
 
To add to this thread, just had another one yesterday.

Was filming a wedding, and while grabbing some Broll of ceremony decor, it crashed in the 1080p 60p 100mbps mode. Then, it crashed in 4K. The weird thing was this was a sandisk 64gb extreme pro 95/mbs card. Surely those are suitable I would've thought? Card was formatted in camera as well.

Anyway, thank god it happened then and not during the ceremony. I've recorded many full ceremonies on those cards, but I went to AVCHD for this one because the thought if it crashing scared me too much. Maybe it was the heat?
 
DBP - did you receive an error message when your camera crashed? Or was this the type I am describing, that just crashes your camera covertly?

A little update on my end - I encountered the same crash again. Same card UHS1 u3 PNY cards, 4k 100mbps custom Cine-D profile, panasonic 12-35 lens, same subject too - overhead shot looking down on highly detailed burlap texture background. Having experienced the crash the previous week, I knew to be cutting more often and not living in the long takes for an extended period. Good thing I did. Because we crashed right out of the gate. 2 minutes in, crash with no warning, no error, just frozen camera. Still upticking timecode, and still blinking record light as if all were well. Had to battery pull. We swapped the texture background to something simpler and I switched to AVCHD 1080p as well, no issues the rest of the day.

I tried to repeat the error later that night using the burlap. No luck. I let the takes run very very long too. No failure, no issue at all. So not sure how "repeatable" the error is, but it has happened twice now under nearly identical circumstances.

Going to buy a few uf ths UHS-1 u3 Sandisk cards just in case.
 
No error message. Same error as you, essentially frozen with record light still going, but non responsive to any buttons. Had to pull the battery. Hasn't happened since. I've done a few more weddings since then.

I had a high shutter speed with a sharp lens stopped down, with a detailed scene (trees, grass blowing etc..), so it might've just been detail overload. Still, scary in that it's ultimately hard to predict and I thought I was 100% safe with these Sandisk cards.
 
How old are the memory cards ? It's possible video makes the likelihood of hitting a bad memory cell more probable.
 
Wow, this whole thread us very disturbing. I've never had the problem, and I only shoot narrative films and documentaries. I don't want to get a reputation as a problem shooter, and in docs, if you miss something, it never comes back.

Is Panasonic aware of this? Is this problem widespread? Have the cameras been sent for repairs?

It's like saying, "well, my brakes only fail ONCE in a while..."
 
estarkey7 said:
How old are the memory cards ? It's possible video makes the likelihood of hitting a bad memory cell more probable.
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Pretty new. Both a year old, at most.

Both have been used repeatedly in my BMPCC with no issues.

Not sure what was up. I mean, I have hours and hours of footage that's fine. It's happened very infrequently in the scheme of things. But with the wrong material, once is enough.
 
estarkey7 - I have 5 of the PNY's. Varying ages on them. 2 64's and 3 128's. Not sure, but I think one crash was an older 64 and another was a newer 128. Is there some way to thoroughly test cards for bad cells? Could very well still be a card thing, though the fact that DBP had it on the Sandisk UHS1 u3 cards isn't too inspiring, as that was supposed to be the gold standard.

DBP - also that you got this error shooting a WEDDING too is really disconcerting, as that's just "regular" footage - not some highly detailed codec-breaking texture. Not sure what to think, but some sort of encoder/buffer issue and/or some card issue are still the main suspects to me.

I will see about forwarding this thread to Panasonic. Maybe they have some insights.
 
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dv416 said:
DBP - also that you got this error shooting a WEDDING too is really disconcerting, as that's just "regular" footage - not some highly detailed codec-breaking texture. Not sure what to think, but some sort of encoder/buffer issue and/or some card issue are still the main suspects to me.
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I think it was actually a result of detailed codec breaking texture. It was outside with lots of trees + grass, water in the background. Windy day. Sharp lens stopped down with shutter speed high. So all the ingredients for a codec to have a rough time. I just thought that they would be designed to be bullet proof pretty much. I expect that kind of thing out of third party hacks, but not stock codecs. I can't garauntee I won't run into that scenario again, so it does make me nervous.
 
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