GH4 GH4 shut itself off while recording! Corrupt clip!

T

thedigitalcurrent

Active member
So I have an unhacked GH4 with genuine Panasonic batteries, and the 12-35 Panasonic lens on. Shooting on SanDisk U3 cards, AVC 1080p quality, and after about an hour of filming a single clip, I checked the camera and the screen was black and it was as if the camera was off, but the power switch was still in the ON position. I turned the camera off and back on and pressed the record button because it was an important event I was filming. When I looked at the footage the hour long clip I had been recording was missing from the card. Thank god I tried the Panasonic software and was able to save the missing clip but this is now the second time this has happened and it only happens after the camera has been recording for more than, like...maybe an hour. Could it be a faulty battery? I mean for the camera to record that long and then just shut off is strange to me. I was able to use the camera for the rest of the day with no issues, but I didn't film anymore clips over 20 minutes long. Any ideas?
 
Did you format the card before using it. Also, you are assuming that the card is good. Try a different card if at all possible. I have never had an issue with recording over 1 hour. I have even recorded up to 2 1/2 hours without any problems whatsoever. Good luck.
 
Yes I did format the card in camera before starting. I am 90% certain the card is good because I use the same card in the same camera almost every weekend and never have problems, plus it's weird that the camera itself went black as if it was turned off even though the switch was still in the on position. Could it be a bad battery?
 
Use a different battery or use the AC battery adapter. Try two different cards and see if both quit after an hour. I'm better your camera has a defective heat sink and after an hour it gets hot enough to shut down.
 
I wonder if only the display had gone black, but the camera was still recording, and you're turning it off is what corrupted the clip.
 
That could be possible, because this time when I got it on video the clip wasn't corrupt. I'm guessing the display isn't supposed to go black though?
 
I have run the camera until the battery dies, and it doesn't corrupt the clip. I have also run it until the card fills, after which it turns itself off, and also didn't have a corrupted clip.
 
A perfectly good card will over time begin to experience problems with slowdown on "writes", interruption of recording, and corrupted files due to incomplete erasure of data and general "clutter" on the card.

The only format option offered by the GH4 is a "quick format", meaning the only thing really zero'ed out is the first 2 or 3 characters of each filename in the file allocation table (FAT). This allows the sectors of the card occupied by that file to be re-used, however the data from the previous file is still there until all overwritten. The "new" file may not completely overwrite the whole previous file which then leaves "chunks", bits 'n pieces of previous files scattered over the card.

Over time this caused the card to slowdown and eventually leads to corrupted files.

The "cure" is a periodic "low level" format which the camera does not offer. Using the PC format utility to do a low level format (uncheck the "quick format" box) usually works, with a MAC some have run into problems so this is best done with the free utility SDFORMATTER (https://www.sdcard.org/downloads/formatter_4/). Available for both MAC and Windows.

I do this low level format once every few card uses and definitely before starting on a new project. Then reformatting in camera sets the card up the way the camera wants it and I have a totally "refreshed" card.
 
Thanks for the help guys. It's strange that last night's test ended up with a completely different result. After last night when the camera just stopped recording, the clip it recorded was still on the card and wasn't corrupt. This is different than when the problem originally happened and the clip didn't appear on the card and the camera seemed like it froze up. So essentially when I tried to replicate the problem, I got a totally different problem all together. These cards are pretty new, and the fact that I ended up using the same card for the rest of the day with no problems makes me want to believe that it is not the card but something with the camera, but I could be wrong!
 
Your video indicates the GH4 had been recording for 2 1/2 hours before shutting itself off. Was the GH4 using its automatic file-spanning feature to spawn multiple 4GB video files that can be seamlessly spliced together? If so, I'd suspect the file-spanning mechanism failed to spawn the new file. I found file-spanning to be a rather fragile juggling act for the GH2 to handle while operating at high bitrates (hacked, of course), comparable to those used in various GH4 video modes.
 
Thanks but it was in avchd mode where the files don't cut off at 4gb, they can be one large file that is GBs in size, I've had some that are 20GB big. In 4K MP4 yes you are correct tho.
 
thedigitalcurrent said:
Thanks but it was in avchd mode where the files don't cut off at 4gb, they can be one large file that is GBs in size, I've had some that are 20GB big. In 4K MP4 yes you are correct tho.
Click to expand...
According to this thread, the GH4 segments long takes into 4GB video files in AVCHD mode as well as in MP4 mode (even with an SDXC card):

http://www.dpreview.com/forums/thread/3693275#forum-post-53952528

However, with AVCHD videos, if you import the entire PRIVATE folder, many video editors can automatically combine the spanned MTS files together when you load in the first video file in the sequence. Perhaps this is what made your AVCHD recordings appear to be a single file longer than 4GB.
 
The GH4 has to juggle a lot of things in real-time in order to seamlessly span across 4GB video files. Closing the old file and creating a new file adds more overhead to the process of encoding and queueing up video and audio frames, and automated functions (like continuous focus) can pile unpredictable burdens on the processor. If the new file cannot be opened quickly enough, the GH4 may run out of temporary frame buffer storage space and be forced to quit recording. High bitrates can make the problem worse, so recording at a lower bitrate may improve reliability. In developing the Flow Motion GH2 hack, I saw many cases where the camera could repeatedly span 4GB files at 60Mbps, but would stop after spanning only a couple 4GB files at 100Mbps.
 
A faster card may help, which also points back to the FAT fragmentation that was mentioned in a previous post.
 
Well I originally said that the cards are class 10 U3 and I'm only shooting AVCHD 1080p so I doubt the card speed isn't fast enough. I tested the card anyways and was getting 70MB write so that can't be it. I tested it again (video below) and it shut off again right at 2 hours 30 minutes. All my other GH4s on the same test recorded for like 5 hours without stopping. So it has to be something in the camera....

 
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