Truncated video file on Vixia HF G50

[PeteGould]

Forgive me if I've missed an existing posting on this because I'm a little desperate.

I shot a critical interview on a Canon HF G50 that ran for about 50 minutes.  The camera seemed at all times to be operating properly.  It still showed that it was recording at the end of the interview and was stopped, seemingly successfully.  The camera was powered down with the power switch.  Returning to the office and removing the SD card, I find an MP4 file that runs about 16 minutes with a file size of 18,305,671 KB (4K file).  There are no other files in the folder for this date.  I tried running Canon's MP4 Join tool and when the folder on the SD card is selected the software reports "Some split MP4 files are missing.  The joined clips will be incomplete.  Continue?"  Since I have no experience with this tool I don't know whether that specifically means it detects a split file (I don't know why it would be split - I've recorded much longer things than this on this camera).  Is there any hope of recovering the rest of the interview?  It will be completely disastrous if the answer is "no."  Any help would be gratefully appreciated.

[rs-eos]

Did you do simultaneous record to both card slots perhaps? If so, are you having the same issues with both cards If you didn't do simultaneous recording, I strongly recommend you do so in the future.

Are these full-sized SD cards or micro-sized with adapters?  The latter can cause issues and are quite unreliable.

What I would first do is transfer the entire card's contents to your computer to at least back it up.   Then, perhaps proceed with the Join Tool (but perhaps run that tool against the copy on your computer in case that causes further issues with the files).

You may need to look into a data recovery service as well.

[PeteGould · Accepted solution]

Good morning,

I took another look at this with fresh eyes this morning and solved it - but I’m still very puzzled.

To answer @rs-eos’s questions: no, the device wasn’t set to dual-record (though perhaps it should have been) and it was using full size SD cards.  Specifically, it was set to record to Slot 1.  But as it happens, there were cards in both slots.  This morning, just for the heck of it (even though the card in Slot 1 was less than half full() I pulled the card from Slot 2 and checked it.  Eureka.  The camcorder had put the first 16 minutes on the first card and then, for no discernible reason, put the rest on the second card.  I was able to transfer both recordings and use the join tool to combine to one file.  Perhaps it encountered a write issue on the first card for some reason.

So - disaster averted.  Note to self: if two cards are inserted, always immediately check the second card in this situation.

Thanks to Ricky for reaching out.