Hi All
I know that this topic seems to appear many times but I still cannot find an answer to the problem!
Basically the 4K footage I have shot on my new Mavic Air looks fantastic for about the first 15-30 seconds of a new clip after which it becomes very choppy and even loses around 5 secs of frames in some places making the video completely unuseable. If I look at the media info in VLC it shows the frame rate of such clips to be around 14fps although shot at 25fps, indicating that frames have truly been dropped and that this is not a playback issue.
I am using the recommended cards Sandisk Extreme Pro U3 A1 V30 etc.
I haven't tried doing an internal recording to eliminate the card as the problem yet, just wonder if anyone else has any thoughts.

It is worth checking this problem when writing to internal memory. The problem may be a damaged card. sometimes a new card may have a disadvantage. You can still try to format the card from the Dji Go application. This can solve the problem.

Plug your drone into your computer and make sure your internal storage is EMPTY. I had this problem only once and it was when my drone storage was full.

"the media info in VLC it shows the frame rate of such clips to be around 14fps although shot at 25fps, indicating that frames have truly been dropped and that this is not a playback issue."

I would think that the playback rate indicated by VLC does indicate a playback problem.4k @ 30 fps can be quite demanding.

To see at their best the files need to be transferred to your computer hard drive, the USB transfers can be flakey at times if trying to view files on SD card.

Transfer one file to your hard drive then right click on file and look at properties of file, that will indicate resolution and frame rate at which file was recorded.

Aardvark Posted at 2018-8-1 01:59
"the media info in VLC it shows the frame rate of such clips to be around 14fps although shot at 25fps, indicating that frames have truly been dropped and that this is not a playback issue."

I would think that the playback rate indicated by VLC does indicate a playback problem.4k @ 30 fps can be quite demanding.

I've just done a test shooting 1min onto card and then the same onto Internal.
The recording to card shows a frame rate of 21.42fps and there are some jumps, the recording to internal memory shows 25 fps and smooth video. Looks like it is a card issue despite using the DJI recommended card.
I have managed to obtain a Lexar UHS2 card which writes at 245MB/s to see if that works any better. (Its not a recommended card)

Lexar Professional UHS-2 Card tested
I have now tested this card and the problem is completely solved.
Apart from the dropped frames issue I was having with the Sandisk Extreme Pro cards I was also noticing a wait while the recorded video was presumably being written to the card at the end of each recording. This does not occur with the Lexar card, recording stops instantly. It would appear that although recommended, the Sandisk Extreme Pro cannot cope with the 4K video.
For those interested, the (expensive) but trouble free Lexar is this one: https://www.amazon.co.uk/gp/prod ... 0?ie=UTF8&psc=1

Glad you fixed it. I've got a LOT of sd cards and though many of them are rated at 100mb/s they are not all equal with speeds. I'm planning on benchmark testing them all so I can see which is the fastest so I never experience choppy footage again.

Strange, I am using the same SanDisk SD card (128GB) and so far had no issues with it.

I always format SD cards before I use them for first time, maybe you could try that, because, if not defective the card is more than capable for 4K 100mbit/s recording.

StephenH Posted at 2018-8-1 02:38
Lexar Professional UHS-2 Card tested
I have now tested this card and the problem is completely solved.
Apart from the dropped frames issue I was having with the Sandisk Extreme Pro cards I was also noticing a wait while the recorded video was presumably being written to the card at the end of each recording. This does not occur with the Lexar card, recording stops instantly. It would appear that although recommended, the Sandisk Extreme Pro cannot cope with the 4K video.

The Sandisk 'Extreme' seem to be the card of choice for these and usually work well. Presumably you've reformatted card in aircraft. If it's a dud get DJI to replace it under warranty.

Aardvark Posted at 2018-8-1 03:17
The Sandisk 'Extreme' seem to be the card of choice for these and usually work well. Presumably you've reformatted card in aircraft. If it's a dud get DJI to replace it under warranty.

Yes, I reformatted the card in the aircraft. tried 2 different cards and both have the same problem.
Incidentally, I'm using the 64Gb cards and I have seen comments about 32Gb being more reliable. Which size do you use?

StephenH Posted at 2018-8-1 03:20
Yes, I reformatted the card in the aircraft. tried 2 different cards and both have the same problem.
Incidentally, I'm using the 64Gb cards and I have seen comments about 32Gb being more reliable. Which size do you use?

It's entirely your choice, regarding card capacity. My Mavic Pro records 4k @ 60Mb/s. For that I get 9 minutes and 20 seconds per 4GB file (system limitation under FAT32, but no frames are lost).

For the Air recording at 100Mb/s it would get proportionally less time (say five minutes 40 seconds per 4GB memory ?).

So a 32 GB card would hold 'about' 45 minutes of 4k video (three batteries ? ) , 32GB might work well for you for a flying session using a couple of spare batteries. It's still a lot of video to lose if chip gets lost or goes faulty. But if that were a concern the 16GB or swap out on battery change is another option.

I usually use the 32GB Sandisk Extreme cards without issue. They're cheap enough now.

Something else to consider is you may have gotten a hold of a counterfeit San Disk card.

I've been on Extreme Pro cards for quite some time and have had zero problems out of them. Until earlier this year when I thought I'd save some money and buy 6 San Disk Extreme Pro 128GB cards at an incredible savings off ebay. I learned the hard way that while they still offered the correct amount of memory, but did not perform as they should for write speeds. I often saw "slow SD card" or even the long record times after I'd quite recording. Gotta be careful and if a deal is too good to be true, it probably is.

Oh, and on a different note.....I have six 128GB San Disk Extreme Pro Micro SD cards for sale at an incredible price if anyone is interested. ;-)

Rockyraaccoon Posted at 2018-8-1 06:25
Something else to consider is you may have gotten a hold of a counterfeit San Disk card.

I've been on Extreme Pro cards for quite some time and have had zero problems out of them. Until earlier this year when I thought I'd save some money and buy 6 San Disk Extreme Pro 128GB cards at an incredible savings off ebay. I learned the hard way that while they still offered the correct amount of memory, but did not perform as they should for write speeds. I often saw "slow SD card" or even the long record times after I'd quite recording. Gotta be careful and if a deal is too good to be true, it probably is.

Thats interesting. I bought my cards from Amazon so assume they are okay.
I have never had a slow card warning.
How do you tell if a card is a counterfeit?

Further to my comment above I notice that if I insert the Sd card directly into my Mac (as opposed to connecting via drone) it shows up as unreadable by the Mac and I cannot even re format it.
The new Lexar card I am using mounts fine. I am wondering if theses cards are indeed counterfeit now in which case I should highlight with Amazon.

Rockyraaccoon Posted at 2018-8-1 06:25
Something else to consider is you may have gotten a hold of a counterfeit San Disk card.

I've been on Extreme Pro cards for quite some time and have had zero problems out of them. Until earlier this year when I thought I'd save some money and buy 6 San Disk Extreme Pro 128GB cards at an incredible savings off ebay. I learned the hard way that while they still offered the correct amount of memory, but did not perform as they should for write speeds. I often saw "slow SD card" or even the long record times after I'd quite recording. Gotta be careful and if a deal is too good to be true, it probably is.

That's strange I have the same card and I love it, all my videos turn out pretty nice, no dropped frames etc.

StephenH Posted at 2018-8-1 07:33
Thats interesting. I bought my cards from Amazon so assume they are okay.
I have never had a slow card warning.
How do you tell if a card is a counterfeit?

I m using the SanDisk with the drone logo, i m happy with it and never have a slow card reminder.

StephenH Posted at 2018-8-1 07:33
Thats interesting. I bought my cards from Amazon so assume they are okay.
I have never had a slow card warning.
How do you tell if a card is a counterfeit?

I read somewhere how to tell the difference, other than once you've purchased it and found out it doesn't work as it's supposed to......but I can't seem to find it.  Maybe try googling Phony Sand Disk or similar.

I have 24 Sandisk Extreme Pro 64GB cards that I've bought from Ebay and Amazon (each seller had very high feedback and reviews). All of these cards function perfectly.

The phony cards I have were purchased from Ebay but from an chinese account with very little feedback. They looked legit and I took the hook.

My advice would be to only buy from sellers with great ratings.

I have now had photographs of my cards checked by SanDisk who have confirmed that they are counterfeit cards
Never again will I buy memory cards from Amazon.
A lesson learned the hard way.

StephenH Posted at 2018-8-1 02:38
Lexar Professional UHS-2 Card tested
I have now tested this card and the problem is completely solved.
Apart from the dropped frames issue I was having with the Sandisk Extreme Pro cards I was also noticing a wait while the recorded video was presumably being written to the card at the end of each recording. This does not occur with the Lexar card, recording stops instantly. It would appear that although recommended, the Sandisk Extreme Pro cannot cope with the 4K video.

A lot of cards post read speeds which are usually much faster than their write speed.  I always get cards marked U3 (the three in side the U) as they are rated for 4K speeds.  

StephenH Posted at 2018-8-4 05:25
I have now had photographs of my cards checked by SanDisk who have confirmed that they are counterfeit cards
Never again will I buy memory cards from Amazon.
A lesson learned the hard way.

Super common man don't feel bad. Amazon is fine but watch who it is fulfilled by, make sure it's coming from a reputable seller.

Ya know, you could always use those prices on Amazon to make one of your local chain stores match their price

Hi Stephen,

Hi there, I have similar issues. Just tried yesterday with all FPS on 4K. I have tried internal and Samsung Extreme card. Same poor results every time. All but given up with 4k and 2k. 1080p gives reliable footage. DJI need to provide what it says on the box.

If using VLC on PC turnoff Hardware acceleration in settings has it works perfect on all cards for me after having issues
Using Samsung , Scandisk