4K (to HD) Video workflow...

Rubik · Sep 2, 2018

AeroJ said:
However, remember the weird little flashes I mentioned before ? Well - turns out they are in the source footage as well, and I just hadn't noticed them before - they are quite subtle except in a few places where they become more prominent. And yet it is not present all the time. I am beginning to think it is related to the angle of the camera to the sun, but not sure about this as I have never seen this particular kind of artefact when recording at 1080. If it is an artefact from the camera at 4k, then I guess a lot of H owners might already have noticed it in their own footage ?

Yes, I get those annoying single white frames also. Perhaps one or two per flight. I don't have a solution other than to edit them out. Viewers often appreciate shorter clips anyway. I don't think the "white frame" problem has anything to do with camera angle relative to the sun. I've seen the flashes when there was no camera rotation.

AeroJ · Sep 2, 2018

Rubik said:
Yes, I get those annoying single white frames also. Perhaps one or two per flight. I don't have a solution other than to edit them out. Viewers often appreciate shorter clips anyway. I don't think the "white frame" problem has anything to do with camera angle relative to the sun. I've seen the flashes when there was no camera rotation.

Thanks for the input Rubik, but no, these are not the distinctive white flashes you get when using Auto settings, and I should be immune to those, because I used locked WB and manual Exposure. My flashes (for want of a better word - perhaps 'disturbances' would be more appropriate) are darkening the frame, and blurring it slightly for 1 or 2 frames, then it resets to normal, and then repeats, roughly 1 a second, with almost metronomic regularity for most of the flight.

AH-1G · Sep 2, 2018

AeroJ said:
I have done some maths. The original footage I get out of the CGO3+ needs a write speed of no more than 6MB/second, and class 10 is certified to at least 10 MB/Sec, and in write tests I did this evening is actually achieving more like 17 MB/sec when I copy a file to it. This pretty much convinces me that the card isn't the problem.

Went out and did another 2 test flights this evening, and tested all the 4K video modes, and without an ND filter, but very disappointed to see that the problem remains in all those modes.
But try as I might, I cannot find any other example of this problem happening in other people's 4K footage, so I must now assume this a problem with my specific CGO3+ and I will try and get a fix or new unit from Yuneec under warranty.

Thanks to everyone that tried to help so far...

Have you tried a U3 card to see if works?

AeroJ · Sep 2, 2018

AH-1G said:
Have you tried to get a aU3 card and see if works?
But hey what do we know?

The trouble is, my friend, you all know different things

You, for example, seem fairly sure it's the card, but manufacturer specifications, mathematics, some other people's posts, and the consistency of the frame rate and bitrate of my 4K footage have rather convinced me that my class 10s are doing OK - they are high quality Sandisk Transcend premium ones with a write speed of 9MB / sec (72 Mbit/sec), way more than the CGO3+ requires for the bitrates it produces (maximum 50 Mbit / sec right ?). In my practical tests I was getting 17 MB/sec write speed, which is way above the highest speed the CGO3+ needs.

But with all that said - my choices now are 'spend the £25 on a U3' or 'send the camera back to Yuneec', and it seems fairly obvious which of those is going to be less hassle ! So yes, I will get one tomorrow and try, even though all my instincts tell me it will make no difference...

rdonson · Sep 2, 2018

@AeroJ The reason many of us suggest the U3 card is because it made a difference for us when we were in the same situation.

YMMV.

AH-1G · Sep 2, 2018

AeroJ said:
The trouble is, my friend, you all know different things You, for example, seem fairly sure it's the card, but manufacturer specifications, mathematics, some other people's posts, and the consistency of the frame rate and bitrate of my 4K footage have rather convinced me that my class 10s are doing OK - they are high quality Sandisk Transcend premium ones with a write speed of 9MB / sec (72 Mbit/sec), way more than the CGO3+ requires for the bitrates it produces (maximum 50 Mbit / sec right ?).

But with all that said - my choices now are 'spend the £25 on a U3' or 'send the camera back to Yuneec', and it seems fairly obvious which of those is going to be less hassle ! So yes, I will get one tomorrow and try, even though all my instincts tell me it will make no difference...

Just because the math works on paper, does not really mean it will work in reality.
It's theory, College 101 basics.
You are trying to engineer this in your favor.
And if the card doesn't work, then is it your computer or software which needs updating or replaced.
You can always return the card for a refund, I hope.

AeroJ · Sep 2, 2018

AH-1G said:
Just because the math works on paper, does not really mean it will work in reality.
It's theory, College 101 basics.
You are trying to engineer this in your favor.
And if the card doesn't work, then is it your computer or software which needs updating or replaced.
You can always return the card for a refund, I hope.

...except in this case it's not theory - it's the actual results of a practical write-speed test on the actual card in question. The only thing I am trying to engineer is to stop 1 frame every second going dark and blurry ! That is not a symptom of any data write speed issue I have ever heard of. Yes, there are hundreds of threads about card speed issues, but not a single one of them I have seen is having this problem - they have jerky video, they have frames missing, they have whole sections that don't record, but what they NEVER have is 1 frame going darker every second, and no other symptoms ! But pointless arguing about it - I'll just get the **** card and post the results !

AH-1G · Sep 2, 2018

I know you know this, but this is what the experts say.
Info may be for a cell phone, but it's the same concept for 4K
Glad to here you're going to get **** card

4K video will just look better with a faster card. 4K video files are gigantic and the data is pulled from the buffer a little differently. Since you're doing something live and in real time, waiting for a buffer to flush isn't an option. The movement from the camera buffer to the SD card is more like streaming video that a direct file copy. When you can't pull data from the buffer fast enough, you get fuzzy video, poor sound, skipped frames or audio and video not synchronizing very well. While 4K video is best when written to the phone's storage, you can get by with a fast UHS class SD card. You can't get by with a slower card.

If you take a lot of pictures or want to run apps from your SD card, buy a class UHS-3 card. Full stop. You will wish you bought a faster card eventually if you don't.

Everything you need to know about SD card speeds and your phone

AeroJ · Sep 2, 2018

I really really hope you are right, and I will be the first to apologise if you are

AH-1G · Sep 2, 2018

AeroJ said:
I really really hope you are right, and I will be the first to apologise if you are

Ditto

FlushVision · Sep 3, 2018

Always worth keeping in mind that when a manufacturer quotes a write bit rate for their card, that speed is really an 'Up to' speed. However, I can see @AeroJ 's point about the blurring at regular 1 second intervals: In my experience, if the card isn't fast enough the major symptom is stuttering particularly in pan footage or in footage where the scene is changing, say in a shot where you are taking footage of the ground while the aircraft is crabbing sideways.

At the end of the day, though, getting a new U3 card is probably the cheapest and most convenient step in trying to resolve the issue...better than being without your camera for however long it takes for service...and far cheaper than a new computer.

Just one point, though. @AeroJ have you experimented with different video editors? I ask this because I was using one particular editor that produced stuttering video even at 1080, but using another editor on the same footage I got nice and smooth results (better results obtained using Filmora). Just a thought.

rdonson · Sep 3, 2018

For my UK friends

The SanDisk Extreme 64GB microSD card has dropped to just £18 | Thrifter

AeroJ · Sep 3, 2018

FlushVision said:
Just one point, though. @AeroJ have you experimented with different video editors?

Just the 2 so far - DVR 15 and an old copy of Sony Vegas Movie Studio 12, which is one version short of dealing with 4K properly, but did OK considering

But because the problem is in the source footage so far, doesn't matter what I use to edit it - it's always there in the final output too. Just about to go into town and try and get that card ! Very much hoping that I don't go from being a man with no working 4K video to being a man with no working 4K video and £25 less than he used to have ! But of course I will be suitably overjoyed if it works, and I have to do it anyway because Yuneec will no doubt laugh me off the phone if I haven't even tried the right card first !

AeroJ · Sep 3, 2018

Ordinarily, it would be nice to be right, but it's not

The card was not the reason. My test footage with a brand new Delkin 660X U3 rated card produced footage with exactly the same problem as with the class 10's. I'll link a sample of that here, but will also upload the 4k original overnight so Yuneec can see when I'm on the phone to them tomorrow...

FlushVision · Sep 4, 2018

AeroJ said:
Ordinarily, it would be nice to be right, but it's not The card was not the reason. My test footage with a brand new Delkin 660X U3 rated card produced footage with exactly the same problem as with the class 10's. I'll link a sample of that here, but will also upload the 4k original overnight so Yuneec can see when I'm on the phone to them tomorrow...

At least you now have an extra card to use, so all is not lost.

AH-1G · Sep 4, 2018

@AeroJ Would you be willing to send me that raw footage to look at?

AeroJ · Sep 4, 2018

AH-1G said:
@AeroJ Would you be willing to send me that raw footage to look at?

Sure thing - I've uploaded it to youtube direct from the camera, you can see the artefacting clearly here...

Here's the 1 minute version...

And here's the raw video file of that whole segment...

Thanks AH.

AH-1G · Sep 4, 2018

Did you have a filter on this?
Mostly cloudy, not much light. I'm wondering if ISO should have been 100 not 150? Even though there isn't much natural sun out there.
Shutter speed 125, 100 or less.
I have noticed when I increased my ISO the video isn't all that great.
Try different shutter setting, but leave ISO at 100, if you haven't done so already.

AeroJ · Sep 4, 2018

Thanks for looking. Unfortunately I have tested in all lighting conditions, with and without filters, and I am getting the same thing every time. About to send it back to Yuneec UK tomorrow.

AH-1G · Sep 4, 2018

AeroJ said:
Thanks for looking. Unfortunately I have tested in all lighting conditions, with and without filters, and I am getting the same thing every time. About to send it back to Yuneec UK tomorrow.

Alright, my apologies for giving you a hard time. I hope they will fix it quickly.
But do keep the card.