How many of you are using the DJI 16GB sdcard for 4k?????

I had issues transferring 4K video from the stock Panasonic card. I recorded 4K and 1080 on my first flight to compare and I could only transfer the 1080 files. Switching out a better card solved my problem. Not sure what the exact issue is or was but this seemed to worked for me.


Sent from my iPhone using PhantomPilots mobile app
 
Just to add a bit of clarity here. The micro sd card transfer rates are not the same as the phantom bitrates. If a sd card states a read rate of 40 MegaBytes per second it can transfer a 40MB file from the card to a device in a second. A write rate of 40 MegaBytes per second means a device can write 40 MB of data to the card in a second.
The phantom 3 Pro captures video at 60 megabits per second. Video is captured using a bitrate (mbps) and that data is saved in Bytes or MegaBytes (MBps) that means for each second of footage (converting bits to bytes) footage captured at 60mbps converts to 7.5 MegaBytes of data per second. So as long as your card can Write at at least 7.5MB or faster there shouldn't be a problem. These are all based on the Max speeds. the card needs to be able to reliably sustain a write speed of at least 7.5MBps and its possible cheaper cards cant do this.
If after editing your footage you get a missing frames issues this is because you are editing the footage straight from the camera without transcoding and are damaging the keyframes. H264 uses keyframes to help reduce the filesize usually every half second, the keyframe is a full frame with all data in it, the subsequent frames are only the changes in data between the previous keyframe and the next one thus reducing filesize. But if you edit this footage and make a cut between the keyframes you break the link between them and this causes all kinds of issues. Try to imagine one second of footage captured at 24fps by frame looking like this. K = keyframe c = compressed frame

KccccccccccKcccccccccccK
^ During editing you make a cut here and end up with this
ccccccKcccccccccccK
^------^ Everything in this part now has no keyframe as a reference so either artifacts out or the renderer fails because its looking for a keyframe.

Transcoding converts every frame to a keyframe so you can edit from any frame without causing a problem.


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End of the day, the panasonic card aint as good? fine
but it can still handle 7.5MBps so what the hell is all this crap in this post.. the thing is most people who use 4k will get a 32m card anyway
brew time ;)
 
End of the day, the panasonic card aint as good? fine
but it can still handle 7.5MBps so what the hell is all this crap in this post.. the thing is most people who use 4k will get a 32m card anyway
brew time ;)
If this were the case, why would dji include a class 10, U1 rated sdcard to begin with?
Using your misguided theory, wouldnt dji simply include a much slower (and cheaper) rated class 6, 10MBps card instead?
Shop around on say amazon for 4k certified sdcards and see what minimum transfer specs they all have in common. The sad truth is that some manufacturers consistently do not perform to the specs that are stamped on the device, panasonic obviously being one of them.
A 4k capable sensor is still 4096 pixels × 2160 lines (max) regardless if its in the phantom or behind a very expensive DSLR camera lens.

Do all you folks enjoy goin to the dentist? Its like tryin to pull teeth to share a point around here.
Now I completely understand the reputation this forum has established for itself...
 
If this were the case, why would dji include a class 10, U1 rated sdcard to begin with?
Using your misguided theory, wouldnt dji simply include a much slower (and cheaper) rated class 6, 10MBps card instead?
Shop around on say amazon for 4k certified sdcards and see what minimum transfer specs they all have in common. The sad truth is that some manufacturers consistently do not perform to the specs that are stamped on the device, panasonic obviously being one of them.
A 4k capable sensor is still 4096 pixels × 2160 lines (max) regardless if its in the phantom or behind a very expensive DSLR camera lens.

Do all you folks enjoy goin to the dentist? Its like tryin to pull teeth to share a point around here.
Now I completely understand the reputation this forum has established for itself...
Sorry you feel that way, but your first post could have been clear saying the panasonic cards aint up to scratch anyone with any sense will run the fastest card and replace a 16g card for 4k anyway end of the day what the p4 camera processes in them pixels is the bloody speed it writes it at.. yes its 4k but slower data rate. hence the bloody 7.5MBps max it writes at its not an SLR
we all are allowed our opinions but seems you dont like others.. post me the card and ill show you a P4 4k vid .. now chill as no one was trying to offend you..
the water pressure in my hose pipe can be the same as firemans jet hose but mine wont fill his bucket as fast as he can because my data rate aint as fast as his :p
 
I have a lexar card in mine. I filmed 1080 at 30 fps last night and had no issues. So, I still don't know if it's my shitty laptop or a 4k issue on the phantom. I will be getting a new 15 inch retina soon and will try to edit 4k then and report back.
 
Got a Lexar 16 gig with mine. It handles 4k no problem. Also got a SanDisk Extreme Pro 64 gig. It too handles 4k no issue. Read and write speeds faster than the stock.

The issue I have is on the PC side of things. I have a fairly high end screaming machine all around and rendering 4k is an absolute bear! Takes a long time. To top that off I live rural and only have 5 meg DSL down and 1/2 meg up. Would take far too long to upload anything. 1080p / 60 fps works just fine for me. Quicker and easier and looks real good across multiple platforms. I mean besides at home viewing on a big tv / monitor do we really need 4k? The 1080 looks stunning on my 60" plasma.
 
Can you explain in a little more detail what you're trying to show us with your screenshots?
My first thread on this forum, was exactly all about this and because nobody understood what I was saying (regarding write speeds and how it is necessary and not just 1s and 0s) like they think it is, I got lambasted by everyone until eventually I was banned.
 
My first thread on this forum, was exactly all about this
Well, welcome to version two of the thread. Do you have any details on why a card that consistently writes at 41MB/s could not handle a 7.5MB/s bitrate?
 
Well, welcome to version two of the thread. Do you have any details on why a card that consistently writes at 41MB/s could not handle a 7.5MB/s bitrate?

There is something wrong with the card? It's not a good benchmark? The findings are wrong. Lot's of reason I could just right but unless I know more about the question, all I an say is what I know. The P4 writes at 60mb/s which is 7.5MB/s or 75mb/s.

Here are the Phantom's camera specs:

Screen%20Shot%202016-03-30%20at%201.34.02%20PM_zpspofyor3f.jpg

As you an see, MAX VIDEO BIT RATE is 60Mbps (small b means bit instead of bits large B which means Byte).

So in order to have a card that writes 60Mb/s or 7.5MB/s (It's a 1:8 ratio so 60/8 = 7.5MB/s...This is the simple way to figure out what MB you need from Mb) or you can use a calculator or an online converter, the card needs to write at an average of 41MBp/s or 328mb/s. So the answer to your question is 41MB/s and above should be able to handle 7.5MBs (or 60mb/s, the stated spec of the speed of the camera writing by the P4 very easily). If I'm not mistaken that is 328mbs when we need 60mbs.

Of course marketing might just put what it comes in at. It also might have a buffer where it holds some video and maybe needs a little less speed on the card (not sure) also, it encodes with a hardware encoder to H264 as soon as it hits the chip so I don't know if that slows it down. If you look at this BlackMagic Resolve Color Corrector Speed Test you can see the results of my card that is currently in there and see that it will do different formats at different speeds. Also, if I change the card to a different one, the brand, the speed, and a bunch of other factors will change these numbers. Read only matters once you're writing to the computer and who cares unless you're talking about an SSD striped array of drives but when it comes to this, it's mostly aboutt the write speed.

See the calculator below shows that at 41Mb/s = 328mb/s (the P4 needs 60mb/s...sorry for the repetition, just trying to beat this in)

Screen%20Shot%202016-03-30%20at%206.04.13%20PM_zpstowsgtxe.jpg


Here is a Black Magic test of my Lexar 633x that comes with the P4 and the latest P3s. I am writing at an average of 68.2 which is

Speed_jpeg_zps5qpvr6sa.jpg


For comparison, I took a grab of the speed of one of my internal SSD striped for performance speed tests. Look at the difference.
Check out what the performance does as the resolutions and formats increase.

Screen%20Shot%202016-03-30%20at%203.04.01%20PM_zps4aqpxuxj.jpg


So the answer to your question Mike, as to why 41.5MB/S can't handle 60mb/s is I have no idea. Something is missing. This gets a little convoluted to me when I try to look at it as a whole actually so I apologize in advance if I wrote anything wrong here, but I tried to the best of my ability.
 
So the answer to your question Mike, as to why 41.5MB/S can't handle 60mb/s is I have no idea. Something is missing. This gets a little convoluted to me when I try to look at it as a whole actually so I apologize in advance if I wrote anything wrong here, but I tried to the best of my ability.
Right -- which is pretty much what everyone in this thread is saying. The stock memory cards (no matter the brand) are certainly not the fastest memory cards available, but they should work just fine for recording 4K video.
 
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Right -- which is pretty much what everyone in this thread is saying. The stock memory cards (no matter the brand) are certainly not the fastest memory cards available, but they should work just fine for recording 4K video.
Yeah. Well you asked the question, I answered it quite thoroughly. Did you just want me to confirm what you knew?
 
Nope. I thought you had something new to add since you chimed in.
Indeed I did. I chimed in to say that the speed of the cards matter quite a bit and everyone jumped on me and than this thread and you asked a direct question so I answered with the best knowledge I could.

TBH, I always get confused, sort of lost in the math with Mbs and MBs so it messes with me but the card that comes with it gets an average speed that is plenty fast for 4k video.

Do you see that first pic of mine? That is the Blackmagic Test of the Lexar 633x and it has green checks down the line meaning it passes at those resolutions/frame-rates/etc. You just need to average out. On the random frame I captured it was at 68 write and 86 read which doesn't matter. That 68MB/s is about 545Mb./s just under the necessary 600 but it will get faster speeds plus there is a buffer that holds it. Now, if you didn't before, know why the X5R needs an SSD because it needs to fly to capture such large files on the fly.

Also, I am curious, and don't know if the 600mb/s that the P4 shoots at is what it comes in at but by the time its encoded and reaches the card, it's a smaller file and might need less bandwidth. I am not sure of this, just a theory, but i would bet it because I have used some slow cards in my P3 in a pinch before and it worked fine. H264 is a VERY compressed even if it is only semi-lossy codec. It's 10:1. It will turn a gig into about 100MB.
 

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