For anyone who ends up with a corrupted video file I managed to repair mine t perfect condition following (almost) a YT video: https://www.youtube.com/watch?v=K3nWw9aX5kw
His links are a bit off for the ffmpeg … you need his second link for it and then choose the windows link, then the builds by BtbN and the ffmpeg-N-99593-g86228ebdb2-win64-gpl-shared-vulkan.zip link - the rest of the instructions work - I may do a video covering it as this ones links are a bit confusing.
It did work once i got all the right stuff though - every frame up to the last spiral!
And for the lazy ones try using VLC with Convert/Save but be careful about the codec you’re using for conversion, it could generate quite a larger file and the quality will not be for the better.
VLC didn’t work for me - I tried that first 
I tried the video, I got to Step 9 and when I run the ffmpeg I get a message that vulkan-1.dll is missing from my system.
I did download the vulkan ffmpeg build but apparently I did not download the correct one.
Any idea which file I actually need to download?
I downloaded the vulcan one and extracted it to its folder but renamed it to keep it simple - but nothing special, just copied the 4 files from the other download into it - do amke sure you run the cmd as administrator or it won’t have enough rights or access to do everything. Also make sure you copy from the top folders and not select files in a folder as .dll’s are hidden files so if you selected all files in a folder to copy you would actually miss them.
Surprisingly for me the VLC method works unexpectedly well, the video is corrected in no time, provided it’s not that corrupted, just the closure is messed up. So for now I’ll stick with that. I might give the ffmpeg method a go some other time.
I have fixed corrupted video with this tool
It need one working video from same record device…
I have been busy doing mods to my EX4 to shield the GPS and move the compass as well as make a 3D printed gimbal cover.
Everything covered in this post if anyone is interested:
https://www.rcgroups.com/forums/showpost.php?p=45696431&postcount=160
Nice one Mark. I’ve only found a rubber filament cover so far on thingiverse and since I don’t have that kind of filament I left the gimbal cover issue hang. Now I’ll give it a go and see how it fits on my EX4 and X12. Yea, I got two of these birds, the EX4 I purchased by mistake, was checking out the price in my local currency and somehow I must have pressed the finalize purchase in PayPal. Now I’m probably one of the few folks who’s got two of these birds.
Anyways will see about the gimbal cover, should be a fun print for my Wanhao i3 Duplicator Mini.
Not sure I’m ready to make changes to the compass though, might be my lack of confidence in my soldering skills or just me being prone to Murphy’s Law but at the moment both quads are working, calibration isn’t an issue - if there’s no metallic or EM interference they calibrate well and keep steady in the air. Toilet bowling is an issue sometimes but recalibration seems to work so not really sure it’s worth the effort to relocate the compass.
I saw that one but had the feeling it was to keep on while flying to protect the gimbal but didn’t fancy doing that. Mine is just for keeping it safe while being stored.
Hope you like it.
Hi Mark,
I’ve printed today the gimbal cover, I used a 0.25mm layer height so naturally there were some “whiskers” on the overhangs but after cleaning those out the whole thing fit quite nicely on my EX4. It fits the X12 obviously but since the carrying bags of each differs, it only fits when mounted in the EX4 bag, which makes sense, you’ve used it for your EX4 so that is to be expected.
I might play around with it to make it somehow fit in the X12 carrying case as well.
Good stuff Denis - I have replied on Thingyverse but do post a “Make” and “Remix” when you get chance.
Mark
Hi Daniele. I completed my experiment about FTP accessing and downloading the footage from my EX4 via WiFi and here the interested person can read the result.
Have a nice day. 
Hi Denis. I completed my experiment about FTP accessing and downloading the footage from my EX4 via WiFi and here the interested person can read the result.
Have a nice day. 
How to download footage from Eachine EX4’ SD to PC via WiFi (maybe appliable also to JJRC X12 and C-Fly Faith) ArduCopter
Any standard comm program can connect and issue the FTP “dele” command. Nice work, but your masking of the user ID and password is rather silly in this instance. But whatever turns you on.
I did notice in the Enjoy Fly App that while connected to the EX4 you can go to its gallery to see the photos and videos it holds on the sd card and they have a download button next to each which downloads the file to you phone.
I assume it works on a similar method but doesn’t seem to give any status of the download (unless I missed it).
Mark
Yeah, photos/videos downloading works, but using the app is indeed relatively cumbersome.
Just an addendum. Standard FTP is on port 21. Any standard comm program can use this port for login and functions such as rename, delete, etc. (to the extent the server supports them, but these are among the standard commands). Obviously you need an actual FTP program to actually transfer files.
Hi gbal,
Nice work, very detailed description. If the user and password are those of your drone then those should pretty much be the root/admin or whatever they were set in the Linux flavor that was installed on the controller. I presume you’re connected to the drone via the controller, right?
The drone itself may have the wifi bit just for the camera interaction, the PX4 doesn’t use FTP or some other standard file or text protocol. It talks MAVLink over UDP I think, port 10005 and I suspect it starts its UDP socket after it gets a command over a TCP connection from the controlling app via the wifi. Now this could be interesting since it opens up the file system of the camera assembly which I now suspect to be also running the linux bit of the drone. In turn this camera module connect over a wired link to the PX4, either on a COM or some other way. Could be interesting to test…
As for the C-Fly app and its media download feature I do find it a bit lacking, particularly when transferring large video files, it takes a while for the download counter to show up, somehow whomever wrote the app didn’t like showing 0% after initiating the connection, only showed the X MOD 10 % of the transferred length. A minor nuisance still it would be nice to see the download starting from 0% and then moving to 10, 20…so on.
It is indeed a nuisance that there’s no indication of progress on the app once you touch that small download button for a video file. Usually the larger ones take some time to download a significant amount so that the app will show some progress. It shows percentage in 10% units so until you download at least 10% of its length you won’t see any progress. I’ve wasted and cursed quite a lot before I gave up and let it do its thing and…lo and behold!! there was the percentage figure…just it doesn’t start from 0%…wish it did